Unveiling Ru(bpy)3 2+-Encapsulated Zeolite Y as Photocatalyst: Harnessing Photocatalytic Singlet Oxygen Generation for Mustard Gas Simulant Detoxification.

This study explores the encapsulation of Ru(bpy)3 2+ within Zeolite Y (ZY) to improve photocatalytic singlet oxygen generation for the degradation of a mustard gas simulant, namely 2-chloroethyl ethyl sulfide (CEES). Mustard gas simulants are known to disrupt several biological processes; thus, their effective degradation is essential. Zeolite Y, with its hierarchical structure and adjustable Si/Al ratios, is an ideal host for Ru(bpy)3 2+, significantly improving its photocatalytic efficiency and stability. It is demonstrated through XRD and spectroscopic analyses that encapsulated Ru(bpy)3 2+ maintains its structural and photophysical properties, which are essential for generating singlet oxygen. Ru(bpy)3(1.0) loaded ZY(15) (where 1.0 and 15 represent the encapsulated amount of Ru(bpy)3 2+ and Si/Al ratio, respectively) outperforms other investigated photocatalytic systems in the oxidation of CEES, demonstrating high conversion rates and selectivity toward nontoxic sulfoxide products. Immobilization of Ru(bpy)3 2+-encapsulated zeolite Y onto cotton fabric results in effective degradation of CEES. The experimental results, validated by theoretical calculations, indicate an improved oxygen affinity and accessibility in zeolites with higher Si/Al ratios. This study advances the design of photocatalytic materials for environmental and defense applications, providing sustainable solutions for hazardous chemical degradation.

Investigating the synergistic effects of various amine groups on Zeolite-Y for CO2 capture.

Growing concern about global warming and greenhouse effects has led to persistent demands for increased energy efficiency and reduced carbon dioxide emissions. As a result, energy-intensive processing of carbon dioxide separation became imperative. Accordingly, energy-efficient, economically viable carbon dioxide separation technologies are sought as carbon dioxide capture options for future industrial process schemes. The article provides an overview of current technology for the separation of carbon dioxide, specifically focusing on adsorption. In this study, amine-loaded Zeolite-Y adsorbents were evaluated to enhance carbon dioxide adsorption capacity through synthesis, characterization, and the adsorption of carbon dioxide, within the context of current trends in separation technology. This study aims to study the ability of amine-loaded Zeolite-Y to adsorb carbon dioxide using three different loadings ethanolamine, diethanolamine, and triethanolamine. The amine-loaded materials were characterized by various technologies, including X-ray diffraction pattern (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), and field emission scanning electron microscope (FESEM) studies. The study suggests that monoethanolamine-loaded Zeolite-Y is a promising and cost-effective adsorbent for carbon dioxide adsorption in comparison to other synthesized amine-loaded adsorbents. The adsorbent has been able to adsorb carbon dioxide in the range of 1.14-2.26 mmol g-1 at 303 K and 1 bar for a loading of 1, 5, and 10 wt.% amine groups.

Composite Photocatalysts with Fe, Co, and Ni Oxides on Supports with Tetracoordinated Ti Embedded into Aluminosilicate Gel during Zeolite Y Synthesis.

Ti-aluminosilicate gels were used as supports for the immobilization of Fe, Co, and Ni oxides (5%) by impregnation and synthesis of efficient photocatalysts for the degradation of ß-lactam antibiotics from water. Titanium oxide (1 and 2%) was incorporated into the zeolite network by modifying the gel during the zeolitization process. The formation of the zeolite Y structure and its microporous structure were evidenced by X-ray diffraction and N2 physisorption. The structure, composition, reduction, and optical properties were studied by X-ray diffraction, H2-TPR, XPS, Raman, photoluminescence, and UV-Vis spectroscopy. The obtained results indicated a zeolite Y structure for all photocatalysts with tetracoordinated Ti4+ sites. The second transitional metals supported by the post-synthesis method were obtained in various forms, such as oxides and/or in the metallic state. A red shift of the absorption edge was observed in the UV-Vis spectra of photocatalysts upon the addition of Fe, Co, or Ni species. The photocatalytic performances were evaluated for the degradation of cefuroxime in water under visible light irradiation. The best results were obtained for iron-immobilized photocatalysts. Scavenger experiments explained the photocatalytic results and their mechanisms. A different contribution of the active species to the photocatalytic reactions was evidenced.

