Yin Shuhu, Chen Long, Yang Jian, Cheng Xiaoyang, Zeng Hongbin, Hong Yuhao, Huang Huan, Kuai Xiaoxiao, Lin Yangu, Huang Rui, Jiang Yanxia, Sun Shigang
State Key Laboratory of Physical Chemistry of Solid Surfaces, Engineering Research Center of Electrochemical Technologies of Ministry of Education, College of Chemistry and Chemical Engineering, and Discipline of Intelligent Instrument and Equipment, Xiamen University, Xiamen, P. R. China.
Center of Advanced Electrochemical Energy, Institute of Advanced Interdisciplinary Studies, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, P.R. China.
Nat Commun. 2024 Aug 29;15(1):7489. doi: 10.1038/s41467-024-51858-w.
Replacement of expensive and rare platinum with metal-nitrogen-carbon catalysts for oxygen reduction reactions in proton exchange membrane fuel cells is hindered by their inferior activity. Herein, we report a highly active iron-nitrogen-carbon catalyst by optimizing the carbon structure and coordination environments of Fe-N sites. A critical high-temperature treatment with ammonium chloride and ammonium bromide not only enhances the intrinsic activity and density of Fe-N sites, but also introduces numerous defects, trace Br ions and creates mesopores in the carbon framework. Notably, surface Br ions significantly improve the interaction between the ionomer and catalyst particles, promoting ionomer infiltration and optimizing the O transport and charge transfer at triple-phase boundary. This catalyst delivers a high peak power density of 1.86 W cm and 54 mA cm at 0.9 V in a H-O fuel cells at 80 °C. Our findings highlight the critical role of interface microenvironment regulation.
用金属-氮-碳催化剂替代质子交换膜燃料电池中用于氧还原反应的昂贵且稀有的铂，因催化剂活性较差而受到阻碍。在此，我们通过优化铁-氮位点的碳结构和配位环境，报道了一种高活性的铁-氮-碳催化剂。用氯化铵和溴化铵进行的关键高温处理不仅提高了铁-氮位点的本征活性和密度，还引入了大量缺陷、痕量溴离子，并在碳骨架中形成了中孔。值得注意的是，表面溴离子显著改善了离聚物与催化剂颗粒之间的相互作用，促进了离聚物的渗透，并优化了三相边界处的氧传输和电荷转移。该催化剂在80°C的氢氧燃料电池中，于0.9V时可提供1.86W/cm²的高峰值功率密度和54mA/cm²的电流密度。我们的研究结果突出了界面微环境调控的关键作用。
