Surface engineering on MnO <sub>2</sub> nanorods by La single atoms to accelerate oxygen reduction kinetics
Zhanglong He, Liu-Qi Wang, Min Jiang, Jianan Xie, Shan Liu, Jincan Ren, Rui Sun, Wenbin Lv, Weibin Guo, Yuling Liu, Bing Li, Qi Liu, Hao He
Abstract
Abstract Surface engineering, which modulates the electronic structure and adsorption/desorption properties of electrocatalysts, is one of the key strategies for improving the catalytic performance. Herein, we demonstrate a facile solid‐phase reaction for surface engineering of MnO 2 to boost the oxygen reduction kinetics. Via reaction with surface hydroxy groups, La single atoms with loading amount up to 2.7 wt% are anchored onto α‐MnO 2 nanorods. After surface engineering, the oxygen reduction reaction (ORR) kinetics is significantly improved with the half‐wave potential from 0.70 to 0.84 V, the number of transferred electrons from 2.5 to 3.9 and the limiting current density from 4.8 to 6.0 mA·cm −2 . In addition, the catalyst delivers superior discharge performance in both alkaline and neutral metal–air batteries. Density functional theory (DFT) calculations reveal that atomic La modulates the surface electronic configuration of MnO 2 , reduces its d‐band center and thus lowers the OOH* and O* reaction energy barrier. This work provides a new route for rational design of highly active electrocatalyst and holds great potential for application in various catalytic reactions.