Co-N-C单原子催化剂电催化氧还原反应的研究进展

Recent progress in Co-N-C single-atom catalysts for the electrochemical oxygen reduction reaction

多孔氮掺杂碳材料负载的Co单原子催化剂(Co-N-C)因其在电催化氧还原反应(ORR)中展现出优异的性能而受到广泛关注.通过对催化剂的设计和对反应条件的优化, Co-N-C可以电催化ORR得到水、过氧化氢等不同产物,因此在金属空气电池、燃料电池以及化工生产等方面具有重要的应用前景.然而,在不同条件下Co-N-C催化ORR反应的电子转移途径,即决定ORR反应选择性的关键因素尚无定论.本文综述了近年来Co-N-C催化ORR反应的相关研究进展,从单原子催化剂位点的微环境、中心金属原子掺杂种类、催化剂载体选择以及催化反应条件等方面进行了分析,着重探讨了氧气吸附能、反应中间体结合能等参数的变化,进而对不同条件下决定ORR反应选择性的关键因素进行了讨论.

Cobalt-based single-atom catalyst supported on porous nitrogen-doped carbon(Co-N-C) has received extensive attention due to the excellent catalytic performance in the electrochemical oxygen reduction reaction(ORR).Co-N-C can catalyze ORR via different electron transfer pathways to generate water(H_(2)O) or hydrogen peroxide(H_(2)O_(2)), respectively. Therefore, the rational design of the active sites and the optimization of the catalytic conditions are the key factors in the development of metal-air batteries, fuel cells and chemical industry. However, the key factors determining the selectivity of the ORR are still undefined. This review reports the recent progress on Co-N-C singleatom catalysts for the electrochemical ORR. The microenvironment of the single-atom sites and the test conditions for oxygen reduction reaction are summarized, with attention on the oxygen adsorption energy and reaction intermediate binding energy. Last, by highlighting the key factors for the selectivity determination, this work is expected to shed some light on the further development of Co-N-C for ORR.