Photocatalytic CO2 methanation over the Ni/SiO2 catalysts for performance enhancement

Abstract

CO2 methanation produces synthetic natural gas, which reduces CO2 emission and generates sustainable energy. Exploring effective approach and developing high performance Ni catalysts are the main focus for the reaction. In this study, we report photocatalytic methanation over Ni/SiO2 catalysts. Through physicochemical properties of BET, XRD, H2-TPR and TEM, optical properties of UV–visual light absorbance and light-illuminated H2-TPR, and the performance of photocatalytic methanation, the structure-performance relationship is tentatively discussed. The strong absorbance of light, the small size of Ni nanoparticles and the strong metal-support interaction of the Ni/SiO2 catalysts, as well as the low activation energy of CH4 production, are correlated to the enhanced photocatalytic performance compared to the conventional catalytic performance. The photocatalytic pathway of methanation on Ni nanoparticles are suggested to understand the enhanced performance. The work demonstrates the higher photocatalytic methanation performance than conventional catalytic methanation, which is applicable for other reactions using photo-sensitive catalysts.