Prof. Xinhe Bao’s research team at Dalian Institute of Chemical Physics, Chinese Academy of Sciences designs and prepares carbon supported Au-CeO_x catalyst with metal-oxide interface structure, and investigates the relationship between the Au-CeO_x interface and catalytic performance of electrochemical CO₂ reduction reaction (CO₂RR). The CO Faradaic efficiency reaches 89.1% over Au-CeO_x/C at −0.89 V vs. reversible hydrogen electrode (RHE), which is significantly higher than 59.0% and 9.8% over Au/C and CeO_x/C at the same potential. The CO geometric current density over Au-CeO_x/C (12.9 mA cm⁻²) is about 1.6 times of that over Au/C (8.3 mA cm⁻²) at −0.89 V vs. RHE.In situ scanning tunnelling microscopy and synchrotron-radiation photoemission spectroscopy show that the Au-CeO_x interface is dominant in enhancing CO₂ adsorption and activation, which can be further promoted by the presence of hydroxyl groups. Density functional theory calculations indicate that the Au-CeO_x interface is the active site for CO₂ activation and the reduction to CO, where the synergy between Au and CeO_x promotes the stability of key carboxyl intermediate (*COOH) and thus facilitates CO₂RR. Similar interface-enhanced CO₂RR is further observed on Ag-CeO_x, demonstrating the generality of the strategy for enhancing CO₂RR.The research results provide a new way to regulate the CO₂RR performance, and enrich and expand the concept of nano-confined catalysis proposed by the research team.

Metal-oxide interface enhances electrocatalytic reduction of CO₂