PHOSPHORUS-CONTAINING ULTRASTABLE Y-TYPE RARE EARTH MOLECULAR SIEVE AND PREPARATION METHOD THEREFOR

摘要

Provided is a phosphorus-containing ultrastable Y-type rare earth (RE) molecular sieve and preparation method therefor. The method is: based on NaY molecular sieve as a raw material, obtaining "one exchange one roast" RE-Na Y-type molecular sieve through the steps of exchanging with RE, pre-exchanging with dispersing, and the first roasting; and then performing ammonium salt exchange, phosphorus modification, and the second roasting on the "one exchange one roast" RE-Na Y-type molecular sieve, wherein the sequence of the RE exchange and the pre-exchange with dispersing is unlimited, and the sequence of the ammonium salt exchange and the phosphorus modification is unlimited as well. The obtained molecular sieve contains RE oxide 1-20wt%, phosphorus 0.1-5wt%, and sodium oxide no more than 1.2wt%, and has a crystallization degree of 51-69% and a unit cell parameter of 2.449-2.469nm. Heavy oil conversion rate can be increased by using the molecular sieve as an active component in a catalytic cracking catalyst.