| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 74760 | Microporous and Mesoporous Materials | 2011 | 10 Pages |
Pure silica zeolite beta materials were synthesized by an unconventional method of aging and drying the starting gels at room temperature followed by the conventional hydrothermal treatment. In addition, organic solvents were added to selected samples as complementary structure directing agents (SDA). The influence of the aging–drying method, complementary SDA addition and crystallization time upon the synthesis of pure silica zeolite beta were studied. Samples were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), thermogravimetric analyses (TGA) and nitrogen adsorption. Results revealed that the aging–drying process increased crystallization rate, produced crystals with unique morphology and scaled-surface and allowed polymorph A enrichments to about 68–70%. It was also found that addition of organic solvents during the thermal treatment tunes the crystal morphology but, does not affect the polymorphic enrichment.
Graphical abstractAn aging–drying method was developed to synthesize 68–70% polymorph A enriched pure silica zeolite beta. Polymorphic A enrichments were calculated by deconvolution of powder X-ray diffraction (PXRD) peak profiles at 5–11, 2q. The TEM image reveals the details of the disordered structure. The disorder shows an intergrowth between polymorph A-type and polymorph B-type stacking..Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Pure silica zeolite beta was synthesized by an aging–drying method. ► Crystallization rate increased related to similar systems. ► Ball-shaped or odd crystals with scaly surfaces were obtained. ► Polymorph A enrichment was about 68%.
