Facultad Regional Córdoba
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Item Synthesis, characterization and catalytic performance of bimetallic Ir-Pt catalysts for tetralin hydrogenation.(Univesidsad Tecnológica Nacional, 2024) Anunziata , Oscar Alfredo; Beltramone, Andrea RaquelBimetallic Pt–Pd catalysts have received considerable attention, because they show high activity in a variety of catalytic applications (1) and stability compared with monometallic Pt or Pd catalysts. For instance, the bimetallic Pt–Pd catalysts have been shown to have higher resistance toward poisonscompared to Pt catalysts (2-4). For supported bimetallic clusters, the surface and bulk composition strongly depend on a series of parameters, for example, preparation procedures, metal–metal and metal–support interactions. The final goal is to find the optimal proportion of each metal in order to be more active in these processes.In this case a series of Ir and Pt modified SBA-15 were prepared by the consecutive wet impregnation method, with different content of each metal. The final catalysts were characterized by XRD, TEM and H2 chemisorption to study the effect of content of metal on the dispersion of iridium/platinum. The catalysts synthesized with similar percentage of both metal showed the best activity measured in tetralin hydrogenation. Platinum (Pt) and Iridium (Ir) nanoparticles were incorporated into SBA-15 support [1-4] by the wet co-impregnation method. The metal precursors were Iridium acetylacetonate and cloroplatinic acid. The samples were calcined at 500°C and previous to the catalytic test the samples were reduced by heating at 2°C/min to 450°C in a H2 stream for 5 h. Hereinafter this catalyst will be referred as Ir-Pt- SBA-15 (x), with x= 1-3. The catalytic activity was measured in a 4563Parr reactor, at 250°C, 15 atm of pressure of hydrogen and 360 rpm for tetralin hydrogenation (feed consisted in 50 mL of 5% v/v of tetralin (98.5% FLUKA) in Dodecane). The Pt-Ir-SBA-15 catalyst with 1 %wt. of each metals had the highest activity measured in tetralin hydrogenation at mild conditions. The good activity was correlated with higher Ir/Pt dispersion on SBA-15 mesostructured material used as support, as we seen by TEM and H2 Chemisorption, with higher active metal sites exposed to reactant. The Ir-Pt-SBA-15 activity is sufficiently high to envisage use in the final stages of a refinery process producing diesel fuel of high Cetane Number by hydrodearomatization.Item Synthesis, characterization and hydrogen storage application of an activated carbon derivated from orange peels waste(2022) Juárez, Juliana María; Ledesma, Brenda Cecilia; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno; Beltramone, Andrea RaquelThe recovery and reuse of orange peel waste (OP) is a sustainable strategy in a circular economy. In this research, OP was used as the raw material for the preparation of a novel carbonaceous nanomaterial to be used in the adsorption of hydrogen as an alternative in the use of green hydrogen. Activated carbons were synthesized from orange peel using different synthesis conditions. The activation of the carbon was carried out by means of a chemical process with phosphoric acid as activating agent, varying the the activating agent/precursor ratio, and the contact time between them. The activating agent used is a solution of phosphoric acid (50 wt %) in different weight ratios of acid/precursor of 3:1 or 6:1, with resting time of 24 hours. The best support was obtained using a carbonization time of 1 h, a carbonization temperature of 470 , 6:1 precursor/acid ratio and 24 hours of resting time. According XRD analysis all samples present amorphous structure of activated carbons with BET surface areas of 1000 to 1400 m /g. With the activated carbons obtained with the best structure and texture, the adsorption of hydrogen and the effects on their meso / microporosity were studied. Said material significantly improved H storage behaviour compared to CMK-3 type nanostructured carbon (3.1% by weight at -196,15 C and 10 bar). The synthesized material shows promise in absorbing hydrogen by weak binding forces (physisorption).Item Orange peel biowaste used as a nanoscopic hydrogen reservoir(2022) Juárez, Juliana María; Ledesma, Brenda; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno; Beltramone, Andrea RaquelThis work addresses the bio-waste vaporization approach for the development of a novel carbonaceous nanomaterial to be used in the adsorption of hydrogen as an alternative in the use of green hydrogen. In this research, activated carbons were synthesized from orange peel using different synthesis conditions. With the activated carbons obtained with the best structure and texture, the adsorption of hydrogen and the effects on their meso / microporosity were studied. The activation of the carbon was carried out by means of a chemical process