Copper anchored MXene regulated metal-oxide interfaces for the CO2 electrocatalytic conversion

Abstract

Electrocatalytic conversion of CO₂ into CO is a promising strategy for mitigating the energy crisis, but simultaneously achieving high selectivity and activity of electrocatalysts remains challenging. Herein, we construct a catalyst with a special interface structure featuring abundant unsaturated coordination surface sites that boost CO₂ conversion. The Cu-Ti₃C₂T_x/ZnO catalyst with interface coupling structure achieved high CO Faraday efficiency (FE_CO=90.71% in H-Cell, FE_CO=98.4% in Flow Cell), and maintained high FE_CO (greater than 85.2%) and stable current density for 20 h under high current conditions (200 mA/cm²), demonstrating excellent selectivity and stability for the conversion of CO₂ to CO. In situ infrared and DFT (density functional theory) calculations reveal that this remarkable performance is attributed to the special interface coupling of Cu-Ti₃C₂T_x/ZnO, which can improve the selectivity of the *COOH intermediates (formation energy: 0.45→0.33 eV) and suppress hydrogen evolution reactions (HER) by increasing electronic donation of Cu and upward shift of the d-band center relative to the Fermi level within ZnO regulated Cu-Ti₃C₂T_x interface. This study successfully demonstrated a practical strategy for MXene-based interface interaction with metal oxide regulation and provided new insights for the design and preparation of high-performance electrocatalysts for CO₂ reduction.