Ag nanoparticles induced abundant Cu sites in CuSe nanoflower rods to promote efficient carbon dioxide electroreduction to ethanol.

Electrocatalytic carbon dioxide reduction reaction (eCORR) is one of the attractive approaches to CO utilization. Nevertheless, it remains a challenge to prepare highly efficient and selective electrocatalysts to realize deep conversion of multi-carbon products. The absence of active sites due to the reconfiguration of copper-based catalysts leads to migration deactivation during catalysis, rendering low catalytic efficiency. In this work, CuSe nanowires (NWs) were obtained from the Cu foam. After further electroreduction for 90 s, Ag nanoparticles (NPs) were modified on the flower rod-shaped CuSe NWs (Ag/CuSe NWs). This interfacial modification strategy, balanced the Cu active valence state on the surface of the Ag/CuSe NWs, led to a high Faradaic efficiency (FE) of ethanol (∼70 %) at -0.52 V (vs. reversible hydrogen electrode (RHE)). Besides, the Ag/CuSe NWs achieved a high partial current (∼13.9 mA) for ethanol, 18.5 μmol/h ethanol yield and an energy efficiency of 47.1 % in the H-type electrolytic cell. The reaction mechanism was investigated at the molecular level through density functional theory (DFT) calculation. The interface-modified Ag NPs provided stable *COOH intermediates during the reaction process, effectively achieving surface *CO enrichment. Besides, the presence of Ag NPs resulted in the generation of abundant Cu active species. The *CO migrated to the Cu active sites to accelerate the asymmetric coupling of *CO and *CHO, which significantly improved the FE of CO electroreduction to ethanol. Our work offers a promising approach for designing CuSe-based nanowires electrocatalysts for CO reduction with excellent activity and selectivity.