Abstract: The Ce-Mn oxygen storage material was prepared by the sol-gel method, and the Pt-TiO2/CeO2-MnO2 composite catalyst was synthesized by loading TiO2 and Pt on the oxygen storage material. The composite catalyst was characterized using X-ray diffraction, scanning electron microscopy, temperature-programmed reduction, and diffuse reflectance ultraviolet-visible spectroscopy. Its catalytic activity for the thermo-photocatalytic degradation of gas-phase benzene was evaluated. The results revealed that Mn entered the TiO2 and CeO2 lattice and formed solid solution, resulting in uniformity of the catalyst. Pt was dispersed uniformly on the catalyst surface. The Ce-Mn oxygen storage material had good oxygen storage capability at 250 ℃. The composite catalyst showed stronger absorption in the UV and visible region than TiO2. The activity of 1.6%Pt-40%TiO2/CeO2-MnO2 was high, and the benzene conversion reached 94.5% during the 10 h of thermo-photocatalytic process.

Key words: thermo-photocatalysis, gas-phase benzene, degradation, cerium-manganese oxygen storage material, titania, platinum, composite catalyst