Asymmetric‐Charge‐Distributed Co─Mn Diatomic Catalyst Enables Efficient Oxygen Reduction Reaction
Yue Zhao, Zhonghui Gao, Shuyao Zhang, Xuze Guan, Wence Xu, Yanqin Liang, Hui Jiang, Zhaoyang Li, Shuilin Wu, Zhenduo Cui, Shengli Zhu
Abstract
Abstract Transition metal (TM)–nitrogen/carbon (M─N/C) catalysts have emerged as the most promising alternatives to precious platinum catalysts for the oxygen reduction reaction (ORR). However, the reported M─N/C catalysts typically exist in TM─N 4 coordination with symmetric charge distribution, resulting in weak adsorption energies for ORR intermediates, which limits the reaction rate. Herein, a novel asymmetrically coordinated Co─Mn diatomic catalyst is synthesized through the adsorption–pyrolysis process of a bimetallic zeolitic imidazolate framework. The catalyst consists of the adjacently sulfur/nitrogen dual‐coordinated Co atoms and the nitrogen‐coordinated Mn atom (CoN 2 S─MnN 3 ), anchored in N‐doped carbon. Atomic structural investigations and density functional theory calculations demonstrate that CoN 2 S─MnN 3 experiences spontaneous OH binding to form CoN 2 S─MnN 3 ─2OH as the real active site. The strong interaction between the Co─Mn diatomic and the orbital multielectron filling effect induced by the asymmetric charge distribution optimizes the adsorption energy of the reaction intermediates. Therefore, the CoMn─NSC catalyst exhibits competitive ORR activity with a high half‐wave potential of 0.901 V, outperforming most of the reported Co‐based catalysts so far. The assembled Zn–air battery has ultralong lifespans of up to 1000 h. This work provides an effective strategy for designing new high‐efficiency oxygen electrocatalysts.