Preparation of hydroxyl-rich zeolites
US5143876A · kind A · utility
11Cited by
7References
28Claims
0Family size
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Key dates
| Filing date | Mar 30, 1990 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Mar 30, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2229/36
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Zeolites (e.g. ZSM-5 and zeolite beta) enriched with hydroxyl groups are prepared by ammonia treatment of sieves which have suffered loss of tetrahedral aluminum from framework positions followed by careful calcination (200.degree.-450.degree. C.). The hydroxyl group created by this method are stable only to 500.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.