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Zhai M, Meng Z, Chen R, Song J, Zhang A, Zhao S, Tian T, Zhu L, Zhang H, Tang H. Evolution of the network structure and voltage loss of anode electrode with the polymeric dispersion in PEM water electrolyzer. J Colloid Interface Sci 2024; 673:934-942. [PMID: 38909492 DOI: 10.1016/j.jcis.2024.06.144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/15/2024] [Accepted: 06/19/2024] [Indexed: 06/25/2024]
Abstract
Exploring the intrinsic relationship between the network structure and the performance of catalyst layer (CL) by rational design its structure is of paramount importance for proton exchange membrane (PEM) electrolyzers. This study reveals the relative effect of polymeric dispersion evolution on oxygen evolution reaction (OER) performance and cell voltage loss and linked to CL network structure. The results show that although the dispersed particle size of the ionomer and ink increases with increasing the solubility parameter (δ) difference between the mixed solvent and the ionomer, MeOH-cat (ink from MeOH aqueous solution) has the largest ionomer and ink particle size resulting in the poorest stability, but has comparable OER overpotential to that of IPA-cat (249 mV@10 mA cm-2), which has the smallest dispersed size. While at 100 mA cm-2, the overpotential of the ink rises as the particle size increases, suggesting that the electrode structure becomes more influential as the current density increases. Quantitatively analyzed the electrolyzers' voltage losses and determined that the CL from MeOH-cat has the lowest kinetic overpotential. However, its performance is the worst because of the insufficient network structure of CL, resulting in an output of 1.96 V at 1.5 A cm-2. Comparatively, the CL from IPA-cat has the highest kinetic overpotential yet can achieve the greatest performance of 1.76 V at 2 A cm-2 due to its homogeneous network structure and optimal mass transport. Furthermore, the performance variation becomes more pronounced as current density rises. Hence, this study highlights the significant impact of CL structure on electrolyzer's performance. To improve performance in PEM water electrolysis technology, especially for large work current density, it is crucial to enhance the CL's network structure.
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Affiliation(s)
- Miaoyan Zhai
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Zihan Meng
- Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan, 528200, China
| | - Rui Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Jiangping Song
- Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan, 528200, China
| | - Aojie Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Shengqiu Zhao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Tian Tian
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China; Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan, 528200, China.
| | - Liyan Zhu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Hao Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Haolin Tang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China; Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan, 528200, China; Hubei Key Laboratory of Fuel Cell, Wuhan 430070, China.
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2
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Gao Y, Liu H, Wang X, Liu X, Shan B, Chen R. Spatially Confined Alloying of Pt Accelerates Mass Transport for Fuel Cell Oxygen Reduction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2405748. [PMID: 39248683 DOI: 10.1002/smll.202405748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 08/24/2024] [Indexed: 09/10/2024]
Abstract
Pt-based alloy with high mass activity and durability is highly desired for proton exchange membrane fuel cells, yet a great challenge remains due to the high mass transport resistance near catalysts with lowering Pt loading. Herein, an extensible approach employing atomic layer deposition to accurately introduce a gas-phase metal precursor into platinum nanoparticles (NPs) pre-filled mesoporous channels is reported, achieved by controlling both the deposition site and quantity. Following the spatially confined alloying treatment, the prepared PtSn alloy catalyst within mesopores demonstrates a small size and homogeneous distribution (2.10 ± 0.53 nm). The membrane electrode assembly with mesoporous carbon-supported PtSn alloy catalyst achieves a high initial mass activity of 0.85 Amg Pt - 1 ${\mathrm{mg}}_{\mathrm{Pt}}^{-1}$ at 0.9 V, which is attributed to the smallest local oxygen transport resistance (3.68 S m-1) ever reported. The mass activity of the catalyst only decreases by 11% after 30000 cycles of accelerated durability test, representing superior full-cell durability among the reported Pt-based alloy catalysts. The enhanced activity and durability are attributed to the decreased adsorption energy of oxygen intermediates on Pt surface and the strong electronic interaction between Pt and Sn inhibiting Pt dissolution.
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Affiliation(s)
- Yuxin Gao
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
| | - Hang Liu
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
| | - Xintian Wang
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Xiao Liu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
| | - Bin Shan
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
| | - Rong Chen
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, P. R. China
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Yang J, Xu H, Li J, Gong K, Yue F, Han X, Wu K, Shao P, Fu Q, Zhu Y, Xu W, Huang X, Xie J, Wang F, Yang W, Zhang T, Xu Z, Feng X, Wang B. Oxygen- and proton-transporting open framework ionomer for medium-temperature fuel cells. Science 2024; 385:1115-1120. [PMID: 39236188 DOI: 10.1126/science.adq2259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 08/01/2024] [Indexed: 09/07/2024]
Abstract
Medium-temperature proton exchange membrane fuel cells (MT PEMFCs) operating at 100° to 120°C have improved kinetics, simplified thermal and water management, and broadened fuel tolerance compared with low-temperature PEMFCs. However, high temperatures lead to Nafion ionomer dehydration and exacerbate gas transportation limitations. Inspired by osmolytes found in hyperthermophiles, we developed α-aminoketone-linked covalent organic framework (COF) ionomers, interwoven with Nafion, to act as "breathable" proton conductors. This approach leverages synergistic hydrogen bonding to retain water, enhancing hydration and proton transport while reducing oxygen transport resistance. For commercial Pt/C, the MT PEMFCs achieved peak and rated power densities of 18.1 and 9.5 Watts per milligram of Pt at the cathode at 105°C fueled with H2 and air, marking increases of 101 and 187%, respectively, compared with cells lacking the COF.
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Affiliation(s)
- Jianwei Yang
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Hengyu Xu
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230022, P. R. China
| | - Jie Li
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Ke Gong
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Feiyu Yue
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Xianghao Han
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Ke Wu
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Pengpeng Shao
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Qingling Fu
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Yuhao Zhu
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Wenli Xu
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Xin Huang
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Jing Xie
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Fengchao Wang
- CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230022, P. R. China
| | - Wenxiu Yang
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Teng Zhang
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Zengshi Xu
- Wuhan Institute of Marine Electric Propulsion, Wuhan Hydrogen Fuel Cell Engineering Research Center, Wuhan 430064, P. R. China
| | - Xiao Feng
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Bo Wang
- Key Laboratory of Cluster Science, Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
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4
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Li M, Ding H, Song J, Hao B, Zeng R, Li Z, Wu X, Fink Z, Zhou L, Russel TP, Liu F, Zhang Y. Transport-Friendly Microstructure in SSC-MEA: Unveiling the SSC Ionomer-Based Membrane Electrode Assemblies for Enhanced Fuel Cell Performance. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2403647. [PMID: 39146196 DOI: 10.1002/advs.202403647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 06/08/2024] [Indexed: 08/17/2024]
Abstract
The significant role of the cathodic binder in modulating mass transport within the catalyst layer (CL) of fuel cells is essential for optimizing cell performance. This investigation focuses on enhancing the membrane electrode assembly (MEA) through the utilization of a short-side-chain perfluoro-sulfonic acid (SSC-PFSA) ionomer as the cathode binder, referred to as SSC-MEA. This study meticulously visualizes the distinctive interpenetrating networks of ionomers and catalysts, and explicitly clarifies the triple-phase interface, unveiling the transport-friendly microstructure and transport mechanisms inherent in SSC-MEA. The SSC-MEA exhibits advantageous microstructural features, including a better-connected ionomer network and well-organized hierarchical porous structure, culminating in superior mass transfer properties. Relative to the MEA bonded by long-side-chain perfluoro-sulfonic acid (LSC-PFSA) ionomer, noted as LSC-MEA, SSC-MEA exhibits a notable peak power density (1.23 W cm-2), efficient O2 transport, and remarkable proton conductivity (65% improvement) at 65 °C and 70% relativity humidity (RH). These findings establish crucial insights into the intricate morphology-transport-performance relationship in the CL, thereby providing strategic guidance for developing highly efficient MEA.
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Affiliation(s)
- Min Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Han Ding
- School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing, 102206, China
| | - Jingnan Song
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bonan Hao
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Rui Zeng
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Zhenyu Li
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xuefei Wu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zachary Fink
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Libo Zhou
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Thomas P Russel
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Feng Liu
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yongming Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Center of Hydrogen Science, Shanghai Key Lab of Electrical Insulation & Thermal Aging, Shanghai Jiao Tong University, Shanghai, 200240, China
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5
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Jo SY, Kim H, Park H, Ahn CY, Chung DY. Investigating Electrode-Ionomer Interface Phenomena for Electrochemical Energy Applications. Chem Asian J 2024; 19:e202301016. [PMID: 38146665 DOI: 10.1002/asia.202301016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/22/2023] [Accepted: 12/22/2023] [Indexed: 12/27/2023]
Abstract
The endeavor to develop high-performance electrochemical energy applications has underscored the growing importance of comprehending the intricate dynamics within an electrode's structure and their influence on overall performance. This review investigates the complexities of electrode-ionomer interactions, which play a critical role in optimizing electrochemical reactions. Our examination encompasses both microscopic and meso/macro scale functions of ionomers at the electrode-ionomer interface, providing a thorough analysis of how these interactions can either enhance or impede surface reactions. Furthermore, this review explores the broader-scale implications of ionomer distribution within porous electrodes, taking into account factors like ionomer types, electrode ink formulation, and carbon support interactions. We also present and evaluate state-of-the-art techniques for investigating ionomer distribution, including electrochemical methods, imaging, modeling, and analytical techniques. Finally, the performance implications of these phenomena are discussed in the context of energy conversion devices. Through this comprehensive exploration of intricate interactions, this review contributes to the ongoing advancements in the field of energy research, ultimately facilitating the design and development of more efficient and sustainable energy devices.
