Search

• Alum sludge is a low-cost alternative Si and Al source for zeolite synthesis. • Recycle alum sludge for zeolite synthesis reduce water treatment's environmental impact. • Zeolite synthesis from alum sludge provides a sustainable way to waste management. • Aluminosilicate synthesis using alum sludge adds an economic/environmental value. Alum sludge (AS) is a by-product generated from drinking water treatment and produced in large amounts around the world. Its chemical composition makes this waste an emerging alternative source of silicon and aluminum for aluminosilicates or zeolite material production, which can add value to residues and contribute to the circular economy process on a global scale. In this sense, and considering the scarcity of information about AS, this review shows data collection about AS in different countries, including generation, chemical composition, and disposal information. The reuse of AS is discussed based on circular economy and the environmental gains derived from such approaches are highlighted, including the possibility of utilization with other residues (e.g., ash, bioproducts, etc). Moreover, this review shows and discusses the benefits and challenges of AS reuse in the synthesis process and how it can be a sustainable raw material for aluminosilicates and zeolite synthesis. The most common conditions (conventional or non-conventional) in zeolite synthesis from AS are mentioned and advantages, limitations and trends are discussed. The discussions and data presented can improve the AS management and reuse legislations, which certainly will collaborate with sustainable AS use and circular economy processes. [ABSTRACT FROM AUTHOR]

Increasing the charging cut‐off voltage can significantly improve the capacity of LiCoO2 cathode. However, when the cut‐off voltage exceeds 4.5 V (vs Li/Li+), LiCoO2 undergoes irreversible phase transitions, leading to particle cracking and structural failure. Additionally, the decomposition of the electrolyte compromises the stability of the cathode/electrolyte interface, resulting in diminished battery capacity. Herein, the elements Al, Mg, and Zr are doped into single‐crystal LiCoO2 to enhance the structural stability of LiCoO2. Moreover, a 3 Å zeolite film is used to regulate the solvation structure to enhance the oxidation resistance of the electrolyte. This design enables a more stable cathode/electrolyte interface during high‐voltage cycling. At a cut‐off voltage of 4.8 V, the Li||LiCoO2 battery exhibits an initial discharge capacity of 236.2 mAh g−1 at 0.1 C and maintains 86.6% capacity retention after 100 cycles at 1 C. The pouch full cell, which utilizes a graphite anode and LiCoO2 cathode, operating within a charge–discharge range of 2.8–4.65 V, achieves a specific energy of 276 Wh kg−1 with 81% capacity retention after 200 cycles. This work introduces a desolvated electrolyte into the LiCoO2 battery system, providing a professional approach to addressing the challenges of high‐voltage LiCoO2. [ABSTRACT FROM AUTHOR]

At present, the regulation mechanism of the number and type of amino groups in the precursor and the number of alkyl chains in amine compounds on afterglow performance is not clear. To address this problem, a series of amine compounds as carbon sources is designed and utilized AlPO‐5 zeolite as the matrix to create a range of carbon dots@zeolite composite materials (CDs@AlPO‐5). N heteroatoms not only increase the potential for triplet emission but also introduce more N/O (C═O/C═N/N─H bonds) into the system as the number of amino groups increases. The introduction of abundant active groups and the strong interaction between carbon dots (CDs) and molecular sieve matrix induces a red shift in the afterglow emission wavelength and an increase in lifetime. The quantum yields (QYs) of CDs@AlPO‐5 are affected by the type of amino groups and the number of alkyl chains in the carbon source. The higher activity of the amino reaction site and the reduction in the number of alkyl chains help to regulate the afterglow emission behavior. Intelligent selection of the type and number of amino groups is an important step toward broadening the basis for controllable preparation of highly efficient afterglow materials based on CDs. [ABSTRACT FROM AUTHOR]

Subnanometer metal clusters show advantages over conventional metal nanoparticles in numerous catalytic reactions owing to their high percentage of exposed surface sites, abundance of under‐coordinated metal sites and unique electronic structures. However, the applications of subnanometer metal clusters in high‐temperature catalytic reactions (>600 °C) are still hindered, because of their low stability under harsh reaction conditions. In this work, we have developed a zeolite‐confined bimetallic PtIn catalyst with exceptionally high stability against sintering. A combination of experimental and theoretical studies shows that the isolated framework In(III) species serve as the anchoring sites for Pt species, precluding the migration and sintering of Pt species in the oxidative atmosphere at ≥650 °C. The catalyst comprising subnanometer PtIn clusters exhibits long‐term stability of >1000 h during a cyclic reaction‐regeneration test for ethane dehydrogenation reaction. [ABSTRACT FROM AUTHOR]

Foam materials produced from biopolymers stand out as a more environmentally friendly insulation material solution. This study presents a comprehensive investigation into the development and optimization of chitosan‐based foam materials using a Box–Behnken design. The foams were engineered using varying proportions of chitosan (0.5–3%), cellulose (0.5–3%), and zeolite (0.5–3%), targeting their application as thermal insulators. The physical and thermal properties of the foams that were produced were affected by the type and ratios of components, with density and thermal conductivity ranging from 0.0853 to 0.1915 g cm−3 and 0.0324 to 0.0921 W mK−1, respectively. Higher chitosan content improved insulation properties and mechanical strength whereas zeolite increments increased density and thermal conductivity. Using statistical analysis through the Box–Behnken design, we optimized the foam formulations, achieving minimum thermal conductivity and maximum compression strength at an averaged density, suggesting a strong potential for environmental sustainability applications. The recommended optimal chitosan:cellulose:zeolite composition ratio of 3:3:0.88 provides a valuable insight for tailored foam material formulation. This study shows the relationships between the composition of a composite material and its resultant properties, optimizing its preparation for industrial applicability in an environmentally conscious way within the context of insulation and construction. This investigation contributes to the field of material science by highlighting the versatility and potential of biopolymers but also aligns with the increasing need for green building materials. [ABSTRACT FROM AUTHOR]

Landfilled solid waste polymers were converted into high octane green fuels and hydrocarbons by a catalytic depolymerization process. Experiments were conducted in a batch catalytic reactor pressurized with methane as a co-feed. Design of Experiments (DOE) methodology was used for process optimization and parametric study. The operating conditions that maximize the liquids aromatic hydrocarbons were found using response optimizer tool. The reaction temperature and polymer to catalyst ratio (PCR) were found to have significant effects on the responses and methane pressure was not significant for yields of solids, liquids and gaseous products. However, pressurized methane facilitated dehydrocyclization reactions resulting in increased monoaromatic hydrocarbons in the final liquid products. Experiments conducted with methane feed at optimized reaction conditions resulted in 89% aromatic hydrocarbons, 8% paraffins and about 3% other hydrocarbons in liquid products. Aromatic products included benzene (6.5%), toluene (25%), xylenes (27%), ethylbenzene (4.5%), other monoaromatics (22%) and polyaromatic hydrocarbons (4%). Gaseous products contained propylene (47%) and hydrogen (23.9%). The utilization of waste polymers as feedstock materials, flare gas (methane) as a co-feed, and zeolite catalysts makes this batch zeolitic slurry process greener, resulting in green hydrocarbons and green fuels. [ABSTRACT FROM AUTHOR]

In the current study, the effects of cement or lime content, fibre content, partial cement or lime replacement with zeolite and curing time on the Unconfined Compressive Strength (UCS) of sand have been investigated. The results reveal that increasing cement or lime content increases Maximum Dry Density (MDD) and Optimum Water Content (OMC). However, increasing zeolite replacement percentage decreases MDD and OMC. Increasing the fibre content from 0 to 4% reduces the MDD and increases OMC. The optimum combination of the stabiliser and fibre has been derived from an array of tests. Results comparison shows the 0.5% fibre content and 8% stabiliser results in maximum effect. Also, the optimum percentage of 80% replacement of lime and 30% and 40% replacement of the cement with zeolite leads to the maximum UCS. Observing failure patterns demonstrates the influential performance of fibre content such as controlling the crack length and brittle behaviour. Moreover, SEM analysis was conducted to compare the microscale behaviour. [ABSTRACT FROM AUTHOR]

