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

Many 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 (FeCl3.6H(2)O), cobalt chloride hexahydrate (CoCl2.6H(2)O), 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 0.83V vs. reversible hydrogen electrode (RHE) and superior stability to the commercial 20wt% 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.