Electron-Deficient Ru δ+ Sites Coupled with Lattice Oxygen at Ru/BaTiO ₃ Interfaces Enable Efficient Photothermal Methane Dry Reforming

Solar-driven dry reforming of methane (DRM) represents a promising pathway for syngas production, yet its practical application is challenged by insufficient activity and rapid deactivation. Here, we report a Ru/BaTiO3 catalyst with interfacial electron-deficient Ruδ+ sites and dynamic lattice oxygens for efficient photothermal DRM. Under light irradiation, the catalyst delivers H2 and CO production rates of 68.43 and 85.18 mol gRu–1 h–1, a methane turnover frequency of 1.08 s–1, a light-to-chemical energy efficiency of 14.2%, and stable operation over 100 h. Combined experimental and theoretical studies reveal that interband electronic transition-induced electrons migrate from Ru nanoparticles to BaTiO3, enriching Ruδ+ sites that drive stepwise C–H bond cleavage in CH4. Meanwhile, lattice oxygens from BaTiO3 oxidize CH* to CHO*, generating oxygen vacancies that convert CO2 into CO and are refilled by the incorporation of an O*, sustaining a closed redox cycle. This dual mechanism of light-triggered electronic modulation and lattice oxygen participation launches a paradigm for optimizing DRM pathways. The findings highlight the critical role of nonplasmonic metal–support interfaces in solar-driven CH4/CO2 conversion.