Light-enhanced hydrogen spillover on Pt/TiO₂ catalysts for efficient flow reverse water-gas shift reaction 

Hydrogen spillover is a key process governing the efficiency and selectivity of CO₂ hydrogenation reactions. Although various static catalyst structural design strategies have been developed for promoting this process, this dynamic regulation by external stimuli has rarely been achieved. Herein, we demonstrate the light-enhanced hydrogen spillover on Pt/TiO₂ and its critical role in catalyst regulation and performance enhancement for RWGS. Under light irradiation, photogenerated electrons transfer from TiO₂ to Pt, making Pt electron-rich to promote H₂ dissociation, while hole on TiO₂ surface promote active hydrogen migration. This synergistic charge redistribution induces a light-enhanced hydrogen spillover, creating abundant oxygen vacancies and delivering more active hydrogen. Consequently, light-driven RWGS process proceeds via a *HCOO-mediated pathway, different from the thermal-driven process. Using light as the sole energy source (2.5 W/cm²), Pt/TiO₂ catalyst achieves a CO production rate of 30.51 mol·g_Pt⁻¹·h⁻¹ with 99.12% CO selectivity in a continuous-flow system at a mild catalyst surface temperature (283 °C), outperforming most thermal and photothermal catalysts. Remarkably, comparable performance is achieved using only concentrated sunlight even under outdoor temperature of −20.7 °C. This work establishes a new paradigm for dynamic charge transfer controlling spillover effects in solar-driven catalysis.