Facultad Regional Córdoba
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Item Study of Ir/Ti-SBA-15 acidity influence on the HDN of indole.(Univesidsad Tecnológica Nacional., 2015) Ledesma , Brenda Cecilia; Vallés , Verónica Alejandra; Rivoira , Lorena Paola; Balangero, Gerardo Simón; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Rivoira , Lorena Paola; Vallés , Verónica AlejandraThe 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 TEOT as Ti source. Ti was incorporated into the framework replacing the Si atoms in the mesoporous structure. Ir/Ti-SBA-15 with and without F and/or Al were prepared to improve the catalytic activity. F and Al have been incorporated by wetness impregnation method. The effect of the incorporation of F and Al in the mesoporous structure was tested in the hydrodenitrogenation reaction of indole. The catalysts were extensively characterized by X-ray diffraction (XRD), N2 adsorption isotherms, TEM, FTIR and UV-vis-DRS and Raman spectroscopy. The low angle X-ray analysis showed for all the materials intensive reflection, characteristic of SBA-15 structure. The mesoporous structure was maintained after F and Al incorporation. The results showed that Ti incorporation reduces significantly the cluster size and improves considerably the Ir cluster dispersion. The catalytic activity of Ir/Ti-SBA-15 modified with F and Al, with higher acidity, avoided the irreversible adsorption of indole. The catalytic activity was studied in a 4563 Parr reactor, at 250°C, 15 atm of pressure of hydrogen and 360 rpm. The catalysts synthesized had good activity measured in hydrodenitrogenation of indole at mild conditions. The preliminary results show these materials as promising catalysts for HDN reactionsItem Hydrogenation of tetralin in presence of nitrogen using a noble-bimetallic couple over a Ti-modified SBA-15.(Univesidsad Tecnológica Nacional., 2017) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma , Brenda CeciliaThe increased attention paid to catalytic hydrogenation in the oil refining industry is due in part to legislation regarding the maximum contents of sulfur, aromatic compounds, and alkenes in traffic fuels. Aromatics in diesel increase the particle emissions in exhaust gases and they have the further effect of lowering the fuel quality. Many factors such as the catalysts, process parameters, feedstock source and quality, reactivities of sulfur compounds, inhibition effects of H2S, nitrogen compounds and aromatics present in the feed, etc. can have significant influences on the degree of hydrogenation of diesel feeds1,2. Recently, studies have been reviewed and the investigations have also been extended to noble metals3 . In our previous investigations with bimetallic catalysts4 , we had very good results preparing the catalysts by co impregnation of the relevant metals on the SBA-15 mesoporous matrix. These studies showed high activity, selectivity and stability as well also greater resistance to poisons compared to monometallic catalysts. In this contribution titanium is incorporated in tetrahedral position replacing silicon in the mesoporous framework. We expect that Ti incorporation improve the dispersion of the bimetallic clusters. In the present work three compounds tetralin, indole and quinoline were used as models for the compounds in diesel. The model compounds were hydrogenated both separately and as mixtures in order to study the inhibition effect.Item Indole HDN using iridium nanoparticles supported on titanium nanotubes(2022) Ledesma, Brenda Cecilia; Martínez, María Laura; Gómez Costa, Marcos Bruno; Beltramone, Andrea RaquelThe HDN of indole was studied over iridium modified titanate nanotube catalyst. Titanium nanotube was prepared by the alkaline hydrothermal method. Iridium was added by wetness impregnation. The activity was compared with Ir–TiO2 and commercial NiMo/Al2O3 catalysts. The catalysts prepared were characterized by X-ray diffraction (XRD), N2 adsorption isotherms, UV–Vis-DRS, FTIR, XPS, TEM, Py-FTIR and H2-Chemisorption. XRD, N2 isotherms and UV–vis-DRS con- firmed the nanotube structure. The analysis showed that the mesoporous structure was maintained after Ir incorporation. The results showed that titanate nanotube as support significantly reduce the size of iridium crystallites and improves its dispersion considerably. Iridium titanate nanotube presented abundant and strong Brönsted acidity compared with TiO2 iridium catalyst. According a kinetic study, Ir–TNT was the most active catalyst for indole HDN, in mild conditions in a Batch reactor. The Brönsted acidity in synergic effect with Lewis acidity and hydrogenolysis capacity of iridium species were the responsible for the good activity.