(330f) Heteroatom Doping in N-Coordinated Metal Site Embedded Graphene for Highly Active Oxygen Reduction Reaction

Metal-N-doped carbon (M-N-C) has been in the spotlight as a potential cost-effective catalyst for oxygen reduction reaction (ORR). To go beyond the state-of-the-art Pt/C, a new design strategy to modulating the electronic structure of the material is necessary. Introducing a heteroatom around the metal center could influence the binding strength of the ORR intermediates by modifying the electronic structure of the metal atom, which could improve the ORR activity. Although several studies on the metal site coordinated by dual heteroatom have been conducted for ORR, systematic investigations depending on the type of heteroatom are still poorly understood. In this study, we investigated the ORR activities and electronic structural changes on metal active site for a total of 24 structures of M-N₃Y (M=Fe, Ni, Co, Mn; Y=B, C, N, O, P, S) based on density functional theory (DFT) calculations. In addition, we investigated the effect of heteroatom doping on the ORR mechanism through microkinetic analysis. As the potential increased, the ORR intermediate poised the active point and affected the adsorption strength. Our findings will provide a useful guidance for designing novel ORR catalysts.