Photothermal CO2 methanation over (NiO/Ru0)/TiO2 catalysts via hydrogen spillover

Photothermal CO2 methanation presents a promising strategy for mitigating the energy crisis and reducing CO2 emissions, however, the critical role of hydrogen migration dynamics in addressing reaction kinetics and thermodynamics has not been thoroughly investigated. Here, we demonstrate the design of a (NiO/Ru0)/TiO2 photothermal catalyst with optimized interfacial architecture and enhanced hydrogen mobility, which facilitates exceptionally selective conversion of CO2-to-CH4. Both experimental and theoretical analyses reveal that H2 dissociates efficiently on Ru0, subsequently undergoing spillover to O in NiO (ONiO). This process not only redistributes active sites but also influences the reaction kinetics, thereby fundamentally altering the energy landscape associated with CO2 methanation. Consequently, the (NiO/Ru0)/TiO2 catalyst achieves complete CO2 conversion and CH4 selectivity, with a CH4 production rate of 2552.49 μmol h-1 (85.08 mmol g-1 h-1) under an irradiation of 25.5 suns without external heat or pressure. This research underscores an innovative engineering approach that leverages hydrogen spillover to enhance photothermal catalytic efficiency and selectivity, thereby providing a robust framework for the advancement of sophisticated photothermal catalysts for selective CO2 hydrogenation. Using sunlight to turn carbon dioxide into fuels is appealing, but reactions are often inefficient. This study shows a photothermal catalyst that lets hydrogen move between sites, enabling selective conversion of carbon dioxide to methane.