Abstract Scope |
Carbon materials doped with transition metals TM (TM=Fe, Co, or Mn) and nitrogen (N) have recently emerged as novel, efficient electrocatalysts, alternative to precious metals, for promoting oxygen reduction reaction (ORR) occurring at the cathode of polymer electrolyte membrane fuel cells. Here, we employed the first-principles density functional theory calculation method to predict the ORR activity on various types of TM-N4 moieties substitutionally embedded into a graphene layer. On each possible active site, we calculated the adsorption energies of all the relevant chemical species, namely, O2, O, OH, OOH, HOOH and H2O, and the activation energies for O-O dissociation reactions involved in ORR. Our high-throughput computation found that the FeN4 moiety bridging the adjacent graphene edges would possess the highest activity for ORR. Hence, our computation suggests that increasing the quantity of micropores in the Fe, N co-doped carbon could enhance its catalytic activity for ORR. |