Preparation and Characterization of Ultrastable Mesoporous Silicated Alumina and Its Application in Catalytic Cracking

The silicated alumina was synthesized by grafting of hydrolytic silicon specials on the surface of AlOOH, and a calcination step. The textural and acidity properties of the resultant materials were characterized by various techniques, i.e. powder X-ray diffraction (XRD), infrared(IR) spectroscopy, N2 adsorption/desorption, nuclear magnetic resonance(NMR) spectroscopy, and temperature programmed desorption of ammonia(NH3-TPD). The results show that the monolayer SiO2 majorly grafts on the alumina surface, where the specific surface reactivity of γ-Al2O3 to realize a new class of silicated alumina catalysts featuring is well-defined. Because of the enhanced Lewis acid sites and new formed Si-O-Al species, the silicated alumina shows high activity in the cracking of hydrocarbon. Such as, the cumene (IPB) cracking conversion for silicated alumina sample with 3.2 Si atoms per square nanometer is 27 times as high as that of starting alumina. The crystal structure and cracking activities of silicated alumina are well preserved after calcination at 800℃ for 4 h in steam or at 1100℃ for 6 h in air. © 2018, Editorial Office of Acta Petrolei Sinica(Petroleum Processing Section). All right reserved.