کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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59839 | 1419430 | 2015 | 8 صفحه PDF | دانلود رایگان |
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 as PowerPoint slide
Journal: Chinese Journal of Catalysis - Volume 36, Issue 6, June 2015, Pages 889–896