Browsing by Author "Blanco, Elodie"
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- ItemAlkali-Boosted Catalytic Activity of Co-Based Catalysts Supported by Nanoporous Carbon in the Hydrodeoxygenation of Guaiacol(2025) Matos, Juan; Samudio González, Diana; Blanco, Elodie; Poon, Po S.; Escalona Burgos, Néstor GuillermoThe catalytic activity and selectivity of Co-based catalysts supported on home-made nanoporous carbon was studied as a function of the type of alkali promoter (Ca and Mg). The catalysts were characterized by N2 adsorption/desorption isotherms, temperature-programmed reduction, CO chemisorption, and X-ray diffraction patterns. The catalysts were compared against carbon-supported alkali-promoted Ni-based catalysts and Re-containing catalysts. The catalytic activity of the Co-based catalyst was clearly enhanced in the presence of Ca and Mg, and it was higher than the Ni-based catalysts and comparable to that obtained using an ReC catalyst. The initial activity of the Mg-promoted catalyst increased by a factor of up to 2.5 times higher compared to the non-promoted catalyst. Moreover, this catalyst showed a turnover frequency of up to 5 times higher than equivalent carbon-supported Re-based catalysts. Significant changes were not observed in the selectivity of products after the incorporation of alkali, with cyclohexane being the main product. However, it was demonstrated that the presence of alkali led to a faster and higher production of cyclohexane from the demethoxylation of phenol and the dehydrogenation of cyclohexanol. The present results suggest that Co-based catalysts are an economical alternative for the catalytic conversion of representative target molecules from bio-oil feed.
- ItemAlkali-driven selectivity of products on carbon-supported Ni-based catalysts during the HDO of guaiacol(2024) Matos, Juan; Samudio-González, Diana; Blanco, Elodie; Poon, Po S.; Escalona Burgos, Néstor GuillermoThe catalytic hydrodeoxygenation (HDO) of guaiacol as a representative bio-oil molecule was studied using a series of carbon-supported Ni-based catalysts. The promoter effect of alkali metals (Ca and Mg) on the catalytic activity and selectivity was verified. Catalysts were prepared by wetness incipient method and N2 gas adsorp tion/desorption isotherms, X-ray diffraction, reduction/desorption temperature-programed, and CO chemi sorption analysis were performed to characterize the catalysts. In terms of the initial reaction-rate catalysts with 1 wt% alkali-promotors showed an increase in the activity up to ca. 1.4 and 1.2 times higher on Ni-Ca(1 %)/AC and Ni-Mg(1 %)/AC, respectively, compared to Ni/AC catalyst. The increase to 5 wt% in alkali promotors slightly reduced the initial activity of Ni. However, the turn-over frequencies estimated showed higher values when alkali content is increased from 1 wt% to 5 wt%. These apparent contradictorial results suggest the formation of new actives sites along reaction, probably constituted by a mixture of oxides NiO-CaO and NiO-MgO. The selectivity of products showed remarkable changes due to the presence of alkali-promotors and a mechanism or reaction is proposed based on the kinetics of formation and evolution of products. Mg-promoted led to the formation of cyclohexane. On the contrary, Ca-promoted catalysts led the mechanism to representative benzene yields. This is remarkable result regarding the efficiency of a HDO biorefinery. In general, it can be concluded that Ni-based catalysts promoted with alkali metals are an economical alternative for the catalytic conversion of representa tive target molecules from a bio-oil feed.
