Browsing by Author "Vallés , Verónica Alejandra"
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Item Eliminación de azufre mediante desulfuración oxidativa con Ti-SBA-16. Parte I. Síntesis y caracterización.(Univesidsad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Ponte , María Virginia; Martínez , María Laura; Beltramone , Andrea Raquel; Martínez , María Laura; Ponte , María Virginia; Ledesma , Brenda Cecilia; Ledesma , Lorena Paola; Vallés , Verónica AlejandraSe desarrollaron catalizadores tipo SBA-16 modificados con Ti como TiO2 y como heteroatomo y se probaron en la desulfuración oxidativa (ODS) del dibenzotiofeno predominante en el combustible líquido. Se utilizó TiO2 puro como referencia para comparar la actividad catalitica. Los catalizadores fueron caracterizados mediante análisis químico, XRD, EDX y TEM. El estado de coordinación tetraédrico del titanio (en la muestra de Ti-SBA-16) u octaédrico (en la muestra de TiO2/SBA-16) en la matriz de sílice se determinó por XPS, UV-vis DRS, FTIR, Raman y XANES. La actividad catalítica se muestra en la Parte 2 de este trabajo.Item Experimental desing optimization of the ODS of DBT using vanadium oxide supported on mesoporous GA-SBA-15.(Univesidsad Tecnológica Nacional ., 2018) Rivoira , Lorena Paola; Cussa , jorgelina; Vallés , Verónica Alejandra; Martínez , María Laura; Beltramone , Andrea Raquel; Martínez , María Laura; Vallés , Verónica Alejandra; Cussa , jorgelinaEn el presente trabajo se utiliza el diseño experimental de superficies de respuesta (RSM) para modelar y optimizar la oxidación de dibenzotiofeno (DBT) utilizando VOx-Ga-SBA-15 como catalizador. Analizamos como influye la naturaleza del catalizador (carga de V y Ga), la relación másica substrato/catalizador y la relación molar oxidante/substrato como variables para el diseño. La respuesta analizada fue la conversión a los 15 min de reacción. Las superficies de respuesta fueron obtenidas mediante el Diseño de Box-Behnken, encontrando así la mejor combinación entre los parámetros de reacción que permita optimizar el proceso. Los mayores valores de función objetivo se obtuvieron mediante el uso de la estadística, empleando el catalizador con 4 % p/p de galio y 6 % p/p de vanadio, la relación óptima entre g DBT/g de catalizador fue 4 y la relación molar H2O2/DBT fue 5. La incorporación de galio como heteroátomo en posición tetraédrica permite el mejor anclaje de las especies activas de vanadio generando un catalizador con muy buena dispersión. El diseño de experimento sirvió para encontrar la mejor combinación entre el heteroátomo y las especies activas de vanadio con el fin de hallar el catalizador mas activo para la oxidación de DBT en las condiciones experimentales óptimas.Item Experimental Desing Optimization of the tetralin Hydrogenation over Ir-Pt-SBA-15.(Univesidsad Tecnológica Nacional, 2016) Vallés , Verónica Alejandra; Ledesma, Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma, BrendaExperiment design-response surface methodology (RSM) is used in this work to model and optimize two responses in the hydrogenation of tetralin to decalin using bimetallic Ir–Pt-SBA-15 catalyst. In this study, we analyze the influence of the nature of the catalyst (metal molar fraction and metal loading), the catalyst/substrate ratio and the temperature of the reaction as factors for the design. The responses analyzed were conversion at 3 h and at 5 h of reaction time. The response surfaces were obtained with the Box–Behnken design, finding the best combination between the reaction parameters that allowed optimizing the process. By applying the statistic methodology, the higher levels of the two objective functions were obtained employing the catalyst with 1 wt.% of iridium and 0.7–0.8 wt.% of platinum; the optimal ratio between mass of catalyst and mole of tetralin was 17–19 g/mol and temperature between 200 and 220 ◦C.Item Experimental desing optimization of the tetralin hydrogenation over Ir-Pt-SBA-15.(Univesidsad Tecnológica Nacional., 2015) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma , Brenda CeciliaExperiment design-response surface methodology (RSM) is used in this work to model and optimize two responses in the hydrogenation of tetralin to decalin using bimetallic Ir–Pt-SBA-15 catalyst. In this study, we analyze the influence of the nature of the catalyst (metal molar fraction and metal loading), the catalyst/substrate ratio and the temperature of the reaction as factors for the design. The responses analyzed were conversion at 3 h and at 5 h of reaction time. The response surfaces were obtained with the Box– Behnken design, finding the best combination between the reaction parameters that allowed optimizing the process. By applying the statistic methodology, the higher levels of the two objective functions were obtained employing the catalyst with 1 wt.