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.