Synthesis and characterization of the very large pore molecular Sieve MCM-9

Abstract

The silicon-containing analogue of the recently identified 18-membered ring aluminophosphate molecular sieve VPI-5, which we herein refer to as MCM-9, has been synthesized using a two-liquid (aqueous and immiscible organic) phase synthesis medium. Silicon incorporation into the aluminophosphate framework is achieved by phase transfer and hydrolysis of a silicon-containing reagent supplied from the immiscible organic phase. Aging of the precursor aluminophosphate gel, before and after the addition of di-n-propylamine as a directing agent, rather low autogeneous crystallization temperature (150°C), and a short crystallization time (5-12 h) yield MCM-9 containing only small amounts of SAPO- 11.