Artículos (Instituto de Ciencia de Materiales de Sevilla (ICMS) – CIC Cartuja)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/10964

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One-step electrosynthesis of nanostructured Mn-V oxides with tunable redox characteristics
(Elsevier, 2026-07-01) Cabello-Illanes, Carmen; Torres-Barrera, Joaquín; Centeno, Miguel Ángel; Ivanova, Svetlana; Domínguez Leal, María Isabel; Martínez Tejada, Marcela; García-Dalí, Sergio; Química Inorgánica; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España
The rational design of nanostructured mixed-metal oxides through scalable and controllable fabrication methods remains a central challenge in nanomaterials science. In this work, we present a one-step, substrate-free electrosynthesis strategy that enables the direct formation of nanostructured Mn-V mixed oxides with tunable physicochemical characteristics. By systematically adjusting the applied current and precursor ratios, the method provides precise control over phase composition, crystallite size within the nanoscale regime, degree of amorphous vs. crystalline order, and textural parameters, allowing access to material architectures that are not attainable through conventional wet-chemical or high-temperature routes. A series of MnO oxides, as well as V 2 O 5 2 and Mn-V mixed for comparative purposes, were prepared under galvanostatic conditions without any further thermal treatment. Pure MnO 2 samples exhibited a mixture of ε- and γ-phases, with lamellar morphologies and outstanding surface areas. However, the incorporation of vanadium induced significant structural and morphological changes, including amorphization and the formation of V-based crystalline domains at higher loadings. Furthermore, catalytic tests showed that all materials achieved complete glucose conversion, while the Mn-V oxides significantly improved selectivity towards formic acid. Specifically, the MnV_5:1 sample exhibited the best performance, along with a notable suppression of CO 2 formation. The enhanced performance could be attributed to a synergistic Mn-V redox interaction that promotes controlled oxidation pathways and stabilizes intermediates. These findings demonstrate the potential of electrosynthesis as a tunable method, additionally offering sustainability, time-efficiency, cost-effectiveness, and reproducibility, for developing advanced and promising sustainable materials.
Formation and Coherent Propagation of Femtosecond-Laser-Induced Periodic Surface Structures (LIPSS) in Fluorine-Doped Tin Oxide: Control, Potential Applications, and Challenges
(American Chemical Society (ACS), 2026-06-22) Gómez-Munoz, Gonzalo; Ariza, Rocío; Núñez Gálvez, Fernando; López Flores, Víctor; Cabello-Pardos, Fátima; Sotillo, Belén; Prieto, Carlos; García López, Francisco Javier; López Santos, Carmen; Solís, Javier; Física Aplicada I; Física Atómica, Molecular y Nuclear; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España; Comunidad Autónoma de Madrid
We have analyzed the formation and coherent propagation of laserinduced periodic surfa cestructures (LIPSS) upon fs-laser irradiation of fluorine-doped tin oxide (FTO) films. The aim is the generation of large electrical anisotropies in macroscopic áreas for applications including laser-written transparent heaters, sensors, or substrates for electrically controlable wettability, among others. The films have been processed with high-repetition-rate (hundreds of kHz) fs-laser pulses at 1030nm using different laser (fluence and pulse duration) and scanning parameters (speedand line overlap). Optimal LIPSS formation and coherent propagation are conditioned by the dynamic evolution of the F content in the laser-processed regions that can be controlled via processing parameters. However, the homogeneity in the spatial distribution of F in the microscale in the pristine samples can generate important issues that are carefully considered and discussed in the present work. Still, the formation of optically and electrically highly anisotropic surfaces for laser scanning speeds well above 1.0m/s has been demonstrated, reaching electrical resistivity anisotropy factors of > 103. Consequently, the large-area applications using LIPSS-structured FTO films seems feasible, as we have demonstrated by fabricating an efficient laser-written electrothermal transparent device as a proof-of-concept.
