Studies on anion promoted Titania 2: Preparation, characterisation and catalytic activity towards aromatic alkylation over sulfated titania

Sulfated titania samples with varying amounts of sulfate have been prepared by solid-solid kneading, as well as aqueous impregnation method, and are c haracterized using X-ray diffraction (XRD), FT-IR and N-2 adsorption-desorp tion isotherm. Surface area, average pore diameter and total pore volume ar e found to increase with the increase in sulfate content up to 7.5 wt.%, an d thereafter decreases. Alkylation of aromatic compounds (benzene, toluene and chlorobenzene) with isopropanol is carried out in a fixed-bed flow reac tor over these catalysts as a function of benzene to isopropanol molar rati o, reaction temperature, wt.% and source of sulfate ion. Among all the cata lysts, the sample with 7.5 wt.% sulfate loading prepared from H2SO4 impregn ation exhibits highest selectivity and yield towards alkylation of aromatic compounds to their corresponding isopropylated products. (C) 2000 Elsevier Science B.V. All rights reserved.