Strong metal-support interactions (SMSI) have gained great attention in the heterogeneous catalysis field, but its negative role in regulating light-induced electron transfer is rarely explored. Herein, we describe how SMSI significantly restrains the activity of Ru/TiO₂ in light-driven CO₂ reduction by CH₄ due to the photo-induced transfer of electrons from TiO₂ to Ru. In contrast, on suppression of SMSI Ru/TiO₂-H₂ achieves a 46-fold CO₂ conversion rate compared to Ru/TiO₂. For Ru/TiO₂-H₂, a considerable number of photo-excited hot electrons from Ru nanoparticles (NPs) migrate to oxygen vacancies (OVs) and facilitate CO₂ activation under illumination, simultaneously rendering Ru^δ+ electron deficient and better able to accelerate CH₄ decomposition. Consequently, photothermal catalysis over Ru/TiO₂-H₂ lowers the activation energy and overcomes the limitations of a purely thermal system. This work offers a novel strategy for designing efficient photothermal catalysts by regulating two-phase interactions.

The effect of suppressive SMSI on regulating electrons transfer and the catalytic performance