Abstract: Using aluminium isopropoxide as aluminum source, TEOS as silicon source, a series of mesoporous molecular sieves of Al-SBA-15 was synthesized directly by one-step method in an acid medium with different amount of hydrochloric acid, followed by preparation of Ni-W hydrocracking catalysts. The molecular sieves and the catalysts were then analyzed by XRD，N2 adsorption and desorption，SEM，TEM and infrared spectrum. The results indicate that the Al-SBA-15 mesoporous molecular sieves have a highly ordered hexagonal structure with a strong acidity when 20 g hydrochloric acid was used in the acid medium. The heavy oil hydrocracking performance of the catalysts was evaluated and compared with the reference. The experimental results reveal that the selectivity and yield of middle distillate of the catalyst containing Al-SBA-15 mesoporous molecular sieves reaches 87.3% and 60.8%, respectively. The catalyst can be used for production of high quality diesel oil and jet fuel and the feed for reforming and ethylene cracking unit.

Key words: hydrochloric acid, aluminium isopropoxide, acidity, Al-SBA-15 mesoporous molecular sieve, hydrocracking catalyst