Electron‐Deficient Cu Sites on Cu3Ag1 Catalyst Promoting CO2 Electroreduction to Alcohols

Abstract Copper‐based catalysts electrochemically convert CO 2 into multicarbon molecules. However, the selectivity toward alcohol products has remained relatively low, due to the lack of catalysts favoring the adsorption of key intermediates in the alcohol pathways. Herein, a Cu 3 Ag 1 electrocatalyst is developed using galvanic replacement of an electrodeposited Cu matrix. The Cu 3 Ag 1 electrocatalyst enables a 63% Faradaic efficiency for CO 2 ‐to‐alcohol production and an alcohol partial current density of −25 mA cm −2 at −0.95 V versus reversible hydrogen electrode, corresponding to a 126‐fold enhancement in selectivity and 25‐fold increase in activity compared to the bare electrodeposited Cu matrix. Density functional theory calculations reveal that the interphase electron transfer from Cu to Ag generates electron‐deficient Cu sites and favors the adsorption of CO 2 reduction intermediates in the alcohol pathway, such as CH 3 CHO* and CH 3 CH 2 O*. Thus, for this electron‐deficient catalyst, the C 2 H 5 OH pathway is more preferable than the ethylene (C 2 H 4 ) pathway, endowing the catalyst with an alcohol/ethylene ratio of 38:1. These findings suggest both experimental approaches and theoretical insights for exploring highly selective CO 2 ‐to‐alcohol conversion.