Nanometer β Zeolite Made from Mesoporous Zeolite and Its Hydrocracking Performance

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.