Tuning the Catalytic Selectivity Toward C 2+ Oxygenate Products by Manipulating Cu Oxidation States in CO Electroreduction.

Enhancing the reaction selectivity for multicarbon products (C 2+ ) is an important goal for the electrochemical CO (2) reduction (ECO (2) R) process. Cuprous compounds have demonstrated promising C 2+ selectivity in the ECO (2) R process, but further investigation is necessary to thoroughly elucidate their catalytic behavior toward C 2+ oxygenate production. In this study, copper nitride-based materials with varying reduction rates were employed as precatalysts. Consequently, a relationship between the selectivity toward C 2+ oxygenates and the Cu oxidation state during the ECOR process is established. Results of theoretical and experimental analyses reveal that the Cu 0 /Cu + interface plays a key role in enhancing *CO adsorption while lowering the formation energy of *CH 2 CO, thereby promoting acetate production. This work highlights the significance of the Cu 0 /Cu + interface in the regulation of C 2+ oxygenate production and paves the way for the development of highly selective catalysts in the future.