Introduction of mesoporosity in low Si/Al zeolites
AssigneeRive Technology, Inc.
InventorsJavier Garcia-Martinez, Marvin M. Johnson, Ioulia Valla
Life of this patent
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Abstract
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.
Claims76
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 ratio (Si/Al) of less than 30, wherein said initial zeolite has an extra-framework aluminum content from 25-100%, 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;
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- (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.
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 an average unit size of at least 24.40 Å, wherein said initial zeolite has an extra-framework aluminum content from 25-100%, 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;
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- (b) subsequent to step (a), forming at least one mesopore within said acid washed zeolite and providing said mesoporous zeolite.
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 having a low silicon-to-aluminum ratio with an acidic medium thereby forming an acid-washed zeolite, wherein said acid washing is carried out at a temperature of not more than 100° C. and for a time period of not more than 12 hours, wherein said initial zeolite has an extra-framework aluminum content from 25-100%, 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;
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- (b) subsequent to step (a), forming at least one mesopore within said acid-washed zeolite thereby forming said mesoporous zeolite, wherein said mesoporous zeolite has an increased mesoporosity and a decreased microporosity relative to said acid treated zeolite.
A method of forming a material comprising at least one mesoporous zeolite, said method comprising the steps of:
- (a) contacting a non-mesoporous initial zeolite with an acidic medium at a temperature of not more than 100° C. and for a time period of not more than 12 hours to thereby form an acid-treated zeolite having reduced crystallinity relative to said initial zeolite, wherein said initial zeolite has an extra-framework aluminum content from 25-100%, 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;
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- (b) subsequent to step (a), contacting said acid-treated zeolite with a basic medium to thereby form said mesoporous zeolite.
Dependencies are inferred from the claim text.