Artículos (Química Inorgánica)
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Artículo Reactive Surface Explored by NAP-XPS: Why Ionic Conductors Are Promoters for Water Gas Shift Reaction(American Chemical Society, 2024) García Moncada, Nuria; Penkova, Anna Dimitrova; González Castaño, Míriam; Odriozola Gordón, José Antonio; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). EspañaNear-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) experiments have been carried out in N2 and N2-H2O atmospheres on a Pt-based catalyst physically mixed with an Eu-doped ZrO2 ionic conductor as a function of temperature under realistic conditions of the water gas shift (WGS) reaction. This work aims to demonstrate the significant effect of having active H2O on the ionic conductor surface at reaction temperatures to provide it to Pt metal sites. The ionic conductor, Eu-doped zirconia matrix, presents defects (oxygen vacancies, Ov) that allows upon H2O dissociation the formation of a hydrogen-bonded molecular water layer favoring diffusion through a Grotthuss mechanism below 300 °C. In the presence of H2O, the Ov are occupied by hydroxyl species as observed in the Eu 4d spectra, which differentiate two types of Eu oxidation states. The Eu3+-to-Eu2+ atomic ratio increases with the occupancy of the Ov by hydroxyls. Moreover, while the Pt-based catalyst alone is unable to create Pt-OH bonds, the physical mixture of the Pt-based catalyst and the ionic conductor allows the formation of Pt-OH bonds from room temperature up to 300 °C. These data demonstrate that the increase in molecular water concentration on the ionic conductor surface up to 300 °C acts as a reservoir to provide water to the Pt surface, enhancing the catalyst performance in the WGS reaction, supporting the importance of the surface H2O concentration in the reaction kinetics.Artículo Pressureless Sintering Kinetics Analysis of Ti3SiC2 and Ti2AlC Powdered MAX Phases(Springer Nature, 2024) Córdoba Gallego, José Manuel; Universidad de Sevilla. Departamento de Química InorgánicaThis paper reports the pressureless sintering behavior and the activation energy of the powdered MAX phases Ti3SiC2 and Ti2AlC. A non-isothermal technique was used to determine the sintering kinetic parameter. The Ti3SiC2 and Ti2AlC MAX phases showed the maximum sintering rate at 1723 K, 0.14 and 0.10 µm/s, respectively. The sintering rate of the sample at different temperatures followed a cubic equation which was determined. The sintering activation energy (Ea) for the Ti3SiC2 and Ti2AlC samples was 362.1 kJ/mol and 640.3 kJ/mol, respectively.Artículo Mechanochemistry for Organic and Inorganic Synthesis(American Chemical Society, 2024) Reynes, Javier F.; León García, Félix; García, Felipe; Universidad de Sevilla. Departamento de Química Inorgánica; Agencia Estatal de Investigación. España; Fundación para el Fomento en Asturias de la Investigación Científica Aplicada y la Tecnología (FICYT); The Marie Skłodowska-Curie Actions (MSCA)In recent years, mechanochemistry has become an innovative and sustainable alternative to traditional solvent-based synthesis. Mechanochemistry rapidly expanded across a wide range of chemistry fields, including diverse organic compounds and active pharmaceutical ingredients, coordination compounds, organometallic complexes, main group frameworks, and technologically relevant materials. This Review aims to highlight recent advancements and accomplishments in mechanochemistry, underscoring its potential as a viable and eco-friendly alternative to conventional solution-based methods in the field of synthetic chemistry.Artículo Cooperative interaction between metallosurfactants, derived from the [Ru(2,2 '-bpy)(3)](2+) complex, and DNA(Elsevier, 2015) Lebrón Romero, José Antonio; Ostos Marcos, Francisco José; Moyá Morán, María Luisa; López López, M.; Carrasco Carrasco, Carlos Jesús; López-Cornejo, María del Pilar; Universidad de Sevilla. Departamento de Química Física; Universidad de Sevilla. Departamento de Química Inorgánica; Junta de Andalucía; European Union (UE)With the idea of improving and advancing the design and preparation of new reagents based on cationic surfactants for gene therapy, two luminescent