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.
(© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)