The efficient storage of strategic gases—CH4, CO2, and H2—remains a critical challenge due to the need for high pressures or cryogenic temperatures to achieve sufficient storage densities, often resulting in energy- and cost-intensive processes. Adsorption-based storage using porous materials offers a promising alternative. In particular, ordered mesoporous carbons, such as CMK-8 and CMK-9, are attractive due to their mechanical, thermal, and chemical stability, as well as their highly tunable textural properties. Surface functionalization can further enhance gas uptake, though the effect is often gas-specific. This study investigates the adsorption performance of four carbon materials: pristine CMK-8 and CMK-9, and their oxygen-functionalized counterparts produced via HNO3 treatment. The adsorption capacities for CH4, CO2, and H2 were evaluated through a combination of experimental gas adsorption measurements and molecular simulations. The results reveal structure–property relationships between surface chemistry and gas-specific adsorption behavior, with implications for the rational design of carbon-based materials for gas storage.

Ordered mesoporous carbons have emerged as versatile supports for Fischer–Tropsch catalysts due to their high surface area, tunable pore architectures, and chemical stability. However, the influence of active-metal identity on product selectivity within a common carbon framework remains insufficiently understood, particularly when Fe and Co are compared under rigorously identical conditions. To address this aspect, we prepared Fe- and Co-based catalysts with comparable nominal metal loadings supported on CMK-5 carbon material and evaluated their structural, surface, and catalytic properties. Comprehensive characterization revealed distinct metal-dependent behaviors, and catalytic testing between 423 and 598 K at 2 MPa showed that the catalyst CMK-5(Co10) exhibited substantially higher activity, whereas CMK-5(Fe10) provided a more stable product distribution and exclusively paraffinic C2–C3 products across the studied temperature range. In contrast, CMK-5(Co10) displayed a pronounced temperature-dependent selectivity, with increasing methane formation and the emergence of olefinic C2–C3 species at intermediate and high temperatures. Chain-growth probabilities were consistent with these trends. Complementary Density Functional Theory and Kinetic Monte Carlo analyses indicated stronger binding of carbonaceous intermediates on Fe clusters and more accessible C–C coupling pathways on Co clusters. Together, these results clarify how active-metal identity governs selectivity within a shared CMK-5 architecture and provide guidelines for designing carbon-supported Fischer–Tropsch catalysts with controlled product distributions.

Worldwide, the push towards intensive food production has resulted in the excessive use of agrochemicals, resulting in considerable environmental problems, a decrease in soil biodiversity, pollution, and food insecurity. These issues have detrimental effects on human health and contribute to pest resistance. Modern agriculture needs to transition into a more sustainable activity and, to achieve this goal, the application of innovative technologies is essential. Layered double hydroxides (LDHs) are versatile and promising nanomaterials that can carry, protect, and release bioactive compounds, such as fertilizers, herbicides, and growth regulators, in a controlled manner. LDH compounds exhibit unique colloidal characteristics, a high adsorption capacity, and a comparatively low cytotoxicity for both plants and animals. As the cation layers and the interlayer anions in LDHs stack via electrostatic interactions, any anion can be incorporated into the gallery space. This chapter reviews the most recent studies related to the development of nanostructured materials based on functionalized LDHs as promising nanocarriers for nutrients, traditional pesticides, and environmentally friendly bioactive substances, including a discussion of the biological efficacy of these formulated agro-inputs and the use of functionalized LDHs on soil and water remediation.

Ordered mesoporous carbons with a three-dimensional cubic structure, CMK-8 and CMK-9, were synthesized using the hard-template method and evaluated, for the first time, as drug delivery systems for cephalexin (CFX), a widely used antibiotic in infectious disease therapy. The materials were functionalized with 3-aminopropyltriethoxysilane via grafting to enhance aqueous dispersion and control drug release. CFX was loaded by adsorption, and its release was studied under simulated oral conditions at acidic (pH 1.2) and intestinal (pH 6.8) environments. Due to its dual mesoporosity and larger surface area, CMK-9 exhibited superior CFX adsorption capacity compared to CMK-8. Both materials facilitated controlled drug release, with CMK-9 achieving the highest release rate (89 %) within 14 h under acidic conditions, whereas pure CFX exhibited a much faster release. Kinetic analysis using the Weibull model indicated a Fickian diffusion mechanism governed by porosity and electrostatic interactions. These findings underscore the potential of ordered mesoporous carbons with cubic structures as promising platforms for controlled antibiotic delivery.

