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

Abstract

Abstract Electrochemical carbon monoxide reduction reaction (CORR) to produce multicarbon (C 2+ ) oxygenates using renewable electricity is a promising carbon utilization pathway. However, the performance of this process suffers from low C 2+ oxygenates selectivity and insufficient current density. Here, we employed a Cu–Ag bimetallic strategy to enhance the selectivity of C 2+ 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 2+ oxygenates. Increasing Ag content favors C 2+ oxygenates formation while inhibiting ethylene production. The optimized Cu 2 Ag catalyst achieved Faradaic efficiency of 71.4% for C 2+ oxygenates at 2.5 A cm −2 . 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 2+ oxygenates formation.