% of iridium and 0.7–0.8 wt.% of platinum; the optimal ratio between mass of catalyst and mole of tetralin was 17–19 g/mol and temperature between 200 and 220 ◦CItem Experimental Desing Optimization of the tetralin Hydrogenation over Pt-Ir/SBA-15.(Univesidsad Tecnológica Nacional., 2015) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma , Brenda Ceciliahe oil refining industry has a difficult challenge to meet the increasingly stringent regula tions on environmental issues. Contaminants such as sulfur, nitrogen, fused ring aromatic compounds or metals are the principal to remove to achieve "green" fuels. The hydrotreating (HDT) is one of the processes most used in the refinery to remove these contaminants. To optimize the gas oil hydrotreater, it is crucial to understand the aromatic hydrogenation reac tion chemistry occurring in the gas oil hydrotreater. To find alternative processes, it is neces sary to develop new and more active catalysts to replace the current ones. Bimetallic Pt–Pd catalysts have received considerable attention, because they show high actvity in a variety of catalytic applications [1,2]. From a fundamental point of view, exploring bimetallic catalysts also allows better understanding of mechanisms and variables involved in the catalytic reac tions. The features of the catalysts here studied are going to be correlated with their catalytic performance in the hydrogenation of tetralin. The final goal is to find the optimal proportion of each metal in order to be more active and the best reaction conditions. The statistical expe riments design is the process of planning an experiment to obtain appropriate data that can be analyzed by statistical methods, to produce concrete and valid conclusions [3]. One of the main advantages in the response curve is to visualize the response for all levels of the experi mental factors Experiment design response surface methodology (RSM) is used in this work to model and to optimize the process.Item Hidrodenitrogenación de Indol utilizandocatalizadores de Ir soportado sobre SBA-15 modificada con Ti.(Univesidsad Tecnológica Nacional., 2016) Ledesma , Brenda Cecilia; Vallés , Verónica Alejandra; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Vallés , Verónica AlejandraLa 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, cinéticaItem Hidrogenación de tetralin sobre Ir-Pt-SBA-15. Parte 1: Síntesis, caracterizacíon y actividad catalítica.(Univesidsad Tecnológica Nacional, 2015) Vallés , Verónica Alejandra; Ledesma, Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Cussa , jorgelina; Rivoira , Lorena PaolaSe estudia aquí la hidrogenación de tetralin a decalin utilizando un catalizador bimetálico Ir-Pt SBA-15. En esta Parte se describe la síntesis de los catalizadores, la preparación de la matriz de SBA 15 y el método de co-impregnacion mediante el cual se incorporaron los metales en diferentes proporciones y carga total metalica. Los catalizadores fueron caracterizados por XRD, TEM, análisis fisicoquimicos, XPS, SEM y EDX. En la Parte 2 de este trabajo se analizará la influencia de la naturaleza del catalizador, la relación catalizador sustrato y la temperatura de reacción como factores de un Diseño de Experimentos para optimizar el proceso.Item Hidrogenación de tetralin sobre Ir-Pt-SBA-15. Parte 2: Optimización por Diseño de Experimentos.(Univesidsad Tecnológica Nacional, 2015) Vallés , Verónica Alejandra; Ledesma, Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma, BrendaLa Metodología Diseño de Experimentos - Superficie de Respuesta – se utiliza en este trabajo para modelar y optimizar 2 respuestas en la reacción de hidrogenación de tetralin a decalin usando un catalizador bimetálico Ir-Pt-SBA-15. En este estudio se analizó la influencia de la naturaleza del catalizador, la relación catalizador/sustrato y la temperatura de reacción como factores del diseño. Las respuestas analizadas fueron conversión a 3 y 5 horas Las Superficies de Respuesta fueron obtenidas mediante un diseño Box-Behnken a fin de encontrar la mejor combinación de los distintos parámetros para optimizar el proceso. La metodología estadística aplicada indica que las conversiones más altas de ambas respuestas, a 3 y 5 horas, se obtienen trabajando en el siguiente rango: Catalizador: 1% Ir y 0.7-0.9 %(p/p) Pt; Relación: 17-19 g cat/ mol TL y Temperatura: 200-220°C.Item Hydrodenitrogenation of over Ir supporteD Ti-SBA-15 modified with F AND AI.