Selective and Stable Electroreduction of CO2 to CO at the Copper/Indium Interface

Electrochemical reduction of CO2 using renewable energy is a promising strategy to mitigate the CO2 emissions and to produce valuable chemicals. However, the lack of highly selective, highly durable, and nonprecious-metal catalysts impedes the applications of this reaction. In this work, copper-nanowire-supported indium catalysts are proposed as advanced electrocatalysts for the aqueous electroreduction of CO2. The catalysts are synthesized by a facile method, which combines In3+ deposition on Cu(OH)2 nanowires, mild oxidation, and in situ electroreduction procedures. With a thin layer of metallic In deposited on the surface of the Cu nanowires, the catalyst exhibits a CO Faradaic efficiency of ∼93% at −0.6 to −0.8 V vs RHE; additionally, an unprecedented stability of 60 h is achieved. The characterization results combined with density functional theory (DFT) calculations reveal that the interface of Cu and In plays an essential role in determining the reaction pathway. The calculation results suggest that the Cu–In interface enhances the adsorption strength of *COOH, a key reaction intermediate for CO production, while destabilizes the adsorption of *H, an intermediate for H2 evolution. We believe that these findings will provide guidance on the rational design of high-performance bimetallic catalysts for CO2 electroreduction by creating the metal–metal interface structure.