UTN- FRC -Producción Académica de Investigación y Desarrollo
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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 EXperimental design optimization of the ODS of DBT using vanadium oXide supported on mesoporous Ga-SBA-15(2020) Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Beltramone, Andrea RaquelEXperiment design-response surface methodology is applied in this work to model and optimize the o Xidation of dibenzothiophene (DBT) using VOX-Ga-SBA-15 catalyst. The analyzed variables are the influence of the nature of the catalyst (V and Ga loading), the s ubstrate/catalyst mass ratio (g DBT/g of catalyst) and the o Xidant/substrate molar ratio (H2O2/DBT). The response analyzed is conversion of DBT at 15 min of reaction time. A set of re- sponse surfaces were obtained applying the BoX-Behnken Design. Based on statistical methodology it was pos- sible to find the best arrangement between the amounts of the gallium heteroatom and the vanadium active species. The higher levels of the objective function were obtained employing the catalyst with 4 wt.% of gallium and 6 wt.% of vanadium; the optimal ratio between g DBT/g of catalyst was 4 and the molar ratio between H2O2/DBT was 5. Gallium incorporation as heteroatom in tetrahedral position allowed the better anchorage ofthe active species of vanadium, generating a very well dispersed catalyst. The optimized catalyst minimized the mass transfer limitation and moreover, was active after several recycles. The best catalyst was likewise very active for the oXidation of the most refractory sulfur compounds as benzothiophene and 4,6-dimetyldi- benzothiopene.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 Iridium-supported SBA-15 modified with Ga and Al as a highly active catalyst in the hydrodenitrogenation of quinoline(2020) Ledesma, Brenda Cecilia; Martínez, María Laura; Beltramone, Andrea RaquelIr-supported SBA-15 was studied in the hydrodenitrogenation (HDN) of quinoline as a model nitrogen com- pound. The activity was improved when Si-SBA-15 support was modified with Ga and Al. Characterization of the catalysts was performed by XRD, N2 adsorption, XPS, H2 chemisorption, TEM, TPR, NMR and Py-FTIR. Dispersion and nature of the iridium species are dependent parameters on the support characteristics. Better activity for the elimination of the nitrogen atom was observed with Ir-Ga-SBA-15 as compared to Ir-Al-SBA-15 at 250 and 300 °C. However, the TON value for Ir-Al-SBA-15 was higher than Ir-Ga-SBA-15 at 300 °C, indicating the influence of the stronger Bronsted acidity in the elimination of the nitrogen atom at higher temperature. The enhanced activity was attributed to the particularly good dispersion of the iridium catalytic centers and to the synergic effect of Bronsted and Lewis acid sites, derived from Ga or Al incorporation. Ga-SBA-15 with 1 wt.% of iridium loading was the most active catalyst for HDN of quinoline. 95% of nitrogen elimination was attained at short time in mild conditions. The reusability of the catalyst presents it as potential catalyst for HDN process.Item Iron-modified mesoporous materials as catalysts for ODS of sulfur compounds(2020) Rivoira, Lorena Paola; Juárez, Juliana María; Martínez, María Laura; Beltramone, Andrea RaquelFe-modified mesoporous catalysts were used in the ODS of DBTs using H2O2 as oXidant and acetonitrile as solvent. SBA-15, MCM-48, CMK-3 and CMK-1 were used as supports. Iron was incorporated using iron nitrate by wetness impregnation. The catalysts were characterized by XRD, N2 isotherms, TEM, XPS and ICP. We developed catalysts with high specific surface area, pore volume and narrow mesopore size distribution and highly dis- persed Fe- species. The catalysts were tested in the o Xidative desulfurization of different sulfur compounds as benzothiophene, dibenzothiopene and 4,6-dimethyl dibenzothiopene. The catalyst prepared using CMK-3 as support was the most active for the ODS reaction. The good activity was related with the high dispersion of the iron oXides, mainly in the magnetite phase. Temperature, hydrogen peroXide and sulfur initial concentration were studied using Fe-CMK-3 in the oXidation of DBT. The optimal operation conditions were determined. Fe- CMK-3 is an active and stable catalyst to be applied in the industrial process of ODS.Item Multiple-wall carbon nanotubes obtained with mesoporous material decorated with ceria-zirconia(2020) Rodríguez, Miguel Angel; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel; Martínez, María LauraIn this work, Ceria-Zirconia on ordered Santa Barbara mesoporous silica (Ce-Zr-SBA-15), has been used directly as a catalyst for the synthesis of carbon nanotubes (CNTs) through Chemical Vapor Deposition (CVD). In addition to cerium oxide, it contains zirconium oxide nano crystallites, which act as catalysts for carbon nanostructures. The catalytic performance of this material was evaluated for the decomposition of ethanol at 900 °C, with N2 flow. The carbon decomposed from absolute ethanol diffuses through the surface of the nanostructured catalytic material and precipitates in the form of MWCNT structures, which could be identified by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), showing average diameters of 30–35 nm.Item Short time synthesis of titania modified-CMK-3 carbon mesostructure as support for Ir-catalyst applied in catalytic hydrotreating(2020) Ledesma, Brenda Cecilia; Juárez, Juliana María; Beltramone, Andrea RaquelTi-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The method developed here, allows to reduce time, energy consumptionand cost. Structural and textural characterization of the titanium modified-mesoporous carbonwas performed by N2 adsorption, XRD, UV–vis-DRS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modi fied-mesoporous carbon was used as support of the iridium nanoparticles, in order to prepare a catalyst to be tested in model hydrotreating reactions. The catalyst obtained by wet impregnation with iridium acetylacetonate were characterized by ICP -AES, H2 chemisorption, TEM, XPS and FTIR of adsorbed pyridine. The high Ir dispersion and small particle size, along with the moderate Lewis acidity generated by the presence of titanium in the support, were responsible for the good performance and stability of the catalyst in the hydrogenation of tetralin in presence of nitrogen com - pounds. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for HDT reactions.