Full-spectrum synergistic mechanism of photothermal catalytic CO2 hydrogenation

Abstract

Solar-driven CO₂ hydrogenation reactions are an attractive approach for the production of chemicals in the CO₂ utilization. We emphasize the importance of reliable temperature measurements for assessing catalyst performance and report the effect of uneven temperature distribution on the product selectivity of the CO₂ hydrogenation reaction of Ru/TiO₂ catalysts, as well as the CO₂ hydrogenation reaction of Ru/TiO₂ catalysts in dark and under UV, visible IR, and full-spectrum light conditions. Full-spectrum utilization exhibits higher activity at the same temperature. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and density functional theory (DFT) calculations clarify the reaction pathway of CO₂ hydrogenation to methane, revealing that UV and visible infrared light promote the adsorption and activation processes at different stages along the chemical reaction pathway, respectively. These findings can facilitate additional innovative ideas for the mechanism study and future development of next-generation photothermal catalysts based on full-spectrum utilization.