metallosurfactants derived from the [Ru(2,2′-bpy)3]2+ complex were synthesized. Their interaction with DNA and the effect they exert on the conformation of the polynucleotide were studied by using different techniques. The equilibrium binding constants, Kb, of the two surfactants to DNA were obtained at different molar ratios X = [surfactant]/[DNA]. The observed sigmoidal dependence of Kb on X confirms the cooperative character of the binding. After the addition of a determined surfactant concentration, the condensation of the polymer was observed. The amount of surfactant needed to produce this conformational change is lower for the double stranded surfactant than for the single chain surfactant due to a stronger hydrophobic interaction. The addition of α-cyclodextrin molecules to the metallosurfactant/DNA solutions results in polynucleotide decompaction, which confirms the importance of the hydrophobic interactions in the condensation of the polynucleotide. Results also show the importance of choosing both a proper system to study and the most seeming measuring technique to use. It is demonstrated that, in some cases, the use of several techniques is desirable to obtain reliable and accurate results.Artículo Induced-aggregates in Photocatalysis: An Unexplored Approach to Reduce the Noble Metal co-catalyst Content(Elsevier, 2024) Bu, E. Q.; Chen, X. W.; López Cartes, Carlos; Monzón, A.; Delgado, J. J.; Ministerio de Economia, Industria y Competitividad (MINECO). España; Universidad de CádizPhotocatalysis has emerged as a promising and environmentally sustainable solution to produce high-purity hydrogen through ethanol photoreforming. It is commonly accepted that adding co-catalysts, especially noble metals, significantly enhances the catalytic activity of semiconductors. However, the high cost of noble metals such as Pt may limit the real application of this emerging technology. Here we evaluate the possibility of reducing the noble metal loading by creating the appropriate interface between pre-formed semiconductor nanoparticles. Commercial titania (P25) was selected as the semiconductor due to its commercial availability, facilitating the straightforward validation and corroboration of our results. Pt was selected as co-catalyst because one of the most efficient photocatalysts for the ethanol photo-reforming is still based on the use of P25 in combination with Pt. We report that the creation of induced aggregates dramatically improves the total hydrogen produced when very low loadings (≤0.05 wt%) of Pt are used. We have developed a pioneering reactor designed for conducting photoluminescence studies under authentic operational conditions of nanoparticle suspensions in the liquid phase. This approach allows us to obtain the average photoluminescence emission from the P25 agglomerates what it would be impossible to obtain by using standard solid samples holders. Thanks to this equipment, we can conclude that this remarkable improvement of the activity is mainly due to creation of an interface that favors the charge transfer between the particles of the aggregates. According to this, the titania nanoparticles of the agglomerates act as an antenna to collect the photons of the sun-light and produce the photo-excited electrons that will be transferred to the platinum nanoparticles located in the same agglomeration. In contrast, raw P25 with low loadings of Pt would have a high number of titania nanoparticles without platinum, and therefore, inactive. This result would be especially relevant in the case of immobilized photocatalytic systems for real future photocatalytic reactors because the immobilization of the semiconductors would generate similar interactions to the one created by our method. Consequently, the initial semiconductor immobilization followed by the subsequent photo-deposition of the co-catalyst emerges as a promising approach for a substantial reduction of the co-catalyst content.Artículo Impact of the Biogas Impurities on the Quality of the Precipitated Calcium Carbonate in the Regenaration Stage of a Chemical Absorption Biogas Upgrading Unit(Elsevier, 2024) Salinero González, Jesús; Gallego Fernández, Luz Marina; Portillo Estévez, Esmeralda; González