Zeolites with tetra-coordinated Lewis aluminum sites and methods for their preparation
US11596931B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 9, 2020 |
| Grant date | Mar 7, 2023 |
| Priority date | — |
| Expiry date | May 7, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2002/82
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Modified crystalline zeolite materials have a zeolite framework with both tetra-coordinate Lewis aluminum single sites and Brønsted aluminum sites. The tetra-coordinate Lewis aluminum single sites include aluminum atoms covalently bonded to a variable group and to two oxygen atoms and further coordinated to a third oxygen atom. The variable group may be alkyl, hydride, or hydroxyl. Methods for incorporating tetra-coordinate Lewis aluminum single sites into a crystalline zeolite material include contacting the crystalline zeolite material with a dialkylaluminum hydride R2AlH, where each R is alkyl, to react the dialkylaluminum hydride with the zeolite framework and form tetra-coordinate alkyl aluminum single sites. Heating the alkyl-aluminum zeolite induces β-hydride elimination of the alkyl groups, whereby tetra-coordinate aluminum hydride single sites are formed. By oxidizing the hydride-aluminum zeolite, at least a portion of the tetra-coordinate aluminum hydride single sites are converted to tetra-coordinate aluminum hydroxide single sites.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.