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Affiliation(s)
- So Yeong Jo
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of, Korea
| | - Hanjoo Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of, Korea
| | - Hyein Park
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of, Korea
| | - Chi-Yeong Ahn
- Alternative Fuels and Power System Research Center, Korea Research Institute of Ships and Ocean Engineering (KRISO), Daejeon, 34103, Republic of, Korea
- Department of Green Mobility, University of Science and Technology (UST), Daejeon, 34113, Republic of, Korea
| | - Dong Young Chung
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of, Korea
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6
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Xu Y, Zhang L, Chen W, Cui H, Cai J, Chen Y, Feliu JM, Herrero E. Boosting Oxygen Reduction at Pt(111)|Proton Exchange Ionomer Interfaces through Tuning the Microenvironment Water Activity. ACS APPLIED MATERIALS & INTERFACES 2024; 16:4540-4549. [PMID: 38227931 DOI: 10.1021/acsami.3c14208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
A proton exchange ionomer is one of the most important components in membrane electrode assemblies (MEAs) of polymer electrolyte membrane fuel cells (PEMFCs). It acts as both a proton conductor and a binder for nanocatalysts and carbon supports. The structure and the wetting conditions of the MEAs have a great impact on the microenvironment at the three-phase interphases in the MEAs, which can significantly influence the electrode kinetics such as the oxygen reduction reaction (ORR) at the cathode. Herein, by using the Pt(111)|X ionomer interface as a model system (X = Nafion, Aciplex, D72), we find that higher drying temperature lowers the onset potential for sulfonate adsorption and reduces apparent ORR current, while the current wave for OHad formation drops and shifts positively. Surprisingly, the intrinsic ORR activity is higher after properly correcting the blocking effect of Pt active sites by sulfonate adsorption and the poly(tetrafluoroethylene) (PTFE) skeleton. These results are well explained by the reduced water activity at the interfaces induced by the ionomer/PTFE, according to the mixed potential effect. Implications for how to prepare MEAs with improved ORR activity are provided.
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Affiliation(s)
- Yujun Xu
- Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Lulu Zhang
- Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Wei Chen
- Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Haowen Cui
- Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jun Cai
- Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yanxia Chen
- Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China
| | - Juan M Feliu
- Instituto de Electroquímica, Universidad de Alicante, Apdo. 99, Alicante E-03080, Spain
| | - Enrique Herrero
- Instituto de Electroquímica, Universidad de Alicante, Apdo. 99, Alicante E-03080, Spain
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Lee DW, Hyun J, Oh E, Seok K, Bae H, Park J, Kim HT. Potential-Dependent Ionomer Rearrangement on the Pt Surface in Polymer Electrolyte Membrane Fuel Cells. ACS APPLIED MATERIALS & INTERFACES 2024; 16:4637-4647. [PMID: 38251952 DOI: 10.1021/acsami.3c15827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
The interface between the catalyst and the ionomer in the catalyst layer of polymer electrolyte membrane fuel cells (PEMFCs) has been a subject of keen interest, but its effect on durability has not been fully understood due to the complexity of the catalyst layer structure. Herein, we utilize a Pt nanoparticle (NP) array electrode fabricated using a block copolymer template as the platform for a focused investigation of the interfacial change between the Nafion thin film and the Pt NP under a constant potential. A set of analyses for the electrodes treated with various potentials reveals that the Nafion thin film becomes densely packed at the intermediate potentials (0.4 and 0.7 V), indicating an increased ionomer-catalyst interaction due to the positive charges formed at the Pt surface at these potentials. Even for a practical PEMFC single cell, we demonstrate that the potential holding at the intermediate potentials increases ionomer adsorption to the Pt surface and the oxygen transport resistance, negatively impacting its power performance. This work provides fresh insight into the mechanism behind the performance fade in PEMFCs caused by potential-dependent ionomer rearrangement.
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Affiliation(s)
- Dong Wook Lee
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jonghyun Hyun
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Euntaek Oh
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Kyunghwa Seok
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hanmin Bae
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jeesoo Park
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Hee-Tak Kim
- Department of Chemical & Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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8
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Kikkawa N, Kimura M. Comprehensive Molecular Dynamics Study of Oxygen Diffusion in Carbon Mesopores: Insights for Designing Fuel-Cell Catalyst Supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1674-1687. [PMID: 38198684 DOI: 10.1021/acs.langmuir.3c02627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Mesoporous carbon is often used as a support for platinum catalysts in polymer electrolyte fuel-cell catalyst layers. Mesopores in the carbon support improve the performance of fuel cells by inhibiting the adsorption of ionomer onto the catalyst particles. However, the mesopores may impair mass transport. Hence, understanding molecular behaviors in the pores is essential to optimizing the mesopore structures. Specifically, it is crucial to understand the oxygen transport in the high-current region. In this study, the diffusion coefficients of oxygen molecules in carbon mesopores were calculated for various pore lengths, pore diameters, filling rates, and water contents in the ionomer via molecular dynamics simulations. The results show that oxygen diffusion slows by 2 orders of magnitude because of pore occlusion, and it slows down by an additional 1 or 2 orders of magnitude if ionomers are present in the pores. The occlusion can be theoretically predicted by considering the surface free energy. This theory provides some insight into mesoporous carbon designs; for instance, the theory suggests that narrow pores should be shortened to prevent occlusion. Slow diffusion in the presence of ionomers was attributed to the localization of oxygen at the dense ionomer-carbon interface. Thus, to improve oxygen transport properties, carbon surfaces and ionomer structures may be designed in such a manner as to prevent densification at the interface.
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Affiliation(s)
- Nobuaki Kikkawa
- Toyota Central RD Laboratories, Inc., Yokomichi 41-1, Nagakute 480-1192, Aichi Japan
| | - Masayuki Kimura
- Toyota Motor Corporation, Toyota 1, Toyota 471-8571, Aichi Japan
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9
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Kim YS. Hydrocarbon Ionomeric Binders for Fuel Cells and Electrolyzers. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303914. [PMID: 37814366 DOI: 10.1002/advs.202303914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/08/2023] [Indexed: 10/11/2023]
Abstract
Ionomeric binders in catalyst layers, abbreviated as ionomers, play an essential role in the performance of polymer-electrolyte membrane fuel cells and electrolyzers. Due to environmental issues associated with perfluoroalkyl substances, alternative hydrocarbon ionomers have drawn substantial attention over the past few years. This review surveys literature to discuss ionomer requirements for the electrodes of fuel cells and electrolyzers, highlighting design principles of hydrocarbon ionomers to guide the development of advanced hydrocarbon ionomers.
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Affiliation(s)
- Yu Seung Kim
- MPA-11: Materials Synthesis and Integrated Devices, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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10
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Tang M, Yan H, Zhang X, Zheng Z, Chen S. Materials Strategies Tackling Interfacial Issues in Catalyst Layers of Proton Exchange Membrane Fuel Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2306387. [PMID: 38018316 DOI: 10.1002/adma.202306387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 08/16/2023] [Indexed: 11/30/2023]
Abstract
The most critical challenge for the large-scale commercialization of proton exchange membrane fuel cells (PEMFCs), one of the primary hydrogen energy technologies, is to achieve decent output performance with low usage of platinum (Pt). Currently, the performance of PEMFCs is largely limited by two issues at the catalyst/ionomer interface, specifically, the poisoning of active sites of Pt by sulfonate groups and the extremely sluggish local oxygen transport toward Pt. In the past few years, emerging strategies are derived to tackle these interface problems through materials optimization and innovation. This perspective summarizes the latest advances in this regard, and in the meantime unveils the molecule-level mechanisms behind the materials modulation of interfacial structures. This paper starts with a brief introduction of processes and structures of catalyst/ionomer interfaces, which is followed by a detailed review of progresses in key materials toward interface optimization, including catalysts, ionomers, and additives, with particular emphasis on the role of materials structure in regulating the intermolecular interactions. Finally, the challenges for the application of the established materials and research directions to broaden the material library are highlighted.
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Affiliation(s)
- Meihua Tang
- Hubei Key Laboratory of Electrochemical Power Sources, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Huangli Yan
- Hubei Key Laboratory of Electrochemical Power Sources, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Xianming Zhang
- Hubei Key Laboratory of Electrochemical Power Sources, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Zhenying Zheng
- Hubei Key Laboratory of Electrochemical Power Sources, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
| | - Shengli Chen
- Hubei Key Laboratory of Electrochemical Power Sources, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China
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11
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Kim BS, Park JH, Park JS. Effect of Blended Perfluorinated Sulfonic Acid Ionomer Binder on the Performance of Catalyst Layers in Polymer Electrolyte Membrane Fuel Cells. MEMBRANES 2023; 13:794. [PMID: 37755216 PMCID: PMC10536539 DOI: 10.3390/membranes13090794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/09/2023] [Accepted: 09/11/2023] [Indexed: 09/28/2023]
Abstract
In this study, blended perfluorinated sulfonic acid (PFSA) ionomers with equivalent weights (EWs, g/mol) of ~1000, 980, and 830 are prepared. Catalyst layers (CLs), using blended PFSA ionomers, with different side chain lengths and EWs are investigated and compared to CLs using single ionomers. The ion exchange capacity results confirm that blended ionomers have the target EWs. As a result, blended ionomers exhibit higher ion conductivity than single ionomers at all temperatures due to the higher water uptake of the blended ionomers. This implies that blended ionomers have a bulk structure to form a competent free volume compared to single ionomers. Blended ionomers with short side chains and low EWs can help reduce the activation energy in proton conduction due to enhanced hydrophobic and hydrophilic segregation. In addition, when using the blended ionomer, the CLs form a more porous microstructure to help reduce the resistance of oxygen transport and contributes to lower mass transfer loss. This effect is proven in fuel cell operations at not a lower temperature (70 °C) and full humidification (100%) but at an elevated temperature (80 °C) and lower relative humidity (50 and 75%). Blended ionomer-based CLs with a higher water uptake and porous CL structure result in improved fuel cell performance with better mass transport than single ionomer-based CLs.
