| 摘要 |
The present invention relates to a process for the preparation of a large-pore molecular sieve, comprising crystallizing the molecular sieve from a starting mixture at a pH in the range of from 3 to 8, and recovering a large-pore molecular sieve, the said starting mixture having a molar composition satisfying the following molar ratio's:(0.01-2)R2/nO):(0-1.5)M2/mO:(0-0.5)X2O3:1YO2:(5-1000)H2O:(0.01-3)F-,wherein n and m are the weighted average valences of R and M respectively, M is an alkali- or alkaline earth metal, X is a trivalent metal and Y is a tetravalent element, wherein R comprises at least one main organic template Rm having the formula R1R2R3R4Q+ wherein Q is nitrogen or phosphorus and wherein at least one and at most three of R1, R2, R3 and R4 is an aryl or alkyl group having 6 to 36 carbon atoms and each of the remainder of R1, R2, R3 and R4 is selected from hydrogen and an alkyl group having 1 to 5 carbon atoms. |
