Preparation of Novel Mesoporous SO42-/TiO2 Solid Acid Catalyst and Its Catalytic Activity for Esterification

A novel mesoporous SO42-/TiO2 solid acid catalyst with whisker morphology was prepared by incipient impregnation using amorphous titanic acid hydrate (H2Ti2O5 center dot xH(2)O) as the catalyst support. Its structural characteristics, surface acidity, and catalytic activity were characterized by X-ray diffraction, N-2 adsorption, scanning electron microscopy, infrared spectroscopy, thermogravimetry, and NH3 temperature-programmed desorption. The catalytic performance was evaluated by the esterification reaction of butanol with acetic acid. The results indicated that the SO42-/TiO2 solid acid catalyst has not only nano-scale particles, whisker morphology, high specific surface area, and mesostructure, but also pure anatase phase, strong acidity, and high thermal stability. SO42- on the surface desorbed gradually, and the number of acid sites decreased when the calcination temperature was above 500 degrees C. Under the optimal reaction conditions, i.e., m(catalyst) = 0.2 g, n (n-butanol)/n(acetic acid) = 1.5, and the reaction time of 3 h, the catalyst calcined at 500 degrees C shows a n-butanol conversion of 94% with a high selectivity for butyl acetate of 100%. Furthermore, the SO42-/TiO2 solid acid catalyst has higher catalytic activity and separation-settling performance than the SO42-/P25 catalyst.