Síntesis de zβ a partir de cenizas volantes, utilizadas en liberación controlada de nitratos
(Universidad Pedagógica y Tecnológica de Colombia, 2020-06-19) García Barrero, Jenny Andrea; Pazos Zarama, Mery Carolina; Chaparro Barajas, Javier Ramiro; Fonseca Martínez, Deisy Alejandra; Pavón González, Esperanza; Alba Carranza, María Dolores; Física de la Materia Condensada
En este trabajo se sintetizó zeolita beta (Zβ) usando cenizas volantes (CV) de la central eléctrica de carbón, Termopaipa, situada en Paipa, Boyacá (Colombia). Las cenizas se utilizaron para extraer el silicio (Si) y aluminio (Al), para lo cual se realizó un pretratamiento ácido seguido de proceso hidrotérmico con NaOH. Para la obtención de la zeolita beta se varió la fuente de silicio y aluminio del gel madre y el tiempo de cristalización, manteniendo una composición nominal igual a 50SiO2: 1Al2O3: 25TEAOH: Na2O: K2O: 17H2O. En el primer experimento, las CV aportaron la fuente de aluminio, mientras que la fuente de silicio se obtuvo a partir de las CV y sílice fumante. La síntesis hidrotérmica se realizó a 170 °C durante 40 h, lo cual condujo a la obtención de ZSM-5 junto con una fase secundaria de mordenita. En el segundo experimento, las CV aportaron la fuente de silicio y se requirió la adición de sulfato de aluminio octadecahidratado como fuente de aluminio. La síntesis hidrotérmica se realizó a 170 °C y 60 h, lo cual condujo a una Zβ de alta pureza. Las zeolitas se caracterizaron usando DRX, FTIR, SEM y XRF. Las zeolitas se modificaron usando (3-aminopropil) trietóxisilano (APTES) y bromuro de hexadeciltrimetilamonio (HDTMA-Br). Los resultados muestran que la Zβ-APTES, con una capacidad de adsorción de 5 mmol NO3 -/100g tiene el mayor potencial para la aplicación de liberación controlada de fertilizantes.
Direct observation of interface-dependent activity in NiO/CeO2 for effective low-temperature CO oxidation
(Elsevier, 2025-01-01) Liu, Kun; Liao, Luliang; Li, Lin; Nawaz, Muhammad Asif; Liao, Guangfu; Xu, Xianglan; Química Inorgánica; National Natural Science Foundation of China; Jiangxi Provincial Natural Science Foundation; Key Laboratory Foundation of Jiangxi Province for Environment and Energy Catalysis
In contemporary catalytic interface exploration, experimental studies often take a backseat to theoretical simulations, hindering the development of pristine catalytic interfaces. This research leverages monolayer dispersion theory to design an efficient CO oxidation catalyst through precise manipulation of non-precious metal NiOsingle bondCeO2 interfaces. Employing the pioneering XRD extrapolation method, we fabricated monolayer dispersed Ni-O-Ce and Ce-O-Ni interfaces, unlocking insights into their impact on the CO oxidation mechanism. The method accurately quantified monolayer dispersion capacities: 0.526 mmol NiO/(100 m2 CeO2) for NiO/CeO2 and 0.0638 mmol CeO2/(100 m2 NiO) for CeO2/NiO, revealing intricate interactions between active components and supports. Utilizing numerical values derived from monolayer dispersion theory, we constructed CeO2-supported NiO (Ni-O-Ce) and NiO-supported CeO2 (Ce-O-Ni) catalysts in a monolayer dispersed state. The Ni-O-Ce interface, generating abundant oxygen vacancies, significantly enhanced CO adsorption and facilitated surface reactive oxygen species production, leading to a remarkable 14-fold increase in intrinsic CO oxidation activity and a notable 4.2-fold improvement in water resistance. Integrating XRD extrapolation, H2-TPR, O2-TPD, CO-TPD, XPS, Raman, and in situ IR techniques, our study demonstrates the feasibility of crafting efficient catalysts with monolayer dispersed atomic-scale catalytic interfaces to elucidate the mechanisms underlying catalytic interface effects on CO oxidation.