Arias, Judith; Baena-Moreno, Francisco M.; Navarrete Rubia, Benito; Vilches Arenas, Luis Francisco; Universidad de Sevilla. Departamento de Química Inorgánica; Universidad de Sevilla. Departamento de Ingeniería Química y Ambiental; Ministerio de Ciencia e Innovación (MICIN). EspañaCombining Carbon Capture and Storage (CCS) with producing competitive secondary raw materials is key to decarbonizing industry and reducing resource extraction. Biogas upgrading to biomethane stand out as an alternative, but a significant gap remains in integrating this process within a circular economy framework. This issue has been recently addressed by a process that integrates biogas upgrading via caustic absorption with the production of Precipitated Calcium Carbonate (PCC) and the recovery of sodium hydroxide from waste brine solution using membrane technologies. The profitability of this approach depends on the quality of the PCC, a critical factor that this work addresses. By characterizing PCC is determined whether trace compounds in biogas contaminate the PCC and potentially affect its commercial value. It also examines the CO2 absorption process and analyzes the aqueous samples from the filtration phase of the PCC slurry. Results confirm the high purity of PCC obtained from biogas treatment using Raman spectroscopy, X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The analyses show that the PCC is pure calcium carbonate, mainly in the stable calcite form, with a typical tetrahedral morphology and no detectable impurities. Characterization of aqueous solutions revealed organic trace compounds from biogas, with TOC concentrations of 9.7 (± 6.4) and 16.0 (± 8) mg C/l. Silicon measurements showed similar concentrations in the absorbent solution and filtrated PCC slurry. Additionally, ammonia escapes as gas, and hydrogen sulfide in the biogas likely contributed to sulfate salt formation. Analysis of the CO₂ absorption shows a first-order reaction with OH-, where the amount of CO₂ absorbed (46.3–50.0 g) closely matches the theoretical value of 48 g. The study reveals that most of the biogas impurities dissolve into the aqueous solution, being crucial for future studies and downstream membrane treatments, and the PCC is unaffected by these impurities with a purity suitable for commercial applications.Artículo Finely Tunable Carbon Nanofiber Catalysts for the Efficient Production of HMF in Biphasic MIBK/H2O Systems(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Bounoukta, Charf Eddine; Megías Sayago, Cristina; Rendón Márquez, Nuria; Ammari, F.; Centeno, M. A.; Ivanova, Svetlana; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). EspañaThis work proposes catalytic systems for fructose dehydration to 5-hydroxymethylfurfural using a series of functionalized carbon nanofibers. The catalysts were synthesized via finely selected covalent grafting in order to include a variety of functionalities like pure Bronsted acid, tandem Brønsted/Lewis acid, and tandem Lewis acid/Lewis base catalysts. After the characterization and evaluation of acidity strength and the amount of acid centers, the catalyst series was screened and related to the product distribution. The best-performing catalyst was also used to optimize the reaction parameters in order to achieve 5-hydroxymethylfurfural yields rounding at 60% without significant humin formation.Artículo Progress and Future Challenges in Designing High-Performance Ni/CeO2 Catalysts for CO2 Methanation: A Critical Review(2025-01-20) Liu, Kun; Nawaz, Muhammad Asif; Liao, Guangfu; Universidad de Sevilla. Departamento de Química InorgánicaThe Ni/CeO2 catalyst stands out among various solid metal oxide catalysts for its exceptional catalytic proficiency, positioning it as a prime candidate for the industrialization of methanation processes. This review thoroughly examines the prevalent challenges associated with Ni/CeO2 in methanation reactions, compiles current strategies to overcome these hurdles, and presents novel perspectives. The review elucidates the structural characteristics of Ni/CeO2 and its applications in catalytic reactions, discusses various synthesis methods and their respective merits and demerits, explores catalytic reaction systems at