Characterization of transition-metal oxides promoted with oxoanions by means of test reactions
The catalytic activity of some transition-metal oxides known to develop strong acidity by promotion with oxoanions was compared with a set of acid-catalyzed test reactions (isomerization of n-butane, isobutene, n-hexane, and cyclohexane). They were further characterized by thermally programmed desor...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/78038 |
| Acceso en línea: | http://hdl.handle.net/11336/78038 |
| Access Level: | acceso abierto |
| Palabra clave: | Transition-Metal Oxides Strong Acidity https://purl.org/becyt/ford/2.7 https://purl.org/becyt/ford/2 |
| Sumario: | The catalytic activity of some transition-metal oxides known to develop strong acidity by promotion with oxoanions was compared with a set of acid-catalyzed test reactions (isomerization of n-butane, isobutene, n-hexane, and cyclohexane). They were further characterized by thermally programmed desorption of pyridine and 2,4,6-trimethylpyridine, X-ray diffraction, and sortometry. SO42--ZrO2) SO4 2--TiO2, SO42--Fe2O 3, WO3-ZrO2, WO3-TiO2, WO3-Fe2O3, B2O3-ZrO 2, B2O3-TiO2, and B 2O3-Fe2O3 were synthesized by impregnation of the oxoanion over a fresh xerogel of the transition-metal hydroxide. Certain promoter-dependent orders, irrespective of the support, could be elucidated, mainly that the number of acid sites generated by promotion follows the order S, W > B. The proportion of strong acid sites is most important for S and B. The most active catalysts are always the zirconia ones, while the Fe2O3 catalysts are the least active. |
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