MODIFIED Y MOLECULAR SIEVE, CATALYTIC CRACKING CATALYST CONTAINING SAME, AND PREPARATION THEREFOR AND APPLICATION THEREOF

摘要

A modified Y molecular sieve, the preparation method therefor, a catalytic cracking catalyst, and the application thereof. In the modified Y molecular sieve, the rare earth content calculated on the basis of oxides is 4-11wt%, and the content of P calculated on the basis of P ₂O ₅ is 0.05-10wt%, the content of Na calculated on the basis of sodium oxide does not exceed about 0.5wt%, and the content of active elements calculated on the basis of oxides is 0.1-5wt%, and the active elements are gallium and / or boron. The total pore volume of the molecular sieve is 0.36-0.48mL/g, the pore volume of secondary pores with a pore diameter of 2-100nm accounts for 20-40% of the total pore volume, the cell constant is 2.440-2.455nm, and the lattice collapse temperature is not lower than about 1060 ° C, the percentage of non-framework aluminum content in the total aluminum content is not higher than about 10%, and the ratio of B acid to L acid in the strong acid amount is not lower than about 3.5. The modified Y molecular sieve is obtained through ion exchange with a rare earth salt solution, hydrothermal ultra-stable modification, gas-phase ultra-stable modification, acid treatment, phosphorus modification, and active element solution impregnation and baking. A catalytic cracking catalyst containing the modified Y molecular sieve, when used in catalytic cracking of hydrogenated light cycle oil (LCO), has higher hydrogenated LCO conversion rate, lower coke selectivity, and higher BTX light aromatic hydrocarbon enriched gasoline yield and the total yield of ethylene and propylene.