Universal Synthesis of Half‐Metallic Diatomic Catalysts for Efficient Oxygen Reduction Electrocatalysis
Yuechao Yao, Tao Jiang, Sung Yul Lim, Cathrine Frandsen, Zhangjian Li, Yibo Dou, Feiyan Wu, Jibo Qin, Jizhao Zou, Eugen Stamate, Wenjing Zhang
Abstract
Abstract Developing efficient and low‐cost noble‐free metal electrocatalysts is an urgent requirement. Herein, a one‐step, solid‐state template‐assisted method for fabricating isolated half‐metallic diatomic M, Zn─N─C (M═Fe, Co, and Ni) catalysts is reported. In particular, the fabricated Fe, Zn─N─C structure exhibits superior oxygen reduction reaction capabilities with a half‐wave potential of 0.867 V versus RHE. The Mossbauer spectra reveal that the Fe, Zn─N─C half‐metallic diatomic catalyst has a large proportion of the D2 site (ferrous iron with a medium spin state). Density functional theory (DFT) reveals that in Fe, Zn─N─C structures, the zinc sites play a unique role in accelerating the protonation process of O 2 in ORR. In assembled zinc–air batteries, a maximum power density of 138 mW cm −2 and a capacity of 748 mAh g zn −1 can be obtained. This work fabricates a series of efficient M, Zn─N─C diatomic electrocatalysts, and the developed solid‐state reaction method can hopefully apply in other energy conversion and storage fields.