Desarrollo, Producción e Innovación en la Investigación científica
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Item Synthesis of SBA-1, SBA-3 and SBA-7 mesoporous materials. Study of the effect of time and temperature.(Universidad Tecnológica Nacional., 2016) Martínez , María Laura; Ponte , María Virginia; Falcón , Horacio; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Ponte , María VirginiaIn recent years, physicists, chemists and engineers have focused their research on the design of new functional materials. In the synthesis and control of materials in nanometer dimensions, the aim is currently directed towards the development of systems and devices that take advantage of chemical properties and physical principles, where their causes lie in the nanometer scale. Although there are numerous investigations about the synthesis of mesoporous materials from inorganic silicon salt, for example the synthesis of SBA-3. Ting et al [1] studied the synthesis of SBA-1; they obtained mesoporous SBA-1 with cubic structures, with a high porous system, by utilizing agents’ routers short chain structure such as the dodecyltrimethyl ammonium chloride. Recent research also showed that the formation of mesophases is affected by the presence of the counter ions and templates or surfactants can adopt a mesophase or other phases. So, Che et al. [2] found a phase shift 2D-hexagonal cubes from P6mm to Pm3n. We have published results for synthesis of SBA-3 with silica gel as silica source; we have found that the formation of mesophase is function of NaOH concentration in the dissolutions of silica gel. The influence of reaction temperature, time and NaOH concentration was investigated. During studies for the best synthesis conditions for synthesis of SBA-3, we also obtained SBA-1 and SBA-7 mesoporous materials.Item Óxidos de vanadio y titanio soportados sobre CMK-3 como un nuevo catalizador para la desulfuración oxidativa de DBT.(Universidad Tecnológica Nacional., 2016) Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Gómez Costa , Marcos Bruno; Falcón , Horacio; Juárez , Juliana Maria; Rivoira , Lorena Paola; Rivoira , Lorena Paola; Juárez , Juliana Maria; Anunziata , Oscar AlfredoEn el presente trabajo se estudiaron catalizadores de vanadio soportados sobre el carbón mesoporosos CMK 3 con diferentes contenidos de Vanadio (1-7 % p/p) en la desulfurización oxidativa de dibenzotiofeno (DBT) como modelo de compuestos sulfurados. La actividad catalítica se comparó con catalizadores de Titanio soportados en CMK-3. Las propiedades estructurales y texturales de los catalizadores se analizaron mediante estudios de adsorción de N2, XRD, UV-Vis-DRS y TEM. Tanto la dispersión como la actividad catalítica dependen fuertemente del contenido de vanadio. La muestra que contiene el 7% p/p de Vanadio es el catalizador con mejor actividad catalítica para la reacción de ODS de DBT utilizando peróxido de hidrógeno ((H2O2) como oxidante y acetonitrilo como solvente. El 100% de la eliminación de DBT se alcanzó a corto plazo en condiciones suaves. El carbon mesoporoso CMK-3 con una alta área superficial y gran volumen de poros promueve el anclaje del metal en la red de carbono, lo que permite alcanzar una alta distribución de sitios activos y nanoclusters más estables. La reutilización del catalizador indica que V-CMK-3 es un catalizador potencial para los ODS de dibenzotiofeno.Item Hidrodenitrogenación de Indol utilizando catalizadores de Ir soportado sobre SBA-15 modificada con Ti.(Universidad 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.Item Probing the Catalytic Activity of Sulfate-Derived Pristine and Post-Teatred Porous TiO2(101) Anatase Mesocrystals by the Oxidative Desulfurization of Dibenzothiophenes.(Universidad Tecnológica Nacional., 2017) Rivoira , Lorena Paola; Martínez , María Laura; Falcón , Horacio; Beltramone , Andrea Raquel; Campos , Martín José; Fierro , José; Tartaj , Pedro; Martínez , María LauraMesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimiza tion of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur com pounds found in fossil fuels). Here, we probe the catalytic activity of anatases for the oxidative desulfuration of dibenzothiophenes under atmospheric pressure and mild temperatures. Specifically, for this study, we have taken advantage of the high stability of the (101) anatase surface to obtain a variety of uniform colloidal mesocrystals (approximately 50 nm) with adequate orientational order and good textural properties (pores around 3−4 nm and surface areas around 200 m2 /g). Ultimately, this stability has allowed us to compare the catalytic activity of anatases that expose a high number of