Interfacial Oxygen Vacancy‐Copper Pair Sites on Inverse CeO2/Cu Catalyst Enable Efficient CO2 Electroreduction to Ethanol in Acid

Renewable electricity‐driven electrochemical reduction of CO2 offers a promising route for production of high‐value ethanol. However, the current state of this technology is hindered by low selectivity and productivity, primarily due to limited understanding of the atomic‐level active sites involved in ethanol formation. Herein, we identify that the interfacial oxygen vacancy‐neighboring Cu (Ov‐Cu) pair sites are the active sites for CO2 electroreduction to ethanol. A linear correlation between the density of Ov‐Cu pair sites and ethanol productivity is experimentally evidenced. Moreover, a high Faradaic efficiency of 48.5% and a partial current density of 344.0 mA cm‐2 for ethanol production are achieved over the inverse CeO2/Cu catalyst with a high density of Ov‐Cu pair sites in acid. Mechanistic studies that combine density functional theory calculations and spectroscopic techniques propose an Ov‐involved mechanism where interfacial Ov sites directly activate and dissociate CO2 into *CO in a thermodynamically spontaneous manner, thus favoring the subsequent *CHO formation and asymmetric CHO‐CO coupling. Besides, the asymmetric Ov‐Cu pair sites could preferentially stabilize the *CH2CHOH intermediate, resulting in the favorable formation of ethanol over ethylene. Our findings provide new atomic‐level insights into CO2 electroreduction to ethanol, paving the way for the rational design of future catalysts.