A metal modified Y zeolite, its preparation and use

摘要

A metal modified Y zeolite contains 1-15wt% of IVB group metal, where the ratio of the zeolite surface's IVB group metal content to the zeolite interior's IVB group metal content is not higher than 0.2. Preferably, the ratio of the distorted tetrahedral-coordinated framework aluminum to the tetrahedral-coordinated framework aluminum in the Y zeolite lattice structure is 0.2-0.8. A process for preparing a metal modified Y zeolite comprises the steps of: (i) dewatering a Y zeolite raw material so that it has a water content of no more than 5%; (ii) contacting the Y zeolite obtained from (i) with a mixture of a compound containing a group IVB metal and an organic solvent; (iii) calcining the Y zeolite obtained from step (ii) with an aqueous acid solution at 400-800ºC to produce a metal modified Y zeolite, the acid concentration being 0.1-0.2mol/L. A catalytic cracking catalyst may contain 10-60wt% of the metal modified Y zeolite, 10-60wt% clay and 5-50wt% binder.