简介 |
A modified Y-type molecular sieve has a rare earth content of about 4-11% by weight on the basis of rare earth oxide, a sodium content of no more than about 0.7% by weight on the basis of sodium oxide, a zinc content of about 0.5-5% by weight on the basis of zinc oxide, a phosphorus content of about 0.05-10% by weight on the basis of phosphorus pentoxide, a framework silica-alumina ratio of about 7-14 calculated on the basis of SiO2/Al2O3 molar ratio, a percentage of non-framework aluminum content to the total aluminum content of no more than about 20%, and a percentage of the pore volume of secondary pores having a pore size of 2-100 nm to the total pore volume of about 15-30%. The modified Y-type molecular sieve has a high crystallinity, a structure comprising secondary pores, and a high thermal and hydrothermal stability. |