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Affiliation(s)
- Beom-Seok Kim
- Department of Green Chemical Engineering, College of Engineering, Sangmyung University, Cheonan 31066, Republic of Korea;
| | - Jong-Hyeok Park
- Department of Civil, Environmental and Biomedical Engineering, The Graduate School, Sangmyung University, Cheonan 31066, Republic of Korea;
- Future Environment and Energy Research Institute, Sangmyung University, Cheonan 31066, Republic of Korea
| | - Jin-Soo Park
- Department of Green Chemical Engineering, College of Engineering, Sangmyung University, Cheonan 31066, Republic of Korea;
- Department of Civil, Environmental and Biomedical Engineering, The Graduate School, Sangmyung University, Cheonan 31066, Republic of Korea;
- Future Environment and Energy Research Institute, Sangmyung University, Cheonan 31066, Republic of Korea
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12
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Kim D, Lim J, Lee JH, Choi J, Kwon SH, Yim SD, Sohn YJ, Lee SG. Investigation of Effect of Platinum Nanoparticle Shape on Oxygen Transport in PEMFC Catalyst Layer Using Molecular Dynamics Simulation. ACS OMEGA 2023; 8:31801-31810. [PMID: 37692235 PMCID: PMC10483685 DOI: 10.1021/acsomega.3c02886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023]
Abstract
For the widespread adoption of polymer electrolyte membrane fuel cells, it is compelling to investigate the influence of the Pt nanoparticle shapes on the electrocatalytic activity. In this study, a catalyst layer was modeled by incorporating four types of Pt nanoparticles: tetrahedron, cube, octahedron, and truncated octahedron, to investigate the relationship between the shapes of the nanoparticles and their impact on the oxygen transport properties using molecular dynamics simulations. The results of our study reveal that the free volume, which has a substantial impact on the oxygen transport properties, exhibited higher values in the sequence of the tetrahedron, cube, octahedron, and truncated octahedron model. The difference in free volume following the formation of less dense ionomers was also related to the surface adsorption of Pt nanoparticles. Consequently, this led to an improved facilitation of oxygen transport. To clarify the dependence of the oxygen transport on the shape of the Pt nanoparticles in detail, we analyzed the structural properties of different Pt shapes by dividing the Pt nanoparticle regions into corners, edges, and facets. Examination of the structural properties showed that the structure of the ionomer depended not only on the shape of the Pt nanoparticles but also on the number of corners and edges in the upper and side regions of the Pt nanoparticles.
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Affiliation(s)
- Danah Kim
- School
of Chemical Engineering, Pusan National
University, Busan 46241, Republic
of Korea
| | - Jihoon Lim
- School
of Chemical Engineering, Pusan National
University, Busan 46241, Republic
of Korea
| | - Ji Hee Lee
- School
of Chemical Engineering, Pusan National
University, Busan 46241, Republic
of Korea
| | - Joohee Choi
- School
of Chemical Engineering, Pusan National
University, Busan 46241, Republic
of Korea
| | - Sung Hyun Kwon
- School
of Chemical Engineering, Pusan National
University, Busan 46241, Republic
of Korea
- Research
Institute of Industrial Technology, Pusan
National University, Busan 46241, Republic
of Korea
| | - Sung-Dae Yim
- Fuel
Cell Laboratory, Korea Institute of Energy
Research (KIER), Yuseong-gu, Daejeon 34129, Republic of Korea
- Hydrogen
Energy Engineering, University of Science
and Technology, Yuseong-gu, Daejeon 34113, Republic
of Korea
| | - Young-Jun Sohn
- Fuel
Cell Laboratory, Korea Institute of Energy
Research (KIER), Yuseong-gu, Daejeon 34129, Republic of Korea
- Hydrogen
Energy Engineering, University of Science
and Technology, Yuseong-gu, Daejeon 34113, Republic
of Korea
| | - Seung Geol Lee
- School
of Chemical Engineering, Pusan National
University, Busan 46241, Republic
of Korea
- Department
of Organic Material Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
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13
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Construction of catalyst layer network structure for proton exchange membrane fuel cell derived from polymeric dispersion. J Colloid Interface Sci 2023; 638:184-192. [PMID: 36738543 DOI: 10.1016/j.jcis.2023.01.132] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/24/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023]
Abstract
A rational design of the structure of catalyst layer (CL) is required for proton exchange membrane fuel cells to attain outstanding performance and excellent stability. It is crucial to have a profound comprehension of the correlations existing between the properties (catalyst ink), network structures of CL and proton exchange membrane fuel cells' performance for the rational design of the structure of CL. This study deeply investigates the effects of a series of alcohol solvents on the properties and network structure of CL. The results demonstrate that the CL aggregates in higher ε solution show smaller particle sizes, and the sulfonic acid groups (∼SO3H) tend to extend more outward due to the strong dissociation. A more continuous and homogeneous ionomer distribution around Pt/C aggregates is observed in the CL, which improves the electrochemically active surface area (ECSA) and performance of the electrode. But, the electrode has a poor performance at high current density regions due to the mass transfer resistance. Based on this, a two-step solvent control strategy is proposed to maintain uniform ionomer and aggerates distribution and optimize the mass transfer for CL. The performance of the cell improves from 0.555 V to 0.615 V at 2000 mA·cm-2.
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14
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Hee Lee J, Hyun Kwon S, Kang H, Hye Lee J, Geol Lee S. Investigation of structural and transport properties of highly oxygen-permeable ionomer in polymer electrolyte membrane fuel cells using molecular dynamics simulations. J IND ENG CHEM 2023. [DOI: 10.1016/j.jiec.2023.03.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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15
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Heizmann PA, Nguyen H, von Holst M, Fischbach A, Kostelec M, Gonzalez Lopez FJ, Bele M, Pavko L, Đukić T, Šala M, Ruiz-Zepeda F, Klose C, Gatalo M, Hodnik N, Vierrath S, Breitwieser M. Alternative and facile production pathway towards obtaining high surface area PtCo/C intermetallic catalysts for improved PEM fuel cell performance. RSC Adv 2023; 13:4601-4611. [PMID: 36760270 PMCID: PMC9900476 DOI: 10.1039/d2ra07780a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/30/2023] [Indexed: 02/09/2023] Open
Abstract
The design of catalysts with stable and finely dispersed platinum or platinum alloy nanoparticles on the carbon support is key in controlling the performance of proton exchange membrane (PEM) fuel cells. In the present work, an intermetallic PtCo/C catalyst is synthesized via double-passivation galvanic displacement. TEM and XRD confirm a significantly narrowed particle size distribution for the catalyst particles compared to commercial benchmark catalysts (Umicore PtCo/C). Only about 10% of the mass fraction of PtCo particles show a diameter larger than 8 nm, whereas this is up to or even more than 35% for the reference systems. This directly results in a considerable increase in electrochemically active surface area (96 m2 g-1 vs. >70 m2 g-1), which confirms the more efficient usage of precious catalyst metal in the novel catalyst. Single-cell tests validate this finding by improved PEM fuel cell performance. Reducing the cathode catalyst loading from 0.4 mg cm-2 to 0.25 mg cm-2 resulted in a power density drop at an application-relevant 0.7 V of only 4% for the novel catalyst, compared to the 10% and 20% for the commercial benchmarks reference catalysts.
