Selective CO Electroreduction to Multicarbon Oxygenates Over Atomically Dispersed Cu-Ag Sites in Alkaline Membrane Electrode Assembly Electrolyzer.

Electrochemical carbon monoxide reduction reaction (CORR) to produce multicarbon (C) oxygenates using renewable electricity is a promising carbon utilization pathway. However, the performance of this process suffers from low C oxygenates selectivity and insufficient current density. Here, we employed a Cu-Ag bimetallic strategy to enhance the selectivity of C oxygenates from CORR in alkaline membrane electrode assembly electrolyzer at ampere-level current densities. The Cu-Ag catalysts prepared by magnetron sputtering feature atomically dispersed Cu-Ag sites on the catalyst surface, which are key to promoting the formation of C oxygenates. Increasing Ag content favors C oxygenates formation while inhibiting ethylene production. The optimized CuAg catalyst achieved Faradaic efficiency of 71.4% for C oxygenates at 2.5 A cm. In situ spectroscopy and density functional theory calculations revealed that atomically dispersed Cu-Ag sites on the catalyst surface promote the dissociation of *COCOH to *CCO, thus favoring C oxygenates formation.