- ItemBiomass and CO2-Derived Fuels Through Carbon-Based Catalysis. Recent Advances and Future Challenges(2023) Peixoto, Andreia F.; Fernandes, Diana M.; Dongil, Ana Belén; Blanco, Elodie; Freire, Cristina
- ItemConversion of guaiacol over metal carbides supported on activated carbon catalysts(2019) Blanco, Elodie; Sepúlveda, C.; Cruces, K.; García-Fierro, José Luis; Ghampson, Isaac Tyrone; Escalona, Néstor
- ItemConversion of Levulinic Acid over Ru/SrZrO 3 and Ru/BaZrO 3 Supported Basic Catalysts(2023) Leal Villarroel, Edgardo; Seguel, Juan; Rodríguez, Pedro; Blanco, Elodie; Escalona, Néstor; Pecchi, Gina; Sepúlveda, Catherine
- ItemEffect of carbon support and functionalization on the synthesis of rhenium carbide and its use on HDO of guaiacol(2023) Blanco, Elodie; Cabeza, Paula; Naharro Ovejero, Verónica; Contreras, Claudio; Dongil, Ana Belén; Ghampson, Isaac Tyrone; Escalona, Néstor
- ItemEffect of Pyrolysis Temperature on Copper Aqueous Removal Capability of Biochar Derived from the Kelp Macrocystis pyrifera(MDPI, 2021) Araya, Matias; Rivas, Jorge; Sepulveda, Graciela; Espinoza Gonzalez, Camila; Lira, Sebastian; Meynard, Andres; Blanco, Elodie; Escalona, Nestor; Ginocchio, Rosanna; Garrido Ramirez, Elizabeth; Contreras Porcia, LorettoSeaweed biochar is an efficient alternative bioadsorbent for Cu2+ removal due to its low cost and heavy metal removal capacity. Using the slow pyrolysis process, we produced biochars from Macrocystis pyrifera at 300 (BC300), 450 (BC450), and 600 & DEG;C (BC600). The physicochemical and structural properties of the biochar samples improved with increasing pyrolysis temperature from 300 to 450 & DEG;C, whereas no significant differences were observed with further increases in temperature to 600 & DEG;C. The yield ranged between 49% and 62% and had a high ash content (57.5-71.1%). BC450 and BC600 presented the highest surface areas and higher porosities. The FTIR spectra indicated that an increase of temperature decreased the acidic functional groups due to depolymerization and the dehydration processes, increasing the aromatic structures and the presence of calcium carbonate. The fittings of the kinetic models were different for the BCs: for the BC450 and BC600 samples, the Cu2+ adsorption was well-represented by a pseudo-first-order model; for BC300, a better fit was obtained with the pseudo-second-order model. The rate-limiting step of Cu2+ adsorption on BCs was represented by both models, liquid film diffusion and intraparticle diffusion, with surface diffusion being more important in BC300 and BC600, and intraparticle diffusion in BC450, in agreement with the pore size of the biochar samples. The adsorption isotherms of all BCs showed Langmuir behavior, representative of a chemisorption process, which was corroborated by the energy adsorption values determined by the D-R model. The maximum monolayer Cu2+ adsorption capacities were 93.55 and 58.0 mg g(-1) for BC600 and BC450, respectively, whereas BC450 presented the highest affinity. Other mechanisms involved in controlling heavy metal removal from aqueous suspensions using these seaweed biochars remain to be explored. We conclude that BC450 and BC600 from M. pyrifera are the most efficient adsorbents for Cu2+ aqueous removal and are thus an appropriate alternative for bioremediation.