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Affiliation(s)
- Philipp A. Heizmann
- Electrochemical Energy Systems, IMTEK – Department of Microsystems Engineering, University of FreiburgGeorges-Koehler-Allee 10379110 FreiburgGermany,Institute and FIT – Freiburg Center for Interactive Materials and Bioinspired Technologies, University of FreiburgGeorges-Köhler-Allee 10579110 FreiburgGermany
| | - Hien Nguyen
- Electrochemical Energy Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg Georges-Koehler-Allee 103 79110 Freiburg Germany .,Hahn-Schickard Georges-Koehler-Allee 103 79110 Freiburg Germany
| | - Miriam von Holst
- Electrochemical Energy Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg Georges-Koehler-Allee 103 79110 Freiburg Germany .,Hahn-Schickard Georges-Koehler-Allee 103 79110 Freiburg Germany
| | - Andreas Fischbach
- Electrochemical Energy Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg Georges-Koehler-Allee 103 79110 Freiburg Germany
| | - Mitja Kostelec
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Francisco Javier Gonzalez Lopez
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia,ReCatalyst d.o.o.Hajdrihova ulica 19Ljubljana1000Slovenia
| | - Marjan Bele
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Luka Pavko
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Tina Đukić
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Martin Šala
- Department of Analytical Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Francisco Ruiz-Zepeda
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Carolin Klose
- Electrochemical Energy Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg Georges-Koehler-Allee 103 79110 Freiburg Germany .,Hahn-Schickard Georges-Koehler-Allee 103 79110 Freiburg Germany
| | - Matija Gatalo
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia,ReCatalyst d.o.o.Hajdrihova ulica 19Ljubljana1000Slovenia
| | - Nejc Hodnik
- Department of Materials Chemistry, National Institute of ChemistryHajdrihova ulica 191000 LjubljanaSlovenia
| | - Severin Vierrath
- Electrochemical Energy Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg Georges-Koehler-Allee 103 79110 Freiburg Germany .,Institute and FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg Georges-Köhler-Allee 105 79110 Freiburg Germany.,Hahn-Schickard Georges-Koehler-Allee 103 79110 Freiburg Germany
| | - Matthias Breitwieser
- Electrochemical Energy Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg Georges-Koehler-Allee 103 79110 Freiburg Germany .,Hahn-Schickard Georges-Koehler-Allee 103 79110 Freiburg Germany
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16
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Yoshimune W. Dependence of oxygen transport properties of catalyst layers for polymer electrolyte fuel cells on the fabrication process. RESULTS IN CHEMISTRY 2023. [DOI: 10.1016/j.rechem.2022.100738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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17
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Kim HY, Jun M, Lee K, Joo SH. Skeletal Nanostructures Promoting Electrocatalytic Reactions with Three-Dimensional Frameworks. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ho Young Kim
- Hydrogen·Fuel Cell Research Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Minki Jun
- Department of Chemistry and Research Institute for Natural Science, Korea University, Seoul 02841, Republic of Korea
| | - Kwangyeol Lee
- Department of Chemistry and Research Institute for Natural Science, Korea University, Seoul 02841, Republic of Korea
| | - Sang Hoon Joo
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
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18
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Yoshimune W, Kikkawa N, Yoneyama H, Takahashi N, Minami S, Akimoto Y, Mitsuoka T, Kawaura H, Harada M, Yamada NL, Aoki H. Interfacial Distribution of Nafion Ionomer Thin Films on Nitrogen-Modified Carbon Surfaces. ACS APPLIED MATERIALS & INTERFACES 2022; 14:53744-53754. [PMID: 36416068 PMCID: PMC10806603 DOI: 10.1021/acsami.2c14574] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Chemically modified carbon supports for the cathode catalyst layers of polymer electrolyte fuel cells (PEFCs) show considerable promise for boosting the oxygen reduction reaction. This study evaluated the ionomer distribution of Nafion ionomer thin films on nitrogen (N)-modified carbon surfaces along their depth direction. Neutron reflectivity (NR) measurements performed using the double-contrast technique with H2O and D2O revealed that the introduction of N functional groups to carbon thin films promoted ionomer adsorption onto the surface under wet conditions (22 °C, 85% relative humidity). Molecular dynamics (MD) simulations conducted to verify the origin of the robust contact between the ionomer and N-modified carbon surface revealed an ionomer adsorption mechanism on the N-modified carbon surfaces, which involved Coulomb interactions between the positively charged carbon surface and the ionomer side chains with negatively charged sulfonic acid groups. The positive surface charge, which was determined using the contents of the N functional groups estimated by X-ray photoelectron spectroscopy, was found to be sufficient as an impetus for ionomer adsorption. This strategy involving NR measurements and MD simulations can provide insights into the solid-ionomer interfacial structures in a cathode catalyst layer and can therefore be extensively employed in studies on PEFCs.
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Affiliation(s)
- Wataru Yoshimune
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Nobuaki Kikkawa
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Hiroaki Yoneyama
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Naoko Takahashi
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Saori Minami
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Yusuke Akimoto
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Takuya Mitsuoka
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Hiroyuki Kawaura
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Masashi Harada
- Toyota
Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi480-1192, Japan
| | - Norifumi L. Yamada
- Institute
of Materials Structure Science, High Energy
Accelerator Research Organization, Naka-gun, Ibaraki319-1106, Japan
| | - Hiroyuki Aoki
- Institute
of Materials Structure Science, High Energy
Accelerator Research Organization, Naka-gun, Ibaraki319-1106, Japan
- Materials
and Life Science Division, J-PARC Center, Japan Atomic Energy Agency, Naka-gun, Ibaraki319-1195, Japan
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19
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Eskandari H, Paul DK, Young AP, Karan K. Humidity-Dependent Hydration and Proton Conductivity of PFSA Ionomer Thin Films at Fuel-Cell-Relevant Temperatures: Effect of Ionomer Equivalent Weight and Side-Chain Characteristics. ACS APPLIED MATERIALS & INTERFACES 2022; 14:50762-50772. [PMID: 36342365 DOI: 10.1021/acsami.2c12667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Studies on the hydration properties, proton conductivity, and water content of perfluorinated ionomer thin films at temperatures relevant to fuel cell operation temperatures (around 80 °C) and the effect of ionomer chemistry are scarce. In this work, we report the water content and proton conductivity properties of thin-film ionomers (30 nm) at 80 °C over a wide range of relative humidity (0-90%) for seven different ionomers differing in the side-chain structure, including the number of protogenic groups, with the equivalent weight ranging from 620 to 1100 g/mol of sulfonic acid. The results show that the acid content or equivalent weight of the ionomer is the strongest determinant of both the swelling and the proton conductivity of ionomer films at a given relative humidity. The molar water content (λ) of ionomer films normalized to the molar protogenic group is observed to be equivalent-weight-dependent, implying that the affinity for water is acid-content-dependent. At high relative humidity conditions (>70%) pertinent to fuel cell operations, the proton conductivity of low-equivalent-weight ionomers was higher than that of higher-equivalent-weight ionomers. However, upon correlating the proton conductivity with molar water content (λ), the differences reduce dramatically, highlighting that water content is the controlling factor for proton conduction. Significantly higher values of both water content and proton conductivity are observed at 80 °C compared to those at 30 °C, implying that room temperature data are not reliable for estimating ionomer properties in the fuel cell catalyst layer.
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Affiliation(s)
- Hamideh Eskandari
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, Calgary, AlbertaT2N 1N4, Canada
| | - Devproshad K Paul
- Ballard Power Systems Inc., 9000 Glenlyon Parkway, Burnaby, British ColumbiaV5J 5J8, Canada
| | - Alan P Young
- Ballard Power Systems Inc., 9000 Glenlyon Parkway, Burnaby, British ColumbiaV5J 5J8, Canada
| | - Kunal Karan
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, Calgary, AlbertaT2N 1N4, Canada
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20
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Sun Y, Tian J, Mu Z, Tian B, Zhou Q, Liu C, Liu S, Wu Q, Ding M. Unravelling the critical role of surface Nafion adsorption in Pt-catalyzed oxygen reduction reaction by in situ electrical transport spectroscopy. Sci China Chem 2022. [DOI: 10.1007/s11426-022-1428-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Zhang Q, Dong S, Shao P, Zhu Y, Mu Z, Sheng D, Zhang T, Jiang X, Shao R, Ren Z, Xie J, Feng X, Wang B. Covalent organic framework-based porous ionomers for high-performance fuel cells. Science 2022; 378:181-186. [PMID: 36228000 DOI: 10.1126/science.abm6304] [Citation(s) in RCA: 75] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Lowering platinum (Pt) loadings without sacrificing power density and durability in fuel cells is highly desired yet challenging because of the high mass transport resistance near the catalyst surfaces. We tailored the three-phase microenvironment by optimizing the ionomer by incorporating ionic covalent organic framework (COF) nanosheets into Nafion. The mesoporous apertures of 2.8 to 4.1 nanometers and appendant sulfonate groups enabled the proton transfer and promoted oxygen permeation. The mass activity of Pt and the peak power density of the fuel cell with Pt/Vulcan (0.07 mg of Pt per square centimeter in the cathode) both reached 1.6 times those values without the COF. This strategy was applied to catalyst layers with various Pt loadings and different commercial catalysts.
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Affiliation(s)
- Qingnuan Zhang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Shuda Dong
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Pengpeng Shao
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Yuhao Zhu
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Zhenjie Mu
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Dafei Sheng
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Teng Zhang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Xin Jiang
- Orthopaedics Department, China-Japan Friendship Hospital, Beijing 100081, P. R. China
| | - Ruiwen Shao
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, School of Medical Technology, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Zhixin Ren
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Jing Xie
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Xiao Feng
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
| | - Bo Wang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Frontiers Science Center for High Energy Material, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China
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22
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Experimental probing of the effect of PFSA ionomer poisoning at different Pt loadings in a PEMFC. J Catal 2022. [DOI: 10.1016/j.jcat.2022.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Choi WY, Seo DJ, Choi H, Lee MH, Choi SW, Yoon YG, Kim TY, Kim H, Jung CY. Ionomer immobilized onto nitrogen-doped carbon black as efficient and durable electrode binder and electrolyte for polymer electrolyte fuel cells. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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24
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Hornberger E, Merzdorf T, Schmies H, Hübner J, Klingenhof M, Gernert U, Kroschel M, Anke B, Lerch M, Schmidt J, Thomas A, Chattot R, Martens I, Drnec J, Strasser P. Impact of Carbon N-Doping and Pyridinic-N Content on the Fuel Cell Performance and Durability of Carbon-Supported Pt Nanoparticle Catalysts. ACS APPLIED MATERIALS & INTERFACES 2022; 14:18420-18430. [PMID: 35417125 DOI: 10.1021/acsami.2c00762] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cathode catalyst layers of proton exchange membrane fuel cells (PEMFCs) typically consist of carbon-supported platinum catalysts with varying weight ratios of proton-conducting ionomers. N-Doping of carbon support materials is proposed to enhance the performance and durability of the cathode layer under operating conditions in a PEMFC. However, a detailed understanding of the contributing N-moieties is missing. Here, we report the successful synthesis and fuel cell implementation of Pt electrocatalysts supported on N-doped carbons, with a focus on the analysis of the N-induced effect on catalyst performance and durability. A customized fluidized bed reduction reactor was used to synthesize highly monodisperse Pt nanoparticles deposited on N-doped carbons (N-C), the catalytic oxygen reduction reaction activity and stability of which matched those of state-of-the-art PEMFC catalysts. Operando high-energy X-ray diffraction experiments were conducted using a fourth generation storage ring; the light of extreme brilliance and coherence allows investigating the impact of N-doping on the degradation behavior of the Pt/N-C catalysts. Tests in liquid electrolytes were compared with tests in membrane electrode assemblies in single-cell PEMFCs. Our analysis refines earlier views on the subject of N-doped carbon catalyst supports: it provides evidence that heteroatom doping and thus the incorporation of defects into the carbon backbone do not mitigate the carbon corrosion during high-potential cycling (1-1.5 V) and, however, can promote the cell performance under usual PEMFC operating conditions (0.6-0.9 V).
