Photocatalytic reduction of CO2 with H2O on Pt-loaded TiO2 catalyst

A gas–solid heterogeneous system for solar–chemical energy conversion of CO2-SCR (Selective Catalytic Reduction) with H2O on different nanostructure photocatalysts and the photocatalysis pathway were discussed. Different crystal phases and sizes of low-dimensional nano-TiO2 and Pt-metal supported photocatalysts are synthesized and characterized with X-ray diffraction, high-resolution transmission electron microscopy, photoluminescence, CO pulse chemisorptions, N2 adsorption–desorption analysis at 77 K and X-ray fluorescence spectrometry. The catalytic activity was tested in a fixed-bed photocatalysis reactor and the CH4 yield on the Pt/TiO2 nanotube photocatalysts is more remarkable. It increased with the increase of the UV irradiation time and accumulated to about 4.8 μmol h−1 gTi−1, enhanced as the increase of the reaction temperature and H2O/CO2 molar ratio as well.