Cerium Dioxide‐Induced Abundant Cu⁺/Cu⁰ Sites for Electrocatalytic Reduction of Carbon Dioxide to C₂₊ Products

Abstract

In recent years, the electrochemical reduction of carbon dioxide (CO2RR) has made many advances in C2+ production. Cu+/Cu0 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 CeO2 with a hollow cube structure and oxygen vacancies was introduced to stabilize and increase Cu+/Cu0 active sites (Ce1Cu2). The catalyst exhibits excellent CO2RR performance, with FEC2+ achieving 73.52% and jC2+ > 280 mA/cm2 at 1.26 V (vs. RHE). Ethanol is the main C2+ product and FEethanol reaches 39% at 1.26 V. The experimental results indicate that the presence of CeO2 provides a large number of oxygen vacancies and forming Cu+‐O2‐‐Ce4+ structure by the strong interaction of CeO2 and Cu NPs. The structure of Cu+‐O2‐‐Ce4+ and abundant oxygen vacancies lay a good foundation for the CO2 adsorption. Moreover, it increases the content of Cu+/Cu0 sites, effectively inhibiting hydrogen evolution reaction, promoting the C‐C coupling interaction, thereby facilitating the generation of C2+ products. The DFT theoretical calculation further demonstrates that Ce1Cu2 is more inclined towards the ethanol pathway, confirming its high selectivity for ethanol.