Investigation of Sn Promoter on Ni/CeO2 Catalysts for Enhanced Acetylene Semihydrogenation to Ethylene
(American Chemical Society, 2024-12-11) Sun, Xueming; Wu, Rundong; Nawaz, Muhammad Asif; Meng, Shuai; Guan, Tong; Zhang, Chong; Sun, Chunyan; Lu, Zhang-Hui; Zhang, Rongbin; Feng, Gang; Ye, Runping; Química Inorgánica; Thousand Talents Plan of Jiangxi Province; Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars; National Natural Science Foundation of China; Natural Science Foundation of Jiangxi Province, China
Ethylene, as an important chemical raw material, could be produced through the coal-based acetylene hydrogenation route. Nickel-based catalysts demonstrate significant activity in the semihydrogenation reaction of acetylene, but they encounter challenges related to catalyst deactivation and overhydrogenation. Herein, the effect of Sn promoter on Ni/CeO2 catalysts has been comprehensively explored for acetylene semihydrogenation. The optimized Ni/8%Sn-CeO2 catalytic performance was significantly improved, with 100% acetylene conversion and 82.5% ethylene selectivity at 250 °C, and the catalyst maintained high catalyst performance within a 1000 min stability test. A series of characterization tests show that CeO2 modified by moderate Sn4+ doping is more conducive to modulating the charge structure and geometry of the Ni active center. Additionally, the in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy and density functional theory results indicated that catalysts doped with Sn4+ facilitated more efficient desorption of ethylene from the catalyst surface compared to Ni/CeO2 catalysts, thus improving ethylene selectivity and yield. This study highlights an effective strategy for improving the catalytic performance of rare-earth-based catalysts through the incorporation of effective metal promoters.
Oxygen vacancy-dependent low-temperature performance of Ni/CeO2 in CO2 methanation
(Royal Society of Chemistry, 2024-09-25) Liao, Luliang; Wang, Kunlei; Liao, Guangfu; Nawaz, Muhammad Asif; Liu, Kun; Química Inorgánica; Jiangxi Provincial Natural Science Foundation
The transformative power of CO2 methanation can efficiently transform greenhouse gases into high-value products, aligning with the carbon neutrality goals. However, achieving this target at low temperature requires cumbersome efforts in designing catalysts that possess high reactivity and selectivity. Focusing on understanding the pivotal role of alkaline (such as Ca) sites in catalyzing these reactions at lower temperature could be a way of strategically creating oxygen vacancies with varying activity gradients. Designing CaCe-SG via a sol–gel method in the current study to integrate Ca into the CeO2 lattice marked the highly active moderate-strength alkaline centers which resulted in the intrinsic activity soaring by an impressive 400% compared to the conventional Ni/CeO2 catalysts. Supported by H2-TPD, Raman, and XPS analyses, a crucial revelation was unveiled where Ca modification induced a surge in the dispersion of active Ni species on Ni/CaCe-SG catalysts, thereby enhancing the abundant surface oxygen vacancies. In situ infrared spectroscopy further confirmed that the modified catalyst diligently followed the reaction pathway of CO3H* → HCOO* → CH4, culminating in the CO2 methanation activity with a low-temperature catalyst via the meticulous optimization of synthesis methods that propelled the process forward to the anticipated oxygen vacancy-induced moderate-strength alkaline centers.
Tailoring electronic and interfacial synergy in Cu-FeGa/Al2O3 for direct CO2 hydrogenation to ethanol
(Elsevier, 2026-03-01) Huang, Shiquan; Fang, Ling; Luo, Siling; Deng, Hao; Ramírez Reina, Tomás; Zou, Guangting; Liu, Qing; Zhang, Rongbin; Fan, Maohong; Ye, Runping; Química Inorgánica; Jiangxi Provincial Natural Science Foundation. China; Thousand Talents Plan of Jiangxi Province. China; National Natural Science Foundation of China; Nanchang University. China; Key Laboratory Foundation of Jiangxi Province. China
Chemical CO2 recycling via direct CO2 hydrogenation to ethanol represents a forward-looking route to curb greenhouse gases emissions while simultaneously alleviating the pressure from fossil fuel extraction and consumption. However, this is a complex chemical process whose successful implementation requires a careful trade- off among its key reaction steps: CO2 activation, selective C-C coupling, and hydrogenation termination. Achieving optimal ethanol synthesis requires a balance of surface intermediates and promoting C-C coupling, as indicated by thermodynamic and kinetic constraints. Herein, we have developed an efficient FeGa-doped Cu/Al2O3 catalyst prepared by the sol-gel method, achieving a space-time yield of 1.48 mmol·gcat-41 1·h-1 for ethanol. The Al2O3 support could disperse Cu active sites and generate oxygen vacancies for CO2 activation. Furthermore, Fe doping and Ga modification synergistically enhance both C-C coupling capability and the non-dissociative CO activation ability of the Cu/Al2O3 catalyst, ultimately boosting CO2 conversion to ethanol. In-situ DRIFTS spectra reveal a potential catalytic mechanism for ethanol formation: CHx* species couple with non-dissociated CO* at the Cu-FeGaOx interface, followed by hydrogenation to ethanol. Overall, this work proposes a dual-promoter strategy that incorporates both Fe and Ga in a multi-competent Cu-based formulation, offering a novel approach to designing tunable catalysts for low-carbon ethanol synthesis.