aligned single crystal-like surfaces while differing in controllable surface characteristics. Thus, we have established that the type of tetrahedral coordination observed in these anatase mesocrystals is not essential for oxidative desulfuration and that both elimination of sulfates and good textural properties significantly improve the catalytic activity. Furthermore, the most active mesocrystals have been used to model the catalytic reaction in three-(oil− solvent−catalyst) and two-phase (solvent−catalyst) systems. Thus, we have been able to observe that the transfer of DBT from the oil to the solvent phase partially limits the oxidative process and to estimate an apparent activation energy for the oxidative desulfuration reaction of approximately 40 kJ/mol in the two-phase system to avoid mass transfer limitations. Our results clearly establish that (101) anatase mesocrystals with excellent textural properties show adequate stability to withstand several post treatments without losing their initial mesocrystalline character and therefore could serve as models for catalytic processes different from the one studied hereItem Pt-Pd-F/AI₂O₃ Catalyst applied in the HDT process.(Universidad Tecnológica Nacional., 2015) Balangero, Gerardo Simón; Falcón , Horacio; Beltramone , Andrea RaquelThe inhibiting effect of basic and non-basic nitrogen compounds on the hydrogenation of polyaromatic compounds and on the hydrodesulphurization (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6DMDBT), has been investigated on Pt-Pd-F/Al2O3 and compared with a commercial NiMo hydrotreating catalyst. Langmuir-Hinshelwood type rate equations were used to describe the reaction kinetics accurately with physically meaningful and well identified parameter values. Model parameters were tuned by fitting experimental data obtained in a continuous flow reactor at 345°C, 1000 psi pressure and different contact times. Pt-Pd-F/Al2O3 was more active than NiMo catalyst and conversion remained constant during 24 h of TOS. The model was able to correctly interpret all the experimental data. Parameter estimation results showed that phenanthrene and naphthalene inhibited the tetralin hydrogenation rate, whereas naphthalene and tetralin had no appreciable effect on the rate of phenanthrene conversion. This inhibition could be explained by the competitive adsorption and was described in the kinetic model by adsorption terms obtained from the multicomponent experiments. The inhibiting effect of different nitrogen compounds on the polyaromatic hydrogenation was determined. The following nitrogen compounds were investigated in this study: quinoline, 1,2,3,4-tetrahydroquinoline, indole, and indoline. The degree of inhibition was expressed in terms of an apparent adsorption constant derived from the kinetics.The inhibiting effect on the HDS of DBT and 4,6 DBT followed the same trendItem Sílica Gel como fuente de silicio: Síntesis y caracterización de matrial mesoporoso.(Universidad Tecnológica Nacional., 2015) Ponte , María Virginia; Martínez , María Laura; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Martínez , María LauraEl material mesoporoso SBA-3 fue sintetizado mediante el método sol-gel, utilizando silicato de sodio como fuente de silicio y bromuro de hexadeciltrimetilamonio (CTAB) como agente director de estructura en condiciones acidas. El silicato sódico se generó in-situ por disolución de silica gel en NaOH. Se estudió el efecto de la variación de temperatura, la concentración de NaOH, y el tiempo de reacción. El mejor material mesoporoso con estructura SBA-3 fue obtenido con las siguientes condiciones de síntesis: temperatura: 25ºC; tiempo de reacción: 45min; concentración de NaOH: 0.8M.Item INIHIBITION BY NITROGEN COMPOUNDS IN THE SIMULTANEOUS HYDROGENATION OF POLYAROMATIC COMPOUNDS OVER Pt-Pd-F/AI₂O₃ CATALYST.(Universidad Tecnológica Nacional., 2015) Balangero , Gerardo Simón; Falcón , Horacio; Beltramone , Andrea RaquelThe inhibiting effect of basic and non-basic nitrogen compounds on the hydrogenation of polyaromatic compounds and on the hydrodesulphurization (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6DMDBT), has been investigated on Pt-Pd-F/Al2O3 and compared with a commercial NiMo hydrotreating catalyst. Langmuir-Hinshelwood type rate equations were used to describe the reaction kinetics accurately with physically meaningful and well identified parameter values. Model parameters were tuned by fitting experimental data obtained in a continuous flow reactor at 345°C, 1000 psi pressure and different contact times. Pt-Pd-F/Al2O3 was more active than NiMo catalyst and conversion remained constant during 24 h of TOS. The model was