Characterization of a Zeolite-Y-Encapsulated Zn(II)Salmphen Complex with Targeted Anticancer Property.

Resistance and severe side effects of classical chemotherapeutic drugs are major challenges to cancer therapy. New therapeutic agents and combination therapy are considered potential solutions that enhance the efficacy of the drug as well as reduce drug resistance. The success of a platinum-based anticancer drug, cisplatin, has paved the way to explore metal-centered anticancer therapeutic agents. Herein, the zeolite-Y-encapsulated Zn(II)Salmphen complex is synthesized using a flexible ligand approach. The Zn(II)Salmphen complex and its encapsulation within the supercage of zeolite-Y were characterized by elemental analysis, Fourier transform infrared (FTIR) spectroscopy, UV-vis, fluorescence, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), NMR, and high-resolution mass spectrometry (HRMS) techniques. Elemental analysis, PXRD, and SEM, all together confirm the integrity of the zeolite framework after the encapsulation of Zn(II)Salmphen complex in it, and elemental analysis provides the Si/Al ratio and Zn content present. FTIR and XPS studies indicate the successful encapsulation of the complex. NMR and HRMS studies confirm that the Zn(II)Salmphen complex is dimer; however, within the supercage of zeolite-Y, it is expected to exist as a monomer. The extent of structural modification of the encapsulated Zn(II)Salmphen complex is intimated by electronic spectroscopic studies. The free-state Zn(II)Salmphen is a fluorescent complex, and even the encapsulated Zn(II)Salmphen complex, when taken in dimethyl sulfoxide (DMSO), shows fluorescence. In comparison to cisplatin, encapsulated Zn(II)Salmphen complex displays comparable cytotoxicity (IC50 = 2.0 ± 0.5 µg/mL at 48 h) toward breast cancer cell line, whereas free Zn(II)Salmphen has better cytotoxicity (IC50 = 1.5 ± 0.5 µg/mL at 48 h). Importantly, elemental analysis has revealed that the IC50 value, if calculated only in terms of Zn(II)Salmphen within Zn(II)Salmphen-Y, is as low as 54.59 ng/mL, indicating a very high efficacy of the drug. Interestingly, a 48 h treatment with the encapsulated Zn(II)Salmphen complex shows no toxicity toward immortal noncancerous keratinocyte cells (HaCaT), whereas cisplatin has an IC50 value of 1.75 ± 0.5 µg/mL. Internalization studies indicate that zeolite-Y targets cancer cells better than it does noncancerous ones. Hence, cellular uptake of the zeolite-encapsulated Zn(II)Salmphen complex in cancer cells is more than that in HaCaT cells, resulting in the generation of more reactive oxygen species and cell death. Significant upregulation of DNA damage response protein indicates that DNA-damage-induced cellular apoptosis could be the mechanism of drug action. Overall, the zeolite-encapsulated Zn(II)Salmphen complex could be a better alternative to the traditional drug cisplatin with minimal effect on noncancerous HaCaT cells and can also be utilized as a fluorescent probe in exploring the mechanistic pathway of its activity against cancer cells.

Co- and Ni-Doped TiO2 Nanoparticles Supported on Zeolite Y with Photocatalytic Properties.

Zeolite Y samples with microporous and hierarchical structures containing Ti-Ni and Ti-Co oxides were obtained as active photocatalysts. Different Ti amounts (5, 10% TiO2) were supported, followed by the loading of Ni or Co oxides (5%). X-ray diffraction evidenced the presence of TiO2 as an anatase. N2 adsorption-desorption results showed type IV isotherms for hierarchical zeolite Y samples, and a combination of type IV and I isotherms for zeolite Y samples. UV-Vis diffuse reflectance spectra showed a shift in the absorption band to visible with increasing Ti loading and especially after Co and Ni addition. A significant effect of the support was evidenced for Ti and its interaction with Co/Ni species. The zeolite Y support stabilized Ti in the 4+ oxidation state while hierarchical zeolite Y support favored the formation of Ti3+ species, Ni0 and Ni2+ and the oxidation of Co to 3+ oxidation state. Photocatalytic activity, under UV and visible light irradiation, was evaluated by the degradation of amoxicillin, used as a model test. The photocatalytic mechanism was investigated using ethanol, p-benzoquinone and KI as ·OH and ·O2- radicals and hole (h+) scavengers. The best results were obtained for the immobilized Ni-Ti species on the hierarchical zeolite Y support.