Upcycling textile derived microplastics waste collected from washer and dryers to carbonaceous products using hydrothermal carbonization
(Elsevier, 2025-06-01) Parrilla Lahoz, Silvia; Jiménez Páez, Elena; Masteghin, Mateus G.; Pawlak, Joel J.; Venditti, Richard A.; Bird, Robert; Servin, Paul; Odriozola Gordón, José Antonio; Ramírez Reina, Tomás; Duyar, Melis S.; Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Union (UE); Engineering and Physical Sciences Research Council (UK)
Microplastics are an emerging pollutant of concern. Many microplastics in the waters arise from washing synthetic textiles in residential and commercial washing machines. The present research evaluated the upcycling of this waste to carbon nanomaterials by hydrothermal carbonization. Real microfiber waste was collected using commercially available washer and dryer filters, and then carbonized to yield graphene and graphite. Via temperature and residence time screening (200ºC, 250ºC, 300ºC and 1h, 4h, 8h) two temperatures of interest were detected (250ºC and 300ºC) with a residence time of 4h. For 250ºC-4h the total solid carbon yield to amorphous carbon was detected as 100% while for 300ºC-4h the total solid carbon yield to filamentous carbon (graphene/graphite) was detected as 88%. To this end, Raman spectroscopy results indicated the production of carbon nanomaterials. The results obtained in this research demonstrated that by varying the reaction conditions, carbon production can be tailored, producing amorphous carbon or graphene/graphite. This process is an intriguing method of incorporating textile residue (microfibers) into the circular economy.
A review on high-pressure heterogeneous catalytic processes for gas-phase CO2 valorization
(Elsevier, 2024-01-01) Villora Picó, Juan J.; González Arias, Judith; Pastor Pérez, Laura; Odriozola Gordón, José Antonio; Ramírez Reina, Tomás; Química Inorgánica; Ingeniería Química y Ambiental; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; Junta de Andalucía
This review discusses the importance of mitigating CO2 emissions by valorizing CO2 through high-pressure catalytic processes. It focuses on various key processes, including CO2 methanation, reverse water-gas shift, methane dry reforming, methanol, and dimethyl ether synthesis, emphasizing pros and cons of high-pressure operation. CO2 methanation, methanol synthesis, and dimethyl ether synthesis reactions are thermodynamically favored under high- pressure conditions. However, in the case of methane dry reforming and reverse water-gas shift, applying high pressure, results in decreased selectivity toward desired products and an increase in coke production, which can be detrimental to both the catalyst and the reaction system. Nevertheless, high-pressure utilization proves industrially advantageous for cost reduction when these processes are integrated with Fischer-Tropsch or methanol synthesis units. This review also compiles recent advances in heterogeneous catalysts design for high-pressure applications. By examining the impact of pressure on CO2 valorization and the state of the art, this work contributes to improving scientific understanding and optimizing these processes for sustainable CO2 management, as well as addressing challenges in high-pressure CO2 valorization that are crucial for industrial scaling-up. This includes the development of cost-effective and robust reactor materials and the development of low-cost catalysts that yield improved selectivity and long-term stability under realistic working environments.
