Iron, Cobalt, and Nitrogen Tri‐Doped Ordered Mesoporous Carbon as a Highly Efficient Electrocatalyst for Oxygen Reduction Reaction

Abstract

AbstractMany heteroatom‐doped carbon materials have recently been fabricated to enhance the electrocatalytic oxygen reduction reaction (ORR) performance as promising alternatives to the scarce and high cost Pt‐based catalysts. Herein, Fe, Co, N‐tri‐doped ordered mesoporous carbon materials (Fe‐Co−N‐OMCs) are synthesized by a facile templating technique using ordered close‐packed silica nanospheres as a hard template and ferric chloride hexahydrate (FeCl3⋅6H2O), cobalt chloride hexahydrate (CoCl2⋅6H2O), dicyandiamide (DCDA), and sucrose as Fe, Co, N and C source, respectively. This method can be easily extended to synthesize a variety of doped carbon‐based materials containing ordered mesopores. The results show that the bimetallic doping in this carbon‐based materials is more favorable than single metal doping in catalyzing the ORR process. The best performing catalyst (Fe‐Co−N‐OMC (1:1)) exhibits comparable ORR activity with a half‐wave potential of 0.83 V vs. reversible hydrogen electrode (RHE) and superior stability to the commercial 20 wt% Pt/C in alkaline medium. The enhanced ORR performance of Fe‐Co−N‐OMC (1:1) could be attributed to the tri‐doping of Fe, Co and N into the carbon skeleton for catalytic reactions and the ordered mesoporous structure for facile mass transport and more exposed active sites.