Copper-based catalysts electrochemically convert CO2 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 Cu3Ag1 electrocatalyst is developed using galvanic replacement of an electrodeposited Cu matrix. The Cu3Ag1 electrocatalyst enables a 63% Faradaic efficiency for CO2-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 CO2 reduction intermediates in the alcohol pathway, such as CH3CHO* and CH3CH2O*. Thus, for this electron-deficient catalyst, the C2H5OH pathway is more preferable than the ethylene (C2H4) 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 CO2-to-alcohol conversion.