Evidence of Ambient Pressure Methanol Production on Ni-Ga-Ca 1 Dual Function Materials and Dynamic Restructuring Effects on Selectivity
(Elsevier, 2025-09-15) Paksoy, Aysun Ipek; Bobadilla Baladrón, Luis Francisco; Blay Roger, José Rubén; Merkouri, Loukia Pantzechroula; López Flores, Víctor; Coppex, Claude; Jelic, Jelena; Studt, Felix; Ramírez Reina, Tomás; Odriozola Gordón, José Antonio; Duyar, Melis Seher; Química Inorgánica; Física Aplicada I; Engineering and Physical Sciences Research Council (EPSRC). UK; Deutsche Forschungsgemeinschaft / German Research Foundation (DFG); Ministerio de Ciencia e Innovación (MICIN). España
This study reports a dual function material (DFM) composed entirely of non-precious metals for methanol production (13.8 μmol/g material) at ambient pressure from passively captured CO2 from the air. While state of the art carbon capture and utilisation (CCU) processes rely on expensive CO2 capture systems and a high-pressure catalytic reactor for methanol synthesis, this Ni-Ga-Ca DFM can be an enabler for significant energy efficiency gains in methanol synthesis from CO2 through the direct utilisation of dilute emissions and substantially lower operating pressures. Using operando DRIFT spectroscopy coupled with density functional theory, XAFS, XRD, and TEM-HAADF, a combination of Ni-Ga intermetallic species and their oxides are identified as the active sites. During cyclic operation a shift in selectivity towards methane is observed, which is associated with dynamic restructuring of the DFM. Guided by mechanistic and structural understanding, a synthesis strategy is developed to enhance cyclic stability by mitigating dealloying and Ni particle agglomeration. It is indicated that cyclic stability can be achieved by strengthening the Ni-Ga-Ca interaction, however, there remains a gradual shift in selectivity towards methane which highlights the need for further material optimisation.
Enhanced low-temperature CO2 methanation over La-promoted NiMgAl LDH derived catalyst: Fine-tuning La loading for an optimal performance
(Elsevier, 2024-06-15) Wang, Ziling; Zhang, Tianyu; Ramírez Reina, Tomás; Huang, Liang; Xie, Wenfu; Musyoka, Nicholas M.; Oboirien, Bilainu; Wang, Qiang; Química Inorgánica; National Key R&D Program of China; National Natural Science Foundation of China
LDH-derived Ni-based catalysts are gathering momentum due to their excellent thermal stability but their low-temperature CO2 methanation is limited. In this study, various concentrations of La were introduced into the LDH-derived Ni-based catalysts for CO2 methanation, and the underlying mechanisms were investigated. The optimal Ni/La0.2-MgAlOx catalyst presented a CO2 conversion level of 69.0% at 225 oC, which is over 7 times higher than that of conventional Ni/MgAlOx. The addition of small amounts of La could significantly enhance H spillover to promote the reduction of Ni species, but the oxygen vacancy concentration became the dominant factor causing changes in low-temperature activity as the La contents continue to increase. CO2 was found to be adsorbed at the oxygen vacancies in the form of bidentate carbonates, which are more reactive under an enhanced electron-rich environment. The research offers guidance to design effective and sustainable catalysts for low-temperature CO2 methanation.
Construction of cellulose nanofiber-Ti3C2Tx MXene/silver nanowire nanocomposite papers with gradient structure for efficient electromagnetic interference shielding
(Springer Nature, 2024-02-16) Zhao, Yao; Miao, Baoji; Nawaz, Muhammad Asif; Zhu, Quinsong; Chen, Qiuling; Ramírez Reina, Tomás; Arsalan, Muhammad; Química Inorgánica; Colleges and Universities in Henan Province; Henan Provincial Science and Technology; Zhengzhou Science and Technology Bureau
With the widespread application of communication equipment with electromagnetic signal transmission to cause electromagnetic radiation pollution, there is an urgent need for high-performance electromagnetic shielding materials. Here, an ultrathin, flexible, alternating multilayered, and conductive gradient-structured cellulose nanofiber–MXene/silver nanowire (CNF-MXene/AgNW) nanocomposite paper with high mechanical strength, strong electromagnetic interference (EMI) shielding, and outstanding thermal management was constructed via the alternating vacuum filtration (AVF) process. The extensive hydrogen bonding interactions between MXene, CNF, and AgNW enhance the interfacial adhesion and conductive synergy between layers, resulting in excellent tensile strength of 194.3 MPa and fracture strain of 7.62% of nanocomposite paper. The alternating conductive gradient structure of the nanocomposite paper greatly increases the interlayer multiple reflections and absorption of electromagnetic waves, resulting in a high conductivity of 3237.35 S cm−1 and excellent electromagnetic shielding efficiency of 65.4 dB for the nanocomposite paper. Under an external low voltage of 3 V, the surface temperature of the nanocomposite paper reaches 107.2 ℃ within 10 s and can be stable for a long time. These results indicate that CNF-MXene/AgNW nanocomposite paper with a conductive gradient structure has potential applications in the fields of aerospace, communication engineering, and wearable devices.
