Preparation and Characterization of CeO_2-TiO_2 Mixed Oxides

CeO2-TiO2 oxides were prepared by sol-gel methods from cheap precursors (TiCl4 and Ce(NO3)3) and their morphology, crystalline phase, surface area and pore structure were characterized by BET, TEM and XRD. The results show that the CeO2-TiO2 mixed oaldes prepared by supercritical fluid drying method (SCFD) have high surface area and large pore volume. With the increase of CeO2 concentration from 5% to 40% in the CeO2-TiO2 mixed oxide, the surface area increases from 67.3m2·g-1 to 219.4m2·g-1, the crystalline phase changes from anatase to amorphous, and the morphology from isolated particle to very small particles interlinked to a three-dimension network structure. But the CeO2-TiO2 mixed oxides prepared by conventional drying method show lower pore volume and surface area with serious aggregation, and amorphous phase compared to the corresponding aerogels.