The Nature of Active Sites for Plasmon-Mediated Photothermal Catalysis and Heat-Coupled Photocatalysis in Dry Reforming of Methane

Solar energy-induced catalysis has been attracting intensive interests and its quantum efficiencies in plasmon-mediated photothermal catalysis (P-photothermal catalysis) and external heat-coupled photocatalysis (E-photothermal catalysis) are ultimately determined by the catalyst structure for photo-induced energetic hot carriers. Herein, different catalysts of supported (TiO2-P25 and Al2O3) platinum quantum dots are employed in photo, thermal, and photothermal catalytic dry reforming of methane. Integrated experimental and computational results unveil different active sites (hot zones) on the two catalysts for photo, thermal, and photothermal catalysis. The hot zones of P-photothermal catalysis are identified to be the metal-support interface on Pt/P25 and the Pt surface on Pt/Al2O3, respectively. However, a change of the active site to the Pt surface on Pt/P25 is for the first time observed in E-photothermal catalysis (external heating temperature of 700 degrees C). The hot zones contribute to the significant enhancements in photothermal catalytic reactivity against thermocatalysis. This study helps to understand the reaction mechanism of photothermal catalysis to exploit efficient catalysts for solar energy utilization and fossil fuels upgrading.

Automated summary

Solar energy-induced catalysis plays a crucial role in plasmon-mediated photothermal catalysis and external heat-coupled photocatalysis, with the catalyst structure determining the quantum efficiencies. In this study, different catalysts (TiO2-P25 and Al2O3) and platinum quantum dots were used in photo, thermal, and photothermal catalytic dry reforming of methane. Experimental and computational results revealed different active sites for the three types of catalysis. The identified hot zones significantly enhance the photothermal catalytic reactivity. This study contributes to the understanding of photothermal catalysis and the development of efficient catalysts for solar energy utilization and fossil fuels upgrading.