| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 59839 | Chinese Journal of Catalysis | 2015 | 8 Pages |
Using tetraethylammonium hydroxide as the organic structure-directing agent and in the presence of fluoride, polymorph A-enriched silica beta zeolite was synthesized under concentrated hydrothermal conditions. The introduction of Al species into the same starting mixture resulted in a decrease in the degree of enrichment of polymorph A in beta zeolite and an Al-incorporated beta zeolite resulted. The crystallized polymorph A-enriched silica beta zeolite and the Al-incorporated beta zeolite and their crystallization processes were investigated by X-ray diffractometry, elemental analysis, thermogravimetric analysis-differential thermal analysis, nitrogen adsorption, scanning electron microscopy, and solid-state magic angle spinning nuclear magnetic resonance. The introduction of Al species accelerated crystallization and reduced the crystal size of Al-incorporated beta zeolite. The intermediate of five-coordinated Al species accounted for a decrease in the degree of enrichment of polymorph A in the crystallization of Al-incorporated beta zeolite.
Graphical AbstractPolymorph A-enriched silica beta zeolite was synthesized. The degree of enrichment of chiral polymorph A was decreased owing to five coordinated Al species.Figure optionsDownload full-size imageDownload as PowerPoint slide
