Imidazolium-silica heterogeneous catalyst (SG-[(CH2) 3SO3H-HIM] HSO4) was prepared by immobilization of acidic ionic liquid 1-(propyl-3-sulfonate) imidazolium hydrosulfate ([(CH2) 3SO3H-HIM] HSO4) on silica–gel using tetraethoxysilane (TEOS) as silica source in this study. The properties of the samples were characterized by FT-IR, SEM and TG/DSC. The results suggested that [(CH2) 3SO3H-HIM] HSO4 had been successfully immobilized on ...