Efficient oxygen reduction by a Fe/Co/C/N nano-porous catalyst in neutral media

Abstract

A stable Fe/Co/C/N nano-porous structure is synthesized using melamine network-polymers, transition metals (iron and cobalt) and carbon nanoparticles for its application as an oxygen reduction reaction (ORR) catalyst. The Fe/Co/C/N catalyst efficiently catalyzes 4-electron reduction of oxygen with an onset potential of 0.88 V and a half-wave potential of 0.78 V (vs. a reversible hydrogen electrode) in neutral media, while its activity does not suffer from crossover effects of organics. The high ORR activity is deduced to be attributed to a high surface area of hierarchical micro/nano-pore structures and dense active sites in the catalyst. Microbial fuel cells (MFCs) equipped with this polymer catalyst on gas-diffusion cathodes exhibit high power outputs, which are more than double the outputs of MFCs with a commercial platinum-based cathode catalyst.