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Affiliation(s)
| | - Thomas Merzdorf
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Henrike Schmies
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Jessica Hübner
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Malte Klingenhof
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Ulrich Gernert
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Matthias Kroschel
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Björn Anke
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Martin Lerch
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Johannes Schmidt
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Arne Thomas
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
| | - Raphaël Chattot
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, Grenoble 38043 Cedex 9, France
| | - Isaac Martens
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, Grenoble 38043 Cedex 9, France
| | - Jakub Drnec
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, Grenoble 38043 Cedex 9, France
| | - Peter Strasser
- Department of Chemistry, Technische Universität Berlin, Berlin 10623, Germany
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25
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Effect of Catalyst Ink and Formation Process on the Multiscale Structure of Catalyst Layers in PEM Fuel Cells. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12083776] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The structure of a catalyst layer (CL) significantly impacts the performance, durability, and cost of proton exchange membrane (PEM) fuel cells and is influenced by the catalyst ink and the CL formation process. However, the relationship between the composition, formulation, and preparation of catalyst ink and the CL formation process and the CL structure is still not completely understood. This review, therefore, focuses on the effect of the composition, formulation, and preparation of catalyst ink and the CL formation process on the CL structure. The CL structure depends on the microstructure and macroscopic properties of catalyst ink, which are decided by catalyst, ionomer, or solvent(s) and their ratios, addition order, and dispersion. To form a well-defined CL, the catalyst ink, substrate, coating process, and drying process need to be well understood and optimized and match each other. To understand this relationship, promote the continuous and scalable production of membrane electrode assemblies, and guarantee the consistency of the CLs produced, further efforts need to be devoted to investigating the microstructure of catalyst ink (especially the catalyst ink with high solid content), the reversibility of the aged ink, and the drying process. Furthermore, except for the certain variables studied, the other manufacturing processes and conditions also require attention to avoid inconsistent conclusions.
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26
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Evaluating the effect of ionomer chemical composition in silver-ionomer catalyst inks toward the oxygen evolution reaction by half-cell measurements and water electrolysis. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.140124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Kodama K, Motobayashi K. Adsorption of ionomer and ionic liquid on model Pt catalysts for polymer electrolyte fuel cells. ELECTROCHEMICAL SCIENCE ADVANCES 2022. [DOI: 10.1002/elsa.202100183] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - Kenta Motobayashi
- Department of Physical Science and Engineering Nagoya Institute of Technology Nagoya Japan
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28
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Lee YJ, Kim HE, Oh H, Yun H, Lee J, Shin S, Lee H, Kim BJ. Lens-Shaped Carbon Particles with Perpendicularly-Oriented Channels for High-Performance Proton Exchange Membrane Fuel Cells. ACS NANO 2022; 16:2988-2996. [PMID: 35080373 DOI: 10.1021/acsnano.1c10280] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Two-dimensional sheet-like mesoporous carbon particles are promising for maximizing the number of active sites and the mass transport efficiency of proton exchange membrane fuel cells (PEMFCs). Herein, we develop a series of lens-shaped mesoporous carbon (LMC) particles with perpendicularly oriented channels (diameter = 60 nm) and aspect ratios (ARs) varying from 2.1 to 6.2 and apply them for the fabrication of highly efficient PEMFCs. The membrane emulsification affords uniform-sized, lens-shaped block copolymer particles, which are successfully converted into the LMC particles with well-ordered vertical channels through hyper-cross-linking and carbonization steps. Then, an ultralow amount (1 wt %) of platinum (Pt) is loaded into the particles. The LMC particles with higher ARs are packed with a higher density in the cathode and are better aligned on the cathode surface compared to the LMC particles with lower ARs. Thus, the well-ordered channels in the particles facilitate the mass transport of the reactants and products, significantly increasing the PEMFC performance. For example, the LMC particles with the AR of 6.2 show the highest initial single cell performance of 1135 mW cm-2, and the cell exhibits high durability with 1039 mW cm-2 even after 30 000 cycles. This cell performance surpasses that of commercial Pt/C catalysts, even at 1/20 of the Pt loading.
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Affiliation(s)
- Young Jun Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hee-Eun Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyunkyu Oh
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hongseok Yun
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea
| | - Joonho Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sangyong Shin
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyunjoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Bumjoon J Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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29
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Kamat GA, Zamora Zeledón JA, Gunasooriya GTKK, Dull SM, Perryman JT, Nørskov JK, Stevens MB, Jaramillo TF. Acid anion electrolyte effects on platinum for oxygen and hydrogen electrocatalysis. Commun Chem 2022; 5:20. [PMID: 36697647 PMCID: PMC9814610 DOI: 10.1038/s42004-022-00635-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 01/20/2022] [Indexed: 01/28/2023] Open
Abstract
Platinum is an important material with applications in oxygen and hydrogen electrocatalysis. To better understand how its activity can be modulated through electrolyte effects in the double layer microenvironment, herein we investigate the effects of different acid anions on platinum for the oxygen reduction/evolution reaction (ORR/OER) and hydrogen evolution/oxidation reaction (HER/HOR) in pH 1 electrolytes. Experimentally, we see the ORR activity trend of HClO4 > HNO3 > H2SO4, and the OER activity trend of HClO4 [Formula: see text] HNO3 ∼ H2SO4. HER/HOR performance is similar across all three electrolytes. Notably, we demonstrate that ORR performance can be improved 4-fold in nitric acid compared to in sulfuric acid. Assessing the potential-dependent role of relative anion competitive adsorption with density functional theory, we calculate unfavorable adsorption on Pt(111) for all the anions at HER/HOR conditions while under ORR/OER conditions [Formula: see text] binds the weakest followed by [Formula: see text] and [Formula: see text]. Our combined experimental-theoretical work highlights the importance of understanding the role of anions across a large potential range and reveals nitrate-like electrolyte microenvironments as interesting possible sulfonate alternatives to mitigate the catalyst poisoning effects of polymer membranes/ionomers in electrochemical systems. These findings help inform rational design approaches to further enhance catalyst activity via microenvironment engineering.
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Affiliation(s)
- Gaurav Ashish Kamat
- Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - José A Zamora Zeledón
- Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | | | - Samuel M Dull
- Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Joseph T Perryman
- Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA
| | - Jens K Nørskov
- Catalysis Theory Center, Department of Physics, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Michaela Burke Stevens
- Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA.
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
| | - Thomas F Jaramillo
- Department of Chemical Engineering, Stanford University, 443 Via Ortega, Stanford, CA, 94305, USA.
- SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA, 94025, USA.
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30
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Tang M, Zhang S, Chen S. Pt utilization in proton exchange membrane fuel cells: structure impacting factors and mechanistic insights. Chem Soc Rev 2022; 51:1529-1546. [PMID: 35138316 DOI: 10.1039/d1cs00981h] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It is essential to realize an expected low usage of platinum (Pt) in proton exchange membrane fuel cells (PEMFCs) for the large-scale market penetration of PEMFC-powered vehicles. As well as seeking Pt-based catalysts with a high specific activity, improving Pt utilization through structure optimization of the catalyst layer (CL) has been the main route and apparently a more practical way so far to develop high-performance low-Pt PEMFCs. Despite the significant progress achieved in the past 2-3 decades, a visible gap remains between the current Pt demand of automobile PEMFCs and the target value. To further increase Pt utilization, insights from previous studies are necessary. This review analyzes the structural factors that impact the current-generation efficiency of Pt in PEMFC electrodes in great detail, with emphasis particularly put on the mechanistic and molecule-level insights into the structural effects. The contents include the so-called local transport resistance associated with the permeation and diffusion of oxygen molecules in the ionomer film covering the Pt surface, regulation of ionomer aggregation through molecular interactions between ink components, modulation of ionomer distribution through pore size exclusion and surface electrostatic interaction of the carbon support, optimization of the coupling between the reaction and transport processes through graded composition, and the formation of highways of protons, electrons, and gas molecules through component alignment. We provide a critical analysis of the measurement methods and theoretical models assessing the local transport resistance, which is considered as a crucial issue in the current-generation efficiency of Pt in ultralow-Pt CL. Finally, new opportunities toward the further promotion of Pt utilization are proposed. These subjects and discussions should be of great significance in the rational design and precise fabrication of PEMFC electrodes, and may also inspire similar subjects in other electrochemical energy technologies such as water electrolysis, CO2 reduction, and batteries.
