Alkylation of Benzene with 1-Dodecene over Silica Gel Supported Phosphotungstic Acid Catalysts

phosphotungstic acid (PW) catalysts supported on silica gel with various PW loadings were prepared by the impregnation method,and characterized by X-ray diffraction,temperature programmed desorption of ammonia and nitrogen adsorption techniques.Their catalytic activity was measured by alkylation of benzene with 1-dodecene in a slurry reactor under atmospheric pressure.Silica gel supported 12-phosphotungstic acid catalysts were found to exhibit very high conversion of 1-dodecene and selectivity of 2-LAB,which could be adjusted by the pretreatment temperature of the catalyst and the PW loading.The catalyst with PW loading of 40% by mass and with a pretreatment temperature of 300 ℃ possessed the highest conversion of 1-dodecene at 71.4%,with high 2-LAB selectivity of 41.9%,which were much higher than those of HY zeolite.The catalytic activity has also been discussed in relation with the catalyst acidity and porous property.