In this study, a natural zeolite supported Co-B catalyst (Co-B/Zeolite) with a Co content of 10 wt.% was prepared by impregnation and chemical reduction method to release hydrogen gas from an alkaline sodium borohydride (NaBH4) solution. The synthesized catalyst was characterized with various characterization techniques, including X-ray diffraction (XRD), X-ray fluorescence (XRF), inductively coupled plasma mass spectroscopy (ICP-MS), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS), etc. It was found that the BET specific surface area of Co-B/Zeolite (26.03 m2 g−1) was roughly double that of the zeolite (13.12 m2 g−1). The Co ratio in the catalyst was found to be 12.02 wt.% by EDX analysis. ICP-MS examination of the catalyst revealed a B/Co atomic ratio of 0.64. No peaks associated with Co-B were observed in the XRD pattern of the catalyst, indicating the amorphous nature of the component. Parameters that have significant effects on the hydrolysis reaction, such as catalyst amount, sodium hydroxide and sodium borohydride concentrations, and reaction temperature, were investigated. The hydrogen generation rate (HGR) was found to be 1732 mL min−1 gcat−1 in the presence of 100 mg of Co-B/Zeolite in 5 wt.% NaOH and 5 wt.% NaBH4 solution at 50 °C. The experimental results were well fitted to the zero-order kinetic model (k0 = 0.0296–0.1619 mol min−1 gcat−1 for 20–50 °C). The activation energy (Ea) of the catalytic reaction was found to be 44.98 kJ mol−1. Meanwhile, the reusability evaluations showed that the catalyst preserves high stability and can still sustain 73% of its initial activity after 5 catalytic cycles. [ABSTRACT FROM AUTHOR]

The solvolysis of ammonia borane (AB) and the hydrogenation of nitroarenes represent significant reactions for hydrogen generation and value-added chemical synthesis. The strategic engineering of the catalysts is imperative for surmounting obstacles associated with their stability and catalytic efficiency. In this work, subnanometric bimetallic Pt–Pd clusters were encapsulated within silicalite-1 (S-1) zeolites through a ligand-protected in-situ hydrothermal synthesis method. The synergetic effect of bimetallic composition and zeolite confinement markedly enhances the catalytic performance of representative Pt0.5 Pd0.5@S-1-H catalyst, affording exceptional turnover frequency (TOF) values of 1,043 and 573 molH2 molmetal−1 min−1 for AB hydrolysis and methanolysis at ambient conditions, respectively, surpassing most of the state-of-the-art Pt-based catalysts. Kinetic and isotopic experiments reveal that the bimetallic catalytic system remarkably boosts the O–H cleavage of water, thereby facilitating the H2 production from AB hydrolysis. Remarkably, a conspicuous synergistic effect is demonstrated in the shape-selective tandem hydrogenation of nitroarenes, with the bimetallic catalyst facilitating both AB hydrolysis and nitroarene hydrogenation, giving a high TOF value of 1,260 h−1 under atmospheric pressure. This study not only demonstrates the effectiveness of bimetallic nanocatalysts encapsulated in zeolites for hydrogen production from chemical hydrogen storage materials, but also paves the way for the design of catalysts with multifunctional active sites capable of synergistically promoting tandem catalytic processes. [ABSTRACT FROM AUTHOR]

The paper presents the results of research on the production of cast composites based on aluminum alloys with a mineral filler with a porous structure. AlSi12 silumin and AlSi12 silumin with the addition of 3% magnesium (AlSi12-Mg3) were used as the matrix material, while particles of natural zeolite, expanded perlite and expanded clay with a size of 4 to 6 mm were used as the mineral filler. In order to increase the efficiency of the production process, the mineral particles have been covered with a sodium silicon solution with the addition of silicon powder. The coated particles were then heated at 400 ℃ for 1 hour to remove moisture from them. The prepared mineral particles were then placed inside a casting mold and flooded with liquid alloy at a temperature of 790 ℃. The obtained composites were subjected to macroscopic observations and analysis using computed tomography (CT). Phase analysis was also performed to determine the phase composition of the obtained composites. In order to determine the mechanical and physical properties, the obtained composites were subjected to compressive strength tests and density measurements. As a result of the research, it was found that the use of the AlSi12-Mg3 alloy and coating in the form of a solution of sodium silicate and silicon powder allows for the most effective production of composites. The low density of the produced composites, combined with their favorable structure and strength properties, suggest the possibility of use as light products transferring compressive stresses, as well as energy-absorbing products. [ABSTRACT FROM AUTHOR]

The cost-effective separation of ethylene (C2H4), ethyne (C2H2), and ethane (C2H6) poses a significant challenge in the contemporary chemical industry. In contrast to the energy-intensive high-pressure cryogenic distillation process, zeolite-based adsorptive separation offers a low-energy alternative. This review provides a concise overview of recent advancements in the adsorptive separation of C2H4, C2H2, and C2H6 using zeolites or zeolite-based adsorbents. It commences with an examination of the industrial significance of these compounds and the associated separation challenges. Subsequently, it systematically examines the utilization of various types of zeolites with diverse cationic species in such separation processes. And then it explores how different zeolitic structures impact adsorption and separation capabilities, considering principles such as cation-π interaction, π-complexation, and steric separation concerning C2H4, C2H2, and C2H6 molecules. Furthermore, it discusses methods to enhance the separation performance of zeolites and zeolite-based adsorbents, encompassing structural design, modifications, and ion exchange processes. Finally, it summarizes current research trends and future directions, highlighting the potential application value of zeolitic materials in the field of C2H4, C2H2, and C2H6 separation and offering recommendations for further investigation. [ABSTRACT FROM AUTHOR]

The advancement of heterogeneous catalysts incorporating metal clusters in the nanometric size range has garnered significant attention due to their extraordinary catalytic activity and selectivity. The detailed characterization and understanding of the atomic structure of these metal clusters within catalysts is crucial for elucidating the underlying reaction mechanisms. In the present study, a distinctive three-atom PdNi cluster, characterized by two Pd atoms at terminal positions and a central Ni atom, was synthesized over mordenite zeolite. The presence of atomic PdNi clusters within the eight-membered ring side pocket area was confirmed by multiple advanced analytical techniques, including magic-angle spinning nuclear magnetic resonance spectroscopy, synchrotron X-ray powder diffraction, extended X-ray absorption fine structure spectroscopy, and high-angle annular dark-field scanning transmission electron microscopy. The catalytic activity of the confined active species was examined by the carbene-mediated reactions of ethyl-2-diazoacetate to ethyl-2-methoxyacetate as a model reaction. Compared to the Pd-mordenite and Ni-mordenite, the PdNi-mordenite catalyst incorporates a PdNi cluster, which demonstrates a superior performance, achieving 100% conversion and high selectivity under the same reaction conditions. Our study elucidates the potential of constructing bimetallic clusters in zeolites, providing valuable insights for developing new heterogeneous catalysts applicable to a wide range of catalytic processes. [ABSTRACT FROM AUTHOR]

The utilization of fossil fuels has been the leading choice in the industrial revolution despite its negative environmental impact. Biodiesel is a well-known alternative to replace fossil fuels because it is a renewable and environmentally friendly fuel. The use of biodiesel increases every year, causing new problems. The transesterification reaction to produce biodiesel also produces a by-product of glycerol. Glycerol is among the world's 12 most essential chemical raw materials. The abundance of glycerol has not been followed by the level of consumption, so it is necessary to increase the value of the glycerol. The transformation of glycerol into high-value-added chemicals is a promising solution to utilizing abundant glycerol. Glycerol transformation can be done through several reaction pathways catalyzed by zeolite. Zeolite is a heterogeneous catalyst with acid-base sites and good framework selectivity, making it suitable for catalytic glycerol transformation. Zeolite can be used to catalyze glycerol through various reactions into high-value-added chemicals such as glycerol oxidation to produce dihydroxyacetone, glycerol hydrogenolysis to produce propylene glycol, glycerol dehydration to produce acrolein, glycerol transesterification with dialkyl carbonate to produce glycerol carbonate, glycerol pyrolysis to produce syngas, and glycerol etherification to produce glycerol ethers. Statement of Novelty: This review highlights the current approaches to upgrade the value of glycerol, a by-product of biodiesel production, through catalytic transformation using zeolite as a heterogeneous catalyst. The catalytic processes of glycerol over zeolite with unique nanopore architectures with abundant acid sites could address the surplus glycerol problem enabling the production of high-value-added chemicals. Moreover, based on the current development, this review also provides areas of future research. [ABSTRACT FROM AUTHOR]

