Browsing by Author "Pavesi Contreras, Camila Andrea"

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    H2 production through aqueous phase reforming of ethanol over molybdenum carbide catalysts supported on zirconium oxide
    (2024) Pavesi Contreras, Camila Andrea; Blanco, Elodie; Pazo Carballo, César Alexander; Dongil, A.B.; Escalona Burgos, Nestor Guillermo
    Molybdenum carbide catalysts supported on monoclinic and tetragonal zirconium oxide were studied for hydrogen production through aqueous phase reforming of ethanol. Catalysts were characterized by N2 physisorption, XRD, TPR and XPS. Results showed that 10%Mo2C/m-ZrO2 was less carburized and had a lower surface area than 10%Mo2C/t-ZrO2 and 10%MoC/t-ZrO2. Mo oxide was identified on the surface as well as two types of Mo oxycarbide and Mo oxynitride. The α crystalline phase of the carbide was more active than β phase and was ascribed to its higher relative superficial distribution. However, the α phase generated less H2 probably because there was less oxycarbide presence. 10%Mo2C/m-ZrO2 produced significantly more H2 and was stable for five consecutive reactions. This catalyst showed higher carburization degree after the reaction, which greatly enhanced the generation of H2, suggesting that carbides species improved H2 production compared to oxycarbides.
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    H2 production through aqueous phase reforming of ethanol over molybdenum carbide catalysts supported on zirconium oxide
    (Wiley, 2024) Pavesi Contreras, Camila Andrea; Blanco, Elodie; Pazo Carballo, César Alexander; Dongil, A.B.; Escalona Burgos, Nestor Guillermo
    Molybdenum carbide catalysts supported on monoclinic and tetragonal zirconium oxide were studied for hydrogen production through aqueous phase reforming of ethanol. Catalysts were characterized by N2 physisorption, XRD, TPR and XPS. Results showed that 10%Mo2C/m-ZrO2 was less carburized and had a lower surface area than 10%Mo2C/t-ZrO2 and 10%MoC/t-ZrO2. Mo oxide was identified on the surface as well as two types of Mo oxycarbide and Mo oxynitride. The α crystalline phase of the carbide was more active than β phase and was ascribed to its higher relative superficial distribution. However, the α phase generated less H2 probably because there was less oxycarbide presence. 10%Mo2C/m-ZrO2 produced significantly more H2 and was stable for five consecutive reactions. This catalyst showed higher carburization degree after the reaction, which greatly enhanced the generation of H2, suggesting that carbides species improved H2 production compared to oxycarbides.
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    Producción de hidrógeno mediante reformado en fase acuosa de etanol utilizando carburos de molibdeno soportados en zirconia
    (2023) Pavesi Contreras, Camila Andrea; Escalona, Néstor; Blanco, Elodie; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
    La creciente crisis climática genera la necesidad de buscar alternativas sustentables a los combustibles fósiles. El H2 tiene un gran potencial como vector energético y puede ser producido desde fuentes renovables como el etanol, un derivado de desechos de biomasa. En esta Tesis, se estudian catalizadores de carburo de molibdeno soportados en óxido de zirconia monoclínica y tetragonal para producir H2 mediante reformado en fase acuosa de etanol. Los catalizadores se caracterizan por fisisorción de N2, DRX, TPR y XPS. Los resultados indican que mientras mayor es la carburización, más activo es el catalizador. Además, 10%Mo es el contenido metálico que alcanza la mayor selectividad a H2, lo que se atribuye a la presencia de oxicarburos en su superficie. Se alcanza el mejor desempeño en el APR a 250°C y 10%Mo2C/ZrO2 es estable durante 5 reacciones con reciclo, a pesar de una leve pérdida de selectividad a H2. Se concluyó que la fase cristalina α del molibdeno es más activa que la β debido a que alcanza una mayor dispersión de la fase activa. Sin embargo, produce menos H2, dada la menor cantidad de oxicarburos sobre su superficie. La temperatura ideal de carburización del catalizador son 650°C puesto que un aumento de 50°C perjudica el desempeño en el APR. Los resultados están en concordancia con la literatura. Finalmente, se cumplen los objetivos propuestos para este trabajo y se concluye que el mejor catalizador para la producción de H2 mediante APR de etanol es 10%Mo2C/ZrO2.