Insights into the Nonthermal Effects of Light in Dry Reforming of Methane to Enhance the H₂/CO Ratio Near Unity over Ni/Ga₂O₃

Abstract

Photothermal catalysis, which couples both solar and thermal energies, has burgeoned as a promising approach to drive catalytic reactions. However, the utilization of light irradiation to tune the reaction paths to obtain ideal product distribution in photothermal catalysis is still of tremendous challenge. Herein, we successfully regulated the relationship between two core competition reactions through light irradiation during photothermal dry reforming of methane over Ni/Ga2O3, resulting in the promotion of H2 formation and the suppression of the reverse water gas shift reaction. The increase in the H2/CO ratio from 0.55 to 0.94 could be achieved. Furthermore, the combination of density functional calculations and X-ray photoelectron spectroscopy reveals that light irradiation impelled the direction of electron transfer to be reversed from Ga2O3 to Ni to form the Ni0 sites, which provides the generation of abundant hot electrons from the electronic interband transition of Ni to boost the formation and desorption of H2. This work promotes the understanding of nonthermal behaviors of light irradiation in light-driven photochemistry, which is significant for designing catalysts with high efficiency and controllable product distribution.