Biomass from agro-industrial waste is a vital renewable resource for addressing energy and environmental challenges. Hydrothermal carbonization (HTC) is utilized to produce hydrochar from various materials, including these wastes, for environmental remediation and other industrial applications. In this work, the effects of temperature and treatment time on the solid and liquid obtained from the application of the HTC process to grape stalks were assessed. The energetic properties of the hydrochar, its physico-chemistry, and that of the activated carbons prepared with it were evaluated by proximate analysis, higher heating value (HHV), BET area, pore volume, FTIR, and SEM. Temperature significantly impacted the hydrochar’s mass yield (50

Clay-based monoliths with incorporation of active phases derived from the waste of the metallurgical and livestock industries (powdered iron and bone meal) and composite with both raw materials were synthesized by the extrusion process and used as adsorbents in the As(V) removal from aqueous solutions. These monoliths exhibited excellent mechanical properties compared to commercial ceramic-based monoliths, with potential for their use in continuous systems due to ease of handling and extraction of the adsorption medium (i.e., packed bed) and having defined meso and macroporosity. Specifically, the clay-based monoliths were obtained along with (i) active iron phases (hematite and magnetite), (ii) bone char and (iii) a combination of both materials. They showed As(V) adsorption capacities of up to 0.56, 3.4 and 8.0 mg g −1 at neutral pH and room temperature conditions. The proposed adsorption mechanism was associated with ligand exchange between the As(V) species and the hydroxyl functional groups, in addition to the presence of inner-sphere bidentate unprotonated arsenate surface complexes that was reflected in the formation of new absorption bands in Fourier Transform Infrared Spectroscopy spectra related to the Metal-O interaction and changes in the bands associated with the -OH groups. The SIPS isotherm model fitted the experimental data obtained at equilibrium and was related to strong adsorbent/adsorbate interactions and high surface heterogeneity. Finally, the composite ceramic monolith synthesized in the present study exhibits capabilities comparable to those reported in the literature, highlighting the low cost of raw materials, as well as its excellent mechanical properties and well-defined porosity.

This study compares two in vitro loading and release systems for the antibiotic cephalexin (CFX), based on ordered mesoporous silica (SBA-15) and carbon (CMK-5) materials, both pure and modified with 3-aminopropyltriethoxysilane. Drug loading was performed using the adsorption method under constant conditions (pH: 6, T: 30 degrees C, and t: 8 h), and the release mechanisms were investigated at gastric and intestinal pH to understand the phenomena involved in the oral delivery of CFX studied. The results revealed a higher adsorption capacity of CMK-5 due to its microporosity and it-it stacking interactions compared to SBA-15. Furthermore, the presence of functional groups prevented the formation of crystalline phases by adsorption on the external surface. A reduction in the release rate of CFX was observed with both carriers, governed by a Fickian diffusion mechanism. Notably, CMK-5 exhibited a higher release rate at gastric pH compared to SBA-15, while the opposite was true at intestinal pH. These findings provide deeper insights into the behavior of carriers with different chemical compositions in antibiotic release, suggesting their potential as an alternative to address issues associated with the dosing frequency of these drugs.