Effects of Aluminosilicate Gel Treatment and TiO2 Loading on Photocatalytic Properties of Au-TiO2/Zeolite Y.

The present work reports the synthesis of efficient Ti-Au/zeolite Y photocatalysts by different processing of aluminosilicate gel and studies the effect of titania content on the structural, morphological, textural, and optical properties of the materials. The best characteristics of zeolite Y were obtained by aging the synthesis gel in static conditions and mixing the precursors under magnetic stirring. Titania (5, 10, 20%) and gold (1%) species were incorporated in zeolite Y support by the post-synthesis method. The samples were characterized by X-ray diffraction, N2-physisorption, SEM, Raman, UV-Vis and photoluminescence spectroscopy, XPS, H2-TPR, and CO2-TPD. The photocatalyst with the lowest TiO2 loading shows only metallic Au on the outermost surface layer, while a higher content favors the formation of additional species such as: cluster type Au, Au1+, and Au3+. A high TiO2 content contributes to increasing the lifetime of photogenerated charge careers, and the adsorption capacity of the pollutant. Therefore, an increase in the photocatalytic performances (evaluated in degradation of amoxicillin in water under UV and visible light) was evidenced with the titania content. The effect is more significant in visible light due to the surface plasmon resonance (SPR) effect of gold interacting with the supported titania.

Hydrophilic interaction liquid chromatography with methanol-water eluent on a zeolite.

BACKGROUND: Hydrophilic interaction chromatography (HILIC) works with organic solvent-water mixtures as eluent and is based on the formation of a water enriched liquid phase on the surface of a hydrophilic stationary phase. Hydrophilic solutes are retained on that stagnant water-rich film depending on the difference of solvation compared to the mobile phase composition. However, the enhancement of selectivity by increasing the fraction of organic cosolvent is coupled with a limitation the analyte solubility, and the improvement of the HILIC principle by new hydrophilic stationary phases is the remaining option. RESULTS: Y-zeolite (faujasite, FAU type) in the Na+-form with an average particle diameter of 5 µm was used as packing material in a 125 mm long HPLC column. The chromatographic response of the column was tested in methanol-water mixtures as eluent after injection of several aliphatic alcohols, polyols and monosaccharides with eluent conditions where no separation occurs on diol functionalized silica. On the zeolite the retention time increases according to ethylene glycol < glycerol < erythritol < sorbitol < inositol. The separation principle is explained to be superposed by two effects: firstly, a partition equilibrium between the water-rich phase in the zeolite micropores exists, and secondly, selective interactions with the inner crystalline pore surface and fixed-position Na+ ions, both serving to enhance the selectivity. Furthermore, arabinose and fructose monosaccharides could be separated into their tautomeric forms. Only upon increasing the temperature from 20 to 60 °C the tautomeric pattern merges into a single peak. SIGNIFICANCE AND NOVELTY: Instead of the stagnant water rich surface layer, zeolite micropores now take over that function. As a result, the selectivity among polyols and between α/ß-arabinopyranose and ß-fructopyranose/ß-fructofuranose tautomers is extraordinary superior towards conventional hydrophilic interaction liquid chromatography (HILIC).

Zeolite Y-supported carbon-doped TiO2 nanocomposites: Efficient solar photocatalysts for the purification of medicinal wastewater.