Reforming of biomass-derived producer gas using toluene as model tar: Deactivation and regeneration studies in Ni and K-Ni catalysts
(Elsevier, 2024-04-15) Azancot Luque, Lola de las Aguas; González Castaño, Míriam; Bobadilla Baladrón, Luis Francisco; Centeno Gallego, Miguel Ángel; Odriozola Gordón, José Antonio; Química Inorgánica; Ministerio de Economía y Competitividad (MINECO). España; Universidad de Sevilla
Within the syngas production from biomass gasification, tar removal constitutes a chief issue to overcome for advanced catalytic systems. This work investigates the performance of Ni and Ni–K catalysts for reforming of derived-biomass producer gas using toluene as model tar. At 750 °C and 60Lg−1h−1, the stability test (70 h) revealed stable performances (CO2, CH4 and C7H8 conversions of 60, 95 and 100%, correspondingly) uniquely for the Ni–K catalyst. Although the efficient protection towards coking let by K was demonstrated, TPO studies over the post-reacted systems still evidenced the presence of carbon deposits for both samples. Conducting three successive reaction/regeneration cycles with different gasifying agents (air, steam and CO2) at 800 °C for 1h, the capability towards regeneration of both catalytic systems was assessed and the spent catalysts were characterized by XRD, SEM and TEM. While none of the regeneration treatments recovered the performance of the unpromoted catalyst, the Ni–K catalysts demonstrated the capability of being fully regenerated by air and CO2 and exhibited analogous catalytic performances after a series of reaction/regeneration cycles. Hence, it is proved that the addition of K into Ni catalysts not only enhances the resistance against deactivation but enables rather facile regenerative procedures under certain atmospheres (air and CO2).
Novel heterostructured NaTaO3/WO3 systems with improved photocatalytic properties for water decontamination under UV and Visible illumination
(Springer Nature, 2024-05-09) Hernández-Laverde, M.; Murcia, J. J.; Navío Santos, José Antonio; Hidalgo López, María del Carmen; Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Salud y Proteccion Social de Colombia; Universidad Pedagogica y Tecnologica de Colombia (UPTC)
In this work, we present the preparation of NaTaO3/WO3 systems, a broad-bandgap and a narrow-bandgap semiconductor, respectively, for photocatalytic applications. The samples were prepared by two different methods, microwave-assisted and conventional hydrothermal method, with different NaTaO3/WO3 molar ratios. All samples were extensively characterized, and the photocatalytic behavior was studied in the degradation reaction of rhodamine B under simulated solar illumination. A significant synergistic effect in the coupling of the two components could be observed, with an important improvement in the rhodamine degradation rate, especially for the microwave-prepared sample with 1:1 (NaTaO3/WO3) molar ratio. The enhancement of the activity can be explained by the formation of type II and Z-Scheme heterojunctions. The obtained results are promising for the development of more efficient photocatalyst materials under solar or visible illumination.
New insights for valorization of polyolefins/light alkanes: catalytic dehydrogenation of n-alkanes by immobilized pincer-iridium complexes
(Royal Society of Chemistry (RSC), 2024-06-03) Centeno Vega, Ignacio; Megías Sayago, Cristina; Ivanova, Svetlana; Química Inorgánica
This scientific review delves into the innovative realm of polyolefins/light alkanes valorization through their catalytic dehydrogenation employing pincer-ligated iridium organometallic complexes. These widely studied catalysts exhibit outstanding properties, although the intrinsic characteristics of homogeneous catalysis (such as challenging product–catalyst separation, poor applicability to continuous-flow processes and low recyclability) limit their activity and industrial application, as well as their thermal stability. Through the immobilization of complexes on inorganic supports, these downsides have been bypassed, harnessing the true potential of these catalysts, affording more selective and stable catalysts in addition to facilitating their implementation in industrial processes. The findings described herein contribute to the advancement in the understanding of catalytic processes in hydrocarbon transformations, offering promising avenues for sustainable and selective production of valuable chemical intermediates from readily available feedstocks.
