MFI-type zeolites from natural materials: a comparative study of MFI-type zeolites generated from different diatomite species (part I)
| Autor: | Hallah Ahmad Alyosef, Wilhelm Schwieger, Hans Roggendorf, Denise Schneider, Julia Welscher, Alexandra Inayat, Dirk Enke, Tom Münster, Suzan S. Ibrahim, Gert Kloess |
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| Rok vydání: | 2016 |
| Předmět: |
Anatase
Materials science Mechanical Engineering Mineralogy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences law.invention Catalysis chemistry.chemical_compound chemistry Chemical engineering Mechanics of Materials law Sodium hydroxide Hydroxide General Materials Science Calcination Crystallization 0210 nano-technology Zeolite Dissolution |
| Zdroj: | Journal of Porous Materials. 23:1609-1618 |
| ISSN: | 1573-4854 1380-2224 |
| Popis: | A new one step approach for the preparation of MFI-type zeolites through direct trans-formation of pre-modified diatomite is reported. Two diatomite species modified by calcination and acid treatment were used as silica and alumina sources. The progress of the transformation was investigated by analyzing samples after different crystallization times at 453 K. Tetrapropylammonium hydroxide was utilized for the first time as bi-functional molecule for silica dissolution in diatomite and structure directing agent during zeolite formation. In this way, the use of an additional alkaline source, such as sodium hydroxide, for silica dissolution was not necessary. The applied diatomite samples contained amorphous silica in combination with impurities like feldspar, anatase and quartz. This allowed the systematic investigation of the influence of modification procedure, amorphous silica content and crystalline impurities of the different diatomite samples on the direct transformation in MFI-type zeolites. During the transformation process, the feldspar was totally dissolved. The quartz content was reduced to |
| Databáze: | OpenAIRE |
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