Single Mn Atom Anchored on Nitrogen‐Doped Graphene as a Highly Efficient Electrocatalyst for Oxygen Reduction Reaction
Lei Li, Yameng Li, Rao Huang, Xinrui Cao, Yu‐Hua Wen
Abstract
Abstract Single Mn atom on nitrogen‐doped graphene (MnN 4 ‐G) has exhibited good structural stability and high activity for the adsorption and dissociation of an O 2 molecule, becoming a promising single‐atom catalyst (SAC) candidate for oxygen reduction reaction (ORR). However, the catalytic activity of MnN 4 ‐G for the ORR and the optimal reaction pathway remain obscure. In this work, density‐functional theory calculations were employed to comprehensively investigate all the possible pathways and intermediate reactions of the ORR on MnN 4 ‐G. The feasible active sites and the most stable adsorption configurations of the intermediates and transition states during the ORR were identified. Screened from all the possibilities, three optimal four‐electron O 2 hydrogenation pathways with an ultralow energy barrier of 0.13 eV were discovered that are energetically more favorable than direct O 2 dissociation pathways. Analysis of the free energy diagram further verified the thermodynamical feasibility of the three pathways. Thus, MnN 4 ‐G possesses superior ORR activity. This study provides a fundamental understanding of the design of highly efficient SACs for the ORR.