Surface Facets Reconstruction in Copper‐Based Materials for Enhanced Electrochemical CO2 Reduction

Abstract The unavoidable and unpredictable surface reconstruction of metallic copper (Cu) during the electrocatalytic carbon dioxide (CO 2 ) reduction process is a double‐edged sword affecting the production of high‐value‐added hydrocarbon products. It is crucial to control the surface facet reconstruction and regulate the targeted facets/facet interfaces, and further understand the mechanism between activity/selectivity and the reconstructed structure of Cu for CO 2 reduction. Based on the current catalyst design methods, a facile strategy combining chemical reduction and electro‐reduction is proposed to achieve specified Cu(111) facets and the Cu(110)/(111) interfaces in reconstructed Cu derived from cuprous oxide (Cu 2 O). The surface facet reconstruction significantly boosted the electrocatalytic conversion of CO 2 into multi‐carbon (C 2+ ) products comparing to the unmodified catalyst. Theoretical and experimental analyses show that the Cu(110)/(111)s interface between Cu(110) and a small amount of Cu(111) can tailor the reaction routes and lower the reaction energy barrier of C–C coupling to ethylene (C 2 H 4 ). The work will guide the surface facets reconstruction strategy for Cu‐based CO 2 electrocatalysts, providing a promising paradigm to understand the structural variation in catalysts.