Abstract: The porous TiO₂ microspheres were prepared by the reversed-phase suspension polymerization and sol-gel method. The CuO/TiO₂ catalysts with porous microspheres composed of TiO₂ nanocrystals as the support were prepared by impregnation method. The properties of the porous TiO₂ microspheres and CuO/TiO₂ catalysts were studied by TG-DTA, X-ray diffraction, XPS and ICP. The catalytic properties of the catalysts for CO oxidation were studied via a microreactor-GC system. The results show that the porous microspheres were mainly composed of anatase TiO₂ nanocrystals with a size of 19.5 nm. The XPS results indicate that there was interaction between the support and the active component, and Cu mainly existed as Cu²⁺ with some other form. The catalytic activity of the catalysts depends on the concentration of the impregnation solution and the calcination temperature of the CuO/TiO₂ catalysts. The catalyst impregnated in 0.5 mol/L Cu(NO₃)₂·3H₂O had a better catalytic activity. The optimum calcination temperature of the CuO/TiO₂ catalysts was 200 ℃.

Key words: Titanium dioxide, Porous microsphere, Impregnation method, CO oxidation, CuO/TiO₂ catalyst