(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 reactions.Item 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 Hydrogenation of tetralin in presence of nitrogen using a noble-bimetallic couple over a Ti-modified SBA-15.(Univesidsad Tecnológica Nacional., 2016) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Pecchi, Gina; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Ledesma , Brenda CeciliaMonometallic Pt- and bimetallic Pt-Ir-modified Ti-SBA-15 were used in the hydrogenation of tetralin to decalin in the presence of 150 ppm of N as quinoline and indole at 250 ◦C and 15 atm of pressure of hydrogen, using a Parr reactor. The catalyst was synthesized using sol-gel method and Ti was added during the synthesis using Tetraethyl Orthotitanate. Pt/Ir was added by wetness impregnation. The catalysts prepared were extensively characterized by X-ray diffraction (XRD), N2 adsorption isotherms, UV–vis DRS, Raman spectroscopy, XPS, TEM-EDS 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 metal incorporation and Ti incorporation helps to reduce significantly the size of the metals clusters and improves its dispersion considerably. Pt-Ir/Ti-SBA 15 was the most active catalyst. The experimental data were quantitatively represented by a modified Langmuir-Hinshelwood type rate equation. The preliminary results show these materials as a promising catalyst for HDT reactions.Item Ir-Pt/SBA-15 applied in the optimization of tetralin hydrogenation.(Univesidsad Tecnológica Nacional., 2015) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Rivoira , Lorena Paola; Cussa , jorgelina; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata; Cussa , jorgelina; Rivoira , Lorena Paola; Ledesma , Brenda CeciliaBimetallic catalysts have received considerable attention for hydrotreating (HDT) because they show high activity. The features of the catalysts here studied are going to be correlated with their catalytic performance in the hydrogenation of tetralin at mild conditions. The final goal is to find the optimal proportion of each metal in order to be more active and the best reaction conditions (temperature and amount of catalyst). The statistical experiments design is the process of planning an experiment to obtain appropriate data that can be analyzed by statistical methods, to produce concrete and valid conclusions. One of the main advantages in the response curve is to visualize the response for all levels of the experimental factors Experiment design response surface methodology (RSM) is used in this work to model and to optimize the process. Platinum and Iridium nanoparticles were incorporated into SBA-15 support by the wet co-impregnation method. Ir content was set as 1wt. % and Pt was varied from 0 to 1wt. %. The catalysts were characterized by XRD, BET, XPS, TEM, ICP and TPR. XRD profiles are characteristic of the two-dimensional p6mm hexagonal mesostructure with d100 spacing of 10.16 nm; where the d100 spacing upon Ir and Pt incorporation were quite similar to pristine SBA-15. The TEM images and XPS demonstrate that the metal particles were mainly present inside the porous and XPS and TPR corroborated the reduced state of the metals. The catalytic activity was measured in a 4563Parr reactor at 15 atm of hydrogen and 360 rpm. Feed consisted in 50 mL of tetralin in Dodecane, the amount of tetralin is set according to the ratio of catalyst mass/mass reagent corresponding to each reaction. The application of this methodology allows a better understanding of the influence of the different factors: content of metal on catalyst (A), relationship: mass of catalyst/reagent mass (B) and reaction temperature (C), on two responses: conversion at 3 h and at 5 h of reaction time. These factors were carefully selected taking account the influence of the parameters in the reaction. The design was analyzed by Statgraphics and Statistica Soft. We found that, the variable Catalyst has the best influence over the Conversion at the 95.0% confidence level, according to the Pareto.Item Noble-bimetallic supported CMK-3 as a novel catalyst for hydrogenation of tetralin in the presence of sulfur and nitrogen.