Monosymmetric Fe-N4 sites enabling durable proton exchange membrane fuel cell cathode by chemical vapor modification

Jingsen Bai; Tuo Zhao; Mingjun Xu; Bingbao Mei; Liting Yang; Zhaoping Shi; Siyuan Zhu; Ying Wang; Zheng Jiang; Jin Zhao; Junjie Ge; Meiling Xiao; Changpeng Liu; Wei Xing

doi:10.1038/s41467-024-47817-0

Monosymmetric Fe-N₄ sites enabling durable proton exchange membrane fuel cell cathode by chemical vapor modification

Nat Commun. 2024 May 17;15(1):4219. doi: 10.1038/s41467-024-47817-0.

Authors

Jingsen Bai^#^{1

2}, Tuo Zhao^#³, Mingjun Xu^#^{1

2}, Bingbao Mei^#⁴, Liting Yang^{1

2}, Zhaoping Shi^{1

2}, Siyuan Zhu^{1

2}, Ying Wang⁵, Zheng Jiang⁶, Jin Zhao^{7

8}, Junjie Ge^{9

10}, Meiling Xiao^{1

2}, Changpeng Liu^{1

2}, Wei Xing^{11

12}

Affiliations

¹ State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
² School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China.
³ Commercial Vehicle Development Institute, FAW Jiefang Automotive CO.LTD., Changchun, 130011, China.
⁴ Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201800, China.
⁵ State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. ywang_2012@ciac.ac.cn.
⁶ National Synchrotron Radiation Laboratory (NSRL), University of Science and Technology of China, Hefei, 230026, China.
⁷ State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. zjin@ciac.ac.cn.
⁸ School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China. zjin@ciac.ac.cn.
⁹ State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. gejunjie@ustc.edu.cn.
¹⁰ School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China. gejunjie@ustc.edu.cn.
¹¹ State Key Laboratory of Electroanalytic Chemistry, Jilin Province Key Laboratory of Low Carbon Chemistry Power, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China. xingwei@ciac.ac.cn.
¹² School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China. xingwei@ciac.ac.cn.

^# Contributed equally.

Abstract

The limited durability of metal-nitrogen-carbon electrocatalysts severely restricts their applicability for the oxygen reduction reaction in proton exchange membrane fuel cells. In this study, we employ the chemical vapor modification method to alter the configuration of active sites from FeN₄ to the stable monosymmetric FeN₂+N'₂, along with enhancing the degree of graphitization in the carbon substrate. This improvement effectively addresses the challenges associated with Fe active center leaching caused by N-group protonation and free radicals attack due to the 2-electron oxygen reduction reaction. The electrocatalyst with neoteric active site exhibited excellent durability. During accelerated aging test, the electrocatalyst exhibited negligible decline in its half-wave potential even after undergoing 200,000 potential cycles. Furthermore, when subjected to operational conditions representative of fuel cell systems, the electrocatalyst displayed remarkable durability, sustaining stable performance for a duration exceeding 248 h. The significant improvement in durability provides highly valuable insights for the practical application of metal-nitrogen-carbon electrocatalysts.

Abstract

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