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Several TiO2 and γ-Al2O3 supported catalyst systems were prepared by a novel way and characterized by X-ray diffraction, Raman spectroscopy and BET surface area measurement. The results show: (1) all the samples, including MoO3/TiO2, WO3/TiO2, V2O5/TiO2, FeSO4/γ-Al2O3, Al2 (SO4)3/γ-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 temperature exhibit much larger surface areas than that of pure TiO2 or γ-Al2O3 calcined at the same temperature; (2) the surface area of the sample increases with the increase in the coverage of active component on the surface of the support; (3) when the content of active component reaches its utmost monolayer dispersion capacity, the surface area of the sample is the largest, and then decreases when the content of active component exceeds its dispersion threshold. |
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