A novel way to prepare TiO2 and gamma-Al2O3 supported catalysts with largesurface areas

several TiO2 and gamma -A(2)O(3) supported catalyst systems were prepared b y a novel way and characterized by X-ray diffraction, Raman spectroscopy an d BET surface area measurement. The results show: (1) an the samples, inclu ding MoO3/TiO2, WO3/TiO2, V2O5/TiO2 FeSO4/gamma -Al2O3 Al-2(SO4)(3)/gamma - Al2O3, K2CO3/-Al2O3 and so on, prepared by impregnating TiO2 H2O or pseudo- boehmite AlO(OH) with the active components then calcining at a high temper ature exhibit much larger surface areas than that of pure TiO2 or gamma -Al 2O3 calcined at the same temperature; (2) the surface area of the sample in creases with the increase in the coverage of active component on the surfac e of the support; (3) when the content of active component reaches its utmo st monolayer dispersion capacity, the surface area of the sample is the lar gest, and then decreases when the content of active component exceeds its d ispersion threshold.