Abstract: MCM-41, a typical mesoporous molecular sieve, was used as silicon source to synthesize β zeolite in hydrothermal process. The β zeolite not only has all characteristics of a microporous zeolite but also inherits some properties of a mesoporous molecular sieve. Its pore diameter and pore volume are 30% and 60%, respectively, higher than that of the β zeolite prepared by the traditional method. Moreover it has smaller crystal grains and much more B acidity. Therefore, when being used as the cracking component in a hydrocracking catalyst, it shows improved catalytic performance. The dynamic activity is promoted by 60% and the middle distillate selectivity is significantly increased by 2.5% compared with the typical commercial hydrocracking catalyst.

Key words: &beta, zeolite, mesoporous zeolite, hydrothermal synthesis, hydrocracking catalyst