The replacement of plastic-based consumables with sustainable biodegradable biopolymers is an enormous challenge. In this study, we report the synthesis of new chitin materials designed for use as a chromatographic matrix in protein adsorption and purification. The internal porous structure of the chitin material was created using calcium carbonate and silica particles (C and S, respectively) as porogens. In addition, a drying treatment was tested before removing each porogen to evaluate whether it improved the structure adopted by chitin, resulting in CO and SO materials. A control material (Ch) was also synthesized. The physicochemical properties were characterized using ATR-FTIR, SEM, BET, swelling, and porosity estimation. Ch and C matrices were rough, while CO, S, and SO were porous. The S matrix exhibited open, interconnected pores measuring 6.29 +/- 2.70 mu m in size, with a surface area of 50 m2 g- 1 and 85.71 % porosity. Adsorptive characterization using pure lysozyme through Langmuir modeling showed that the highest Qm value was found for Ch (55.499 +/- 2.214 mg g- 1), while the lowest Kd value was observed for the S matrix (0.491 +/- 0.096 mg mL-1). The results suggest that the new chitin-based material synthesized with silica particles has promising properties for chromatographic applications.

The development of cost-effective and environmentally sustainable electrocatalysts for the oxygen reduction reaction (ORR) is critical for advancing oxygen-based energy conversion and storage technologies. Herein, a guanine-derived Zn single-atom nitrogen-doped carbon (ZnNC) electrocatalyst featuring high-density Zn-N4 active sites and exceptional catalytic performance is reported. Using a molten salt templating method, ZnNC nanoparticles were synthesized, exhibiting high specific surface areas and both micro and mesopores. Electrochemical studies demonstrated that ZnNC electrocatalyst outperforms commercial Pt/C catalysts, achieving a higher onset potential, greater half-wave potential, and enhanced current density. Density Functional Theory (DFT) calculations reveal that the tetrapyrrolic Zn-N4 sites are crucial in facilitating O2 adsorption and hydroperoxyl (OOH*) intermediate formation, thereby driving the ORR through a highly efficient four-electron transfer pathway. These findings highlight the potential of ZnNC electrocatalysts as promising alternatives to precious-metal catalysts in fuel cells and oxygen-based batteries.

Este estudio presenta la síntesis de nanopartículas de óxido de cobre (NPsCuO) mediante el método de precipitación química, con énfasis en su caracterización estructural por difracción de rayos X (XRD) y espectroscopia fotoelectrónica de rayos X (XPS). Las nanopartículas presentan morfología semiesférica y un promedio de tamaño de partícula de 124 nm, según lo revelado por microscopía electrónica de barrido (MEB). El análisis de DRX confirmó la formación de la fase monoclínica, con tamaños de cristalito de ~22 nm. Por medio del refinamiento de Rietveld (Chi² = 1.2) de los espectros de DRX se pudo confirmar que la distancia Cu–O es de 1.96 Å y los ángulos de enlace son 60.67° y 154.57°. El análisis XPS mostró picos Cu 2p?/? (~942.7 eV) y Cu 2p?/? (~962.7 eV), característicos del estado de oxidación del Cu²? en CuO. Los resultados confirman la eficacia del método para obtener NPs de CuO de alta pureza.

Ni-ZSM-5 catalysts with different Ni loadings were synthesized by the one-pot method, using ethylenediamine as a complex agent to prevent precipitation during the hydrothermal synthesis. The effect of nickel content and synthesis time on the crystallinity of the solids was characterized by X-ray diffraction. The results showed that an increase in the synthesis time was needed to obtain catalysts with high crystallinity. The increment in the reduction temperature for the catalyst with lower Ni content indicated the formation of Ni species with higher interaction with the support. All the solids were active for the dry reforming of methane, showing the catalyst with 1.3 wt.% of Ni superior activity per gram of Ni and lower carbon formation. This catalyst was stable under the DRM reaction even after 48 h. The performance of this solid could be attributed to the greater confinement of Ni crystallites within the support, which improved metal support interaction, as evidenced by temperature- programmed reduction and X-ray Photoelectron Spectroscopy and suggested by transmission electron microscopy.

