Hidrodenitrogenación de Indol utilizandocatalizadores de Ir soportado sobre SBA-15 modificada con Ti.
Date
2016
Journal Title
Journal ISSN
Volume Title
Publisher
Univesidsad Tecnológica Nacional.
Abstract
La hidrodenitrogenación de indol se estudió utilizando una serie de catalizadores de Ir soportado sobre SBA 15 modificada con Ti. El mesoporoso modificado Ti-SBA-15 se sintetizó usando el método sol-gel. El iridio fue
incorporado mediante la técnica de impregnación húmeda incipiente. Con el fin de mejorar la actividad
catalítica se modificó la acidez del material mesoporoso añadiendo F o Al. Los catalizadores fueron
caracterizados por difracción de rayos X (XRD), isotermas de adsorción de N2, UV-Vis-DRS, espectroscopía
Raman, espectroscopía 27Al-MAS-RMN, XPS, TEM, Py-FTIR y TPR. Los análisis confirman que el Ti fue
incorporado en coordinación tetraédrica dentro de la SBA-15 y que la estructura mesoporosa se mantuvo
después de la incorporación de F o Al. La espectroscopía27Al-MAS-RMN indica que el aluminio se incorporó
principalmente en posicion tetraédrica. Los resultados mostraron que la incorporación del Ti ayuda a reducir
significativamente el tamaño de los clusters de Iridio y mejora considerablemente su dispersión. El
catalizador Ir-Ti-SBA-15, modificado con Al, fue el catalizador más activo para la hidrodenitrogenación de
indol, en condiciones suaves en un reactor discontinuo. Los datos experimentales para la
hidrodenitrogenación de indol fueron cuantitativamente representados por una ecuación de velocidad del
tipo Langmuir-Hinshelwood.
Palabras claves: hidrodenitrogenación, titanio, mesoporoso, clusters de Iridio, cinética
The hydrodenitrogenation of indole has been studied over a series of Ti-modified SBA-15 supports and their respective Ir-catalysts. Ti-SBA-15 was synthesized using sol-gel method and Ti was added during the synthesis using Tetraethyl Orthotitanate. Iridium was added by wetness impregnation. The acidity of Ti-SBA-15 was modified adding F or Al in order to improve the catalytic activity. The catalysts prepared were extensively characterized by X-ray diffraction (XRD), N2 adsorption isotherms, UV-Vis-DRS, Raman spectroscopy, 27Al MAS-NMR spectroscopy, XPS, TEM-EDS, Py-FTIR and TPR. UV-Vis-DRS and Raman spectroscopy confirmed that Ti was incorporated in tetrahedral coordination in the framework of the SBA-15. The analysis showed that the mesoporous structure was maintained after F or Al incorporation. 27Al-MAS-NMR spectroscopy indicated that aluminum was incorporated mainly in Td positions. The results showed that Ti incorporation helps to reduce significantly the size of iridium clusters and improves its dispersion considerably. Ir-Ti-SBA 15 modified with Al, with Bronsted acidity, was the most active catalyst for indole HDN, in mild conditions in a Batch reactor. The experimental data for indole hydrodenitrogenation was quantitatively represented by a Langmuir–Hinshelwood type rate equation
The hydrodenitrogenation of indole has been studied over a series of Ti-modified SBA-15 supports and their respective Ir-catalysts. Ti-SBA-15 was synthesized using sol-gel method and Ti was added during the synthesis using Tetraethyl Orthotitanate. Iridium was added by wetness impregnation. The acidity of Ti-SBA-15 was modified adding F or Al in order to improve the catalytic activity. The catalysts prepared were extensively characterized by X-ray diffraction (XRD), N2 adsorption isotherms, UV-Vis-DRS, Raman spectroscopy, 27Al MAS-NMR spectroscopy, XPS, TEM-EDS, Py-FTIR and TPR. UV-Vis-DRS and Raman spectroscopy confirmed that Ti was incorporated in tetrahedral coordination in the framework of the SBA-15. The analysis showed that the mesoporous structure was maintained after F or Al incorporation. 27Al-MAS-NMR spectroscopy indicated that aluminum was incorporated mainly in Td positions. The results showed that Ti incorporation helps to reduce significantly the size of iridium clusters and improves its dispersion considerably. Ir-Ti-SBA 15 modified with Al, with Bronsted acidity, was the most active catalyst for indole HDN, in mild conditions in a Batch reactor. The experimental data for indole hydrodenitrogenation was quantitatively represented by a Langmuir–Hinshelwood type rate equation
Description
Keywords
Ir, SBA-15, Ti
Citation
XXV Congreso Iberoamericano de Catálisis 2016.
Endorsement
Review
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