Estudio del efecto del Pt en el catalizador CoMoS soportado en Al2O3-TiO2 en la Hidrodesoxigenación de Guayacol
The main objective of this work was the comparative evaluation of trimetallic catalysts based on Pt-CoMoS supported on Al2O3 and Al2O3-TiO2 for the HDO of guaiacol as an oxygenated model molecule. The synthesis of the supports was carried out by sol-gel method in order to have better textural proper...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis de maestría |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:3197xm063 |
| Acceso en línea: | https://doi.org/10.24275/uami.3197xm063 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Metal catalyst info:eu-repo/classification/LEM/Catalizadores metálicos info:eu-repo/classification/LEM/Catalysts info:eu-repo/classification/LEM/Catalizadores info:eu-repo/classification/LEM/Recursos energéticos renovables info:eu-repo/classification/LEM/Energía biomásica info:eu-repo/classification/LEM/Renewable energy sources info:eu-repo/classification/cti/1 |
| Sumario: | The main objective of this work was the comparative evaluation of trimetallic catalysts based on Pt-CoMoS supported on Al2O3 and Al2O3-TiO2 for the HDO of guaiacol as an oxygenated model molecule. The synthesis of the supports was carried out by sol-gel method in order to have better textural properties, such as, surface area, volume and pore diameter. The catalysts were prepared by the incipient impregnation technique using an atomic ratio of Co / (Co + Mo) = 0.3 and a density of 2.8 atoms of Mo / nm2. Subsequently, they were impregnated with Pt with the same procedure described, using 1% by weight of this metal. The above was carried out with a previous sulfurization step at 400ºC / 4 h with a 15% mixture of H2S / H2. The catalysts were characterized by temperature programmed desorption (TPD), temperature programmed reduction (TPR), X-ray diffraction and Diffuse Reflectance Spectroscopy (DRS). The catalysts with the greatest interest were also characterized by X-ray photoelectron spectroscopy and HRTEM. Likewise, all the catalysts were evaluated in the HDO reaction of guaiacol in a batch reactor with a volume of 100 ml at conditions of 320ºC and 800 psi. From the reaction tests it was found that the catalysts containing platinum and supported in mixed oxides showed higher activity than conventional sulfur catalysts. In addition, it was found that these catalysts improve the selectivity towards HDO products. In this sense, from the analyzes by DRS and TPR it was possible to conclude that when adding TiO2 to the support the quantity of octahedral species, which are easier to reduce and sulphide, increase significantly compared to the supported catalyst in Al2O3. However, having a higher content of TiO2 in the support these species decrease causing a low activity. In addition, with the analysis by HRTEM it was observed that there is a low dispersion of the MoS2 for the catalyst with the presence of Pt, indicating that they have longer layers, resulting in a decrease in the number of Mo atoms at the edges. In this sense, the analysis by XPS showed that the degree of sulphuration is not affected by the presence of Pt, indicating that this metal is not in its sulphurated state. However, the high-resolution spectra showed that there is a better sulfurization for catalysts supported in mixed oxides. Also, it was found that there is a large amount of platinum on the surface of the catalyst, which indicates that the Pt is only segregated. Thus, the Pt-CoMoS / AT1 catalyst was the most active due to the large amount of Pt it has on its surface |
|---|