Enhancement of photothermal catalytic activity by suppression of thermal conduction in dry reforming of methane over silica-supported Ni catalysts

Abstract

As global energy demand continues to rise, the development of sustainable alternatives to fossil fuels has become increasingly critical. This study investigates the photothermal dry reforming of methane (PT-DRM) over Ni/SiO₂ catalysts mixed with various ceramics, focusing on the interplay between thermal conductivity and catalytic activity. Catalysts mixed with low thermal conductivity ceramics effectively suppressed heat dissipation from the light-irradiated surface, resulting in enhanced photothermal catalytic performance. Furthermore, the catalysts mixed with low light-absorbing ceramics, such as SiO₂, Al₂O₃ and AlN, exhibited reasonable catalytic activity relative to the measured surface temperature. In contrast, high light-absorbing ceramics such as SiC and TiC hindered efficient light absorption by the Ni nanoparticles (Ni NPs), resulting in lower catalytic activity than expected from the surface temperature. These results highlight the critical roles of thermal conductivity of catalysts and direct light absorption by active sites in optimizing photothermal catalysts, providing valuable insights for the design of advanced solar-driven catalytic systems for effective solar energy utilization and greenhouse gas mitigation.