with phosphoric acid as activating agent, varying the acid concentration, the substrate / activating agent ratio, and the contact time between them. The best support was obtained using a carbonization time of 1 h, a carbonization temperature of 470oC, a phosphoric acid concentration of 50% by weight and a BET area of 1402 m2 / g. Said material significantly improved H2 storage behaviour compared to CMK-3 type nanostructured carbon (3.1% by weight at -196,15 oC and 10 bar). The synthesized material shows promise in absorbing hydrogen by weak binding forces (physisorption).Item Nanoscopic hydrogen reservoir orange peel biowaste(2022) Juárez, Juliana María; Ledesma, Brenda Cecilia; Anunziata, Oscar A.; Gómez Costa, Marcos Bruno; Beltramone, Andrea RaquelThis work addresses the bio-waste valorization approach for the development of a novel carbonaceous nanomaterial to be used in the adsorption of hydrogen as an alternative in the use of green hydrogen. In this research, activated carbons were synthesized orange peel using different synthesis conditions. With the activated carbons obtained with the best structure and texture, the adsorption of hydrogen and the effects on their meso / microporosity were studied. The activation of the carbon was carried out by means of a chemical process with phosphoric acid as activating agent, varying the acid concentration, the substrate / activating agent ratio, and the contact time between them. The best support was obtained using a carbonization time of 1 h, a carbonization temperature of 470oC, a phosphoric acid concentration of 50% by weight and a BET area of ??1402 m2 / g. Said material significantly improved H2 storage behaviour compared to CMK-3 type nanostructured carbon (3.1% by weight at -196,15 oC and 10 bar). The synthesized material shows promise in absorbing hydrogen by weak binding forces (physisorption).Item Esterification of succinic acid using sulfated zirconia supported on SBA-15(2021) Aguzin, Federico L.; Martínez, María Laura; Beltramone, Andrea Raquel; Padró, Cristina L.; Okulik, NoraCatalytic esterification of succinic acid with ethanol to obtain diethyl succinate (DES), a nontoxic plasticizer, is reported. Three sulfated zirconias supported on SBA-15 [SZ-SBA-15(X)] with Si/Zr molar ratios (X) of 10, 20, and 30 were syn- thesized and characterized. N2 adsorption/desorption isotherms and X-ray dif- fraction patterns evidenced preservation of the ordered mesoporous structure of the catalysts after incorporation of Zr. Yields of DES greater than 85 % were obtained at the final reaction time by using SZ-SBA-15(10) and SZ-SBA-15(20) catalysts, which were higher than those achieved with Amberlyst 36. Reuse of the SZ-SBA-15(20) catalyst showed that, even though the structure of the support was preserved, decreases in sulfur concentration and in the DES yield occurred.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.Item Influence of ti incorporation to bimetallic mesoporous carbon in the production of 2,5‑dimethylfuran from biomass derivatives(2021) Ledesma, Brenda Cecilia; Juárez, Juliana María; Domine, Marcelo E.; Beltramone, Andrea RaquelMonometallic and bimetallic supported catalysts were developed to produce 2,5-dimethylfuran (DMF) trough hydrogenolysis of 5-(hydroxymethyl)furfural (HMF). Detailed physicochemical characterization was done to understand structure–activity correlation. Through a series of experiments and comparatives tests, the synergistic effect among Pt, Ir, and Ti incorporated in the support was investigated. Results revealed that using the titanium contained ordered mesoporous carbon, synthesized by a novel technique, high selectivity to DMF was achieved. In the case of the best catalyst PtIr-TiC, the good activity and excellent selectivity to the desired product DMF (98% yield) was related to the high hydrogenating capacity of the bimetal- lic sites, the acid support characteristics and the high metal nanoparticles dispersion achieved on the mesoporous titanium modified carbon support.Item Hydrodenitrogenation of indol using iridium catalyst 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. Titaniun 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, XPS, TEM, Py- FTIR and H2-Chemisorption. XRD, N2 isotherms and UV–vis-DRS confirmed 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 Bronsted acidity compared with TiO2 iridium catalyst. Ir-TNT was the most active catalyst for indole HDN, in mild conditions in a Batch reactor. The Bronsted acidity in synergic effect with Lewis acidity and hydrogenolysis capacity of iridium species were the responsible for the good activity.The HDN of indole was studied over iridium modified titanate nanotube catalyst. Titaniun 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, XPS, TEM, Py- FTIR and H2-Chemisorption. XRD, N2 isotherms and UV–vis-DRS confirmed 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 