F-coordinated Single-atom Ru Species: Efficient and Durable Catalysts for Photo-Thermal Synergistic Catalytic CO2 Hydrogenation to Methane

Abstract

Elucidating the correlation between coordination structures and catalytic performances of single-atom active site is imperative for the precise design of highly efficient catalysts; however, the feasible regulation of coordination environment in single-atom catalysts presents a formidable challenge. Herein, we fabricate single-atom Ru-based catalysts with Ru-F4 and Ru-O4 configurations (named as Ru-F4 SAs/PA and Ru-O4 SAs/PA, respectively), showcasing fine-tuning of the coordination structure of Ru sites can significantly enhance performances for CO2 hydrogenation to methane under mild conditions in a photo-thermal synergistic catalytic process. Comparative studies reveal that Ru-F4 SAs/PA outperformed Ru-O4 SAs/PA counterparts, giving a superior CO2 methanation performances with CH4 production rate of 47.4 mmol gcat−1 h−1 and CH4 selectivity of 93.8% at 200 ℃ in the presence of light irradiation (200-1100 nm, 1.9 W cm−2) under atmospheric pressure. Theoretical investigations unravel that the transition from Ru-O4 to Ru-F4 coordination environments optimizes the electronic states, thereby enhancing the adsorption of reactants and intermediates. Moreover, the optimized electronic structure promotes the production and transformation of key intermediate species, lowers the energy barrier for CO2 conversion, and thus elevates the catalytic activity. This comprehensive study not only clarifies the relationship between the coordination structures of active sites and catalytic performance at atomic-level but also offers a novel paradigm for the design of efficient CO2 conversion catalysts.