Artículos SCI
2023
2023
Fotocatálisis Heterogénea: Aplicaciones
Photocatalytic treatment based on TiO2 for a coal mining drainage
Murcia-Mesa, JJ; Patino-Castillo, CG; Rojas-Sarmiento, HA; Navio-Santos, A; Hidalgo-Lopez, MD; Angel-Botero, ARevista Facultad de Ingeniería-Universidad de Antioquia, 107 (2023) 88-101
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The aim of the present work was to evaluate the effectiveness of a heterogeneous photocatalyst based on TiO2 in the treatment of coal mining drainage which contains a variety of heavy metals and high concentration sulfates and sulfides. The photocatalytic behavior of the commercial reference Sigma Aldrich and the different materials synthesized using the Sol-gel methodology with surface modifications using sulfation and fluorination processes were analyzed. To find a possible correlation between the physicochemical properties of photocatalysts and their behavior, a characterization was carried out using X-Ray Diffraction (XRD), X-Ray Fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance Spectra (UV-Vis DRS), N2 physisorption, X-ray photoelectron spectroscopy (XPS), and particle size analysis. Results indicated that the modification of the TiO2 prepared in the laboratory using sulfation and fluorination allowed the successful control of the physicochemical properties of this oxide. However, commercial TiO2 showed the greatest effectiveness in removing metals such as: Fe, Cu, Cr, and As after a photocatalytic reaction for a maximum of 1 hour under continuous nitrogen flow and a light intensity of 120 W/m2.
Abril, 2023 | DOI: 10.17533/udea.redin.20211063
Química de Superficies y Catálisis
In-situ DRIFTS steady-state study of CO2 and CO methanation over Ni-promoted catalysts
González-Castaño, M; González-Arias, J; Bobadilla, LF; Ruíz-López, E; Odriozola, JA; Arellano-García, HFuel, 338 (2023) 127241
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![](https://icms.us-csic.es/sites/icms.us-csic.es/files/1-s2_409.png)
Promoting the performance of catalytic systems by incorporating small amount of alkali has been proved effective for several reactions whilst controversial outcomes are reported for the synthetic natural gas production. This work studies a series of Ni catalysts for CO2 and CO methanation reactions. In-situ DRIFTS spectroscopy evidenced similar reaction intermediates for all evaluated systems and it is proposed a reaction mechanism based on: i) formate decomposition and ii) hydrogenation of lineal carbonyl species to methane. Compared to bare Ni, the enhanced CO2 methanation rates attained by NiFe/Al and NiFeK/Al systems are associated to promoted formates decomposition into lineal carbonyl species. Also for CO methanation, the differences in the catalysts' performances were associated to the relative concentration of lineal carbonyl species. Under CO methanation conditions and opposing the CO2 methanation results where the incorporation of K delivered promoted catalytic behaviours, worsened CO methanation rates were discerned for the NiFeK/Al system.
Abril, 2023 | DOI: 10.1016/j.fuel.2022.127241
Materiales y Procesos Catalíticos de Interés Ambiental y Energético
Facile Synthesis of Heterogeneous Indium Nanoparticles for Formate Production via CO2 Electroreduction
Perez-Sequera, AC; Diaz-Perez, MA; Angulo, MAL; Holgado, JP; Serrano-Ruiz, JCNanomaterials, 13 (2023) 3052
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In this study, a simple and scalable method to obtain heterogeneous indium nanoparticles and carbon-supported indium nanoparticles under mild conditions is described. Physicochemical characterization by X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed heterogeneous morphologies for the In nanoparticles in all cases. Apart from In-0, XPS revealed the presence of oxidized In species on the carbon-supported samples, whereas these species were not observed for the unsupported samples. The best-in-class catalyst (In-50/C-50) exhibited a high formate Faradaic efficiency (FE) near the unit (above 97%) at -1.6 V vs. Ag/AgCl, achieving a stable current density around -10 mA center dot cm(geo)(-2), in a common H-cell. While In-0 sites are the main active sites for the reaction, the presence of oxidized In species could play a role in the improved performance of the supported samples.
Abril, 2023 | DOI: 10.3390/nano13081304
Reactividad de Sólidos
Electrical performance of orthotropic and isotropic 3YTZP composites with graphene fillers
Lopez-Pernia, C; Muñoz-Ferreiro, C; Moriche, R; Morales-Rodriguez, A; Gallardo-Lopez, A; Poyato, RJournal of The European Ceramic Society, 43 (2023) 1605-1612
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3 mol% yttria tetragonal zirconia polycrystal (3YTZP) composites with orthotropic or isotropic microstructures were obtained incorporating few layer graphene (FLG) or exfoliated graphene nanoplatelets (e-GNP) as fillers. Electrical conductivity was studied in a wide range of contents in two configurations: perpendicular (sigma(perpendicular to)) and parallel (sigma(//)) to the pressing axis during spark plasma sintering (SPS). Isotropic e-GNP composites presented excellent electrical conductivity for high e-GNP contents (sigma(perpendicular to)similar to 3200 S/m and sigma(//) similar to 1900 S/m for 20 vol% e-GNP), consequence of their misoriented distribution throughout the matrix. Optimum electrical performance was achieved in the highly anisotropic FLG composites, with high electrical conductivity for low contents (sigma(perpendicular to) similar to 680 S/m for 5 vol%), percolation threshold below 2.5 vol% FLG and outstanding electrical conductivity for high contents (sigma(perpendicular to) similar to 4000 S/m for 20 vol%), result of the high aspect ratio and low thickness of FLG.
Abril, 2023 | DOI: 10.1016/j.jeurceramsoc.2022.11.068
Materiales de Diseño para la Energía y Medioambiente
The Role of Protective Surface Coatings on the Thermal Stability of Delithiated Ni-Rich Layered Oxide Cathode Materials
Reissig, F; Ramirez-Rico, J; Placke, TJ; Winter, M; Schmuch, R; Gomez-Martin, ABatteries-Basel, 9 (2023) 245
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To achieve a broader public acceptance for electric vehicles based on lithium-ion battery (LIB) technology, long driving ranges, low cost, and high safety are needed. A promising pathway to address these key parameters lies in the further improvement of Ni-rich cathode materials for LIB cells. Despite the higher achieved capacities and thus energy densities, there are major drawbacks in terms of capacity retention and thermal stability (of the charged cathode) which are crucial for customer acceptance and can be mitigated by protecting cathode particles. We studied the impact of surface modifications on cycle life and thermal stability of LiNi0.90Co0.05Mn0.05O2 layered oxide cathodes with WO3 by a simple sol-gel coating process. Several advanced analytical techniques such as low-energy ion scattering, differential scanning calorimetry, and high-temperature synchrotron X-ray powder diffraction of delithiated cathode materials, as well as charge/discharge cycling give significant insights into the impact of surface coverage of the coatings on mitigating degradation mechanisms. The results show that successful surface modifications of WO3 with a surface coverage of only 20% can prolong the cycle life of an LIB cell and play a crucial role in improving the thermal stability and, hence, the safety of LIBs.
Abril, 2023 | DOI: 10.3390/batteries9050245
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