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

CO₂-to-hydrocarbon fuel conversion via artificial photosynthesis is limited by catalyst poisoning under high O₂ partial pressures and sluggish C₂-product formation. Herein, Ru_0.6Cu₁(Cu⁰-Cu¹⁺)/CeO₂ catalysts with adaptive O₂ tolerance are prepared by O₂-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 H₂O dissociation. Photothermal effect promotes O₂-driven self-assembly of Cu⁰-Cu¹⁺ 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 C₁ to C₂, as determined by operando spectroscopy and electronic structure analysis. Under concentrated solar irradiation, the catalyst produces 549 ± 20 μmol·g^-1 C₂H₄ 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.