Surface engineering on MnO_(2)nanorods by La single atoms to accelerate oxygen reduction kinetics

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 a-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.