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Zhang L, Li T, Du T, Dai X, Zhang L, Tao C, Ding J, Yan C, Qian T. Manipulation of Electronic States of Pt Sites via d-Band Center Tuning for Enhanced Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells. Inorg Chem 2024; 63:2138-2147. [PMID: 38237037 DOI: 10.1021/acs.inorgchem.3c04058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Expediting the torpid kinetics of the oxygen reduction reaction (ORR) at the cathode with minimal amounts of Pt under acidic conditions plays a significant role in the development of proton exchange membrane fuel cells (PEMFCs). Herein, a novel Pt-N-C system consisting of Pt single atoms and nanoparticles anchored onto the defective carbon nanofibers is proposed as a highly active ORR catalyst (denoted as Pt-N-C). Detailed characterizations together with theoretical simulations illustrate that the strong coupling effect between different Pt sites can enrich the electron density of Pt sites, modify the d-band electronic environments, and optimize the oxygen intermediate adsorption energies, ultimately leading to significantly enhanced ORR performance. Specifically, the as-designed Pt-N-C demonstrates exceptional ORR properties with a high half-wave potential of 0.84 V. Moreover, the mass activity of Pt-N-C reaches 193.8 mA gPt-1 at 0.9 V versus RHE, which is 8-fold greater than that of Pt/C, highlighting the enormously improved electrochemical properties. More impressively, when integrated into a membrane electrode assembly as cathode in an air-fed PEMFC, Pt-N-C achieved a higher maximum power density (655.1 mW cm-2) as compared to Pt/C-based batteries (376.25 mW cm-2), hinting at the practical application of Pt-N-C in PEMFCs.
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Affiliation(s)
- Luping Zhang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
| | - Tongfei Li
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
| | - Tianheng Du
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
| | - Xinyi Dai
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
| | - Lifang Zhang
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
| | - Chen Tao
- School of Electrical Engineering, Nantong University, Nantong226019, China
| | - Jinjin Ding
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
| | - Chenglin Yan
- School of Petrochemical Engineering, Changzhou University, Changzhou213164, China
- Key Laboratory of Core Technology of High Specific Energy Battery and Key Materials for Petroleum and Chemical Industry, College of Energy, Soochow University, Suzhou215006, China
| | - Tao Qian
- School of Chemistry and Chemical Engineering, Nantong University, Nantong226019, China
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Chen Y, Zhao X, Yan H, Sun L, Chen S, Zhang S, Zhang J. Manipulating Pt-skin of porous network Pt-Cu alloy nanospheres toward efficient oxygen reduction. J Colloid Interface Sci 2023; 652:1006-1015. [PMID: 37639923 DOI: 10.1016/j.jcis.2023.08.134] [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: 07/31/2023] [Revised: 08/12/2023] [Accepted: 08/20/2023] [Indexed: 08/31/2023]
Abstract
Designing Pt-skin on the catalyst surface is critical to developing efficient and stable electrocatalysts toward oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. In this paper, an acidic reductant is proposed to synchronously manipulate in-situ growth of Pt-skin on the surface of alloyed Pt-Cu nanospheres (PtCuNSs) by a facile one-pot synthesis in an aqueous solution. Ascorbic acid can create a Pt-skin of three atomic layers to make the typical PtCu-alloy@Pt-skin core/shell nanostructure rather than the uniform alloys generated by using alkaline reductants. Surfactant as soft-template can make the alloyed PtCuNSs with a three-dimensional porous network structure. Multiple characterizations of XRD, XPS and XAFS are used to confirm Pt-alloying with Cu and formation of core/shell structure of such a catalyst. This PtCuNSs/C exhibits a half-wave potential of 0.913 V (vs. RHE), with mass activity and specific activity about 3.5 and 6.4 times higher than those of Pt/C, respectively. Fuel cell tests verify the excellent activity of PtCuNSs/C catalyst with a maximum power density of about 1.2 W cm-2. Moreover, this catalyst shows excellent stability, achieving a long-term operation of 40,000 cycles. Furthermore, theoretical calculations reveal the enhancement effect of characteristic PtCu-alloy@Pt-skin nanostructure on both catalytic ORR activity and stability.
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Affiliation(s)
- Yizhe Chen
- Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China
| | - Xiao Zhao
- Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China
| | - Huangli Yan
- College of Chemistry and Molecular Sciences, Wuhan University, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan 430072, Hubei, China
| | - Liangyu Sun
- Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China
| | - Shengli Chen
- College of Chemistry and Molecular Sciences, Wuhan University, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan 430072, Hubei, China
| | - Shiming Zhang
- Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China.
| | - Jiujun Zhang
- Institute for Sustainable Energy/College of Sciences, Shanghai University, Shanghai 200444, China.
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