Background: Interest is growing in the search for alternatives to traditional feed additives, so this study aimed to investigate the effect of adding zeolite to the concentrate diets of Awassi lambs with or without urea on growth performance, nutrient digestion, and health status. A total of 45 Awassi lambs similar in weight (24 ± 2 kg) and age (3 months ± 4 days) were divided into three groups: the first group (G1) fed on a concentrate diet supplemented with 1% urea; the second group (G2) fed on the concentrate diet supplemented with 1% urea and 3% zeolite, and the third group (G3) fed on a urea-free diet supplemented with 3% zeolite. Results: The results showed a significant increase (P ≤ 0.05) in final live weight, daily and total weight gain for group G2 compared to groups G1and G3, with a significant superiority (P ≤ 0.05) of group G3 over the control group G1. Significant improvement (P < 0.05) was also observed in feed consumption and feed conversion ratio in diets supplemented with zeolite for groups G2 and G3 compared to the control group G1. Additionally, there was a significant increase (P ≤ 0.05) in nutrient digestion and nutritional value in the diet of group G2 containing urea with added zeolite compared to groups G1 and G3. Zeolite did not affect the levels of glucose, triglycerides, cholesterol, and albumin in the blood, but a significant increase (P ≤ 0.05) in total blood protein level and a significant decrease (P ≤ 0.05) in blood urea level were noted for groups G2 and G3 compared to the control group G1. Conclusions: Adding zeolite to urea-containing concentrate diets improved growth rates and nutrient digestion, of Awassi lambs. In diets without urea, zeolite improved growth rates without affecting nutrient digestion coefficients, in both types of diets, zeolite increased total protein levels and decreased blood urea levels, with all physiological indicators in lambs blood remaining within normal limits. [ABSTRACT FROM AUTHOR]

Microporous aluminosilicate zeolites are useful industrial catalysts. However, their hydrothermal synthesis is a multistep process with complicated and unclear reactions, limiting their rational functional design. Herein, we compare the formation pathway and the structural and catalytic properties of several CHA zeolites to obtain fundamental knowledge for intentionally controlling the catalytic function of zeolites. Three CHA zeolites were synthesized using different starting silica/alumina sources in the presence of tetraethylammonium hydroxide as an inexpensive organic structure‐directing agent. FAU zeolite and an amorphous synthesis gel prepared using two different methods were used as starting materials. The obtained CHA zeolites were applied for exhaust gas purification (selective catalytic reduction of NOx with ammonia, NH3‐SCR), and their structural characteristics and formation pathways were investigated using a combination of analytical methods. Stepwise gel preparation (SGP), which divides the compositional control of the amorphous synthesis gel, promotes the decomposition of the initial additive (zeolite seed), resulting in the formation of CHA zeolites with abundant micropores and paired Al sites. This structural feature obtained using the SGP method improves the catalytic durability of the NH3‐SCR reaction. The present relationship, including different crystallization phenomena, structures, and catalytic abilities, provides useful insights into rational zeolite synthesis and its application. [ABSTRACT FROM AUTHOR]

Designing photoluminescence sensing devices for gaseous oxygen that combine ease of acquisition with efficient performance is a critical yet challenging task. Herein, a novel oxygen‐sensing probe based on zeolite Y confined silver clusters prepared via a simple approach, is proposed. The large Ag6 clusters formed after hydrogenation exhibit a bright orange emission. They are characterized by a high photoluminescence quantum yield (≈31%) and a long luminescence decay time (>500 µs). A possible formation mechanism of these clusters, which are for the first time observed in Faujasite zeolites, is proposed. Luminescence switching‐off, triggered by oxygen, can be detected in a dual‐channel combination of linear emission‐quenching and lifetime‐reduction, enabling a visual and ultrasensitive (limit of detection of 58 Pa) quantitative detection of oxygen in a wide pressure range (0–100 kPa) with fast response (<1 s), reversibility and reproducibility. A more detailed analysis shows that this high sensitivity is due to the long decay time of the orange emission and the high affinity of the zeolite for O2 adsorption rather than to a high rate constant for quenching. This work contributes to the development of optical oxygen sensing technology and lays the foundation for the design of silver cluster‐based zeolites for photo‐functional applications. [ABSTRACT FROM AUTHOR]

Featured Application: Improvement of biogas production reactors by inserting bacterial species conditioned for the decomposition of specific biomass. The production of biogas is achieved during anaerobic digestion (AD) using organic matter as a substrate. In Mediterranean countries, a promising substrate is lignocellulose biomass of perennial grass Miscanthus x giganteus, due to its potentially high biogas yields, which could be comparable to maize silage. During AD, bacteria convert biomass into more minor compounds, which are further converted to methane by methanogenic archaea. The selection of appropriate microbes for the degradation of the substrate is crucial, and the enhancement of this step lies in the immobilization of microbes on biocarriers. Described here, a microbial consortium, de novo isolated and conditioned to degrade the Mischantus biomass, was immobilized onto several natural biocarriers: natural zeolitized tuff, ZeoSand® (Velebit Agro, Zagreb, Croatia), perlite, and corncob. There was no statistically significant difference in the number of immobilized bacteria across the different materials. Therefore, all proved to be suitable for the immobilization of the consortium. In the consortium, five bacterial species with different shares in the consortium were identified: Enterobacter cloacae, Klebsiella pneumoniae, Enterobacter asburiae, Leclercia adecarboxylata, and Exiguobacterium indicum. After immobilization on each carrier, the share of each species changed when compared to starting conditions, and the most dominant species was E. cloacae (71–90%), while the share for other species ranged from 2 to 23%. The share of E. indicum was 14% at the start. However, it diminished to less than 1% because it was overgrown during the competition with other bacterial species, not due to an inability to immobilize. [ABSTRACT FROM AUTHOR]

High ammonia concentrations in anaerobic degradation systems cause volatile fatty acid accumulation and reduced methane yield, which often derive from restricted activity of syntrophic acid-oxidising bacteria and hydrogenotrophic methanogens. Inclusion of additives that facilitate the electron transfer or increase cell proximity of syntrophic species by flocculation can be a suitable strategy to counteract these problems, but its actual impact on syntrophic interactions has yet to be determined. In this study, microbial cultivation and molecular and microscopic analysis were performed to evaluate the impact of conductive (graphene, iron oxide) and non-conductive (zeolite) additives on the degradation rate of acetate and propionate to methane by highly enriched ammonia-tolerant syntrophic cultures derived from a biogas process. All additives had a low impact on the lag phase but resulted in a higher rate of acetate (except graphene) and propionate degradation. The syntrophic bacteria 'Candidatus Syntrophopropionicum ammoniitolerans', Syntrophaceticus schinkii and a novel hydrogenotrophic methanogen were found in higher relative abundance and higher gene copy numbers in flocculating communities than in planktonic communities in the cultures, indicating benefits to syntrophs of living in close proximity to their cooperating partner. Microscopy and element analysis showed precipitation of phosphates and biofilm formation in all batches except on the graphene batches, possibly enhancing the rate of acetate and propionate degradation. Overall, the concordance of responses observed in both acetate- and propionate-fed cultures highlight the suitability of the addition of iron oxide or zeolites to enhance acid conversion to methane in high-ammonia biogas processes. Key points: • All additives promoted acetate (except graphene) and propionate degradation. • A preference for floc formation by ammonia-tolerant syntrophs was revealed. • Microbes colonised the surfaces of iron oxide and zeolite, but not graphene. [ABSTRACT FROM AUTHOR]

The formal kinetics of the interaction of acrylonitrile (AN) and cyclopentadiene (CPD) by the Diels–Alder reaction in the presence of industrial zeolites has been studied. The dependence of the reaction rate constants of interacting components on the geometric properties of porous materials was revealed. The established dependence had a negative extremum at a zeolite pore diameter of 4 Å. It was shown that, in the presence of zeolites, the rate constant of the reaction under consideration was lower than that in the reaction carried out without porous materials. [ABSTRACT FROM AUTHOR]