(Univesidsad Tecnológica Nacional., 2016) Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Juárez , Juliana María; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Juárez , Juliana María; Ledesma , Brenda CeciliaCarbon ordered mesoporous CMK-3 with high surface area and high pore volume promotes a very good dispersion of Pt or Ir monometallic and Pt-Ir-bimetallic crystallites in the carbon framework. High active and stable nanospecies are responsible for the good activity and selectivity found in the hydrogenation of tetralin to decalin in the presence of N as indole and S as dibenzothiophene under mild conditions in a Batch reactor. The catalysts prepared were extensively characterized by XRD, N2 adsorption isotherms, XPS, TEM, ICP, CO Chemisorption and TPR. The analysis showed that the carbon mesoporous structure was maintained after metal incorporation, and very high dispersed metal-supported catalyst was obtained. The activity was compared using the turnover number, Pt-Ir-CMK-3 being the most active cat alyst in the presence of the inhibitors. The bimetallic catalyst showed more resistance to inhibition than monometallic catalysts. The reusability of Pt-Ir-CMK-3 suggests that it is a potential catalyst for hydrotreating reactions.Item Novel preparation of titania-modified CMK-3 nanostructured material as support for Ir catalyst applied in hydrodenitrogenation of indole.(Univesidsad Tecnológica Nacional., 2018) Ledesma , Brenda Cecilia; Juárez , Juliana María; Vallés , Verónica Alejandra; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Vallés , Verónica Alejandra; Juárez , Juliana MaríaIridium catalyst was prepared using a novel titanium oxide-CMK-3 support synthesized as a replica of Ti-SBA-15. The catalyst was applied in the hydrodenitrogenation of indole. The activity was compared with an iridium catalyst supported over a grafted titanium CMK-3. Structural and textural characterization of the catalysts was performed by means of N2 adsorption, XRD, UV–Vis–DRS, Raman spectroscopy, XPS, TEM and H2 Chemisorption. Ir-Ti-CMK-3 was the most active catalyst for the hydrodenitrogenation reaction at mild conditions. Titanium oxide contained in carbon ordered mesoporous CMK-3 promotes a very good anchorage of iridium metallic clusters in the carbon framework reaching high active site distribution and more stable nanoclustersItem Novel preparation of titania-modified CMK-3 nanostructured material as support for Ir catalyst applied in hydrodenitrogenation of indole.(Univesidsad Tecnológica Nacional., 2017) Ledesma , Brenda Cecilia; Juárez , Juliana María; Vallés , Verónica Alejandra; Anunziata , Oscar Alfredo; Beltramone, Andrea RaquelAbstract Iridium catalyst was prepared using a novel tita nium oxide-CMK-3 support synthesized as a replica of Ti SBA-15. The catalyst was applied in the hydrodenitrogena tion of indole. The activity was compared with an iridium catalyst supported over a grafted titanium-CMK-3. Struc tural and textural characterization of the catalysts was per formed by means of N2 adsorption, XRD, UV–Vis–DRS, Raman spectroscopy, XPS, TEM and H2 Chemisorption. Ir Ti-CMK-3 was the most active catalyst for the hydro denitrogenation reaction at mild conditions. Titanium oxide contained in carbon ordered mesoporous CMK-3 promotes a very good anchorage of iridium metallic clusters in the carbon framework reaching high active site distribution and more stable nanoclusters.Item ODS of dibenzothiopene with titanium-modified SBA-16.(Univesidsad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María LauraOver the past, oxidative desulfurization (ODS) has drawn considerable interest as a new alter native method for deep sulfur elimination from light oils. This can be attributed to its attrac tive properties, including lower temperature and pressure conditions and lower operating cost [1-3] than conventional hydrodesulfurization (HDS) process. Oxidation of organosulfur com pounds results in the formation of sulfoxides/sulfones, highly polar and hence easily removed by both extraction into polar solvents or by adsorption. Due to their low reactivity, diben zothiophene derivatives (DBTs) are the most refractory species to be eliminated from oils. Hence, the ODS process through which DBTs are converted to their corresponding sulfones involves great interest at present [4-6]. We recently reported a good performance of this sup port in hydrotreating processes [7]. In this work, we describe the preparation and characteriza tion of new mesoporous catalytic materials based on Ti-containing SBA-16. We study here, the effect of the preparation method of titania-modified SBA-16 (characteristics of the active Ti and/or TiO2 species) and the effect of the different operation conditions in ODS of DBT under mild conditions in order to find the best performance. TiO2-modified mesoporous SBA 16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction tempe rature, nature of the substrate and reuse of catalysts)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 Sulfur elimination by ODSwith titanium-modified SBA-16.