PROCESS FOR THE PREPARATION OF MESOPOROUS MOLECULAR SIEVES AND POROUS CRYSTALLINE MATERIALS

摘要

The invention provides 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 and an organic template at a temperature in the range of at most 90 .degree.C; (b) adjusting the pH of the solution to such value in the range of from 5.0 to 12.5 that a precipitate is formed; (c) recovering the precipitate; and (d) calcination of the precipitate to obtain the mesoporous, crystalline, acidic molecular sieve, wherein an aluminium 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 aluminium source the Si/Al atomic ratio is at least 3; molecular sieves obtained by the process; and their use as hydroprocessing catalysts or catalyst carriers.