Catalyst samples were synthesized by the method of impregnation on the basis of NaX zeolite and Ni metal and their activity was studied in the oxidation process of n-propanol in the temperature range of 423-723K. It has been established that the conversion rate of alcohol and the yield of reaction products on the modified samples increase significantly compared to the original NaX sample. According to the results of the research, it was found that if the reactions of intramolecular and intermolecular dehydration of alcohol predominate at relatively low temperatures, then the reactions of its partial and complete oxidation are accelerated at high temperatures. It was determined that the method of modifying the original NaX zeolite makes it possible to optimize the phase composition of the synthesized catalyst and the size of the active component, which allows to adjust the yield of the main reaction products and reduce the temperature limit of the reaction. As a result of the study, it was found that the average size of NiO particles included in the structure of NaX zeolite is 28314 nm. This suggests that the size of NiO particles in the zeolite structure is at the nanoparticle level. [ABSTRACT FROM AUTHOR]

To develop atmospheric water harvesting (AWH) technology, Zeolite 13X (Z) powder was hydrothermally produced with the addition of different grain sizes of carbon black additive (C) to adsorb air moisture at night and release the water adsorbed by solar irradiation during the day. Various characterization techniques were utilized, including X-ray diffractometry, Brunauer–Emmett–Teller (BET) nitrogen adsorption, field emission scanning electron microscopy (FESEM), UV‒Vis analysis, and a solar simulator, It was determined that the composition of 95%zeolite 13X-5% carbon black with a particle size of ~50 nanometers (ZC55) yielded the best result. The mentioned composition (ZC55) after one hour of exposure under a standard solar simulator flux of 1000 W/m2 by bringing the temperature of the composition to 110°C achieved the highest moisture removal in the composite. This compound evaporated 50% of the adsorbed water after one hour (0.15 g/g), from 0.31 g/g sorption capacity. [ABSTRACT FROM AUTHOR]

Water adsorption capacities of various adsorbents reported in the literature were investigated to define a hydrophobicity index that was plotted vs. water capacity. In this plot, logarithmic curves were proposed to be used as indicators of performance limits of adsorbents, especially for adsorption heat pumps. In spite of their useful adsorption properties, zeolites generally exhibited quite low hydrophobicity, remaining well below the logarithmic curve. In this study, the use of composites of zeolite NaY was examined both theoretically and experimentally for improvements in the water capacity and hydrophobicity. Salt impregnation and hydrothermal synthesis experiments were performed to prepare composites of zeolite NaY with LiCl/MgCl2 salts and activated carbon, respectively. Water capacity and hydrophobicity of zeolite NaY composites were generally superior to those of pure zeolite. Zeolite composites may be advantageous for enhancing adsorption capacity and hydrophobicity of zeolites while eliminating low stability and slow adsorption kinetics of other adsorbents. Interface between two different phases might indicate another opportunity to provide improved adsorption properties for zeolite composites. [ABSTRACT FROM AUTHOR]

Zeolites are aluminosilicates with a lattice structure consisting of tetrahedral AlO4 and SiO4 molecules. Due to the lattice structure of zeolites, there are many areas of use from agriculture to industry and studies continue in these areas. In addition, they are used as herbicides, pesticides, and plant nutrient carriers because of their adsorption properties. One of the main issues that is focused is that zeolite, which is loaded with plant nutrients, spreads its content to the soil over time with a slow release mechanism. Even when zeolite is mixed directly with soil, it affects the use of nitrogen, phosphorus, and potassium in the soil. In addition, if there is heavy metal pollution in the soil, it also collects them. Additionally, as a result of research studies, it is seen that zeolite mixed with soil is effective in reducing the negative effects of salinity and drought stress on plants. Zeolites are seen to have positive effects in many areas in the agricultural field. In this review, the use of zeolite in the agricultural field has been investigated in a multifaceted way, and the results of the studies have been compiled. We compiled the use of zeolite in agriculture. We have compiled the herbicide, pesticide, and fungicide carrier properties of zeolite. We compiled the plant nutrient carrier properties of zeolite. We compiled the effects of zeolite on nitrogen, phosphorus, and potassium usage in the soil. We compiled the response of plants to zeolite under different stress conditions. [ABSTRACT FROM AUTHOR]

Pharmaceutical drugs, including antibiotics and hormonal agents, pose a significant threat to environmental and public health due to their persistent presence in aquatic environments. Colistin (KOL), fluoxetine (FLUO), amoxicillin (AMO), and 17-alpha-ethinylestradiol (EST) are pharmaceuticals (PhCs) that frequently exceed regulatory limits in water and wastewater. Current removal methods are mainly ineffective, necessitating the development of more efficient techniques. This study investigates the use of synthetic zeolite (NaP1_FA) and zeolite-carbon composites (NaP1_C), both derived from fly ash (FA), for the removal of KOL, FLUO, AMO, and EST from aquatic environments. Batch adsorption experiments assessed the effects of contact time, adsorbent dosage, initial concentration, and pH on the removal efficiency of the pharmaceuticals. The results demonstrated that NaP1_FA and NaP1_C exhibited high removal efficiencies for all tested pharmaceuticals, achieving over 90% removal within 2 min of contact time. The Behnajady-Modirshahla-Ghanbary (BMG) kinetic model best described the adsorption processes. The most effective sorption was observed with a sorbent dose of 1–2 g L−1. Regarding removal efficiency, the substances ranked in this order: EST was the highest, followed by AMO, KOL, and FLUO. Sorption efficiency was influenced by the initial pH of the solutions, with optimal performance observed at pH 2–2.5 for KOL and FLUO. The zeolite-carbon composite NaP1_C, due to its hydrophobic nature, showed superior sorption efficiency for hydrophobic pharmaceuticals like FLUO and EST. The spectral analysis reveals that the primary mechanism for immobilizing the tested PhCs on zeolite sorbents is mainly due to physical sorption. This study underscores the potential of utilizing inexpensive, fly ash-derived zeolites and zeolite-carbon composites to remove pharmaceuticals from water effectively. These findings contribute to developing advanced materials for decentralized wastewater treatment systems, directly addressing pollution sources in various facilities. [ABSTRACT FROM AUTHOR]

At present, cobalt belongs to what are called critical raw materials due to its scarcity and its economic importance. Cobalt is a crucial element in the development of new technologies and applications for decarbonization, with around 40% of cobalt consumption being used for rechargeable battery materials. Additionally, cobalt-based catalysts are used in the production of hydrogen fuel cells, and this element is also employed in the production of superalloys for aerospace and power generation industries. For this reason, it is imperative to increase cobalt recycling by recovering from secondary sources, such as decommissioned lithium-ion batteries. Among the technologies for cobalt recovery, adsorption is a reliable alternative as it allows its recovery even at low concentrations in aqueous solutions and is relatively low in cost. Among the potential adsorbents for cobalt recovery, this paper reviews two of the most promising adsorbents for cobalt recovery from aqueous solutions: zeolitic and carbonaceous materials. Regarding zeolitic materials, the maximum adsorption capacities are reached by FAU-type zeolites. In the case of carbonaceous materials, the actual trend is to obtain activated carbons from a wide range of carbon sources, including waste, the adsorption capacities, on average, being larger than the ones reached with zeolitic materials. Additionally, activated carbons allow, in many cases, the selective separation of cobalt from other ions which are present at the same time in the aqueous solutions such as lithium. [ABSTRACT FROM AUTHOR]

Zeolites are crystalline aluminosilicates with open-framework structures and have been widely used in refinery processes. One of the significant utilization processes is cracking heavy feedstocks into lighter fractions, which can be used as a feedstock for subsequent processes such as petrochemical applications. This work aimed to study the effect of the zeolite's different Si/Al ratios on heavy crude cracking under different salt content conditions. The feedstock used for this study is a heavy hydrocarbon fraction contains a large amount of metal and salt. Two synthesized prototype catalysts were prepared and characterized by different physical–chemical methods (SEM–EDX, XRD, N2 physisorption, TPD and TGA). Later the catalysts were mixed with the crudes in a 500 ml autoclave and the catalytic activities were performed in a batch reactor at a temperature of 380–450 °C, 150 rpm, and nitrogen pressure of 10 MPa. The reaction's outlet gases were analysed directly in online Gas Chromatography (GC). The results showed a wide range of impacts on catalyst performance and a noticeable increase in C2 and C3 yield for the desalted crude. Moreover, a higher C3 was produced for both catalysts at 430–450 °C due to the catalyst's large pore. [ABSTRACT FROM AUTHOR]