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Affiliation(s)
- Meihua Tang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
| | - Shiming Zhang
- Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China
| | - Shengli Chen
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
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31
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Xie M, Chu T, Wang T, Wan K, Yang D, Li B, Ming P, Zhang C. Preparation, Performance and Challenges of Catalyst Layer for Proton Exchange Membrane Fuel Cell. MEMBRANES 2021; 11:879. [PMID: 34832108 PMCID: PMC8617821 DOI: 10.3390/membranes11110879] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 11/17/2022]
Abstract
In this paper, the composition, function and structure of the catalyst layer (CL) of a proton exchange membrane fuel cell (PEMFC) are summarized. The hydrogen reduction reaction (HOR) and oxygen reduction reaction (ORR) processes and their mechanisms and the main interfaces of CL (PEM|CL and CL|MPL) are described briefly. The process of mass transfer (hydrogen, oxygen and water), proton and electron transfer in MEA are described in detail, including their influencing factors. The failure mechanism of CL (Pt particles, CL crack, CL flooding, etc.) and the degradation mechanism of the main components in CL are studied. On the basis of the existing problems, a structure optimization strategy for a high-performance CL is proposed. The commonly used preparation processes of CL are introduced. Based on the classical drying theory, the drying process of a wet CL is explained. Finally, the research direction and future challenges of CL are pointed out, hoping to provide a new perspective for the design and selection of CL materials and preparation equipment.
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Affiliation(s)
- Meng Xie
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Tiankuo Chu
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Tiantian Wang
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Kechuang Wan
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Daijun Yang
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Bing Li
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Pingwen Ming
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
| | - Cunman Zhang
- School of Automotive Studies, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China; (M.X.); (T.C.); (T.W.); (K.W.); (D.Y.); (P.M.); (C.Z.)
- Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), 4800 Cao’an Road, Shanghai 201804, China
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32
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Ahn CY, Park JE, Kim S, Kim OH, Hwang W, Her M, Kang SY, Park S, Kwon OJ, Park HS, Cho YH, Sung YE. Differences in the Electrochemical Performance of Pt-Based Catalysts Used for Polymer Electrolyte Membrane Fuel Cells in Liquid Half- and Full-Cells. Chem Rev 2021; 121:15075-15140. [PMID: 34677946 DOI: 10.1021/acs.chemrev.0c01337] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A substantial amount of research effort has been directed toward the development of Pt-based catalysts with higher performance and durability than conventional polycrystalline Pt nanoparticles to achieve high-power and innovative energy conversion systems. Currently, attention has been paid toward expanding the electrochemically active surface area (ECSA) of catalysts and increase their intrinsic activity in the oxygen reduction reaction (ORR). However, despite innumerable efforts having been carried out to explore this possibility, most of these achievements have focused on the rotating disk electrode (RDE) in half-cells, and relatively few results have been adaptable to membrane electrode assemblies (MEAs) in full-cells, which is the actual operating condition of fuel cells. Thus, it is uncertain whether these advanced catalysts can be used as a substitute in practical fuel cell applications, and an improvement in the catalytic performance in real-life fuel cells is still necessary. Therefore, from a more practical and industrial point of view, the goal of this review is to compare the ORR catalyst performance and durability in half- and full-cells, providing a differentiated approach to the durability concerns in half- and full-cells, and share new perspectives for strategic designs used to induce additional performance in full-cell devices.
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Affiliation(s)
- Chi-Yeong Ahn
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - Ji Eun Park
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - Sungjun Kim
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - Ok-Hee Kim
- Department of Science, Republic of Korea Naval Academy, Jinhae-gu, Changwon 51704, South Korea
| | - Wonchan Hwang
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - Min Her
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - Sun Young Kang
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - SungBin Park
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
| | - Oh Joong Kwon
- Department of Energy and Chemical Engineering, Incheon National University, Incheon 22012, South Korea
| | - Hyun S Park
- Center for Hydrogen-Fuel Cell Research, Korea Institute of Science and Technology, Seoul 02792, South Korea
| | - Yong-Hun Cho
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,Department of Chemical Engineering, Kangwon National University, Samcheok 25913, South Korea
| | - Yung-Eun Sung
- Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, South Korea.,School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, South Korea
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33
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Sun Y, Polani S, Luo F, Ott S, Strasser P, Dionigi F. Advancements in cathode catalyst and cathode layer design for proton exchange membrane fuel cells. Nat Commun 2021; 12:5984. [PMID: 34645781 PMCID: PMC8514433 DOI: 10.1038/s41467-021-25911-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 09/09/2021] [Indexed: 11/17/2022] Open
Abstract
Proton exchange membrane fuel cells have been recently developed at an increasing pace as clean energy conversion devices for stationary and transport sector applications. High platinum cathode loadings contribute significantly to costs. This is why improved catalyst and support materials as well as catalyst layer design are critically needed. Recent advances in nanotechnologies and material sciences have led to the discoveries of several highly promising families of materials. These include platinum-based alloys with shape-selected nanostructures, platinum-group-metal-free catalysts such as metal-nitrogen-doped carbon materials and modification of the carbon support to control surface properties and ionomer/catalyst interactions. Furthermore, the development of advanced characterization techniques allows a deeper understanding of the catalyst evolution under different conditions. This review focuses on all these recent developments and it closes with a discussion of future research directions in the field. The high platinum loadings at the cathodes of proton exchange membrane fuel cells significantly contribute to the cost of these clean energy conversion devices. Here, the authors critically review and discuss recent developments on low- and non-platinum-based cathode catalysts and catalyst layers.
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Affiliation(s)
- Yanyan Sun
- The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany.,School of Materials Science and Engineering, Central South University, 410083, Changsha, Hunan, China
| | - Shlomi Polani
- The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| | - Fang Luo
- The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| | - Sebastian Ott
- The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany
| | - Peter Strasser
- The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany.
| | - Fabio Dionigi
- The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, Straße des 17. Juni 124, 10623, Berlin, Germany.
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34
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Ott S, Bauer A, Du F, Dao TA, Klingenhof M, Orfanidi A, Strasser P. Impact of Carbon Support Meso‐Porosity on Mass Transport and Performance of PEMFC Cathode Catalyst Layers. ChemCatChem 2021. [DOI: 10.1002/cctc.202101162] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sebastian Ott
- Department of Chemistry Chemical Engineering Division Technical University of Berlin Straße des 17 Juni 124 10623 Berlin Germany
| | | | | | | | - Malte Klingenhof
- Department of Chemistry Chemical Engineering Division Technical University of Berlin Straße des 17 Juni 124 10623 Berlin Germany
| | | | - Peter Strasser
- Department of Chemistry Chemical Engineering Division Technical University of Berlin Straße des 17 Juni 124 10623 Berlin Germany
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35
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The Activity Enhancement Effect of Ionic Liquids on Oxygen Reduction Reaction Catalysts: From Rotating Disk Electrode to Membrane Electrode Assembly. Catalysts 2021. [DOI: 10.3390/catal11080989] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ionic liquids (ILs) have been explored as a surface modification strategy to promote the oxygen reduction reaction (ORR) on Pt/C and their chemical structures were identified to have strong influence on the ORR activities. To better understand the roles of anion and cation of ILs on the catalytic reaction, two cations ([MTBD]+ and [bmim]+) were paired with three anions ([TFSI]−, [beti]−, and [C4F9SO3]−) to form various IL structures. By systematically varying the IL combinations and studying their effects on the electrochemical behaviors, such as electrochemical surface area and specific ORR activities, it was found that cation structure had a higher influence than anion, and the impact of the [MTBD]+ series was stronger than the [bmim]+ series. In addition to the investigation in the half-cell, studies were also extended to the membrane electrode assembly (MEA). Considerable performance enhancements were demonstrated in both the kinetic region and high current density region with the aid of IL. This work suggests that IL modification can provide a complementary approach to improve the performance of proton exchange membrane fuel cells.
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36
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Jinnouchi R, Kudo K, Kodama K, Kitano N, Suzuki T, Minami S, Shinozaki K, Hasegawa N, Shinohara A. The role of oxygen-permeable ionomer for polymer electrolyte fuel cells. Nat Commun 2021; 12:4956. [PMID: 34400643 PMCID: PMC8368003 DOI: 10.1038/s41467-021-25301-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 07/19/2021] [Indexed: 11/19/2022] Open
Abstract
In recent years, considerable research and development efforts are devoted to improving the performance of polymer electrolyte fuel cells. However, the power density and catalytic activities of these energy conversion devices are still far from being satisfactory for large-scale operation. Here we report performance enhancement via incorporation, in the cathode catalyst layers, of a ring-structured backbone matrix into ionomers. Electrochemical characterizations of single cells and microelectrodes reveal that high power density is obtained using an ionomer with high oxygen solubility. The high solubility allows oxygen to permeate the ionomer/catalyst interface and react with protons and electrons on the catalyst surfaces. Furthermore, characterizations of single cells and single-crystal surfaces reveal that the oxygen reduction reaction activity is enhanced owing to the mitigation of catalyst poisoning by sulfonate anion groups. Molecular dynamics simulations indicate that both the high permeation and poisoning mitigation are due to the suppression of densely layered folding of polymer backbones near the catalyst surfaces by the incorporated ring-structured matrix. These experimental and theoretical observations demonstrate that ionomer's tailored molecular design promotes local oxygen transport and catalytic reactions.
