Ag Stabilized Cu+/Cu0 Interface Catalysts for Enhanced CO2 Electroreduction to C2+ Products at Ampere Level Current Density.

Electrochemical carbon dioxide reduction reaction (CO2RR) to yield multicarbon (C2+) products still suffers from a great hardship, which requires high current density and Faradaic efficiency (FE) accompanied by favorable stability for the purpose of industrial applications. Herein, we display 5.6 atom % Ag/Cu2O-Cu catalyst with abundant and steady Ag/Cu+/Cu0 interfaces for the efficient conversion of CO2-to-C2+ at ampere level current density. 5.6 atom % Ag/Cu2O-Cu catalyst attains a desirable FE of 76.5 ± 1.2% toward C2+ products at 1.0 A/cm2 in 1 M KOH electrolyte and remains stable CO2 electrolysis at 0.50 A/cm2 for 20 h using a flow cell apparatus. In situ Raman spectrometry and density functional theory calculations indicate that a steady Ag/Cu+/Cu0 interface can promote CO2-to-C2+ conversion through adjusting the energy barrier for the formation and dimerization of *CO intermediates. The synergistically heterogeneous interfaces promote the activity, selectivity, and stability of CO2 electroreduction to C2+ products via a tandem route of *COOH, *CO, and *OCCO intermediates over Ag/Cu+/Cu0 cooperative sites.