High selective electrocatalytic reduction of carbon dioxide to ethylene enabled by regulating the microenvironment over Cu-Ag nanowires

Copper-based tandem catalysts are effective candidates for yielding multi-carbon (C2+) products in electrochemical reduction of carbon dioxide (CO₂RR). However, these catalysts still face a significant challenge regarding in the low selectivity for the production of a specific product. In this study, we report a high selectivity of 77.8 %±2 % at −1.0 V (vs RHE) for the production of C₂H₄ by using a Cu₈₈Ag₁₂NW catalyst which is primarily prepared through a combined Cu-Ag co-deposition and wet chemical method, employing an attractive strategy focused on regulating the microenvironment over Cu-Ag nanowires. The experimental and computational studies show that the higher *CO coverage and lower intermediate adsorption energy are important reasons for achieving the high C₂H₄ selectivity of Cu₈₈Ag₁₂NW catalyst. Comsol simulation results indicate that dense nanowires exhibit a nano-limiting effect on OH⁻ ions, thereby leading to an increase in local pH and promoting coupling reactions. The catalyst demonstrates no noticeable decrease in current density or selectivity even after 12 h of continuous operation. The Cu-Ag nanowire composite exhibits remarkable catalytic activity, superior faradaic efficiency, excellent stability, and easy synthesis, which highlights its significant potential for electro-reducing carbon dioxide into valuable products.