Metal-Oxide Interfaces for Selective Electrochemical C-C Coupling Reactions

Abstract

Metal-oxide interfaces provide a new opportunity to improve catalytic activity based on electronic and chemical interactions at the interface. Constructing a high density of interfaces is essential in maximizing synergistic interactions. Here, we demonstrate that Cu-ceria interfaces made by sintering nanocrystals facilitate C-C coupling reactions in electrochemical reduction of CO2. The Cu/ceria catalyst enhances the selectivity of ethylene and ethanol production with the suppression of H-2 evolution in comparison with Cu catalysts. The intrinsic activity for ethylene production is enhanced by decreasing the atomic ratio of Cu/Ce, revealing the Cu atoms near ceria are an active site for C-C coupling reactions. The ceria is proposed to weaken the hydrogen binding energy of adjacent Cu sites and stabilize an *OCCO intermediate via an additional chemical interaction with an oxygen atom of the *OCCO. This work offers new insights into the role of the metal-oxide interface in the electrochemical reduction of CO2 to high-value chemicals.