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Affiliation(s)
| | - Kenji Kudo
- Toyota Central R&D Labs., Inc, Nagakute, Aichi, Japan
| | | | - Naoki Kitano
- Toyota Central R&D Labs., Inc, Nagakute, Aichi, Japan
| | | | - Saori Minami
- Toyota Central R&D Labs., Inc, Nagakute, Aichi, Japan
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Xu S, Wang Z, Dull S, Liu Y, Lee DU, Lezama Pacheco JS, Orazov M, Vullum PE, Dadlani AL, Vinogradova O, Schindler P, Tam Q, Schladt TD, Mueller JE, Kirsch S, Huebner G, Higgins D, Torgersen J, Viswanathan V, Jaramillo TF, Prinz FB. Direct Integration of Strained-Pt Catalysts into Proton-Exchange-Membrane Fuel Cells with Atomic Layer Deposition. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007885. [PMID: 34110653 DOI: 10.1002/adma.202007885] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/31/2021] [Indexed: 06/12/2023]
Abstract
The design and fabrication of lattice-strained platinum catalysts achieved by removing a soluble core from a platinum shell synthesized via atomic layer deposition, is reported. The remarkable catalytic performance for the oxygen reduction reaction (ORR), measured in both half-cell and full-cell configurations, is attributed to the observed lattice strain. By further optimizing the nanoparticle geometry and ionomer/carbon interactions, mass activity close to 0.8 A mgPt -1 @0.9 V iR-free is achievable in the membrane electrode assembly. Nevertheless, active catalysts with high ORR activity do not necessarily lead to high performance in the high-current-density (HCD) region. More attention shall be directed toward HCD performance for enabling high-power-density hydrogen fuel cells.
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Affiliation(s)
- Shicheng Xu
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Zhaoxuan Wang
- Department of Material Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Sam Dull
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Yunzhi Liu
- Department of Material Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Dong Un Lee
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
| | | | - Marat Orazov
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
| | | | - Anup Lal Dadlani
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim, 7491, Norway
| | - Olga Vinogradova
- Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Peter Schindler
- Department of Material Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Qizhan Tam
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
| | | | | | | | | | - Drew Higgins
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA
- Department of Chemical Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada
| | - Jan Torgersen
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim, 7491, Norway
| | - Venkatasubramanian Viswanathan
- Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
- Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | | | - Fritz B Prinz
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
- Department of Material Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim, 7491, Norway
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38
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Guo Y, Yang D, Li B, Yang D, Ming P, Zhang C. Effect of Dispersion Solvents and Ionomers on the Rheology of Catalyst Inks and Catalyst Layer Structure for Proton Exchange Membrane Fuel Cells. ACS APPLIED MATERIALS & INTERFACES 2021; 13:27119-27128. [PMID: 34086430 DOI: 10.1021/acsami.1c07070] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study investigated the effects of the dielectric constant (ε) of a dispersion solvent and ionomer content on the rheology of graphitized carbon (GC)-supported Pt catalyst ink and the structure of catalyst layers (CLs). The ionomer dispersions and catalyst inks were tested using rheological techniques, zeta (ξ) potential, and dynamic light scattering measurements. Results showed that increases in the solvent ε or ionomer content increased the ξ-potential of catalyst particles in the ink, which reduced the catalyst agglomerate size. Steady-state and oscillation scans showed that the Pt/GC catalyst ink had shear-thinning properties and gel-like behavior. The ink with a solvent ε of 40 tended to be more Newtonian fluid, with low yield stress (σy). The ionomer content altered the rheology of the ink by changing the internal interaction of inks. Solvents with ε of 70 and 55 enhanced the adsorption of ionomers onto catalysts, thereby increasing the adhesion between ink particles and reducing the risk of CL cracking. As the ionomer content increased, the catalyst absorbed more ionomers in inks, increasing the fracture toughness of CLs, which reduced the crack width.
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Affiliation(s)
- Yuqing Guo
- School of Automotive Studies, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
- Clean Energy Automotive Engineering Center, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
| | - Daozeng Yang
- School of Automotive Studies, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
- Clean Energy Automotive Engineering Center, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
| | - Bing Li
- School of Automotive Studies, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
- Clean Energy Automotive Engineering Center, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
| | - Daijun Yang
- School of Automotive Studies, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
- Clean Energy Automotive Engineering Center, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
| | - Pingwen Ming
- School of Automotive Studies, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
- Clean Energy Automotive Engineering Center, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
| | - Cunman Zhang
- School of Automotive Studies, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
- Clean Energy Automotive Engineering Center, Tongji University, Jiading Campus, 4800 Cao'an Road, Shanghai 201804, China
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39
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In situ/operando vibrational spectroscopy for the investigation of advanced nanostructured electrocatalysts. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213824] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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40
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Kumeda T, Hoshi N, Nakamura M. Effect of Hydrophobic Cations on the Inhibitors for the Oxygen Reduction Reaction on Anions and Ionomers Adsorbed on Single-Crystal Pt Electrodes. ACS APPLIED MATERIALS & INTERFACES 2021; 13:15866-15871. [PMID: 33755425 DOI: 10.1021/acsami.1c01421] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Weakening of the poisoning by the specifically adsorbed anions assists in developing next-generation electrocatalysts for use in low-temperature fuel cells. In this study, we evaluated how hydrophobic cations with different alkyl chain lengths affect the oxygen reduction reaction (ORR) activities on the single-crystal Pt surfaces in contact with sulfuric acid solution and Nafion ionomers. Interfacial tetraalkylammonium cations with longer alkyl chains activated the ORR on the Pt(111) surface. In a solution containing tetrahexylammonium cations (THA+), the ORR activities on Pt(111) in sulfuric acid solution and on Nafion-modified Pt(111) in perchloric acid solution were four and eight times higher than those in the solutions without THA+, respectively. Infrared spectroscopy revealed the reduction of the amount of (bi)sulfate anions and the sulfonate group of Nafion adsorbed on Pt(111) due to the presence of THA+. The hydrophobic cations weaken the noncovalent interactions between specifically adsorbed species and promote the ORR.
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Affiliation(s)
- Tomoaki Kumeda
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522, Japan
| | - Nagahiro Hoshi
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522, Japan
| | - Masashi Nakamura
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Yayoi-cho 1-33, Inage-ku, Chiba 263-8522, Japan
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Eliminating the need for craftsmanship: Facile and precise determination of oxygen reduction reaction activity by spraying catalyst ink on rotating disk electrode. J Electroanal Chem (Lausanne) 2021. [DOI: 10.1016/j.jelechem.2021.115115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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42
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Kodama K, Nagai T, Kuwaki A, Jinnouchi R, Morimoto Y. Challenges in applying highly active Pt-based nanostructured catalysts for oxygen reduction reactions to fuel cell vehicles. NATURE NANOTECHNOLOGY 2021; 16:140-147. [PMID: 33479539 DOI: 10.1038/s41565-020-00824-w] [Citation(s) in RCA: 196] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 11/25/2020] [Indexed: 06/12/2023]
Abstract
The past 30 years have seen progress in the development of Pt-based nanocatalysts for the oxygen reduction reaction, and some are now in production on a commercial basis and used for polymer electrolyte fuel cells (PEFCs) for automotives and other applications. Further improvements in catalytic activity are required for wider uptake of PEFCs, however. In laboratories, researchers have developed various catalysts that have much higher activities than commercial ones, and these state-of-the-art catalysts have potential to improve energy conversion efficiencies and reduce the usage of platinum in PEFCs. There are several technical issues that must be solved before they can be applied in fuel cell vehicles, which require a high power density and practical durability, as well as high efficiency. In this Review, the development history of Pt-based nanocatalysts and recent analytical studies are summarized to identify the origin of these technical issues. Promising strategies for overcoming those issues are also discussed.
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43
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Guo Y, Pan F, Chen W, Ding Z, Yang D, Li B, Ming P, Zhang C. The Controllable Design of Catalyst Inks to Enhance PEMFC Performance: A Review. ELECTROCHEM ENERGY R 2020. [DOI: 10.1007/s41918-020-00083-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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44
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Takeshita T, Kamitaka Y, Shinozaki K, Kodama K, Morimoto Y. Evaluation of ionomer coverage on Pt catalysts in polymer electrolyte membrane fuel cells by CO stripping voltammetry and its effect on oxygen reduction reaction activity. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114250] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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45
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Transport and Electrochemical Interface Properties of Ionomers in Low-Pt Loading Catalyst Layers: Effect of Ionomer Equivalent Weight and Relative Humidity. Molecules 2020; 25:molecules25153387. [PMID: 32722653 PMCID: PMC7435395 DOI: 10.3390/molecules25153387] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/02/2020] [Accepted: 07/18/2020] [Indexed: 11/17/2022] Open
Abstract
Catalyst layer (CL) ionomers control several transport and interfacial phenomena including long-range transport of protons, local transport of oxygen to Pt catalyst, effective utilization of Pt catalyst, electrochemical reaction kinetics and double-layer capacitance. In this work, the variation of these properties, as a function of humidity, for CLs made with two ionomers differing in side-chain length and equivalent weight, Nafion-1100 and Aquivion-825, was investigated. This is the first study to examine humidity-dependent oxygen reduction reaction (ORR) kinetics in-situ for CLs with different ionomers. A significant finding is the observation of higher ORR kinetic activity (A/cm2Pt) for the Aquivion-825 CL than for the Nafion-1100 CL. This is attributed to differences in the interfacial protonic concentrations at Pt/ionomer interface in the two CLs. The differences in Pt/ionomer interface is also noted in a higher local oxygen transport resistance for Aquivion-825 CLs compared to Nafion-1100 CLs, consistent with stronger interaction between ionomer and Pt for ionomer with more acid groups. Similar dependency on Pt utilization (ratio of electrochemically active area at any relative humidity (RH) to that at 100% RH) as a function of RH is observed for the two CLs. As expected, strong influence of humidity on proton conduction is observed. Amongst the two, the CL with high equivalent weight ionomer (Nafion-1100) exhibits higher conduction.
