Tailoring the d-band electronic structure of deficient LaMn0.3Co0.7O3-δ perovskite nanofibers for boosting oxygen electrocatalysis in Zn-Air batteries

XinYu Gao; Huan Liu; Yong Wang; JiaHui Guo; XingWei Sun; WeiYan Sun; Haitao Zhao; Jie Bai; ChunPing Li

doi:10.1016/j.jcis.2023.07.008

Tailoring the d-band electronic structure of deficient LaMn_0.3Co_0.7O_3-δ perovskite nanofibers for boosting oxygen electrocatalysis in Zn-Air batteries

J Colloid Interface Sci. 2023 Nov 15;650(Pt A):951-960. doi: 10.1016/j.jcis.2023.07.008. Epub 2023 Jul 3.

Authors

XinYu Gao¹, Huan Liu², Yong Wang¹, JiaHui Guo¹, XingWei Sun¹, WeiYan Sun¹, Haitao Zhao³, Jie Bai⁴, ChunPing Li⁵

Affiliations

¹ Chemical Engineering College, Inner Mongolia University of Technology, Hohhot 010051, PR China; Inner Mongolia Key Laboratory of Industrial Catalysis, Hohhot 010051, PR China.
² Chemical Engineering College, Inner Mongolia University of Technology, Hohhot 010051, PR China; Inner Mongolia Key Laboratory of Industrial Catalysis, Hohhot 010051, PR China. Electronic address: huanliu@imut.edu.cn.
³ ShenZhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, PR China.
⁴ Chemical Engineering College, Inner Mongolia University of Technology, Hohhot 010051, PR China; Inner Mongolia Key Laboratory of Industrial Catalysis, Hohhot 010051, PR China. Electronic address: baijie@imut.edu.cn.
⁵ Chemical Engineering College, Inner Mongolia University of Technology, Hohhot 010051, PR China; Inner Mongolia Key Laboratory of Industrial Catalysis, Hohhot 010051, PR China. Electronic address: hgcp_li@126.com.

PMID: 37453319
DOI: 10.1016/j.jcis.2023.07.008

Abstract

The development and design of efficient bifunctional electrocatalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for rechargeable Zinc-air batteries (ZABs). Optimizing the d-band structure of active metal center in perovskite oxides is an effective method to enhance ORR/OER activity by accelerating the rate-determining step. Herein, we report a deficient method to optimize the d-band structure of Co ions in LaMn_0.3Co_0.7O_3-δ (LMCO-2) perovskite nanofibers, which regulates the mutual effect between B-site Co ions and reactive oxygen intermediates. It is proved by experiment and theoretical calculation that the d-band center (M_d) of transition metal ions in LMCO-2 is moved up and the electron filling number of e_g orbital in B site is 1.01, thus leading to the reduction of Gibbs free energy required for ORR rate-determining step (OH*→H₂O*) to 0.22 eV and promoting reaction proceeds. In this manner, LMCO-2 showed good bifunctional oxygen electrocatalytic activity, with a half-wave potential of 0.71 V vs. RHE. Furthermore, the high specific capacity of 811.54 mAh g^-1 and power density of 326.56 mW cm^-2 were obtained by using LMCO-2 as the cathode catalyst for ZABs. This study proved the feasibility of d-band structure regulation to enhance the electrocatalytic activity of perovskite oxides.

Keywords: Deficient; Oxygen reduction reaction; Perovskite oxides; Zinc-air batteries; d-band structure.