The existence of antibiotics in aquatic streams destroys water quality and thereby poses serious ecological hitches. Photocatalysis involving nanosemiconductors is an environmentally benign technique for the mineralization of antibiotics. Herein, we prepared a new visible light-sensitive photocatalyst, zeolite Y-supported carbon-doped TiO2 nanocomposite (zeolite Y-c-TiO2), for the elimination of cefazolin antibiotic in wastewater systems. The structural and optical properties of the synthesized nanocomposites were investigated by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller surface area analysis (BET) as well as diffuse reflectance spectroscopy (UV-DRS) and photoluminescence spectroscopy (PL). The UV-Vis absorbance spectrum of zeolite Y-c-TiO2 exhibited a red shift towards longer wavelength with an increase in visible light absorption as compared to pure TiO2 nanoparticles and zeolite Y-supported TiO2 nanocomposites (zeolite Y-TiO2). Accordingly, the photocatalytic action of the zeolite Y-c-TiO2 for the degradation of methylene blue was evaluated under solar simulator, and it turned out to be highly efficient (100%) mineralization as compared to TiO2-nanoparticles (42%) and zeolite Y-TiO2 (62%) after 70 min irradiation for a 50mg L-1 methylene blue solution. Radical scavenging experiments revealed the involvement of hydroxyl radicals, superoxide radicals, and photogenerated holes in the degradation process. Consequently, zeolite Y-c-TiO2 was applied for the photocatalytic degradation of the cefazolin antibiotic in water, and complete degradation of cefazolin (50 mg L-1) was observed within 6 h of solar light irradiation on zeolite Y-c-TiO2. The degradation pathway of cefazolin was proposed by considering various intermediates detected via LC-MS analysis. The study points to the significant potential of zeolite Y-c-TiO2 photocatalyst for the purification of medicinal wastewater under sunlight.

Application of oxidized multi-walled carbon nanotubes and zeolite nanoparticles for simultaneous preconcentration of codeine and tramadol in saliva prior to HPLC determination.

In this work, a dispersive micro-solid phase extraction technique along with high-performance liquid chromatography-UV detection was developed for simultaneous preconcentraion and determination of trace levels of codeine and tramadol in human saliva. This method is based on the adsorption of codeine and tramadol on a mixture of oxidized multi-walled carbon nanotubes and zeolite Y nanoparticles with 1:1 ratio as an efficient nanosorbent. Various analytical parameters influencing the adsorption step including the amount of adsorbent, the pH of the sample solution, the temperature, the stirring rate, the contact time of the sample solution, and the adsorption capacity were investigated. Based on the results, 10 mg adsorbent, sample solutions with pH = 7.6, temperature of 25 °C, stirring rate 750 rpm and contact time 15 min, in the adsorption step shows the best results for both drugs. Then the effective parameters on the analyte desorption stage such as the type of desorption solution, pH of the desorption solution, desorption time and desorption volume were investigated. Studies have shown that water/methanol (50:50 v/v) as desorption solution, pH = 2.0, desorption time of 5 min and desorption volume of 2 ml gives the best results.Chromatographic separation was performed on a RP-Shim-pack CLC-ODS-C18 column (250 mm × 4.6 mm, 5 µm) with isocratic mode. The mobile phase contained of acetonitrile:phosphate buffer (18:82, v/v) at pH = 4.5 and the flow rate was 1 ml.min-1. The wavelength of UV detector was adjusted at 210 nm and 198 nm for codeine and tramadol, respectively.Under optimum conditions, the extraction efficiencies of 98.5% and 99.2% were achieved for codeine and tramadol respectively. Enrichment factor of 13, detection limit of 0.3 µg L-1, relative standard deviation of 4.07 for codeine; and an enrichment factor of 15, a detection limit of 0.15 µg L-1, and standard deviation of 2.06 for tramadol were calculated. The linear range of the procedure for each drug was 1.0 to 1000 µg L-1. This method was successfully applied for the analysis of codeine and tramadol in saliva samples.

Benzothiazole Clubbed Imidazolone Derivatives: Synthesis, Molecular Docking, DFT Studies, and Antimicrobial Studies.

