Atomically Dispersed Co2MnN8 Triatomic Sites Anchored in N‐Doped Carbon Enabling Efficient Oxygen Reduction Reaction

Abstract

AbstractAtomically dispersed transition metal–nitrogen/carbon (M–N/C) catalysts have emerged as the most promising substitutes to the precious platinum counterparts toward the oxygen reduction reaction (ORR). However, the reported M–N/C catalysts are usually in the form of common M–N4 moieties with only a single metal active site, and they suffer from insufficient activity. Herein, an unusual trinuclear active structure is elaborately developed with a nitrogen‐coordinated single Mn atom adjacent to two Co atoms (Co2MnN8) anchored in N‐doped carbon as a highly efficient ORR catalyst via adsorption–pyrolysis of a bimetallic zeolitic imidazolate framework precursor. Atomic structural investigations and density functional theory (DFT) calculations reveal that Co2MnN8 would experience a spontaneous OH binding to form Co2MnN8‐2OH as the real active site, leading to a single electron‐filled state in the orbital and an optimized binding energy of intermediates. Accordingly, the as‐developed Co2MnN8/C exhibits an unprecedented ORR activity with a high half‐wave potential of 0.912 V and outstanding stability, not only surpassing the Pt/C catalyst but also representing a new record for the Co‐based catalyst.