Unraveling the improved CO2 adsorption and COOH* formation over Cu-decorated ZnO nanosheets for CO2 reduction toward CO

Electrocatalytic conversion of CO2 to valuable chemicals is a compelling route to develop anthropogenic carbon cycle and achieve carbon neutrality. Controlling interfacial chemistry has been a long-standing challenge. Herein, we report the preparation of Cu-decorated ZnO nanosheets with an impressively catalytic performance for yielding CO in CO2 reduction. In situ infrared spectroscopy, multiple Quasi in situ characterizations, control experiments combined with density functional theory calculations unveil that the cooperation of Cu clusters and ZnO nanosheets at the interface reduces the ∠O*-Zn-O angle on reactive sites and achieves surface modification and electron transfer from ZnO to Cu. More importantly, the Cu decoration alleviates the mass transfer limitation of CO2 by enhancing CO2 physisorption and chemisorption on the catalyst surface, lowers the reaction energy barrier of CO2*→COOH* and facilitates the formation of key COOH* intermediate through a coupling effect, resulting in the selectively electrocatalytic CO2 towards CO.