Síntesis y caracterización de catalizadores de Ni y de Rh soportados en sistemas CeO₂-ZrO₂ para la reformación de etanol con vapor de agua para producir hidrógeno
Ethanol steam reforming was studied in the low temperature range (300 – 400ºC) with CexZr1-xO2 (x = 0, 0.5, 0.75 and 1) supported Ni(10wt%) and Rh(1wt%) catalysts. CexZr1-xO2 oxides were prepared by coprecipitation of the corresponding hydroxides using two different cerium salt precursors: ammonium...
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:nc580m916 |
| Acceso en línea: | https://doi.org/10.24275/uami.nc580m916 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Catalysts info:eu-repo/classification/LEM/Catalizadores info:eu-repo/classification/LEM/Hydrocarbons info:eu-repo/classification/LEM/Hidrocarburos info:eu-repo/classification/cti/7 |
| Sumario: | Ethanol steam reforming was studied in the low temperature range (300 – 400ºC) with CexZr1-xO2 (x = 0, 0.5, 0.75 and 1) supported Ni(10wt%) and Rh(1wt%) catalysts. CexZr1-xO2 oxides were prepared by coprecipitation of the corresponding hydroxides using two different cerium salt precursors: ammonium cerium nitrate (ex-A series) and cerium nitrate hexahydrate (ex-N series). Catalysts were characterized by N2 physisorption, X-ray diffraction, hydrogen temperatureprogrammed reaction and diffuse reflectance UV-Vis electronic spectroscopy. Important structural and textural differences were observed when using different cerium salt precursors. Ex-A mixed oxides formed solid solutions and showed a 2-fold increase in their specific surface areas in comparison with pure oxides and ex-N mixed oxides. Rhodium catalysts were more active and more selective towards hydrogen production at low temperatures (300ºC) than nickel catalysts while the latter were more active and more selective at higher temperatures (400ºC). The Zr in the mixed oxides showed a positive effect in the ex-A Rh catalysts, increasing their activity and promoting the oxidation of CO and CH4 towards CO2. The effect of the cerium salt precursor was different for the Ni and Rh catalysts. Ex-N Ni catalysts were more active and selective towards hydrogen production than the ex-A Ni catalysts were. On the contrary, ex-A Rh catalysts were more active than the ex-N series Rh catalysts. Characterization of the more selective Rh catalysts showed that CexZr1-xO2 solid solutions leaded to catalysts with metal-support interactions suitable for the ethanol steam reforming hydrogen production. Further characterization is needed to give further insight about the interaction between Rh and Ni and the support and its role in the steam reforming of ethanol. |
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