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

Abstract

Electrochemical carbon monoxide reduction reaction (CORR) to produce multicarbon (C2+) oxygenates using renewable electricity is a promising carbon utilization pathway. However, the performance of this process suffers from low C2+ oxygenates selectivity and insufficient current density. Here, we employed a Cu–Ag bimetallic strategy to enhance the selectivity of C2+ 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 C2+ oxygenates. Increasing Ag content favors C2+ oxygenates formation while inhibiting ethylene production. The optimized Cu2Ag catalyst achieved Faradaic efficiency of 71.4% for C2+ 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 C2+ oxygenates formation.