- ItemEffect of the Carbon Support and Conditions on the Carbothermal Synthesis of Cu-Molybdenum Carbide and Its Application on CO2 Hydrogenation to Methanol(2022) Dongil, Ana Belén; Blanco, Elodie; Villora-Pico, Juan José; Sepúlveda-Escribano, Antonio; Rodríguez-Ramos, Inmaculada
- ItemEffect of the Support Functionalization of Mono- and Bimetallic Ni/Co Supported on Graphene in Hydrodeoxygenation of Guaiacol(2021) Blanco, Elodie; Carrales-Alvarado, Damarys; Dongil, Ana Belén; Escalona, Néstor
- ItemEffect of the Support on Rhenium Carbide in the Hydrodeoxygenation of Guaiacol as Lignin-Derived Model Compound(2022) Blanco, Elodie; Dongil, Ana Belén; Ghampson, Isaac Tyrone; Escalona, Néstor
- ItemElectrodes based on zeolites modified with cobalt and/or molybdenum for pesticide degradation: part II-2,4,6-trichlorophenol degradation(2021) Castro, Jorge; Fernandez, Francisco; Olivares, Felipe; Berrios, Cristhian; Garrido-Ramirez, Elizabeth; Blanco, Elodie; Escalona, Nestor; Aspee, Alexis; Barrias, Pablo; Soledad Ureta-Zanartu, M.2,4,6-trichlorophenol (TCP) is a persistent pollutant introduced in water by industrial processes and pesticides. We have studied the electrooxidation of TCP on glassy carbon (GC) electrodes drop-coated with a suspension containing Mo- and/or Co-modified zeolite, graphite, and Nafion (R) perfluorinated ion-exchange resin in distilled water. Three zeolites, Linde type A (ZA), Faujasite (ZY) and MFI (ZSM-5), of different hydrophilic/hydrophobic character, were modified with molybdenum and/or cobalt by the wet impregnation method and characterized by Fourier-transform infrared spectroscopy with attenuated total reflection and temperature programmed reduction. The electrochemical study included cyclic voltammetry, electrochemical impedance spectroscopy, and electrolysis at controlled potential. High performance liquid chromatography and mass spectrometry allowed detecting the following reaction products: 2,6-dichloro-1,4-benzoquinone, 2,6-dichloro-1,4-hydroquinone, 3,5-dichloro-2-hydroxy-1,4-benzoquinone, and malic, maleic, picric, and acetic acids. A maximum degradation of about 90% was reached after 4 h of electrolysis at 0.83 V vs Ag/AgCl/KCl 3 M, using a GC/graphite-ZSM5(Mo) electrode. The electrodes modified with Mo, and especially that with ZSM5, the most hydrophobic zeolite, were active for the degradation of TCP. We conclude that the main role of the Mo species is to catalyze the hydrogen peroxide decomposition yielding reactive singlet oxygen, as evidenced by the pink color of 3,5-dichloro-2-hydroxy-1,4-benzoquinoneand confirmed by mass spectrometry.
- ItemInsights in supported rhenium carbide catalysts for hydroconversion of lignin-derived compounds(2020) Blanco, Elodie; Dongil, Ana Belén; García-Fierro, José Luis; Escalona, Néstor
- ItemModification of a commercial activated carbon with nitrogen and boron: Hydrogen storage application(2023) Morande, Arturo; Lillo, Patricio; Blanco, Elodie; Pazo, Cesar; Belen Dongil, Ana; Zarate, Ximena; Saavedra-Torres, Mario; Schott, Eduardo; Canales, Roberto; Videla, Alvaro; Escalona, NestorThe present study evaluates the effect of heteroatom doping (N and B) and thermal treatment modification of activated carbon, in different sequences over hydrogen storage capacity. All the materials were characterized by N2-physisorption, XRD, TPD, and XPS. H2 adsorption was measured at-196 degrees C and correlated with physico-chemical properties, while a density-functional theory model was employed to analyze the hydrogen adsorp-tion. Results have shown that there is an effect of the modification order on the storage capacity, which was related to increments of the specific surface area or the nature of the functional groups. An optimum nitrogen doping temperature was detected at 500 degrees C and was associated with the presence of pyridone groups. This sample had the highest hydrogen capacity ca. 2.34 % at 0.93 bar. Such value was extrapolated to 7.86 wt% at 30 bar using the Dubinin-Astakhov adsorption model, making it a promising material for hydrogen storage.
