Electrochemical reduction of CO2 to produce value-added feedstock chemicals using high-performance electrocatalysts is a promising protocol to address the excessive CO2 in the atmosphere and the energy crisis.However,the high overpotential,low current density,and poor product selectivity for CO2 electroreduction greatly impede their practical applications.In this work,we develop an efficient catalystfor CO2 reduction to CO consisting of well-dispersed ZrO2 nanoparticles tightly anchored on nitrogen doped carbon nanosheets (ZrO2/N-C) for the first time.Importantly,the ZrO2 nanoparticles possess oxygen vacancies and defects,which regulate the electronic structure of catalyst and thus greatly enhance the electrocatalytic activity.Specifically,ZrO2/N-C demonstrates a high CO Faradaic efficiency (FE) of 64％ at-0.4V vs.the reversible hydrogen electrode (RHE) and a respectable current density of ～2.6mA cm-2 in CO2-saturated 0.5 M KHCO3 solution.This work opens a new avenue for developing excellent catalysts for CO2 electroreduction with metal oxide/heteroatom-doped carbon composite structure.