The catalytic performance of Hβ zeolite treated with different concentration of NaOH on the alkylation of tert-butanol with phenol was studied. The effect of NaOH concentration on the crystallinity, morphology, textural property and acidity of Hβ zeolite was studied by X-ray diffraction (XRD), scanning electron microscope characterization (SEM), N2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR) and pyridine adsorption infrared spectra (Py-IR) techniques. A certain concentration of NaOH treatment can regulate the pore structure of Hβ zeolite and remove part of framework aluminum and framework silicon, thus achieving the purpose of regulating the pore structure and acidity of the catalyst. Though lower Bronsted to Lewis acid amount ratio when treated NaOH concentrations were 0.15 mol/L, leading to the increasing of selectivity to 4-TBP. The Hβ-0.2 M showed the high selectivity of 90.21% for synthesis of 4-tert-butyl-phenol (4-TBP), compared with the unmodified parent zeolite, the selectivity of 4-TBP improved 16.7%. [ABSTRACT FROM AUTHOR]

Catalysis is a foundational pillar of modern synthetic chemistry, essential for countless industrial processes. Traditional catalysts are often static, either immobilized or dispersed in fluid media. The innovative concept of catalytic microrobots allows the introduction of self‐propelled and navigable catalyst particles that are engineered for dynamic and customizable catalysis. Catalytic microrobots are microscale devices with the inherent ability to move and swarm, designed to execute complex tasks in diverse environments, including biomedicine, and environmental remediation. Typically confined to aqueous media, their use in synthetic chemical reactions remains largely unexplored. Here, microrobots are presented as adaptable self‐propelled, self‐mixing micro‐catalysts for the Baeyer–Villiger oxidation, a key industrial process. Zeolite microstructures are tailored, outfitted with magnetic nanoparticles to create zeolite‐based microrobots (ZeoBOTs) that are maneuverable in magnetic fields. Uniquely, these ZeoBOTs are not limited to water but can operate in organic solvents, facilitating the Baeyer–Villiger oxidation in non‐aqueous conditions. Comparative analysis with static ZeoBOTs reveals that the dynamic, “on‐the‐fly” movement of the microrobots significantly enhances reaction yields. The findings herald a new era for synthetic chemistry, demonstrating the potential of microrobots as versatile catalysts beyond aqueous systems, and setting the stage for their broader application in synthetic processes. [ABSTRACT FROM AUTHOR]

Wheat is the most consumed crop worldwide. Zeolite application combined with good tillage practices are good combinations that provide better soil conditions for wheat crops. Zeolite also provides a good layer for carbon to be absorbed into the soil and can retain carbon for hundreds of years. The current study aimed to investigate the effect of tillage practices and zeolite treatments on soil carbon retention and wheat crop productivity. Arranging the treatments implemented according to a factorial randomized block design which includes three replications. Tillage treatments include three levels vis: T1= 6 tillage practices with the help of cultivator (farmer practice/control), T2 (minimum tillage), and T3 (2 cultivation with cultivator + Mold-board plough). The zeolite applications consist of four levels: Z1 = 0, Z2 = 5, Z3 = 10 and Z4 = 15 t ha−1. The effect of the interaction between zeolite treatments and tillage practices on various factors related to soil and crops such as emission of carbon dioxide (CO2), dissolved organic carbon, soil organic carbon, and the productivity and components of wheat productivity. Zeolite applied at 10 t ha−1 in combination with minimum tillage gave significant differences in terms of CO2 emission, dissolved organic carbon, and on soil organic carbon. The experimental results showed that minimum CO2 emission (25.43 and 31.12 (kg CO2-C ha−1 h−1), dissolved organic carbon (4.80 and 4.90 g C kg−1), soil organic carbon (7.88 and 7.97 g C kg−1), plant height (92.14 and 92.97 cm), spike length (11.88 ad 12.11 cm), number of spikelets (20.11 and 20.98), number of tillers (278.65 and 283.93) per unit area, 1000 grain weight (50.74 and 51.54 g), biological yield (8134.87 and 8187.38 kg ha−1) and grain yield (2984.28 and 3028.96 kg ha−1) and harvest index (36.69 and 37.04%) of wheat was observed in zeolite applied at 10 t ha−1 with minimum tillage practice (T2 × Z3) compared to control and other treatments for both the years, respectively. It is therefore concluded that minimum tillage should be practiced in wheat crops with the application of zeolite at 10 t ha−1 to obtain better yield and soil carbon retention under rain-fed conditions. [ABSTRACT FROM AUTHOR]

This study focuses on investigating the relationship between binder chemical composition, microstructure development in alkali-activated paste (AAP), and the sulfuric acid resistance of alkali-activated concrete (AAC). Experimental analyses, including x-ray diffraction, thermogravimetric, and scanning electron microscopy (SEM) tests, were performed on the AAP to understand the impact of critical chemical compositions on the formation of hydrotalcite, portlandite, CSH, and CASH during the alkali-activation process. The sulfuric acid resistance of AAC was evaluated through various tests, including compressive strength, porosity, chemical titration analysis, and weight loss tests. These tests aimed to assess the ability of AAC to withstand sulfuric acid attacks and investigate how the binder's chemical composition influenced its resistance to acid exposure. The results revealed that higher alumino-silicate ratios (Al/Si) and magnesium oxide (MgO) content in the binder composition led to increased amounts of hydrotalcite and CASH in the alkali-activated system when zeolite and metakaolin were used as replacement materials for slag. The AAC specimens with slag and metakaolin showed lower porosity at the same replacement ratio. The increased amounts of hydrotalcite and CASH in the AAC microstructure contributed to a reduction in the concentration of sulfate ions penetrating the AAC, leading to improved sulfuric acid resistance. This information can contribute to optimizing binder formulations for improving AAC's mechanical properties and durability in corrosive environments. Practical Applications: Concrete samples containing metakaolin and synthetic zeolite tested throughout this research project can be utilized in different construction and civil engineering applications, all with differing degrees of suitability. Metakaolin and synthetic zeolites can be used as a slag replacement in concrete samples and used in masonry bricks, commonly used in masonry walls, columns, and partitions. Furthermore, load-bearing or nonload-bearing masonry structures for building and civil engineering can also adopt the incorporation of AAC. Metakaolin and synthetic zeolite types utilized in this research project could also be applied to produce slag granular mixtures for use in the construction of roads and airfields. The requirements for the relevant constituents, composition and laboratory performance classification are specified in BS EN 12390-1:2019. [ABSTRACT FROM AUTHOR]

Abstract—The possibility of using finely dispersed additives made of local mineral raw materials for the manufacture of concrete based on sulfur binder has been established. At the same time, additives with a high specific surface area contribute to the formation of uniform small sulfur crystals on the surface of fine fillers, which makes it possible to improve the strength properties of sulfur concrete. [ABSTRACT FROM AUTHOR]

Asbestos fibres have been considered an environmental hazard for decades. However, little is known about the attempts of circulating immune cells to counteract their toxicity. We addressed the early effects of fibre‐released soluble factors (i.e. heavy metals) in naïve immune cells, circulating immediately below the alveolar/endothelial cell layer. By comparison, the direct fibre effects on endotheliocytes were also studied since these cells are known to sustain inflammatory processes. The three mineral fibres analysed showed that mainly chrysotile (CHR) and erionite (ERI) were able to release toxic metals in extracellular media respect to crocidolite (CRO), during the first 24 h. Nevertheless, all three fibres were able to induce oxidative stress and genotoxic damage in indirectly challenged naïve THP‐1 monocytes (separated by a membrane). Conversely, only CHR‐released metal ions induced apoptosis, NF‐κB activation, cytokines and CD163 gene overexpression, indicating a differentiation towards the M0 macrophage phenotype. On the other hand, all three mineral fibres in direct contact with HECV endothelial cells showed cytotoxic, genotoxic and apoptotic effects, cytokines and ICAM‐I overexpression, indicating the ability of these cells to promote an inflammatory environment in the lung independently from the type of inhaled fibre. Our study highlights the different cellular responses to mineral fibres resulting from both the nature of the cells and their function, but also from the chemical–physical characteristics of the fibres. In conclusion, CHR represented the main pro‐inflammatory trigger, able to recruit and activate circulating naïve monocytes, through its released metals, already in the first 24 h after inhalation. The early effects of mineral fibre‐released heavy metals in THP‐1 cells, mimicking the immune cells in the alveolar capillaries, were investigated, and by comparison, also the direct fibre effects on the endothelial cell layer. The study highlights that the cellular responses result from the nature of the cells, their function and from the fibre chemical–physical characteristics. CHR represented the main pro‐inflammatory trigger, able to recruit and activate circulating monocytes, through its released metals, already at 24 h after inhalation. [ABSTRACT FROM AUTHOR]

