文献类型：期刊文献

英文题名：Iron-Free Cathode Catalysts for Proton-Exchange-Membrane Fuel Cells: Cobalt Catalysts and the Peroxide Mitigation Approach

作者：Wang, Xiao Xia[1,2];Prabhakaran, Venkateshkurnor[3];He, Yanghua[1];Shao, Yuyan[3];Wu, Gang[1]

机构：[1]Univ Buffalo State Univ New York, Dept Chem & Biol Engn, Buffalo, NY 14260 USA;[2]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[3]Pacific Northwest Natl Lab, Richland, WA 99352 USA

年份：2019

卷号：31

期号：31

外文期刊名：ADVANCED MATERIALS

收录：;EI(收录号：20190606463884);WOS:【SCI-EXPANDED(收录号:WOS:000484129400015)】；

基金：G.W., Y.S., and V.P. acknowledge the financial support from U.S. Department of Energy, Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office. G.W. also thanks National Science Foundation (CBET-1604392, 1804326) for partial financial support. X.X.W. thanks National Nature Science Foundation of China under Grant No. 21805089, Shanghai Natural Science Foundation of China under Contract No. 16ZR1408600, and the Fundamental Research Funds for the Central Universities under Grant No. 222201814024.

语种：英文

外文关键词：Co catalysts; fuel cells; H2O2 mitigation; oxygen reduction; PGM-free catalysts

摘要：High-performance and inexpensive platinum-group-metal (PGM)-free catalysts for the oxygen reduction reaction (ORR) in challenging acidic media are crucial for proton-exchange-membrane fuel cells (PEMFCs). Catalysts based on Fe and N codoped carbon (Fe-N-C) have demonstrated promising activity and stability. However, a serious concern is the Fenton reactions between Fe2+ and H2O2 generating active free radicals, which likely cause degradation of the catalysts, organic ionomers within electrodes, and polymer membranes used in PEMFCs. Alternatively, Co-N-C catalysts with mitigated Fenton reactions have been explored as a promising replacement for Fe and PGM catalysts. Therefore, herein, the focus is on Co-N-C catalysts for the ORR relevant to PEMFC applications. Catalyst synthesis, structure/morphology, activity and stability improvement, and reaction mechanisms are discussed in detail. Combining experimental and theoretical understanding, the aim is to elucidate the structure-property correlations and provide guidance for rational design of advanced Co catalysts with a special emphasis on atomically dispersed single-metal-site catalysts. In the meantime, to reduce H2O2 generation during the ORR on the Co catalysts, potential strategies are outlined to minimize the detrimental effect on fuel cell durability.