Patent ID: 6190639
Filing Date: 2001-02-20
Classification: C01B

Abstract:
A process for the preparation of a mesoporous, crystalline, acidic molecular sieve comprising the successive steps of(a) preparing an aqueous mixture comprising a silicon source, a fluorine source, and an organic template at a temperature in the range of at most 90.degree. C. such that crystallization starts;(b) adjusting the pH of the solution to such value in the range of from about 5.0 to about 12.5 that a precipitate is formed;(c) recovering the precipitate; and(d) calcining the precipitate to obtain the mesoporous, crystalline, acidic molecular sieve, wherein an aluminum source is added in one or more of steps (a) and (b) and/or between steps (c) and (d) in such amount that after addition of all aluminum source the Si/Al atomic ratio is at least about 3.