both laboratory and industrial scales, and clarifies the underlying reaction mechanisms. Furthermore, it underscores the mainstream approaches to enhance the low-temperature activity of Ni/CeO2 in methanation and to mitigate activity decrement due to Ni agglomeration. The review concludes by proposing future directions for improving low-temperature methanation activity and preventing catalyst deactivation, encompassing the development of innovative catalyst architectures, integrating in-situ characterization with theoretical calculations, and investigating photothermal methanation catalytic systems. Undoubtedly, scientific researchers will persistently strive to develop Ni/CeO2 catalysts with high activity across a broad temperature range and robust stability, driving the industrialization of CO2 methanation technology in the foreseeable future.Artículo Effect of Calcination Temperature on the Synthesis of Ni-based Cerium Zirconate for Dry Reforming of Methane(Elsevier, 2024) Martín Espejo, Juan Luis; Merkouri, Loukia Pantzechroula; Odriozola Gordón, José Antonio; Ramírez Reina, Tomás; Pastor Pérez, Laura; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). EspañaDry reforming of methane (DRM) represents an alluring approach to the direct conversion of CO2 and CH4, gases with the highest global warming potential, into syngas, a value-added intermediate used in chemical industry. In this study, mixed oxide structures of cerium and zirconium doped with 10 wt% Ni were used due to the high thermal stability. This study showcased the importance of choosing suitable conditions and explored the impact of calcination temperature on Ce–Zr mixed oxides with Ni. XRD analysis confirmed the existence of different crystalline phases according to the calcination temperature. Redox characterisation showed a trade-off among calcination temperature, the dispersion of Ni clusters and its interaction with the support structure. Calcined catalysts at 900 and 1000 °C underwent harsh, long-term DRM conditions. Despite the low surface area of the designed catalysts, the stability experiments proved a relation between dispersion of Ni active phase and catalytic performance, showing an optimum calcination temperature of 1000 °C.
Artículo Integrating catalytic tandem reactions for the next generation of biofuels: A perspective(Cell Press, 2024-08-15) Blay Roger, José Rubén; Carrasco Ruiz, Sergio; Ramírez Reina, Tomás; Bobadilla Baladrón, Luis Francisco; Odriozola Gordón, José Antonio; Nawaz, Muhammad Asif; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Union (UE)In this piece, we explore the transformative potential of sustainable biofuel production as a solution to the energy crisis and a pivotal element in realizing the environmental and societal ambitions of Society 5.0. Through a critical examination of “bottom-up” and “top-down” strategies for converting bio-feedstocks sourced from anthropogenic activities into renewable fuels, the work underscores the need for innovation in catalysts and process intensification. By highlighting the advances and challenges in harnessing unconventional feedstocks and integrating renewable energy, this work points to a future where biofuels stand as a cornerstone of a sustainable energy landscape. The significance of this discussion extends beyond the technical realm, offering a vision for a circular economy that reduces dependence on fossil fuels, addresses climate change, and promotes global energy security. It calls for a united front among researchers, industry leaders, and policymakers to drive the biofuel sector toward efficiency, scalability, and widespread adoption.Artículo Influence of the atmosphere on the formation of high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system via reactive flash sintering(Elsevier, 2024-08-05) Manchón Gordon, Alejandro Fernando; Lobo-Llamas, C.; Molina Molina, Sandra; Perejón Pazo, Antonio; Sánchez-Jiménez, P. E.; Pérez-Maqueda, L. A.; Universidad de Sevilla. Departamento de Física de la Materia Condensada; Universidad de Sevilla. Departamento de Química Inorgánica; Junta de Andalucía; Ministerio de Ciencia e Innovación (MICIN). España; European Union (UE)In this study, the feasibility of preparing