Photothermal Approach on Chemical Looping Method for Reverse Water Gas Shift Reaction Using Defective Molybdenum Oxide

CO2 conversion technologies utilizing solar light have garnered significant attention for establishing sustainable societies. Despite the extensive investigation of photothermal approaches, the effect of direct light irradiation on oxygen carriers on the reverse water gas shift chemical looping (RWGS-CL) reaction has not yet been explored. In this study, we investigated the effects of light irradiation on the activity of Pt-loaded metal oxides in the RWGS-CL reaction at 473 K. The Pt/MoO3–x material exhibited remarkable activity for the photo-assisted RWGS-CL reaction, which was attributed to its high concentration of oxygen vacancies and photothermal property. Moreover, it is notable that the light-induced heating was more effective than uniform heating in the exothermic H2-reduction step due to the preferable temperature gradient in the material. This study opens up new potentials for the photothermal-assisted CL method, including the separation of the endothermic and exothermic processes of reactions and the strategic use of light-induced temperature gradients.