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Harada M, Kajiya S, Mitsuoka T, Takata SI, Iwase H, Aoki H. Scattering investigations into the structures of polymer-electrolyte-fuel-cell catalyst layers exhibiting robust performance against varying water fractions of catalyst ink solvents. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2023.131183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
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2
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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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Zhang X, Truong-Phuoc L, Asset T, Pronkin S, Pham-Huu C. Are Fe–N–C Electrocatalysts an Alternative to Pt-Based Electrocatalysts for the Next Generation of Proton Exchange Membrane Fuel Cells? ACS Catal 2022. [DOI: 10.1021/acscatal.2c02146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiong Zhang
- Institute of Chemistry and Processes for Energy, Environment and Health (ICPEES), UMR 7515 CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex
02, France
| | - Lai Truong-Phuoc
- Institute of Chemistry and Processes for Energy, Environment and Health (ICPEES), UMR 7515 CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex
02, France
| | - Tristan Asset
- Institute of Chemistry and Processes for Energy, Environment and Health (ICPEES), UMR 7515 CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex
02, France
| | - Sergey Pronkin
- Institute of Chemistry and Processes for Energy, Environment and Health (ICPEES), UMR 7515 CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex
02, France
| | - Cuong Pham-Huu
- Institute of Chemistry and Processes for Energy, Environment and Health (ICPEES), UMR 7515 CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg Cedex
02, France
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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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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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Ito K, Harada M, Yamada NL, Kudo K, Aoki H, Kanaya T. Water Distribution in Nafion Thin Films on Hydrophilic and Hydrophobic Carbon Substrates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12830-12837. [PMID: 33085483 DOI: 10.1021/acs.langmuir.0c01917] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We performed H2O and D2O double-contrast neutron reflectivity measurements on ∼25 nm thick Nafion thin films on hydrophilic and hydrophobic carbon in water and 80% relative humidity vapor to investigate the depth profile of the water and Nafion distribution. We found a dense Nafion layer at the air or water interface regardless of the carbon hydrophilicity. On the other hand, a water-rich Nafion dense layer was observed at the carbon interface only for hydrophilic carbon. The double-contrast measurements provided quantitative information about the depth profile but simultaneously indicated that the sum of the volume occupancies of water and Nafion in the film was less than unity. We assessed the problem based on two possibilities: voids in the film or "residual water", which cannot be exchanged or is difficult to exchange with water outside.
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Affiliation(s)
- Kanae Ito
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Masashi Harada
- Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Norifumi L Yamada
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Kenji Kudo
- Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Hiroyuki Aoki
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
| | - Toshiji Kanaya
- Materials and Life Science Division, J-PARC Center, 2-4 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1106, Japan
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Kimura T, Kawamoto T, Aoki M, Mizusawa T, Yamada NL, Miyatake K, Inukai J. Sublayered Thin Films of Hydrated Anion Exchange Ionomer for Fuel Cells Formed on SiO 2 and Pt Substrates Analyzed by Neutron Reflectometry under Controlled Temperature and Humidity Conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4955-4963. [PMID: 32310665 DOI: 10.1021/acs.langmuir.0c00440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Anion-conductive ionomers are used for electrolyte membranes in membrane-electrode assemblies and for binders in catalyst layers in anion exchange membrane fuel cells (AEMFCs). The conformations of these ionomers as well as their water distribution are important for designing new efficient/durable anion-conductive ionomers for AEMFCs. For a deeper understanding of the distribution of deuterium oxide (D2O) as a function of depth, neutron reflectometry (NR) was carried out on thin films of an anion exchange ionomer, BAF-QAF, with a thickness of approximately 60 nm formed on a thermally formed SiO2 film on Si(100) and on a 20 nm Pt layer deposited on the SiO2 film at a temperature of 60 °C and relative humidities of 0, 50, 70, and 90%. Clear NR modulation was obtained under each condition. The NR data were fit very well with a three-sublayered model parallel to the substrate with different densities of BAF-QAF and D2O. The influence of the SiO2 and Pt substrates was observed not only at the BAF-QAF/substrate interface but also on the entire thin film. The D2O absorption/desorption behavior in each sublayer differed in the BAF-QAF films cast on SiO2 and Pt. The BAF-QAF/SiO2 interface was rather hydrophilic, while the BAF-QAF/Pt interface was very hydrophobic.
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Affiliation(s)
- Taro Kimura
- Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi, 4 Takeda, Kofu, Yamanashi 400-8510, Japan
| | - Teppei Kawamoto
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu 400-0021, Japan
| | - Makoto Aoki
- Division of Life, Medical, Natural Sciences and Technology, Organization for Advanced and Integrated Research, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 658-8501, Japan
| | - Takako Mizusawa
- Comprehensive Research Organization for Science and Society Neutron Science and Technology Center, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Norifumi L Yamada
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, 203-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Kenji Miyatake
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu 400-0021, Japan
- Clean Energy Research Center, University of Yamanashi, 4 Takeda, Kofu 400-8510, Japan
| | - Junji Inukai
- Fuel Cell Nanomaterials Center, University of Yamanashi, 6-43 Miyamae-cho, Kofu 400-0021, Japan
- Clean Energy Research Center, University of Yamanashi, 4 Takeda, Kofu 400-8510, Japan
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KAWAMOTO T, AOKI M, KIMURA T, CHINAPANG P, MIZUSAWA T, YAMADA NL, NEMOTO F, WATANABE T, TANIDA H, MATSUMOTO M, IMAI H, MIYAKE J, MIYATAKE K, INUKAI J. Sublayered Structures of Hydrated Nafion ® Thin Film Formed by Casting on Pt Substrate Analyzed by X-ray Absorption Spectroscopy under Ambient Conditions and Neutron Reflectometry at Temperature of 80°C and Relative Humidity of 30–80%. ELECTROCHEMISTRY 2019. [DOI: 10.5796/electrochemistry.19-00042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
| | - Makoto AOKI
- Division of Life, Medical, Natural Sciences and Technology, Organization for Advanced and Integrated Research, Kobe University
| | - Taro KIMURA
- Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi
| | | | | | - Norifumi L. YAMADA
- Institute of Materials Structure Science, High Energy Accelerator Research Organization
| | - Fumiya NEMOTO
- Institute of Materials Structure Science, High Energy Accelerator Research Organization
| | | | | | | | | | - Junpei MIYAKE
- Clean Energy Research Center, University of Yamanashi
| | - Kenji MIYATAKE
- Fuel Cell Nanomaterials Center, University of Yamanashi
- Clean Energy Research Center, University of Yamanashi
| | - Junji INUKAI
- Fuel Cell Nanomaterials Center, University of Yamanashi
- Clean Energy Research Center, University of Yamanashi
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9
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Yoshimune W, Harada M. Effect of Pt Loading on the Adsorption of Perfluoro-sulfonic Acid Ionomer in Catalyst Ink for Polymer Electrolyte Fuel Cells. CHEM LETT 2019. [DOI: 10.1246/cl.190017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Wataru Yoshimune
- Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Masashi Harada
- Toyota Central R&D Labs, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
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