Solar pilot plant scale hydrogen generation by irradiation of Cu/TiO2 composites in presence of sacrificial electron donors
(Elsevier, 2018-08-05) Maldonado, M. I.; López Martín, Ángeles; Colón, G.; Peral, J.; Martínez-Costa, J. I.; Malato, S.; Química Inorgánica; Ministerio de Economía y Competitividad (MINECO). España
A Cu/TiO2 photocatalyst has been synthesised by reducing a Cu precursor with NaBH4 onto the surface of a sulphate pretreated TiO2 obtained by a sol-gel procedure. The catalyst, that shows a clearly defined anatase phase with high crystallinity and relatively high surface area, and contains Cu2O and CuO deposits on its surface, has been used to produce hydrogen in a solar driven pilot plant scale photocatalytic reactor. Different electron donor aqueous solutions (methanol, glycerol, and a real municipal wastewater treatment plant influent) have been tested showing similar or even higher energy efficiency than those obtained using more expensive noble metal based photocatalytic systems. The glycerol solutions have provided the best reactive environments for hydrogen generation.
AgBr and Ag3PO4 Coupled with TiO2 as Active Powder Photocatalysts and Glass Coatings
(MDPI, 2025-11-23) Murcia, J. J.; Marín-Polanco, P.; Hernández-Laverde, M.; Puga, F.; Navío Santos, José Antonio; Hidalgo, M. C.; Brijaldo, M.; Química Inorgánica; Ministerio de Ciencia, Tecnología e Innovación. Colombia; Ministerio de Salud y Protección Social. Colombia; Universidad Pedagógica y Tecnológica de Colombia (UPTC).
In this work, different materials based on TiO2 coupled with either AgBr or Ag3PO4 were synthesized. The Ag3PO4(50%)/TiO2 powder photocatalyst prepared by deposition–precipitation method showed higher antimicrobial activity than the bare TiO2 and also than the same coupled powder obtained by sol–gel method. This material achieved 100% E. coli, coliforms, and other enterobacteria elimination. The high bactericidal efficiency of this material could be attributed to the improved properties obtained by coupling Ag3PO4 and TiO2, such as high absorption in the visible region, low band-gap value, and high surface hydroxylation. The sol–gel method was chosen for the production of photocatalytic coatings on borosilicate glass tubes based on TiO2 and Ag3PO4/TiO2 materials due to the ease of its preparation procedure and its suitability for dip coating. In this series, the most effective elimination of E. coli, coliforms, and other enterobacteria was achieved with the glass tubes coated with the laboratory–prepared TiO2 sol. Interestingly, this material presented superior antimicrobial performance as coating (100% of E. coli elimination) compared to its powder form. The titania coating also showed the best efficiency in the degradation of methylene blue (i.e., 95.2%), though this material lost 30% of its photoactivity after four reaction cycles.