Lithium recovery from natural sources such as continental brines is an alternative to reaching high lithium demands. However, the current evaporitic technology is recognized for its techno-economic disadvantages and negative environmental impacts. Lithium manganese oxides were synthesized, characterized, and evaluated in this work regarding their capacity for selective lithium recovery from natural brine through adsorption. Two synthetic methodologies were assessed, a solid-state synthesis and a hydrothermal method, and the conditions of formulations were modified to prepare 13 different lithium manganese oxides with very high lithium recovery capacity. The formulated sub-micrometer sized particles showed diameters ranging from 149 nm to particles of about 1500 nm. Several lithium manganese oxide ion sieves were obtained from different Li:Mn ratios of precursors: LiMn2O4, Li1.33Mn1.67O4, and Li1.6Mn1.6O4. Lithium adsorption capacity showed significant differences depending on the chemical structure, but especially on the particle size of the adsorbent, with some influence of the mesoporosity. The maximum lithium recovery capacity was 35.4 mgLi/gHMO when Li1.6Mn1.6O4 of 317 nm or 166 nm was used. The cyclability showed a high dependence on particle size. The general trend is that the adsorption capacity is more significant when particle size is smaller. All lithium-ion sieves showed high lithium selectivity in complex media, such as natural brine. Mn was not detected in neither the lithium deprived brine, nor in the HCl recovery solution, which was attributed to the room temperature and the neutral pH of the adsorption tests, as compared with previous studies.

In this work, MgO-based sorbents for CO2 capture at intermediate temperatures were developed by modifying MgO through a hydration-dehydration technique assisted by organic acids and incorporating an alkaline nitrate salt mixture. The effect of oxalic, citric, and acetic acid on the physicochemical properties of MgO was investigated using XRD, FTIR, SEM, CO2-TPD, and N2-adsorption-desorption (at -196 degrees C) techniques. Notably, MgO modified with oxalic acid exhibited significant enhancements of textural, morphological, and basic properties when compared to other samples. Before the capture measurements, the unmodified and modified MgO samples were impregnated with a mixture of Na-Li-K nitrate salts. The sample modified with oxalic acid achieved the highest capture capacity of 0.54 gCO2/g compared to 0.34 gCO2/g for the unmodified material. Stability tests showed that the modified sample retained up to 80 % of its capture capacity after 10 consecutive cycles. The hydration-dehydration process with oxalic acid appeared as a potential treatment to enhance the performance of MgO-based sorbents in the CO2 capture at intermediate temperatures.

This work presents the synthesis of activated carbons from coffee husk pre- treated with steam explosion. The influence of the impregnation ratio (H3PO4/precursor) and impregnation time was evaluated. The synthesised materials were characterised by N-2 adsorption-desorption isotherms at 77 K and CO2 adsorption at 273 K, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. These techniques confirmed the success of activated carbons from the coffee industry waste. Two selected activated carbons were further evaluated for their CO2, CH4, and H-2 adsorption capacities at 308 K, 298 K, and 77 K, respectively, under pressures of up to 10 bar. CA-1 and CA-5 exhibited promising H(2)adsorption capacities, comparable to values reported. These findings open up new possibilities for developing porous carbon- based activated materials for advanced gas separation applications.

Mineral aerosols are one of the most important ice nucleating particles (INPs) because their efficiency in nucleating ice, wide transport and largest mass contribution to particulate matter in the atmosphere. They are sourced from the arid regions of the world. In this context, this work evaluates the INP potential of fourteen topsoil samples collected from subtropical South American deserts, the major source of mineral aerosols in South America, in the immersion freezing mode. Samples were obtained from three distinct regions located in the South American Arid Diagonal and recognized as potential dust source areas: the Puna-Altiplano Plateau in the north, the central-west of Argentina, and Patagonia in the south. In general, results reveal that samples from the Puna-Altiplano and Patagonia regions, and the central-west of Argentina region exhibit the highest and lowest INP abilities, respectively. The active sites per unit surface area for a given temperature were calculated and compared with previously reported values. The results demonstrate that soil mineral particles from the region of study exhibit ice nucleating abilities comparable to the inorganic fraction of agricultural soils of central Argentina. No direct relationship was identified between INP ability and the major minerals observed in the samples. This study is the first to analyze the ice nucleation properties of soil samples collected along the South American Arid Diagonal and one of the few in South America. Since the analyzed topsoil particles were collected from potential dust source regions, this work contributes to understanding the role of aerosols in initiating atmospheric ice formation, providing valuable data for empirical parameterizations. This could contribute to the improvement in the performance of climate models, as the obtained results suggest that the underestimation of coarse and super-coarse aerosols at altitudes relevant for cloud formation may lead to underestimations in INP concentrations, particularly in regions near to the emission sources.

