Facultad Regional Córdoba
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Item Direct synthesis of ordered mesoporous carbon applied in hydrogen storage(Springer Science+Business Media, 2018) Juárez, Juliana María; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoIn this work, we present a direct, novel and low cost method for the preparation of an ordered mesoporous carbon (OMC). OMC was successfully synthesized by the carbonization of the silica/triblock copolymer/sucrose composite in the presence of sulfuric acid. The resulting material was characterized by XRD, N2 sorption analysis and TEM techniques. The novel synthesis technique improved significantly the H2 storage properties (3.78 wt%) compared with that of CMK-3 synthesized using the nanocasting strategy (2.2 wt%) at 77 K and 10 bar.Item Nanoclusters of iron oxice included in CMK-3mesoporous carbon use as hydrogen storage material(Materials Research Society, 2019) Juárez, Juliana María; Venosta, Lisandro F.; Gómez Costa , Marcos Bruno; Anunziata, Oscar AlfredoIn this work we studied the influence of the incorporation of iron oxide nanoparticles inside the channels of the nanostructured mesoporous carbon CMK-3. This research includes synthesis of the mesoporous silicate and synthesis of CMK-3 by nanocasting strategy, incorporation of the iron oxide nanoclusters by wetness impregnation, characterization of these nanomaterials by XRD, N2 adsorption, XPS, and TEM, and study of the improvement in hydrogen adsorption. This material is promising in hydrogen adsorption and storage application for energy harvesting. According to XRD studies, the incorporation of oxide nanoclusters does not compromise the overall structure of the mesoporous carbon CMK-3. In the wide angle region it has been found typical reflections of iron oxide corresponding to the magnetite phase (Fe2+Fe3+ 2 O4). The modified sample Fe-CMK-3 reveal a reduced specific surface area and smaller pore diameter compared to pristine CMK-3 which involves the formation of magnetite nanoparticles within the mesoporous channels of CMK-3. TEM images of Fe-CMK-3 presents metallic oxide nanoparticles well dispersed. The incorporation of iron oxide nanoparticles improved significantly the H2 storage behavior (4.45% wt at 77K and 10 bar) compared to its respective support (CMK-3). Magnetite nanoclusters increased the capacity of hydrogen adsorption in pristine materials. Supposing that weakly orbital interactions occur between H2 and the metal nanocluster, physisorption is the main interaction, all cases have the potential to uptake H2 weakly as physisorption process and the last interaction achieves sufficiently strong energies to store more hydrogen to reach the level adsorption in Fe-CMK-3. In addition, no hydrogen chemisorption was detected. The materials synthesized are promising in hydrogen uptake by weak link forces (physisorption).Item Sustainable utilization of orange peels waste for preparation of activated carbon: Synthesis, Characterization and Hydrogen storage application(2022) Juárez, Juliana María; Ledesma, Brenda Cecilia; Beltramone, Andrea Raquel; Gómez Costa, Marcos Bruno; Anunziata, Oscar AlfredoThe 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 470oC, 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 m2 /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 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)