Novel mesoporous TiO2(B) whisker-supported sulfated solid superacid with unique acid characteristics and catalytic performances

Abstract Mesoporous TiO 2 (B) whisker was firstly applied as a support for synthesizing the novel sulfated solid superacid (SO 4 2− /TiO 2 (B)). According to NH 3 -TPD, TG and Py-IR characterization results, it was found that the similar amount of sulfate group on TiO 2 (B) and anatase showed significantly different acid characteristics and catalytic performances. The total acid amount of SO 4 2− /TiO 2 (B) was about 1.8 times as anatase-supported sulfated solid superacid (SO 4 2− /Anatase). Simultaneously, the SO 4 2− /TiO 2 (B) possessed higher percentage of Bronsted acid and more weak-medium acid strength than SO 4 2− /Anatase. These acidic properties endowed SO 4 2− /TiO 2 (B) with the increased esterification reaction rate and decreased alkylation byproduct selectivity compared with that of SO 4 2− /Anatase. Structure-performance analysis exhibited that there were more bridged bidentate sulfate groups coordinated to the TiO 2 (B) in SO 4 2− /TiO 2 (B), which could induce more Ti cations than that of the chelating one. This was the key factor to be responsible for the unique acid characteristics of SO 4 2− /TiO 2 (B). The present work provides a novel solid superacid and might open a strategy to mediate the acid characteristic for sulfated solid superacid.