Oxygen-modulated engineering of Cu0–Cu+ interfaces for CO2-to-C2H4 photoreduction

CO 2 -to-hydrocarbon fuel conversion via artificial photosynthesis is limited by catalyst poisoning under high O 2 partial pressures and sluggish C 2 -product formation. Herein, Ru 0.6 Cu 1 (Cu 0 –Cu 1+ )/CeO 2 catalysts with adaptive O 2 tolerance are prepared by O 2 -mediated dynamic interfacial reconstruction. Single-atom Ru doping at Ce lattice sites creates a trigonal prismatic coordination configuration, enabling proton-coupled electron transfer and accelerating H 2 O dissociation. Photothermal effect promotes O 2 -driven self-assembly of Cu 0 –Cu 1+ charge-gradient interfaces within Ru/Cu alloy clusters, thereby optimizing the adsorption behavior of * CHOCO intermediates and restructuring the C–C coupling pathway. Interfacial charge cascade transfer and geometric site synergy thermodynamically shift the product selectivity from C 1 to C 2 , as determined by operando spectroscopy and electronic structure analysis. Under concentrated solar irradiation, the catalyst produces 549 ± 20 μmol·g −1 C 2 H 4 with 74.3% selectivity and 0.5% solar-to-chemical energy conversion efficiency—25-fold higher than that in non-concentrated systems. Dynamic interfacial regulation facilitates precise carbon chain synthesis in complex reaction networks.