(Univesidsad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma, Brenda Cecilia; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María Laura; Ledesma, Brenda; Vallés , Verónica AlejandraNanostructured carbon CMK-3 and mesoporous silica SBA-15 modified with Fe by using different sources of Fe, were used in the oxidative desulfurization (ODS) of dibenzothiophene (DBT) as a model sulfur compound. Fe-CMK-3 and Fe-SBA-15 were prepared by wetness impregnation using FeCl3.6H2O and FeNO3.9H2O as different sources of Fe. A solution of FeCl3.6H2O/ FeNO3.9H2O in ethanol was mixed with the corresponding material solution (CMK-3 or SBA-15) at room temperature. The solution was placed in a rotary evaporator to remove excess of ethanol at about 333 K and 60 rpm. Afterwards, the sample was dried at 373 K for 18 h and was thermally treated in a dynamic inert (N2) atmosphere. The percentage of Fe has been 2 wt.% with respect to carbon in the final FeCl3-CMK-3 and FeNO3-CMK-3 material. Four samples modified with Fe have been prepared and were characterized by XRD, FTIR, XPS, BET, TEM and SEM. These studies indicated that it was possible to obtain a CMK-3 replica successfully from SBA-15, using sucrose as a carbon precursor. Wide angle XRD pattern of the sample modified with FeCl3.6H2O implies the formation of the magnetite phase in the silica channels. The nanomaterial area is significantly smaller with the incorporation of the metal, SBA-15 and CMK-3`s characteristic structure is maintained after the metal is within the host, in agreement with the XRD studies. The catalytic activity was improved when the nanoporous materials were modified with Fe. The nanoporous carbon modified with FeCl3.6H2O was the most active catalyst for ODS of DBT, using hydrogen peroxide (H2O2) as oxidant and acetonitrile as solvent. 100% of DBT elimination was attained at a short time in mild conditions.Item Sulfur elimination by oxidative desulfurization with titanium-modified SBA-16.(Univesidsad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Ponte , María Virginia; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone, Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María Laura; Ponte , María Virginia; Ledesma , Brenda Cecilia; Vallés , Verónica AlejandraTiO2-modified mesoporous SBA-16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. Pure TiO2 was used as reference. The titania-based catalysts were characterized by chemical analysis, XRD, EDX and TEM. The titanium state as tetrahedral (in Ti-SBA-16 sample) or octahedral (in TiO2/SBA-16 sample) coordination surrounding in the silicate matrix was determined by XPS, UV–vis DRS, FTIR, Raman and XANES. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction temperature, nature of the substrate and reuse of catalysts). In addition, we carried out a kinetic study and the activation energy was determined. We achieved 90% of S removal from a 0.2 wt.% dibenzothiophene solution at 60 ◦C in less than 1 h of reaction. The best catalytic results are obtained with high exposed surface of nanometric TiO2 species of TiO2/SBA-16 sample. The activated catalyst is very active in ODS reaction and can be reused four times with no loss in activity.Item Sulfur elimination by oxidative desulfurization with titanium-modified SBA-16L.(Univesidsad Tecnológica Nacional., 2016) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Ledesma , Brenda Cecilia; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María Laura; Ledesma , Brenda Cecilia; Vallés , Verónica AlejandraOver the past, oxidative desulfurization (ODS) has drawn considerable interest as a new alter native method for deep sulfur elimination from light oils. This can be attributed to its attrac tive properties, including lower temperature and pressure conditions and lower operating cost [1-3] than conventional hydrodesulfurization (HDS) process. Oxidation of organosulfur com pounds results in the formation of sulfoxides/sulfones, highly polar and hence easily removed by both extraction into polar solvents or by adsorption. Due to their low reactivity, diben zothiophene derivatives (DBTs) are the most refractory species to be eliminated from oils. Hence, the ODS process through which DBTs are converted to their corresponding sulfones involves great interest at present [4-6]. We recently reported a good performance of this sup port in hydrotreating processes [7]. In this work, we describe the preparation and characteriza tion of new mesoporous catalytic materials based on Ti-containing SBA-16. We study here, the effect of the preparation method of titania-modified SBA-16 (characteristics of the active Ti and/or TiO2 species) and the effect of the different operation conditions in ODS of DBT under mild conditions in order to find the best performance. TiO2-modified mesoporous SBA 16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction tempe rature, nature of the substrate and reuse of catalysts).