Nowadays a major energy transition aimed at cutting CO 2 emissions has begun, with the ambitious goal of drastically reducing the dependence on fossil fuels and promoting the use of renewable energy sources. In this context, energy storage systems play a key role in ensuring a stable, secure and time-aligned energy availability. Open sorption thermal energy storages (TESs) can contribute to such transition, since they are simple and cheap devices able to provide a hot airflow with a high energy density and to store energy for long time. In this work, open sorption TES systems operated with Zeolite 13 X are investigated with a focus on the integration in practical applications. First, the experimental analysis and modelling of the sole TES system is described. Then, the integration of the TES at system level is carried out. The analysis evidences that a significant reduction of storage capacity occurs if air humidification is necessary before the adsorption process or afterwards to keep adequate indoor comfort conditions for the occupants. For the exemplary case study considered, an energy density of 150 kWhm-3 can drop to 40 kWhm-3 in case of complete compensation of the adsorbed water through a humidifier. This paper provides useful guidelines for evaluating the performance of a TES integrated system in terms of specific energy and efficiency. It also identifies applications involving high latent loads (e.g., swimming pools, locker rooms) or for which low relative air humidity is required (e.g. interior of vehicles to prevent condensation on windows) as particularly beneficial for using a TES system. [ABSTRACT FROM AUTHOR]

Due to its remarkable surface properties, natural clinoptilolite-tuff interacts with a variety of biochemical, pharmaceutical, chemical, and microbiological entities, including human viruses. In the present work, the virucidal activity of purified clinoptilolite-tuff (PCT) was investigated using a variety of viruses, differing in their structure and composition. Influenza A virus, Herpes Simplex virus, Rhinovirus, and Parvovirus were chosen to represent enveloped and non-enveloped viruses with RNA and DNA genomes. Beside human viruses, Canine Parvovirus and bacteriophages T4 and MS2 were used to represent animal and bacterial viruses, respectively. The virucidal activity of PCT was quantified by examining the residual viral activity on susceptible cell lines upon incubation with PCT. A wide range of antiviral efficiencies was observed, ranging from up to 99% for Herpes Simplex virus to no activity for Rhinovirus and both bacteriophages. This study reveals that the virucidal potential of PCT is not universal and depends on a complex set of factors including virus structure and medium composition. The environmental and medical implications of this research are discussed for uses such as wastewater treatment or wound healing. [ABSTRACT FROM AUTHOR]

The oxidative condensation between renewable furfural and fatty alcohols is a crucial avenue for producing high-quality liquid fuels and valuable furan derivatives. The selectivity control in this reaction process remains a significant challenge. Herein, we report the strategy of confining well dispersed gold species within ZSM-5 structure to construct highly active Au@ZSM-5 zeolite catalysts for the oxidative condensation of furfural. Characterization results and spectroscopy analyses demonstrate the efficient encapsulation of isolated and cationic Au clusters in zeolite structure. Au@ZSM-5(K) catalyst shows remarkable performance with 69.7% furfural conversion and 90.2% furan-2-acrolein selectivity as well as good recycle stability. It is revealed that the microstructure of ZSM-5 zeolite can significantly promote oxidative condensation activity through confinement effects. This work presents an explicit example of constructing zeolite encaged noble metal catalysts toward targeted chemical transformations. [ABSTRACT FROM AUTHOR]

Regulation of aluminum distribution in zeolite framework is an effective method for improving its catalytic performance for propane aromatization. Herein, we found that recrystallization and post-realuminization of ZSM-5 cannot only create hollow structures to enhance the diffusion ability, but also adjust the content and position of paired aluminum species in its framework. Various characterizations results confirmed that increase of paired aluminum content and inducement of more aluminum atoms sited in the intersection cavity are beneficial to the formation of aromatic products in propane aromatization. As a result, the hollow-structured ZSM-5 zeolite with more paired aluminum (H-200-hollow) showed higher propane conversion and aromatics selectivity than other samples at the same conditions. The catalytic performance of H-200-hollow can be further improved by ion-exchanging with a small amount of Ga(III) species. The propane conversion and aromatics selectivity of Ga-200-hollow reached as high as 95% and 70%, respectively, at 540 °C and 1 atm. [ABSTRACT FROM AUTHOR]

Radon is a radioactive noble gas omnipresent in the environment, being part of the 238U and 232Th decay chains present in the Earth's crust. The gas can easily leak through the ground but also be present in natural construction materials and migrate into indoor places where it can be a carcinogen when inhaled. Studying the content and removal of indoor radon is crucial for the evaluation and mitigation of its radiological risks to public health. For more than 100 years, the removal by adsorption of the radon has been performed on activated charcoal. There is little progress in the field of radon adsorption at ambient conditions; the main progress is in the use of zeolite materials, having well-defined three-dimensional porous structures and radiation resistance. This study concerns a report on the state of the art of the application of zeolites in radon adsorption. Furthermore, an optimized approach for measuring the radon content in indoor environments and, consequently, its removal has been proposed. Adsorption systems based on zeolites have the potential to replace activated charcoal as a material of choice, allowing to facilitate the development of simple and compact radon adsorption systems. [ABSTRACT FROM AUTHOR]

The present investigation studies the use of three natural precursors of volcanic origin (pozzolana, ignimbrite and pumice) in the synthesis of low-cost and environmentally friendly zeolites. The developed zeolites were evaluated as sustainable catalysts for the catalytic pyrolysis process in the chemical recycling of polypropylene. A zeolite was synthesized from each precursor. The hydrothermal treatment was performed with NaOH (3M) at 160 °C for 72 h and NH4Cl (1M) was added to convert it into proton form. The synthesized zeolites were characterized by FTIR, XRD, SEM and BET. The evaluation of the catalytic ability of the obtained zeolites was carried out with polypropylene mixed with a 4, 6 and 8 wt.% catalyst in a ceramic crucible. Pyrolysis was always carried out at 450 °C and for 30 min in a tubular furnace with a continuous flow rate of 250 L·min−1 of gaseous nitrogen. The gases generated were captured in the cooling system. The characterized zeolites show a resemblance to the ZSM-5 commercial zeolite, especially for the ignimbrite and pozzolan zeolites. Likewise, in pyrolysis, liquid products, gases and waxes were obtained. As the amount of catalyst was increased (from 4 to 8%), the yield of the desired liquid–gas products was also increased. The synthesized zeolites showed similar pyrolytic characteristics to ZSM-5, although they did not reach the same pyrolytic efficiency. Zeolites improved the pyrolysis products, especially at 8 wt.%, when compared to thermal pyrolysis. This study highlights the potential of the developed zeolite catalysts to efficiently convert PP into valuable light olefins, advancing sustainable polyolefin recycling technologies. [ABSTRACT FROM AUTHOR]

Methylene blue dye (MB), prevalent in textiles like cotton, wood, and silk, raises environmental and health concerns. This study presents a successful synthesis of a Bayerite/zeolite nanocomposite powder using fumed silica by-product and aluminum nitrate. Hydrothermal exploration of factors, including duration, temperature, and Al/Si ratios, revealed that high temperature (160°C) and short duration (6h) favored optimal crystallization of bayerite/zeolite phases. Subsequently, an integrated photocatalytic adsorbent (IPA) was developed by mechanically mixing the synthesized bayerite/zeolite with TiO2, followed by calcination (500 °C, 2 h), demonstrating superior efficiency in MB photodegradation under UV–Vis light. The IPA achieved 100% degradation efficiency for 60 mg/L of MB and maintained good photostability over three cycles. The bayerite/zeolite-supported TiO2 nanocomposite exhibited the generation of positive holes (h +) and active hydroxyl radicals (OH•), showcasing its potential as a promising material for wastewater treatment applications. Highlights: • Successful synthesis of Bayerite/zeolite nanocomposite powder from fumed silica waste and aluminum nitrate. • Development of an integrated photocatalytic adsorbent (IPA) by mixing synthesized bayerite/zeolite with TiO2. • IPA demonstrated superior efficiency in Methylene Blue (MB) photodegradation under UV-Vis light • The bayerite/zeolite-supported TiO2 nanocomposite maintained good photostability over three cycles, showcasing its potential for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