- ItemOptimizing the carburization conditions of supported rhenium carbide for guaiacol conversion(2021) Blanco, Elodie; Dongil, Ana Belén; Ghampson, Isaac Tyrone; García-Fierro, José Luis; Escalona, Néstor
- ItemProducción de hidrógeno mediante reformado en fase acuosa de etanol utilizando carburos de molibdeno soportados en zirconia(2023) Pavesi Contreras, Camila Andrea; Escalona, Néstor; Blanco, Elodie; Pontificia Universidad Católica de Chile. Escuela de IngenieríaLa creciente crisis climática genera la necesidad de buscar alternativas sustentables a los combustibles fósiles. El H2 tiene un gran potencial como vector energético y puede ser producido desde fuentes renovables como el etanol, un derivado de desechos de biomasa. En esta Tesis, se estudian catalizadores de carburo de molibdeno soportados en óxido de zirconia monoclínica y tetragonal para producir H2 mediante reformado en fase acuosa de etanol. Los catalizadores se caracterizan por fisisorción de N2, DRX, TPR y XPS. Los resultados indican que mientras mayor es la carburización, más activo es el catalizador. Además, 10%Mo es el contenido metálico que alcanza la mayor selectividad a H2, lo que se atribuye a la presencia de oxicarburos en su superficie. Se alcanza el mejor desempeño en el APR a 250°C y 10%Mo2C/ZrO2 es estable durante 5 reacciones con reciclo, a pesar de una leve pérdida de selectividad a H2. Se concluyó que la fase cristalina α del molibdeno es más activa que la β debido a que alcanza una mayor dispersión de la fase activa. Sin embargo, produce menos H2, dada la menor cantidad de oxicarburos sobre su superficie. La temperatura ideal de carburización del catalizador son 650°C puesto que un aumento de 50°C perjudica el desempeño en el APR. Los resultados están en concordancia con la literatura. Finalmente, se cumplen los objetivos propuestos para este trabajo y se concluye que el mejor catalizador para la producción de H2 mediante APR de etanol es 10%Mo2C/ZrO2.
- ItemStudy of supported bimetallic MoRe carbides catalysts for conversion(2021) Blanco, Elodie; Diaz de León, J. Noe; García-Fierro, José Luis; Escalona, Néstor
- ItemSynergy between Ni and Co Nanoparticles Supported on Carbon in Guaiacol Conversion(2020) Blanco, Elodie; Dongil, Ana Belén; Escalona, Néstor
- ItemTheoretical and Experimental Study for Cross-Coupling Aldol Condensation over Mono- and Bimetallic UiO-66 Nanocatalysts(2023) Pazo Carballo, César Alexander; Blanco, Elodie; Camu, Esteban; Leiva Campusano, Ángel; Hidalgo-Rosa, Yoan; Zarate, Ximena; Dongil, Ana Belén; Schott Verdugo, Eduardo Enrique; Escalona, NéstorMono- and bimetallic UiO-66 nanocatalysts were synthesized using the solvothermal synthesis method and evaluated in the aldol condensation reaction of benzaldehyde and acetone in a batch reactor. N2 physisorption, thermogravimetric analysis, temperature-programmed desorption of ammonia, X-ray diffraction, field-emission scanning electron microscopy–energy-dispersive X-ray, X-ray photoelectron spectroscopy, potentiometric titration, and Fourier transform infrared were used to characterize the nanocatalysts. The higher activity exhibited by the Zr/Hf-UiO-66 catalyst could be attributed to the lower orbital energy interaction with benzaldehyde, as shown by density functional theory. A synergetic effect is observed for the bimetallic UiO-66 nanocatalyst between Zr and Hf, obtaining a higher reaction rate than the monometallic nanocatalysts. Meanwhile, this antagonistic effect was shown in the bimetallic catalysts between Zr and Ce, which was less active than the monometallic UiO-66 catalyst due to free COOH generated during the synthesis. Finally, the selectivity results showed that incorporating Hf and Ce on Zr-UiO-66 favors benzalacetone formation by cross-coupling condensation of benzaldehyde and acetone at isoconversion conditions.