quinary equimolar high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system was explored using the reactive flash sintering (RFS) technique. Various compositions were tested using this technique under atmosphere pressure, leading to the formation of two primary phases: rock-salt and spinel. Conversely, a new high-entropy oxide was produced as a single-phase material with the composition (Co0.2,Cu0.2,Mg0.2,Mn0.2,Ni0.2)O when RFS experiments were conducted in nitrogen atmosphere. The reducing conditions achieved in nitrogen enabled the incorporation of cations with oxidation states different from +2 into the rock-salt lattice, emphasizing the critical role of the processing atmosphere, whether inert or oxidizing, in the formation of high-entropy oxides. The electrical characterization of this material was obtained via impedance spectroscopy, exhibiting a homogeneous response attributed to electronic conduction with a temperature dependence characteristic of disordered systems.Artículo Effect of Na/Ca Adsorbents on NiRu-DFM Performance for Integrated CO2 Capture and Hydrogenation(2024-10-09) Gharamaleki, Soudabeh Bahrami; Carrasco Ruiz, Sergio; Penkova, Anna Dimitrova; Ramírez Reina, Tomás; Duyar, MeIis S.; Universidad de Sevilla. Departamento de Química InorgánicaIntegrated carbon dioxide capture and utilization (ICCU) technology is being developed to address the challenge of increasing atmospheric CO2 levels. Dual function materials (DFMs) are designed with catalytic and adsorbent components that enable the capture and utilization of CO2 within a single reactor. In this investigation, we systematically evaluated the performance of NiRu-DFMs incorporating oxides of Ca, Na, or a combination to identify effects on both activity and selectivity. Our findings underscore not only the role of adsorbent selection in dictating the overall performance of DFMs but also the pretreatment conditions (in situ reduction). Notably, the highest methanation activity is observed on an as-synthesized (oxidized) 10% Ca-DFM (223.21 μmol/gDFM) at 380 °C, surpassing all other as-synthesized or reduced DFMs. This study sheds light on the relationships between composition, pretreatment, temperature, and performance in DFMs, offering valuable insights into the advancement of new compositions for DFMs.Artículo Plasma-flash Sintering: Metastable Phase Stabilization and Evidence of Ionized Species(John Wiley & Sons, 2025) Gil González, Eva; Taibi, A.; Perejón Pazo, Antonio; Sánchez Jiménez, Pedro Enrique; Pérez Maqueda, L. A.; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; Universidad de SevillaThe first demonstration of plasma-flash sintering (PFS) is presented in this work. PFS is performed under a low-pressure atmosphere that consecutively generates plasma and flash events. It is shown, by using several combined characterization techniques, that PFS stabilizes metastable phases on the surface of the material, which may be partially, but not solely, attributed to the generation of oxygen vacancies, and induces the absorption of ionized species, if a reactive atmosphere is employed. Even though additional research is required to understand the fundamentals of PFS, it is evidenced its potential to be used as a material surface engineering tool, which may widen the technological capabilities of flash sintering.Artículo Synthesis and structural characterization of homochiral coordination polymers with imidazole-based monocarboxylate ligands(Royal Society of Chemistry, 2019-05-15) Borrego, Elena; Nicasio, Antonio I.; Álvarez, Eleuterio; Montilla Ramos, Francisco Javier; Córdoba Gallego, José Manuel; Galindo del Pozo, Agustín; Universidad de Sevilla. Departamento de Química InorgánicaChiral Na[(S)-LR] (R = Me, 1a; iPr, 1b; CH2iPr, 1c, and (S)-secBu, 1d) and Na[(R)-LR] (R = Me, 1a′) compounds were synthesised following standard procedures. New compounds 1d and 1a′ were analytically and spectroscopically characterised. 