This study presents the successful synthesis of a vibrant blue nanopigment derived from the metastable structure of Na‐heulandite zeolite. Employing ion exchange and coprecipitation methods with cobalt and zinc ions, followed by thermal treatment at 1100°C, resulted Co‐willemite and gahnite phases, confirmed by x‐ray diffraction and Rietveld refinement. Optical analyses verified the blue coloration, with cobalt ion transitions evident. CIE L* a* b* colorimetric analysis placed the pigment in the blue region (L* = 49.19, b* = −22, a* = −11). Application to ceramic tiles, followed by sodium dodecyl sulfate (SDS) modification, produced a nearly superhydrophobic surface (contact angle 140°, sliding angle 8°), attributed to the nano–micro structure and SDS–silica interaction. Field emission‐scanning electron microscopy images confirmed the pattern‐like surface with small patterns. These findings indicate potential self‐cleaning capabilities when exposed to dirt or water, highlighting the research's promise in enhancing ceramic functionality. [ABSTRACT FROM AUTHOR]

Magnetite (Fe3O4) particles deposited with zeolite, which was made from sodium hydroxide (NaOH), sodium aluminate (NaAlO2) and sodium trisilicate (Na2O7Si3) using the hydrothermal process, were used in the adsorption of methylene blue (MB). A continuous stirred tank reactor (CSTR) system was used for the adsorption of MB using zeolite/Fe3O4. This study encircled the continuous reactor with a magnet to prevent the adsorbent from flowing to the output, thus producing clean water devoid of Fe3O4 particles. The performance of the adsorbent was assessed based on the effects of adsorbent mass, flow rate, pH and concentration. The adsorbent was able to remove approximately 90% of the 20 mg L−1 methylene blue from a 500 mL solution in 2 h, with a maximum adsorption capacity of 30.8528 mg g−1. This adsorption process also exhibited high removal efficiency even after 5 regeneration cycles and 55 h of operation, confirming the successful production of zeolite/Fe3O4 as an effective MB adsorbent. [ABSTRACT FROM AUTHOR]

Nitrification inhibitors, such as nitrapyrin (NI), are increasingly co‐applied with nitrogen (N) fertilizers as part of sustainable agricultural practice. Several studies in temperate regions have documented the effectiveness of NI in retaining soil ammonium (NH4+), minimizing N loss and increasing crop yields. However, less is known about the effects of NI in Mediterranean regions, where agricultural production is challenging and requires intensive irrigation and fertilization. We investigated the short‐term impact of the nitrification inhibitor nitrapyrin (2‐chloro‐6‐(trichloromethyl)pyridine) in a two‐factor mesocosm experiment, using a typical Mediterranean soil, where NI was co‐applied with a selection of urea‐based fertilizers: urea (U), U with urease inhibitors (U + UI), methylene urea (MU) and zeolite‐coated urea (ZU). NI co‐applied with urea fertilizers resulted in higher availability of soil NH4+ and a concurrent increase in NH3 volatilization. Net cumulative soil NH4+ availability was 1.5–3.3 fold greater when NI was applied. Concurrently, net cumulative nitrate (NO3−) and nitrite (NO2−) availability was reduced by 10%–60%; this was found for all the tested fertilizer types except MU fertilizer, where the net cumulative soil NO3− and NO2− doubled. Nitrous oxide (N2O) emissions from urea fertilization were reduced by 40% with UI, 50% with NI and 66% with NI + UI. Interestingly, after 28 d, the composition of soil microbial communities was distinctly different, due to NI application. Specifically, NI application dramatically reduced the abundance of ammonia‐oxidizing and denitrifying bacterial functional groups. NI was effective in reducing N2O emissions in this calcareous soil; however, NH3 emissions were remarkably enhanced. These findings have important implications for the large‐scale adoption of inhibitor technologies in Mediterranean agroecosystems and for the reduction of greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

The performance of catalysts prepared from hierarchical Y zeolites has been studied during the conversion of vacuum gas oil (VGO) into higher-value products. Two different catalysts have been studied: CatY.0.00 was obtained from the standard zeolite (Y-0.00-M: without alkaline treatment) and CatY.0.20 was prepared from the desilicated zeolite (Y-0-20-M: treated with 0.20 M NaOH). The cracking tests were carried out in a microactivity test (MAT) unit with a fixed-bed reactor at 550 ◦C in the 20–50 s reaction time range, with a catalyst mass of 3 g and a mass flow rate of VGO of 2.0 g/min. The products obtained were grouped according to their boiling point range in dry gas (DG), liquefied petroleum gas (LPG), naphtha, and coke. The results showed a greater conversion and selectivity to gasoline with the CatY.0.20 catalyst, along with improved quality (RON) of the C5–C12 cut. Conversely, the CatY.0.00 catalyst (obtained from the Y-0.00-M zeolite) showed greater selectivity to gases (DG and LPG), attributable to the electronic confinement effect within the microporous channels of the zeolite. The nature of coke has been studied using different analysis techniques and the impact on the catalysts by comparing the properties of the fresh and deactivated catalysts. The coke deposited on the catalyst surfaces was responsible for the loss of activity; however, the CatY.0.20 catalyst showed greater resistance to deactivation by coke, despite showing the highest selectivity. Given that the reaction occurs in the acid sites of the zeolite and not in the matrix, the increased degree of mesoporosity of the zeolite in the CatY.0.20 catalyst facilitated the outward diffusion of products from the zeolitic channels to the matrix, thereby preserving greater activity [ABSTRACT FROM AUTHOR]

The direct conversion of syngas into hydrocarbons, catalyzed by a combination of metal oxide and acidic zeolite, has garnered increasing attention in the scientific community. The remarkable hydrocarbon selectivity achieved in the OX‐ZEO process is a key factor in this growing interest. This process involves two distinct steps: CO activation over the oxide and subsequent C−C coupling within the zeolite pores, connected by an unidentified oxygenate intermediate. In this study, we explored three proposed oxygenates as potential intermediates and compared their conversion within the OX‐ZEO process. Using a bifunctional ZnCr2O4/H‐MOR catalyst in a syngas‐fed batch reactor, we found that methanol (MeOH) and dimethyl ether (DME) produced a hydrocarbon distribution similar to syngas conversion. However, the conversion of acetic acid (AcOH) resulted in a notably distinct range of hydrocarbons, including short olefins not detected with other reagents. Our findings suggest that methanol/DME might serve as active intermediates in the OX‐ZEO process over the ZnCr2O4/H‐MOR catalyst. This study provides a deeper insight into the transformation of proposed intermediates, contributing to the identification of the bridging intermediate that links the two catalytic functions. [ABSTRACT FROM AUTHOR]

In aquatic environments, the presence of iodine species, including radioactive isotopes like 129I and I2, poses significant environmental and health concerns. Iodine can enter water resources from various sources, including nuclear accidents, medical procedures, and natural occurrences. To address this issue, the use of natural occurring nanoporous minerals, such as zeolitic materials, for iodine removal will be explored. This study focuses on the adsorption of iodine by silver-modified zeolites (13X-Ag, 5A-Ag, Chabazite-Ag, and Clinoptilolite-Ag) and evaluates their performance under different conditions. All materials were characterized using scanning electron microscopey (SEM), energy-dispersive X-ray spectroscopy (EDS), powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), and nitrogen adsorption studies. The results indicate that Chabazite-Ag exhibited the highest iodine adsorption capacity, with an impressive 769 mg/g, making it a viable option for iodine removal applications. 13X-Ag and 5A-Ag also demonstrated substantial adsorption capacities of 714 mg/g and 556 mg/g, respectively, though their behavior varied according to different models. In contrast, Clinoptilolite-Ag exhibited strong pH-dependent behavior, rendering it less suitable for neutral to slightly acidic conditions. Furthermore, this study explored the impact of ionic strength on iodine adsorption, revealing that Chabazite-Ag is efficient in low-salinity environments with an iodine adsorption capacity of 51.80 mg/g but less effective in saline conditions. 5A-Ag proved to be a versatile option for various water treatments, maintaining its iodine adsorption capacity across different salinity levels. In contrast, Clinoptilolite-Ag exhibited high sensitivity to ionic competition, virtually losing its iodine adsorption ability at a NaCl concentration of 0.1 M. Kinetic studies indicated that the pseudo-second-order model best describes the adsorption process, suggesting chemisorption mechanisms dominate iodine removal. Chabazite-Ag exhibited the highest initial adsorption rate with a k2 value of 0.002 mg g−1 h−1, emphasizing its superior adsorption capabilities. Chabazite and Clinoptilolite, naturally occurring minerals, provide eco-friendly solutions for iodine adsorption. Chabazite superior iodine removal highlights its value in critical applications and its potential for addressing pressing environmental challenges. [ABSTRACT FROM AUTHOR]

