Solid Superacid S_2O_8~(2-)/TiO_2 Supported on MCM-41: Preparation and Catalytic Performance for Esterification

The solid superacid S2O82-/TiO2 supported on mesoporous MCM-41 was prepared by the liquid-phase precipitation, and the mechanism for the formation of superacid was suggested. The esterification reation of acetic acid and iso-amyl alcohol was selected as a probe reaction to test the catalytic performance. The optimum conditions for preparation of the catalyst were obtained as follows: molar ratio of Ti to Si was 1∶1, concentration of (NH4)2S2O8 was 0.5 mol·L-1, impregnation time was 5 h, calcinations temperature and time were 550 ℃ and 4 h, respectively. The structure of the solid superacid was characterized by XRD, N2 Adsorption/desorption and FTIR. The results showed that mesoporous structure of MCM-41was maintained in the catalyst system with a high BET surface area of 211 m2·g-1 and better solid acidity.