Customizable CO2 Electroreduction to C1 or C2+ Products through Cuy/CeO2 Interface Engineering

Cu-catalyzed CO2 electroreduction can produce various hydrocarbons and oxygenates. However, it suffers from low activity and poor selectivity. Herein, Cu-decorated CeO2 composites (Cu-y/CeO2) with distinct interfacial characteristics were fabricated through a highly controllable synthesis, based on chemical prelithiation of CeO2 and then galvanic displacement with Cu. The Cu decoration induced a strong-binding site for CO2 adsorption at the Cu and CeO2 interface, facilitating the CO2 activation and conversion to the *CO intermediate on the nearby Cu surface. Selective CO2 conversion to C-1 or C2+ products was customized by adjusting the Cu decoration amount. With the increase in the Cu loading, the C-1 and C2+ products exhibited a declining and volcano-shaped trend, showing a maximum faradaic efficiency of 70 and 63%, respectively. In situ infrared and Raman spectroscopy revealed that the reduction pathway depended on the relative ratio of the low-frequency band *COLFB to the high-frequency band *COHFB. Our findings may contribute to the rational design of heterostructured catalysts toward CO2 electroreduction.

Automated summary

This study achieved efficient electroreduction of CO2 by decorating Cu on CeO2 and controlling the selectivity of products. The dependence of reduction pathway on the relative ratio of the low-frequency band *COLFB to the high-frequency band *COHFB was revealed using in situ infrared and Raman spectroscopy, providing a theoretical basis for the design of heterostructured catalysts for CO2 electroreduction.