Engineering Surface Oxophilicity of Copper for Electrochemical CO(2) Reduction to Ethanol

Copper‐based materials are known for converting CO(2) into deep reduction products via electrochemical reduction reaction (CO(2)RR). As the major multicarbon products (C(2+)), ethanol (C(2)H(5)OH) and ethylene (C(2)H(4)) are believed to share a common oxygenic intermediate according to theoretical studies, while the key factors that bifurcate C(2)H(5)OH and C(2)H(4) pathways on Cu‐based catalysts are not fully understood. Here, a surface oxophilicity regulation strategy to enhance C(2)H(5)OH production in CO(2)RR is proposed, demonstrated by a Cu‐Sn bimetallic system. Compared with bare Cu catalyst, the Cu‐Sn bimetallic catalysts show improved C(2)H(5)OH but suppressed C(2)H(4) selectivity. The experimental results and theoretical calculations demonstrate that the surface oxophilicity of Cu‐Sn catalysts plays an important role in steering the protonation of the key oxygenic intermediate and guides the reaction pathways to C(2)H(5)OH. This study provides new insights into the electrocatalyst design for enhanced production of oxygenic products from CO(2)RR by engineering the surface oxophilicity of copper‐based catalysts.