Study on the Preparation of Mesoporous WO3/SiO2 Catalysts Using Silicotungstic Acid as Tungsten Source
Using silicotungstic acid as tungsten source,rice husk as both silicon source and mesoporous template,a series of mesoporous WO3/SiO2 catalysts with different WO3 loadings were prepared by an incipient-wetness impregnation method.The samples were characterized by means of XRD,UV-Vis and N2 adsorption-desorption isotherms.The results showed that,when the WO3 loading was lower than 2.4％,the WO3 grains in the samples were well dispersed on the carrier SiO2.When the WO3 loading was higher than 2.4％,monoclinic WO3 crystals be-gan to appear in the samples.The samples had a large specific surface area and a pronounced mesoporous structure,and the most probable pore size of samples was 3.6 nm.Under optimized oxidative desulfurization conditions,the 2.4％WO3/SiO2 sample gave a dibenzothiophene conver-sion of 99.7％and a 4,6-dimethyldibenzothiophene conversion of 99.6％.
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