Boosting CO2 methanation activity on Ru/TiO2 catalysts by exposing (001) facets of anatase TiO2

Catalytic reduction of CO 2 to methane has been recognized as one of the most important strategic reactions to produce highly valuable chemicals and for storage of renewable energy (power-to-gas). This study demonstrates a crystal facet-dependent catalytic reduction of CO 2 to CH 4 on ruthenium nanoparticles deposited over TiO 2 nanocrystal with exposed (001) and (101) facets. Compared with TiO 2 (101) nanocrystal with the same Ru loading, Ru nanoparticles supported by TiO 2 (001) exhibited a highly enhanced CO 2 conversion rate and significantly improved methanation reactivity, along with a considerable durability. The physicochemical properties of the samples were characterized by HR-TEM, XRD, BET, FT-IR, UV–vis, Raman, ICP, and temperature-programmed reaction with CO 2 , and CO 2 + H 2 . In view of the difference in catalytic activity and the physicochemical properties of the supported Ru/TiO 2 catalysts, the results uncovered that the nature of the catalyst support of Ru/TiO 2 strongly affected the dispersion of Ru species and the synergistic effect between Ru and underlying TiO 2 supporting materials due to the strong metal-support interaction, and thus affected their capability to activate CO 2 and determined the catalytic activity for CO 2 methanation. Our work demonstrated the important role of the exposed crystal facets of the underlying support and the resulting Ru particle which had a large effect on CO 2 methanation.