Bronsted acidity compared with TiO2 iridium catalyst. Ir-TNT was the most active catalyst for indole HDN, in mild conditions in a Batch reactor. The Bronsted acidity in synergic effect with Lewis acidity and hydrogenolysis capacity of iridium species were the responsible for the good activity.Item Activated carbons synthetized from orange peel to produce clean energy(2022) Rivoira, Lorena Paola; Gómez Costa, Marcos Bruno; Ledesma, Brenda Cecilia; Beltramone, Andrea RaquelAs we all know, a clean energy revolution is taking place all over the world in pursuit of replacing oil. The present work stands out an environmental point of view by proposing biomass wastes from different industrial areas to produce not only a biofuel but also as raw material to synthetize the catalyst involved in the HDO reaction. In this way the process ceases to rely on the antiquated and obsolete linear economy where products, services, wastes, materials, water and energy have a beginning and an end to become a process with greater tendency to the modern circular economy, closely related to the idea of sustainability. Products, materials and resources are expected to last as long as possible while minimizing waste as much as possible too. Agricultural and forestry waste are available everywhere being a low cost raw material and it is possible to provide added value to the organic wastes of small and medium size enterprises. The hydrodeoxygenation (HDO) of guaiacol has been performed in a batch reactor under 12 atm of H2 and different temperatures over activated carbon synthetized from orange peel discarded from juice industry. Carbon activation was carried out through a chemical process with phosphoric acid as an activating agent, varying the acid concentration, the ratio substrate/activating agent and time of contact between them. The best support was obtained using carbonization time of 1 h, temperature of carbonization of 470oC, phosphoric acid concentration of 50 wt.% and with BET area of 1429 m2/g. Subsequently, the metallic nanoparticles were deposited in the activated carbon to use the solid as a catalytic material for the hydrodeoxygenation of guaiacol. The catalytic material was modified with metallic nanoparticles of Pt. The catalysts were characterized by means of X-ray diffraction, N2 isotherms, XPS, SEM and TEM. Good structure, narrow pore size distribution and high platinum dispersion were achieved in the synthesized catalysts. The objective of this investigation is the evaluation of the catalytic activity and to compare it with SBA-15 support studied previously. The catalyst presented excellent performance for biofuels generation.Item HDT process performance over noble metal-mesoporous catalysts(2022) Vallés, Verónica Alejandra; Ledesma, Brenda Cecilia; Beltramone, Andrea RaquelThe greater concentration of market demand in the diesel range forces refiners to consider redirecting internal refinery cuts to new hydrocracking units to increase the contribution to the gasoline and diesel pool. These requirements drive advances particularly in hydrotreating technologies (HDT). The need to reduce the level of sulfur and polyaromatics in diesel fuel to values ??of a few ppm and the need to process heavy cuts with a high degree of aromaticity has motivated the appearance of new, more efficient processes. In recent years, bimetallic catalysts have received much attention, since they can combine two or more functions. The functionality of a catalyst can be due to active sites generated by supported metals and the interaction with the support. Pt-Pd catalysts have been extensively studied in order to improve tolerance to sulfur and other contaminants. They showed higher activity, stability and resistance to poisons compared to monometallic Pt or Pd catalysts. In bimetallic catalysts, the formation of the alloy creates electrondeficient species, more resistant to poisoning, in the case of Pd, which alone or alloyed with Pt, has a high hydrogenating and thio-resistant capacity and has begun to be used in industrial dearomatization units. The objective of this work is to evaluate the activity of all the synthesized catalysts in typical catalytic hydrotreating reactions. Performing first a kinetic study in a Batch reactor to the best catalysts that will then be tested in a continuous flow reactor in operating conditions close to industrial ones. With this objective, catalysts supported on SBA-16 were synthesized. This mesoporous has a high surface area and good characteristics of thermal stability, against the conditions set. The support was modified by incorporating Al indirectly and then impregnated with Ir, Pt and Pd. The behavior of the synthesized catalysts was studied against a commercially used catalyst and another support widely used in the industry, such as alumina. The catalysts were characterized by XRD, FTIR, NMR, TPR and N2 adsorption- desorption isotherms.