Preparation and characterization of terbium palygorskite clay as acid catalyst
| Autor: | M Schmall, E. V. Sobrinho, D.M Araújo Melo, Marcus Antônio de Freitas Melo, J.A.C Ruiz |
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| Rok vydání: | 2000 |
| Předmět: |
Diffuse reflectance infrared fourier transform
Ion exchange Inorganic chemistry Infrared spectroscopy chemistry.chemical_element Palygorskite Terbium General Chemistry Condensed Matter Physics Catalysis Adsorption chemistry Mechanics of Materials medicine General Materials Science Lewis acids and bases medicine.drug |
| Zdroj: | Microporous and Mesoporous Materials. 38:345-349 |
| ISSN: | 1387-1811 |
| Popis: | Palygorskite clays containing 5% and 10% terbium (W/W) were prepared by ion exchange from acid-leached natural clay. Samples were calcined at 523, 573, 623 and 673 K to verify the effect of the temperature over the physical–chemical properties. Characterization was using X-ray diffraction, infrared spectroscopy (n-butylamine adsorption), UV–visible diffuse reflectance spectroscopy and N2 adsorption. Isopropyl alcohol (IPA) transformation was also performed in order to improve the acid behavior. TB3+ introduction does not change the palygorskite structure, albeit leading to an increase in the surface area and generation of Lewis acid sites. Results from the DRS spectra along with a decrease in the catalytic activity suggested the formation of terbium oxide for relatively high TB3+ contents. |
| Databáze: | OpenAIRE |
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