Introduction of mesoporosity in low Si/Al zeolites

摘要

Compositions and methods for preparing mesoporous materials from low Si/Al ratio zeolites. Such compositions can be prepared by acid wash and/or isomorphic substitution pretreatment of low Si/Al ratio zeolites prior to introduction of mesoporosity.

主权项

1. A method of forming a material comprising at least one mesoporous zeolite, said method comprising the steps of:
(a) acid washing a non-mesoporous initial zeolite with an acidic medium thereby forming an acid-washed zeolite, wherein said initial zeolite has a total silicon-to-aluminum (Si/Al) ratio of less than 30, wherein said acid washing of step (a) removes aluminum atoms from said initial zeolite such that said acid-washed zeolite has a higher Si/Al ratio than said initial zeolite, wherein said acidic medium does not comprise hydrofluoric acid; and (b) subsequent to step (a), contacting said acid-washed zeolite with a mesopore-forming medium different than said acidic medium thereby forming at least one mesopore within said acid-washed zeolite and providing said mesoporous zeolite.