Structural and electronic modulation by Ce-doping in MOF-derived In2O3@CeO2-ZrO2 catalysts for CO2 hydrogenation
(Elsevier, 2026-01-01) Bracciotti, Edoardo; Salusso, Davide; López-Luque, Iván; Bertinetti, Stefano; Luque-Álvarez, Ligia A.; Bobadilla Baladrón, Luis Francisco; Prieto, Gonzalo; Moliner, Manuel; Bordiga, Silvia; Rojas-Buzo, Sergio; Química Inorgánica; European Union (UE); Ministerio de Ciencia e Innovación (MICIN). España
Indium oxide (In2O3) has emerged as a promising catalyst for CO2 hydrogenation to methanol due to its exceptional selectivity compared with conventional Cu-based systems, which typically yield undesired by-products despite higher conversion rates. However, the reduction of In2O3 under reaction conditions limits its long-term stability, motivating the development of robust oxide supports. In this work, we present a systematic study on the influence of cerium concentration in CeO2–ZrO2 supports on the performance of In2O3-based catalysts. A series of In2O3@Ce(100−x)Zrx materials were synthesized via a scalable and reproducible MOF-templated approach using UiO-66(Ce/Zr) precursors and subsequent calcination. Comprehensive characterization by in situ PXRD, XAS and H2-TPR revealed that low cerium incorporation (≈5 %) promotes unique Ce-Zr-In interfacial interactions, enhancing indium oxide dispersion and suppressing its reduction to metallic indium. Catalytic tests under CO2 hydrogenation conditions (25 bar, 513–573 K) demonstrated unprecedented methanol selectivity and stability for the low-Ce composition. These findings highlight the critical role of controlled Ce doping in tuning the structural and electronic properties of CeO2–ZrO2 supports and demonstrate the scalability of MOF-derived synthesis routes for designing next-generation catalysts for sustainable methanol production
Process parameters' influence on integrated CO2 capture and methanation: finding optimal conditions by Bayesian optimisation
(IOP Publishing, 2025-12-31) Gharamaleki, Soudabeh Bahrami; Short, Michael; Ramírez Reina, Tomás; Duyar, Melis S.; Química Inorgánica; European Union (UE). H2020
Process parameters can significantly influence the performance of dual functional materials (DFMs) in CO₂ capture and methanation applications. In this experimental and computational optimisation study, the effects of temperature, CO₂ concentration, H₂ concentration, adsorption time, hydrogenation time, and weight hourly space velocity (WHSV) on CO₂ capture and its subsequent hydrogenation to methane were investigated for a 15%Ni1%Ru,10%Ca/Al₂O–CeO₂ DFM. Results from the parametric analysis indicate that temperature, hydrogen concentration, hydrogenation time, and WHSV markedly affect methane yield. In contrast, adsorption time and CO₂ concentration exert relatively limited influence. Further insights obtained through hybrid Gaussian process modelling and Bayesian optimisation demonstrate that determining the optimal process parameters is challenging due to the trade-off between hydrogen consumption and methane production. Nonetheless, by employing a human-in-the-loop optimisation approach, optimal conditions were identified and experimentally validated as: temperature, of both adsorption and conversion steps, 374 °C, hydrogenation time of 16 min, and a WHSV of 14 l g−1h−1 for both adsorption and conversion steps, with a 10% increase in methane production at optimal conditions. Under these conditions, methane production reached 345.44 μmol gDFM−1. This study demonstrates the power of computational approaches to speed up process optimisation and design of DFMs for improved future integrated carbon capture and utilisation applications.
Photo-assisted degradation of rhodamine B with H2O2: Kinetics, modern machine learning prediction, and insights into a novel iron oxide catalyst
(Elsevier, 2025-08-29) Zahi, Salah Eddine; Hidalgo, M. C.; Navío Santos, José Antonio; Heddam, Salim; Yacine, Kerchich; Química Inorgánica; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
This study introduces a dual strategy that combines kinetic modeling and advanced machine learning (ML) models to enhance the prediction and optimization of Rhodamine B (RhB) degradation using an H2O2/UV system. As a novel scientific contribution, we report the first-time synthesis of an iron-based catalyst, integrating α-Fe2O3 with structural ions (SO₄2−, OH−, Cl−), synthesized via a microwave-assisted hydrothermal method, a rapid and energy-efficient approach conducive to scalability. The synthesized catalyst was thoroughly characterized by XRD, FTIR, SEM-EDX, XPS and BET, confirming its crystalline integrity, surface richness, and robust textural properties. In the machine learning analysis, CatBoost regression outperformed XGBoost, ERT, and GPR, delivering the highest predictive accuracy for RhB degradation under varying operational conditions of H2O2/UV. SHAP (SHapley Additive exPlanations) interpretation revealed that reaction time held the greatest predictive importance, followed by the initial concentrations of H2O2 and RhB. Experimental results showed that the α-Fe2O3 catalyst consistently achieved complete RhB discoloration within 60 min under illuminated conditions, demonstrating exceptional photocatalytic activity. Most interestingly, the integration of the catalyst with H2O2, under both dark and illumination conditions (heterogeneous Fenton and photo-Fenton processes), resulted in complete RhB discoloration in as little as 1 min. Overall, this work highlights the transformative potential of ML-assisted process design in environmental catalysis and introduces a robust, scalable iron-based material, for water treatment applications, particularly in scenarios with variable light expos

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