A comparative study of the activity and stability of SO42-/MxOy (M = Zr, Sn, Ti) for dehydration of sorbitol and glucose

摘要

Three kinds of typical solid superacid catalysts SO42-/SnO2, SO42-/TiO2 and SO42-/ZrO2 were prepared by impregnation-calcination method, and subsequently used for the dehydration of bio-based sorbitol and glucose to make a systematic comparative study of their catalytic activity and reusability. It was found that the ratio of Bronsted to Lewis acid sites of sulfated metal oxides depended much on the coverage degree of surface sulfate species, which further significantly affected the dehydration efficiency. SO42-/SnO2 and SO42-/TiO2 with higher Bronsted acid ratio possessed higher catalytic activity in sorbitol dehydration, however displayed worse in glucose dehydration due to the lack of Lewis acid sites. Furthermore, SO42-/ZrO2 possessed stronger bonding ability between sulfur species and metal oxide surface, thus showed obviously better stability and reusability compared with SO42-/TiO2 and SO42-/SnO2.