Lewis Acidic Support Boosts C-C Coupling in the Pulsed Electrochemical CO Reaction.

Copper-oxide electrocatalysts have been demonstrated to effectively perform the electrochemical CO reduction reaction (CORR) toward C products, yet preserving the reactive high-valent CuO has remained elusive. Herein, we demonstrate a model system of Lewis acidic supported Cu electrocatalyst with a pulsed electroreduction method to achieve enhanced performance for C products, in which an optimized electrocatalyst could reach ∼76% Faradaic efficiency for C products (FE) at ∼-0.99 V reversible hydrogen electrode, and the corresponding mass activity can be enhanced by ∼2 times as compared to that of conventional CuO. time-resolved X-ray absorption spectroscopy investigating the dynamic chemical/physical nature of Cu during CORR discloses that an activation process induced by the KOH electrolyte during pulsed electroreduction greatly enriched the CuO/ZnO interfaces, which further reveals that the presence of ZnO species under the cathodic potential could effectively serve as a Lewis acidic support for preserving the CuO species to facilitate the formation of C products, and the catalyst structure-property relationship of CuO/ZnO interfaces can be evidently realized. More importantly, we find a universality of stabilizing CuO species for various metal oxide supports and to provide a general concept of appropriate electrocatalyst-Lewis acidic support interaction for promoting C products.