Cerium Dioxide-Induced Abundant Cu + /Cu 0 Sites for Electrocatalytic Reduction of Carbon Dioxide to C 2+ Products

In recent years, the electrochemical reduction of carbon dioxide (CO RR) has made many advances in C production. Cu /Cu site is beneficial for C-C coupling process, but the oxidation state of copper cannot be well maintained during the reaction process, resulting in a decrease in catalyst activity. Based on this consideration, in this work, transition metal oxide CeO with a hollow cube structure and oxygen vacancies was introduced to stabilize and increase Cu /Cu active sites (Ce Cu ). The catalyst exhibits excellent CO RR performance, with FE achieving 73.52 % and j >280 mA/cm at 1.26 V (vs. RHE). Ethanol is the main C product and FE reaches 39 % at 1.26 V. The experimental results indicate that the presence of CeO provides a large number of oxygen vacancies and forming Cu -O -Ce structure by the strong interaction of CeO and Cu NPs. The structure of Cu -O -Ce and abundant oxygen vacancies lay a good foundation for the CO adsorption. Moreover, it increases the content of Cu /Cu sites, effectively inhibiting hydrogen evolution reaction, promoting the C-C coupling interaction, thereby facilitating the generation of C products. The DFT theoretical calculation further demonstrates that Ce Cu is more inclined towards the ethanol pathway, confirming its high selectivity for ethanol.