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46
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Li Y, Intikhab S, Malkani A, Xu B, Snyder J. Ionic Liquid Additives for the Mitigation of Nafion Specific Adsorption on Platinum. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01243] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Yawei Li
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Saad Intikhab
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Arnav Malkani
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Bingjun Xu
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Joshua Snyder
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
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47
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Li Y, Van Cleve T, Sun R, Gawas R, Wang G, Tang M, Elabd YA, Snyder J, Neyerlin KC. Modifying the Electrocatalyst-Ionomer Interface via Sulfonated Poly(ionic liquid) Block Copolymers to Enable High-Performance Polymer Electrolyte Fuel Cells. ACS ENERGY LETTERS 2020; 5:1726-1731. [PMID: 38434232 PMCID: PMC10906942 DOI: 10.1021/acsenergylett.0c00532] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Polymer electrolyte membrane fuel cell (PEMFC) electrodes with a 0.07 mgPt cm-2 Pt/Vulcan electrocatalyst loading, containing only a sulfonated poly(ionic liquid) block copolymer (SPILBCP) ionomer, were fabricated and achieved a ca. 2× enhancement of kinetic performance through the suppression of Pt surface oxidation. However, SPILBCP electrodes lost over 70% of their electrochemical active area at 30% RH because of poor ionomer network connectivity. To combat these effects, electrodes made with a mix of Nafion/SPILBCP ionomers were developed. Mixed Nafion/SPILBCP electrodes resulted in a substantial improvement in MEA performance across the kinetic and mass transport-limited regions. Notably, this is the first time that specific activity values determined from an MEA were observed to be on par with prior half-cell results for Nafion-free Pt/Vulcan systems. These findings present a prospective strategy to improve the overall performance of MEAs fabricated with surface accessible electrocatalysts, providing a pathway to tailor the local electrocatalyst/ionomer interface.
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Affiliation(s)
- Yawei Li
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
| | - Tim Van Cleve
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
| | - Rui Sun
- Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ramchandra Gawas
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Guanxiong Wang
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
| | - Maureen Tang
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Yossef A. Elabd
- Department
of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Joshua Snyder
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - K. C. Neyerlin
- Chemistry
and Nanoscience Center, National Renewable
Energy Laboratory, Golden, Colorado 80401, United States
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48
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Sakaushi K, Kumeda T, Hammes-Schiffer S, Melander MM, Sugino O. Advances and challenges for experiment and theory for multi-electron multi-proton transfer at electrified solid–liquid interfaces. Phys Chem Chem Phys 2020; 22:19401-19442. [DOI: 10.1039/d0cp02741c] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Understanding microscopic mechanism of multi-electron multi-proton transfer reactions at complexed systems is important for advancing electrochemistry-oriented science in the 21st century.
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Affiliation(s)
- Ken Sakaushi
- Center for Green Research on Energy and Environmental Materials
- National Institute for Materials Science
- Ibaraki 305-0044
- Japan
| | - Tomoaki Kumeda
- Center for Green Research on Energy and Environmental Materials
- National Institute for Materials Science
- Ibaraki 305-0044
- Japan
| | | | - Marko M. Melander
- Nanoscience Center
- Department of Chemistry
- University of Jyväskylä
- Jyväskylä
- Finland
| | - Osamu Sugino
- The Institute of Solid State Physics
- the University of Tokyo
- Chiba 277-8581
- Japan
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49
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Van Cleve T, Khandavalli S, Chowdhury A, Medina S, Pylypenko S, Wang M, More KL, Kariuki N, Myers DJ, Weber AZ, Mauger SA, Ulsh M, Neyerlin KC. Dictating Pt-Based Electrocatalyst Performance in Polymer Electrolyte Fuel Cells, from Formulation to Application. ACS APPLIED MATERIALS & INTERFACES 2019; 11:46953-46964. [PMID: 31742376 DOI: 10.1021/acsami.9b17614] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In situ electrochemical diagnostics designed to probe ionomer interactions with platinum and carbon were applied to relate ionomer coverage and conformation, gleaned from anion adsorption data, with O2 transport resistance for low-loaded (0.05 mgPt cm-2) platinum-supported Vulcan carbon (Pt/Vu)-based electrodes in a polymer electrolyte fuel cell. Coupling the in situ diagnostic data with ex situ characterization of catalyst inks and electrode structures, the effect of ink composition is explained by both ink-level interactions that dictate the electrode microstructure during fabrication and the resulting local ionomer distribution near catalyst sites. Electrochemical techniques (CO displacement and ac impedance) show that catalyst inks with higher water content increase ionomer (sulfonate) interactions with Pt sites without significantly affecting ionomer coverage on the carbon support. Surprisingly, the higher anion adsorption is shown to have a minor impact on specific activity, while exhibiting a complex relationship with oxygen transport. Ex situ characterization of ionomer suspensions and catalyst/ionomer inks indicates that the lower ionomer coverage can be correlated with the formation of large ionomer aggregates and weaker ionomer/catalyst interactions in low-water content inks. These larger ionomer aggregates resulted in increased local oxygen transport resistance, namely, through the ionomer film, and reduced performance at high current density. In the water-rich inks, the ionomer aggregate size decreases, while stronger ionomer/Pt interactions are observed. The reduced ionomer aggregation improves transport resistance through the ionomer film, while the increased adsorption leads to the emergence of resistance at the ionomer/Pt interface. Overall, the high current density performance is shown to be a nonmonotonic function of ink water content, scaling with the local gas (H2, O2) transport resistance resulting from pore, thin film, and interfacial phenomena.
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Affiliation(s)
- Tim Van Cleve
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Sunilkumar Khandavalli
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Anamika Chowdhury
- Energy Conversion Group, Energy Technologies Area , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Department of Chemical and Biomolecular Engineering , University of California , Berkeley , California 94720 , United States
| | - Samantha Medina
- Colorado School of Mines , Golden , Colorado 80401 , United States
| | - Svitlana Pylypenko
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
- Colorado School of Mines , Golden , Colorado 80401 , United States
| | - Min Wang
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Karren L More
- Oak Ridge National Laboratory , Oak Ridge , Tennessee 37830 , United States
| | - Nancy Kariuki
- Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Deborah J Myers
- Argonne National Laboratory , Lemont , Illinois 60439 , United States
| | - Adam Z Weber
- Energy Conversion Group, Energy Technologies Area , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Scott A Mauger
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Michael Ulsh
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - K C Neyerlin
- Chemistry and Nanoscience Center , National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
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50
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Karan K. Interesting Facets of Surface, Interfacial, and Bulk Characteristics of Perfluorinated Ionomer Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13489-13520. [PMID: 30753782 DOI: 10.1021/acs.langmuir.8b03721] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ion-containing perfluorinated polymers possess unique viscoelastic properties, excellent proton conductivity, and nanophase-segregated structure all arising from the clustering of hydrophilic sulfonic acid groups within a matrix of hydrophobic fluorocarbons. When these ionomers are confined to nanothin films, a broad swathe of structural organization imparting a rich variety of surface, interfacial, and bulk characteristics can be expected. However, our understanding of perfluorinated ionomer thin film behavior is still in a rudimentary stage, and much of the research focus to date has been on its hydration-related structure and properties pertinent to electrochemical applications. Thus, many hidden gems-their interesting surface and interfacial properties-have been overlooked. In this Invited Feature Article, which is a summary of the key contributions by the author's group, including several collaborative publications on ionomer thin films, we unravel many of these facets. In addition, the article attempts to integrate knowledge acquired from a variety of investigations of different aspects of the ionomer thin films to refine and develop a consistent picture of their structure and behavior. First, we focus on the self-assembly of ionomers and show that dispersion media and hydrophobicity/hydrophilicity of the substrate can result in partial or even no coverage of substrates, shedding light on the complexity of polymer-substrate, polymer-solvent, and polymer-polymer interactions, an insight completely obscured when the spin-coating method is adopted for film creation. We demonstrate that the same ionomer can be used to create a variety of surfaces ranging from superhydrophilic to highly hydrophobic by controlling the film thickness or through the choice of substrate material. The ultrathin, hydrophilic surfaces of self-assembled Nafion ionomer films exhibit wettability switching behavior which opens the door to creating stimuli-responsive smart surfaces. The thermoresponsive behavior of the films is discussed in the context of surface (wettability) and bulk (thermal expansion) characteristics as well as a newly discovered vibrational mode. The substrate- and film thickness-dependent thermal expansion coefficients reinforce the importance of interfacial interactions and confinement on the structure/properties of these films. They also open up the potential of tuning ionomer bulk properties via substrate chemistry. The discovery of a vibrational mode that becomes thermally activated at high temperature has provided new insights into the origins of the molecular motions responsible for the α-relaxation of the Nafion ionomer as well as the underlying reason for wettability switching. Our recent neutron reflectometry study of different ionomers varying in side-chain composition/length on a platinum substrate shows that the interfacial hydration level is correlated to the side-chain length, which opens up the possibility of the controlling the interfacial electrochemistry. Finally, a systematic analysis of factors affecting proton conduction is presented to elucidate the yet-unresolved origins of the suppressed conduction of nanothin ionomer films compared to that of the bulk membrane. By revealing these interesting yet poorly understood facets of ionomer thin films, the article aims to stimulate further scientific pursuit on this topic.
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Affiliation(s)
- Kunal Karan
- Department of Chemical & Petroleum Engineering , The University of Calgary , Calgary , Alberta T2N1N4 , Canada
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