able to correctly interpret all the experimental data. Parameter estimation results showed that phenanthrene and naphthalene inhibited the tetralin hydrogenation rate, whereas naphthalene and tetralin had no appreciable effect on the rate of phenanthrene conversion. This inhibition could be explained by the competitive adsorption and was described in the kinetic model by adsorption terms obtained from the multicomponent experiments. The inhibiting effect of different nitrogen compounds on the polyaromatic hydrogenation was determined. The following nitrogen compounds were investigated in this study: quinoline, 1,2,3,4-tetrahydroquinoline, indole, and indoline. The degree of inhibition was expressed in terms of an apparent adsorption constant derived from the kinetics.The inhibiting effect on the HDS of DBT and 4,6 DBT followed the same trend.Item ODS of dibenzothiopene with titanium-modified SBA-16.(Universidad Tecnológica Nacional., 2015) Rivoira , Lorena Paola; Vallés , Verónica Alejandra; Beltramone , Andrea Raquel; Martínez , María Laura; Ledesma , Brenda Cecilia; Anunziata , Oscar Alfredo; Anunziata , Oscar Alfredo; Ledesma , Brenda Cecilia; Martínez , María Laura; 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).Item Vanadium oxide supported on mesoporous SBA-15 modified with AI and Ga as a highly active catalyst in the ODS of DBT.(Universidad Tecnológica Nacional., 2017) Rivoira , Lorena Paola; Martínez , María Laura; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Martínez , María LauraIn order to adapt current processes to the strict regulatory requirements, several technologies have been developed for deep desulfurization of diesel fuel. The major portion of sulfur in light cycle oils (LCO) is found in dibenzothiophene (DBT) and alkyl-dibenzothiophenes, which are not easily removable by hydrotreating, because they require high pressure and hydrogen consumption. Vanadium oxides supported on mesoporous SBA-15 catalysts with different vanadium loadings were studied in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. The catalytic activity was improved when SBA-15 framework was modified with Al and Ga as heteroatom substituting framework Si. Structural and textural characterization of the catalysts were performed by means of XRD, N2 adsorption, UV–Vis–DRS, XPS, NMR, TEM, Raman, TPR and Py-FTIR. UV–Vis–DRS and Raman demonstrated that highly dispersed vanadium VO4-3 species are responsible for the high activity in the sulfur removal. The Ga modified support with an intermediate V/Si ratio of 1/30 was the most active catalyst for ODS of DBT, using hydrogen peroxide as oxidant and acetonitrile as solvent. 100% of DBT elimination was attained at a short time in mild conditions. Gallium and aluminum incorporation into the support modified successfully the nature of the SBA-15 surface by generating Bronsted and Lewis acidity. The interaction between the acid sites with the active vanadium sites improved the activity of the catalysts. The high dispersion depended on the vanadium loading and on the nature of the support. The more acidic support allowed better dispersion of the vanadium species due to stronger interaction metal-support. The reusability of the catalysts indicates that vanadium oxide supported on mesoporous SBA-15 modified with Ga and Al are potential catalysts for the ODS of dibenzothiophene.Item Synthesis and characterization of a nanoporous carbon CMK-3 modified with iron for the ODS of DBT.(Universidad Tecnológica Nacional., 2017) Juárez , Juliana María; Rivoira , Lorena Paola; Gómez Costa, Marcos Bruno; Anunziata , Oscar Alfredo; Beltramone , Andrea Raquel; Anunziata , Oscar Alfredo; Rivoira , Lorena PaolaA nanostructured Carbon CMK-3 modified with Fe by using different sources of Fe, were used in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. Ordered mesoporous carbon CMK-3 was synthesized via a two-step impregnation of the SBA-15 silica mesonanopores with a solution of sucrose using an incipient wetness method. The sucrose–silica composite was heated at 1173 K for 4 h under nitrogen flow. The silica A nanostructured Carbon CMK-3 modified with Fe by using different sources of Fe, were used in the oxidative desulfurization (ODS) of dibenzothiophene as a model sulfur compound. Ordered mesoporous carbon CMK-3 was synthesized via a two-step impregnation of the SBA-15 silica mesonanopores with a solution of sucrose using an incipient wetness method. The sucrose–silica composite was heated at 1173 K for 4 h under nitrogen flow. The silica The catalytic activity was improved when the nanoporous carbon was modified with Fe. The sample 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.