Synthesis and Characterization of CoMo/Al2O3-MgO-(X) catalysts doped with alkaline oxides (K, Li)
CoMo catalysts were prepared using Al2O3-MgO-(X) hybrid supports, where X = K2O or Li2O. The textural, structuraland acid-base properties of these materials were characterized by several techniques. The catalysts were preliminarilyevaluated in the hydrodesulfurization (HDS), hydrogenation (HYD) and...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2007 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:94220405 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=94220405 |
| Access Level: | acceso abierto |
| Palabra clave: | Física, Astronomía y Matemáticas Lithium Magnesia Potassium Acid sites Hydrogenation |
| Sumario: | CoMo catalysts were prepared using Al2O3-MgO-(X) hybrid supports, where X = K2O or Li2O. The textural, structuraland acid-base properties of these materials were characterized by several techniques. The catalysts were preliminarilyevaluated in the hydrodesulfurization (HDS), hydrogenation (HYD) and hydrocracking (HCK) model reactions. The aimsof this work are to identify the effect of the addition of an alkaline oxide (either K2O or Li2O) to the Lewis acid sites in theCoMo/Al2O3-MgO formulation; and on the other hand, to establish a relationship between the acidity and the catalyticperformance (hydrogenation function). The results obtained from the pyridine thermodesorption analysis and the n-butylamine titration techniques show that the incorporation of an alkaline oxide to the CoMo/Al2O3-MgO formulation causes aslight decrease in the total number of acid sites (TNAS) with respect to Al2O3 and the Al2O3-MgO hybrid supports. Boththe enhanced textural and structural stability of the CoMo/Al2O3-MgO-(X) catalytic formulations, which could beprobably attributed to the incorporation of Li or K cations to the MgO framework, stabilizing it, can also be observed. Asfor the catalytic performance, the CoMo/Al2O3-MgO-(X) catalysts containing either Li2O or K2O, show a decrease in boththe HYD and HYC conversions; however, the formulation containing Li2O shows the best catalytic behavior due to boththe low n-octane yield and the low hydrocracking activity. |
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