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 (CORR). 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 CH by using a CuAgNW 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 CH selectivity of CuAgNW 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.