The hydroprocessing of gasoline on modified alumina catalysts makes it possible to obtain high-octane products. The implementation and development of the process have largely become possible due to the development of modified alumina catalysts that do not contain noble metals and exhibit special catalytic properties. This article discusses topical issues of petrochemistry, namely the creation of catalysts with improved characteristics for the production of high-octane gasoline with low sulfur content. New catalytic systems based on alumina and other carriers modified with transition metals, lanthanum and phosphorus were synthesized. By physico-chemical methods of analysis TPD of ammonia, TEM and XRD, we studied the acid–base and structural characteristics of the developed catalysts. The activity of the developed catalysts in the studied process of hydrotreating gasoline fractions depends on the structure and condition of the active centers. The process of hydrotreating straight-run gasoline in the presence of synthesized catalysts was carried out on a laboratory flow unit. It was shown that, during the hydrotreating of straight-run gasoline on the NiO-MoO3-La-P-HZSM-HY-Al2O3 catalyst, the octane number in the final product increased to 88.6, and the sulfur content decreased from 0.0088 to 0.001%. It was found that the minimum sulfur content in the gasoline hydrotreating product of 0.0005% was achieved on the catalyst CoO-WO3-La-P-HZSM-HY-Al2O3, which is significantly lower than for other studied catalytic systems. The obtained results of the sulfur content in the hydrotreating products fully comply with the Euro-5 standard. Thus, the efficiency of hydrotreating the gasoline fractions studied in this work was mainly determined by the nature of the carriers and modifiers used for the synthesis of catalysts and the technological parameters of the process. The synthesized catalysts showed high activity and selectivity, resulting in high-octane gasoline with a low sulfur content that meets international quality standards. [ABSTRACT FROM AUTHOR]

The self-made slow-release membrane material with water-based copolymer (polyvinyl alcohol PVA, polyvinyl pyrrolidone PVP), zeolite and epoxy resin as raw materials was tested for degradation in buried soil. The effects of soil temperature T (T15, T25, T35) and moisture W (W60, W80, W100) on the degradability of membrane materials were investigated by a comprehensive experimental design, and a hydrothermal coupling model K (T, W) was established. The effects of degradation on the chemical structure, functional groups, and morphology of membrane materials were revealed by infrared spectroscopy and SEM electron microscopy. The results showed that the degradation degree of membrane material was an exponentially positive response to the increase in soil temperature and moisture. The degradation rate of membrane materials under different treatments was 13.7%-17.3%, and the maximum degradation rate was 17.3% under the T35W100 condition. The determination coefficient R² of the constructed K (T, W) model reached 0.927, and the average relative error of the predicted degradation rate was 1.58%, indicating good accuracy of the model. The infrared spectrum showed that the -OH stretching vibration absorption peak of the degraded membrane becomes wider and the peak intensity increases; the absorption peak intensity of C-H, -CH2, and Si-O weakens; and the peak of the C=C absorption peak appears as a continuous staircase after degradation. The SEM electron microscopy showed there were differences in the pores and cracks of the membrane materials under different treatments, and the degradation was the most obvious under the T35W100 condition. [ABSTRACT FROM AUTHOR]

Dry reforming of methane (DRM) has garnered significant attention because it is featured by the conversion of the two most representative greenhouse gases CH4 and CO2 into syngas composed of H2 and CO as target products. In our previous studies, we demonstrated the high catalytic activity and stability in DRM for the nickel silicate BEA-type zeolite (Ni-BEA) catalyst synthesized by interzeolite transformation. Here, the molybdenum modified Mo/Ni-BEA was prepared by deposition precipitation method on Ni-BEA, and its DRM activity was evaluated. Compared to the bare Ni-BEA, the modified Mo/Ni-BEA showed the more enhanced activity and stability with low carbon deposition, e.g., 9% lower coke content after 12 h on stream under harsh DRM reaction conditions, because of the promoter effect of molybdenum. Furthermore, Mo/Ni-BEA exhibited the stronger stability, i.e., both the deactivation rates for CH4 and CO2 were less than half compared to those of Ni-BEA, in a long-term DRM test for 55 h. To investigate the role of molybdenum as a promoter, the catalysts before and after reactions were analyzed through various characterization methods. [ABSTRACT FROM AUTHOR]

The development of stabilized silver nanoparticles (AgNP) is paramount in preventing the build-up of pathogenic biofilms. AgNP also requires a suitable support system to deliver the AgNP directly to the bacteria. Herein, AgNP-supported zeolite A was prepared via the in situ phytosynthesis method using Orthosiphon aristatus extract based on our previous work. The optimal condition of AgNP biosynthesis was achieved at 0.4 mL of the leaf extract in 10 mL AgNO3 1 mM. The AgNP was incorporated into zeolite A using the in situ approach. The developed materials were characterized by their porosity, surface area, thermogravimetry, and zeta potential. The morphology of samples was distinguished using field emission scanning electron microscopy (FESEM). The distribution of AgNP into the macroporous zeolite A was measured according to the reduction of specific pore volume from 0.1033 to 0.0346 cm3/g. Anti-biofilm and morphological assessments revealed that AgNP-supported zeolite A induced a good biofilm inhibition against bacteria Staphylococcus aureus (p < 0.0001) than Pseudomonas aeruginosa at 1 mg/mL because of less intolerance against AgNP. The biofilm formation was reduced by more than 50% and 15%, respectively, compared to the untreated bacteria. Bacteria tend to attach to the zeolite surface, and the AgNP incorporated in the zeolite would easily interact with the bacteria, inducing peptide bond alteration, which leads to structural disintegration. Therefore, these AgNP-supported zeolite materials exhibited the 'cut its source' strategy to capitulate the biofilm inhibition action. [ABSTRACT FROM AUTHOR]

Zeolite has been identified as a potential low-temperature CO2 adsorbent with the highest adsorption capacity among adsorbents in its category. However, its adsorption capacity remains relatively low, limiting its industrial application for CO2 adsorption. Additionally, there is a need to increase the optimal adsorption temperature of this porous material to effectively adsorb CO2 emitted from flue gas, which has an average temperature of 100 - 125°C. To address these challenges, a preliminary study on Zn-doped zeolite has been conducted. This study aims to investigate the ability of Zn-doped zeolite to enhance CO2 adsorption capacity and its effect on the optimal temperature for CO2 adsorption. Zinc-doped zeolite was synthesized by doping zinc oxide into natural zeolite using a zinc ion exchange method at different doping concentrations (0.2 M & 1.0 M). Undoped natural zeolite was studied as a benchmark. Their CO2 adsorption performance was tested using TGA at 30°C, 50°C, and 100°C. The effects of temperature and doping concentration on adsorption capacity were investigated. The adsorbent samples were characterized using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) analysis. It was found that increasing the temperature from 30°C to 50°C increased the CO2 adsorption capacity, but the capacity decreased when the temperature was further increased to 100°C. Furthermore, increasing the doping concentration tended to enhance the CO2 adsorption capacity. The highest adsorption capacity of 0.0281 g CO2/g sorbent was observed in zinc-doped zeolite with a 1.0 M doping concentration at 50°C. The improvement was mainly attributed to the zinc oxide doped on the zeolite, which provided a functional group that formed chemical bonds with CO2. This study also found that the adsorption rate of CO2 was predominantly influenced by temperature, while the effect of doping concentration was less significant. All testing and characterization results suggested that the zinc-ion exchange method improved the CO2 adsorption capacity of zeolite. [ABSTRACT FROM AUTHOR]