1a and 1c were structurally identified by single-crystal X-ray diffraction methods as homochiral 2D coordination polymers, {Na(H2O)[(S)-LMe]}n and {Na[(S)-LCH2iPr]}n, respectively. Both (S)-2alkyl,2-(1H-imidazol-1-yl)acetate anions displayed unprecedented coordination modes in these coordination polymers: μ3κ2OκO′ for 1a and μ4κ2Oκ2O′ for 1c. Enantiomeric species 1a′, {Na(H2O)[(R)-LMe]}n, showed the same X-ray powder diffractogram (XRPD) as 1a, in agreement with a similar crystal structure. DFT calculations on the [LR]− anions confirmed their coordination capabilities as ditopic linkers. In fact, the reaction of Na[LR] with several metal salts yielded the following coordination polymers: {Ag[(S)-LMe]}n, 2a, {Ag[(R)-LMe]}n, 2a′, {Cu[(S)-LR]2}n (R = Me, 3a; iPr, 3b), {Cu[(R)-LMe]}n, 3a′, {Zn[(S)-LR]2}n (R = Me, 4a; iPr, 4b; (S)-secBu, 4d) and {Zn[(R)-LMe]2}n, 4a′. For the known compounds 3a and 4a, this procedure is a new synthetic route that avoided high temperature reaction conditions. New complexes 2, 3a′, b, and 4a′, b, d were characterised by elemental analysis, infrared and XRPD methods and complex 2a by single-crystal X-ray diffraction. This complex is also a two-dimensional coordination polymer in which the [(S)-LMe]− anion acts as a μ4κN,κ2O,κ2O′ bridging ligand. Compounds 1–4a′ are the first examples of homochiral coordination polymers with imidazole-monocarboxylate ligands based on non-natural amino acids. Preliminary studies on the metal-catalysed preparation of chiral α-aminophosphonates were carried out but, unfortunately, no enantioselectivity was observed.Artículo Low CO2 hydrogen streams production from formic acid through control of the reaction pH(Elsevier, 2023-01-01) Santos, José Luis; Ruiz López, Estela; Ivanova, Svetlana; Monzón, Antonio; Centeno Gallego, Miguel Ángel; Odriozola Gordón, José Antonio; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; Junta de AndalucíaThere are multiple factors that influence the catalyst performance in the reaction of formic acid dehydrogenation: the nature of catalyst and/or support, the used solvent and reaction variables such as temperature, time, formic acid concentration, presence/absence of formates and pH of the solution. This work evaluates a series of important parameters like the influence of the pH by itself, the influence of the nature of used alkali agents and the effect of direct formate addition as reactive on hydrogen production via formic acid dehydrogenation over a commercially available catalyst. The catalytic performance appears to depend on the ionic radius of the cations of the used base which reflects consequently on the hydrogen selectivity. The best base to be used must have lower hydrated cationic radii and a starting pH around 4 to achieve important hydrogen selectivity for medium term formic acid conversion.Artículo P atom as ligand in transition metal chemistry: structural aspects(Elsevier, 2021-02-09) Conejo Argandoña, María del Mar; Pastor Navarro, Antonio; Montilla Ramos, Francisco Javier; Galindo del Pozo, Agustín; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; European Union (UE); Junta de AndalucíaThe chemistry of transition metal compounds that contain a phosphorus atom acting as ligand, sometimes called “naked” phosphorus, started at the end of the last century. However, it is still an area of permanent interest and expansion, in which new examples of complexes with novel structural features are appearing in the literature. In this review, the phosphide complexes are classified based on the different coordination modes found in structurally characterised complexes for coordination numbers from 1 to 4 at the phosphorous atom. Structural aspects are discussed and, in some cases, the bonding patterns rationalised. Additionally to the structural analysis, data from 31P NMR spectroscopy, as a potent characterization tool, are also revised and briefly analysed.Artículo A low-coordinate platinum(0)-germylene for E–H bond activation and catalytic hydrodehalogenation(Springer Nature, 2024-11-07) Bajo Velázquez, Sonia; Soto, Enrique; Fernández-Buenestado, Marta; López Serrano, Joaquín; Campos, Jesús; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; European Union (UE); Junta de AndalucíaPairing transition metals and heavier tetrylenes (Si, Ge, Sn, Pb) holds great potential for cooperative bond activation and catalysis. In this work, we investigate the reactivity of a low-coordinate Pt(0)/Ge(II) system that emerges from the reaction between the