This research focuses on developing MIL-53-type compounds with Fe obtained with ligands derived from PET waste, followed by the controlled addition of hydrofluoric acid (HF). Incorporating HF into the MOF structure induced substantial changes in the material textural properties, resulting in a significant change in CO2 adsorption. Furthermore, a distinctive structural alteration (breathing effect) was observed in the CO2 isotherms at different temperatures; these structural changes have not been observed by X-ray diffraction (XRD) because this characterization has been performed at room temperature, whereas the adsorption experiments were conducted at 260, 273, and 303 K and different pressures. Subsequently, DFT studies were performed to investigate the CO2-filling mechanisms and elucidate the material respiration effect. This approach offers promising opportunities for sustainable materials with improved gas adsorption properties.

Herein, ordered mesoporous materials like SBA-15 and Al/SBA-15 were prepared using the pH adjustment method. Thus, these materials were developed in different pH of synthesis, from the pH adjustment method using a KCl/HCl solution and varying the Si/Al molar ratio (5, 25, and 75). All the ordered mesoporous materials were characterized by FRX, 27Al NMR, SEM, XRD, N2 adsorption/desorption, and CO2 adsorption. From the applied method, it was possible to obtain SBA-15 and Al/SBA-15 with high mesoscopic ordering based on the XRD patterns, independent of the pH employed. From the chemical composition, the insertion of higher amounts of Al into the synthesis caused a progressive improvement in the structural and textural properties of the ordered mesoporous materials. Thus, the chosen synthesis conditions can lead to different aluminum coordination (tetrahedral and octahedral), which gives these materials a greater potential to be applied. The presence of Al in high amounts provides material with the ability to form micropores. Finally, the proposed method proved to be innovative; low-cost; less aggressive to the environment, with efficient insertion of aluminum in the framework of SBA-15 mesoporous material; and practical, based on only one step.

In this work, we present the preparation of a hybrid material constituted by a Metal-Organic Framework (type MIL-101(Fe)) and a natural clay ceramic monolith (NCCM), the materials were successfully assembled through an in-situ hydrothermal method. The composites were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms at 77 K and CO2 adsorption at 273 K; these techniques confirmed the obtaining of the hybrid material and, in addition, through studies before and after adsorption mechanisms involved were identified. Then, the As(V) adsorption capacity of the materials was evaluated using an aqueous arsenic solution; from which high adsorption capacities of up to 268 mg g- 1 and 61.5 mg g- 1, respectively. In addition, kinetic and equilibrium studies of As(V) adsorption were carried out. Finally, the potential capacities of the hybrid material consisting of Al2O3, AlO6-SiO4 and Fe3O4 for the adsorption of H3AsO4, were studied through density functional theory calculations.

Extensive efforts have been dedicated to developing conductive carbon materials for cementitious composites to impart multifunctional properties to these materials. Due to environmental concerns, there is a growing demand for abundant, sustainable, and eco-friendly resources. In this context, biochars emerge as a promising option for multifunctional material advancement. Their production process is straightforward and cost-effective, making biochar an attractive carbon-based material choice. This study explores the potential of powdered biochar derived from peanut shells as a conductive additive for cement-based composites. Biochar was generated through thermochemical conversion of peanut shells under oxygen-deficient (OD) conditions, achieving a low resistivity of 0.01 Ω·m at 1300 ºC. The properties of cement composite pastes incorporating up to 50 wt