Light-Driven Hydrogenation of Bicarbonate into Formate over Nano-Pd/TiO2

Efficient conversion of CO2/bicarbonate into chemicals using solar energy as driving force is meaningful to alleviate global warming caused by excessive CO2 emission. In this work, a direct light-driven method of bicarbonate hydrogenation into formate over a nanocatalyst Pd/TiO2 is proposed. Formic acid has recently attracted increasing attention as a promising hydrogen storage carrier. By using the Pd/TiO2, the reaction system achieved a self-heating effect under irradiation, promoting the hydrogenation of bicarbonate. Owing to its extraordinary photothermal conversion ability and efficient light utilization, the 5 wt % Pd/TiO2 exhibited a high photothermal conversion efficiency of 30.9% under experimental illumination. The desirable performance of the Pd/TiO2 catalyst for hydrogenation of bicarbonate is attributed to the elevated temperature from the localized surface plasmon resonance effect of nano-Pd and the direct participation of photogenerated carriers in hydrogenation of bicarbonate. This study combined the merits of photocatalysis and thermocatalysis, providing a promising method for light-driven conversion of CO2 using the photothermal synergistic effect.