monoligated platinum(0) precursor [(PMe2ArDipp2)Pt(olefin)] with germylene dimer [ArDipp2GeCl]2 (where ArDipp2 = C6H3−2,6-(C6H3−2,6-iPr2)2). The resulting complex reveals ability for cooperative bond activation. Stoichiometric reactions with dihydrogen, water, methanol, ammonia and alkynes unveil the formation of Pt(II)-germyl com pounds, characterized by distinct isomeric forms, whose flexibility derives from the particularly low-coordination. We explore its catalytic potential in the hydrodehalogenation of aliphatic, aromatic and main-group halides under dihydrogen atmosphere using both thermal and photochemical conditions, demonstrating promising conversions even for more challenging alkyl chlorides.Artículo Effect of the sulphonating agent on the catalytic behavior of activated carbons in the dehydration reaction of fructose in DMSO(Elsevier, 2021-05-05) Bounoukta, Charf Eddine; Megías Sayago, Cristina; Ivanova, Svetlana; Penkova, Anna Dimitrova; Ammari, Fatima; Centeno Gallego, Miguel Ángel; Odriozola Gordón, José Antonio; Universidad de Sevilla. Departamento de Química Inorgánica; Ministerio de Economía y Competitividad (MINECO). EspañaA series of -SO3R functionalized activated carbons (R=H, O, aryl) were prepared and applied in fructose dehydration reaction to 5-hydroxymethylfurfural. Different sulphonating methods introduce groups on catalyst surface with distinct donor-acceptor and hydrophilic properties. Their nature influences significantly not only activated carbon's textural and chemical properties but also the product yields and selectivity in fructose dehydration reaction. The viability of the solvent free reaction was also investigated and compared to the performance of the catalyst series in presence of DMSO, where the best catalytic results were obtained.Artículo Potentialization of bentonite properties as support in acid catalysts(2020-03) Amaya, Jahaziel; Bobadilla Baladrón, Luis Francisco; Centeno, Miguel; Moreno, Sonia; Molina, Rafael; Azancot Luque, Lola de las Aguas; Universidad de Sevilla. Departamento de Química InorgánicaEnhancement of the main physicochemical properties of a natural bentonite was carried out by means of modifications using surfactant, reflux, microwave treatment and, subsequently, the incorporation of AlZr and AlCe species. The evolution of the main changes in each modification stage was evaluated by means of X-ray diffraction, N2 sortometry, scanning microscopy (SEM), NH3-TPD, NH3-DRIFTS and CO adsorption at low temperature. For the evaluation of the catalytic behavior, the dehydration-dehydrogenation reactions of 2-propanol and hydro-conversion of decane were used; both of which generate, in addition, information regarding the acidic properties of the materials. The correlation of the number, type and acid strength with the catalytic behavior, allowed establishing the effect produced by both the delamination method and the nature of the incorporated cation. This generated tools that allow controlling the physicochemical properties, and more specifically, the enhancement of the acidity of new supports based on this type of natural clay mineral.Artículo Clase invertida síncrona en asignaturas STEM(Ministry Education and Science, 2021-03) Maya Díaz, Celia María; Iglesias Sigüenza, Francisco Javier; Giménez Font, Xavier; Universidad de Sevilla. Departamento de Química Inorgánica; Universidad de Sevilla. Departamento de Química orgánicaSe presenta una metodología de clase invertida, con modificaciones sincrónicas para adaptarse a la dificultad propia de las materias STEM. La clase Invertida Síncrona refuerza la tutoría inicial, para resolver las dudas de los alumnos que les impiden progresar a través del material que trabajan fuera del aula. A continuación, una dinámica de trabajo en grupo, aprendizaje basado en problemas, cuestionarios de integración, y evaluación formativa por pares, dan lugar a una destacable mejora de los resultados académicos, junto a una reducción del tiempo de trabajo y un incremento significativo en el grado de satisfacción del alumnado. Se discute su aplicación a tres asignaturas del Grado en Química de la Universidad de Sevilla, así como una asignatura del Grado de Química de la Universidad de Barcelona.