Facultad Regional Córdoba

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Author: search.filters.author.Juárez, Juliana MaríaSubject: search.filters.subject.CMK-3

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    Síntesis y caracterización del material nanoestructurado Fe-CMK-3 utilizado en almacenamiento de hidrógeno
    (Sociedad Argentina de Catálisis, 2019) Venosta, Lisandro F.; Juárez, Juliana María; Gómez Costa , Marcos Bruno; Anunziata, Oscar Alfredo
    En este trabajo, informamos la síntesis y caracterización de nanoclusters de óxido de hierro soportados en el carbón nanoestructurado (CMK-3). Este material es prometedor en la aplicación de almacenamiento y adsorción de hidrógeno para almacenamiento de energía. Los materiales con nanoclusters de óxido de hierro (Fe-CMK-3) se sintetizaron exitosamente y se caracterizaron mediante difracción de rayos X, propiedades texturales y análisis de microscopía electrónica de transmisión. La incorporación de oxidos de hierro mejoró significativamente el comportamiento de almacenamiento de H2 (4,45% en peso a 77K y 10 bar) en comparación con su respectivo soporte (CMK-3). El material sintetizado es prometedor en la adsorción de hidrógeno por fuerzas de enlace débil (fisisorción). Se propuso un mecanismo de adsorción de hidrógeno y los nanoclusters de óxido de Fe en fase de magnetita tienen un rol importante en la absorción de hidrógeno.
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    H2 storage using Zr-CMK-3 developed by a new synthesis method
    (2021) Juárez, Juliana María; Venosta, Lisandro F.; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
    One of the biggest problems in using hydrogen as an alternative fuel is that its storage must be safe and portable. This work addresses a new direct synthesis technique used to obtain a novel mesoporous carbon (CMK-3) modified with zirconium oxide. This novel material shows promise for hydrogen adsorption and storage application for energy harvesting. Zirconium oxide (Zr-CMK-3) material is achieved through successful synthesis and characterized by XRD, SEM, Raman, BET, UV-Vis-DRS, XPS and TEM analyses. Zr-CMK-3 signifi- cantly improved H2 storage performance (reaching at 77 K and 10 bar 4.6 wt%) compared to the pristine CMK-3. The novel material is favorable for H2 uptake by using weak bonding (physisorption). A hydrogen uptake mechanistic approach is proposed and the role of the Zr+4 cation in hydrogen adsorption is discussed.
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    Synthesis and characteristics of CMK-3 modified with magnetite nanoparticles for application in hydrogen storage
    (2022) Juárez, Juliana María; Cussa, Jogelina; Anunziata, Oscar Alfredo; Gómez Costa, Marcos Bruno
    In this work, we report the synthesis and characterization of iron oxide nanoparticles supported in nanostructured carbon (CMK-3). This material is promising in the application of hydrogen adsorption for energy storage. The material with iron oxide nano- particles (Fe-CMK-3) was successfully synthesized and characterized by X-ray diffraction, textural properties analysis, transmission and scanning electron microsco- py, X-ray photoelectron spectroscopy, and magnetiza- tion studies. A large amount of the iron incorporated as iron oxide nanoparticles was in the magnetite phase. The incorporation of magnetite on the CMK-3 carbon surface significantly improved the storage capacity of hydrogen (4.45 wt% at 77 K and 10 bar) compared with the CMK-3 framework alone (2.20 wt% at 77 K and 10 bar). The synthesized material is promising for hy- drogen adsorption by weak bond forces (physisorption). A hydrogen adsorption mechanism was proposed in which the nanoparticles of magnetite have an important role.
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    Iron-modified mesoporous materials as catalysts for ODS of sulfur compounds
    (2020) Rivoira, Lorena Paola; Juárez, Juliana María; Martínez, María Laura; Beltramone, Andrea Raquel
    Fe-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.