UTN- FRC -Producción Académica de Investigación y Desarrollo - Artículos

Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/2453

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Author: search.filters.author.Martínez, María LauraSubject: search.filters.subject.Synthesis

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    Influence of vanadium nanoclusters in hydrogen uptake using hybrid nanostructured materials
    (Springer Science+Business Media, 2018) Juárez, Juliana María; Gómez Costa , Marcos Bruno; Martínez, María Laura; Anunziata, Oscar Alfredo
    In this work, we report the synthesis and characterization of vanadium oxide nanoclusters (V2O5) supported in silica nano- structured material (SBA-15) and nanostructured carbon (CMK-3). This material is promising in hydrogen adsorption and storage application for energy harvesting. The materials with vanadium oxide nanoclusters (VxOy-SBA-15 and VxOy-CMK-3) were successfully synthesized and characterized by X-ray diffraction, textural properties, UV–Vis-DRS, X-ray photoelec- tron spectroscopy, temperature programmed reduction and transmission electron microscopy analyses. VxOy-SBA-15 and VxOy-CMK-3 improved significantly the H2 storage behavior (1.33 wt% and 3.43 wt% at 77 K and 10 bar) compared with their respective supports SBA-15 and CMK-3. The materials synthesized are promising in hydrogen uptake by weak link forces (physisorption). A mechanism of hydrogen adsorption was proposed and V5+ cation roll in hydrogen uptake was discussed
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    Optimización de la sínstesis del material mesoestructurado SBA-3 mediante diseño experimental
    (CICat, 2016) Ponte , María Virginia; Rivoira, Lorena Paola; Cussa, Jorgelina; Martínez, María Laura; Beltramone, Andrea Raquel
    hexagonal, diámetro de poro >3nm; presenta alta área superficial y alto volumen de poro. Se utilizó la metodología de Superficie de Respuesta para el modelado y optimización de las condiciones de síntesis de SBA‐3. Se analizaron como factores del Diseño la influencia de la relación molar entre el surfactante (CTAB) y la fuente de silicio (TEOS), el tiempo de envejecimiento, la temperatura y el pH de la síntesis utilizando HCl. La respuesta analizada fue la intensidad de difracción de rayos X para el plano [100]. Las superficies de respuestas se obtuvieron con el diseño Box–Behnken, buscando la combinación de los parámetros que dieran como resultado la mejor estructura en el material sintetizado. Mediante la aplicación de metodología estadística, los mayores valores de la función objetivo (intensidad de DRX para el plano [100]) se obtuvieron utilizando valores de la relación molar CTAB/TEOS de 0,07‐0,16; HCl/TEOS de 8‐11; temperatura de síntesis de 35‐45 (ºC) y tiempos de envejecimiento de 12‐24hr.
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    Multiple-wall carbon nanotubes obtained with mesoporous material decorated with ceria-zirconia
    (2020) Rodríguez, Miguel Angel; Anunziata, Oscar Alfredo; Beltramone, Andrea Raquel; Martínez, María Laura
    In 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.