AIM: This study aims to synthesize antimicrobial agents and their molecular docking, and DFT studies of benzothiazole-imidazolone scaffolds. BACKGROUND: Benzothiazole and imidazolone analogues are of interest due to their potential activity against microbial infections. In search of suitable antimicrobial compounds, we report here the synthesis, characterization, and biological activities of benzothiazole and imidazolone analogues (4a-l). OBJECTIVE: The benzothiazole clubbed imidazolone motifs were synthesized, characterized, and screened for their antimicrobial activity. Molecular docking was carried out for the development of antimicrobial agents based on the results of biological activity obtained. METHODS: We have synthesized a new series of benzothiazole-clubbed imidazolone hybrids by using multi-step reactions in the search for antimicrobial agents (4a-l). The structures were determined by 1H NMR, 13C NMR, IR, and mass spectroscopy techniques. Moreover, synthesized compounds were evaluated for their antimicrobial activity by using a Serial Broth Dilution method. In addition, molecular electrostatic potential, geometric optimization, and molecular reactivity analyses (HOMO-LUMO) of 4c, which is one of the compounds with the highest antibacterial activity, were performed. RESULTS: The in vitro antimicrobial activity was evaluated against pathogenic strains. Among them, compounds 4c showed the most potent biological activity against Gram-negative bacteria, E. coli with MIC values of 50 µg/mL, and compound 4c active against A. clavatus with MIC values of 100 µg/mL. Active compound 4c HUMO-LUMO energies, molecular electrostatic potential analysis, and geometric optimization parameters were calculated with a 6-31G ** base set using DFT/B3LYP theory, and the results were displayed. Molecular docking studies were performed on E. coli DNA Gyrase B to understand the binding interaction of compound 4c, and it was observed that compound 4c interacted with Arg76 amino acid of the active site through hydrophobic interaction. CONCLUSION: Benzothiazole-clubbed imidazolone hybrids (4a-l) indicated promising antimicrobial activity. Among them, compounds 4b (MIC=50 µg/mL C. albicans), 4c (MIC=50 µg/mL, E. coli), 4e (MIC= 100 µg/mL, A. niger), and 4g (MIC= 50 µg/mL, S. pyogenes) with electronwithdrawing bromo, chloro, and fluoro group at the para position of the phenyl ring on benzothiazole-imidazolone hybrids indicated remarkable potency compared to the standard drug. The geometric optimization, molecular reactivity, and MESP analyses of 4c were calculated with the B3LYP/6-31G ** base set and ΔE = ELUMO-EHOMO, which was found to be - 0.12096 eV. In addition, the binding affinity scores correlated well with the in vitro antimicrobial activity (4c), while their binding modes proposed the involvement of steric, electrostatic, and hydrogen- bonding interactions with the active site.

Variously Prepared Zeolite Y as a Modifier of ANFO.

In the presented research, we investigated Ammonium Nitrate Fuel Oil (ANFO), with the addition of variously modified zeolite Y as an attractive explosive. Analysis of both blasting tests and thermodynamic models of blasting properties led to the conclusion that the addition of zeolite Y enhanced the detonation properties of such prepared ANFO via the growth of the detonation pressure, temperature, compression energy, and heat of the explosion. Generally, the modification of ANFO with variously prepared zeolite Y also reduced the volume of (COx + NOx) post-blast fumes. Furthermore, it was found that the ANFO's velocity of detonation (VOD) could be controlled by the choice of the way of zeolite Y modification. Namely, for zeolite Y without Mg, as well as Mg-Y prepared via the impregnation method, the VOD rose. The opposite effect was observed when ANFO was modified with Mg-Y, obtained from the deposition of Mg over zeolite Y via the ultrasonic-assisted procedure.

Effective catalytic hydrodechlorination removal of chloroanisole odorants in water using palladium catalyst confined in zeolite Y.

Chloroanisoles is a class of odorous pollutants commonly identified in drinking water. In the present study, we confined noble metal palladium (Pd) in the micropores of zeolite Y (ie-Pd@Y) using an ion exchange method, and applied it for the catalytic hydrodechlorination removal of chloroanisoles (represented by 2,4,6-trichloroanisole/TCA) in water. Pd supported on zeolite Y surface (im-Pd/Y, prepared by conventional impregnation method) was used as the benchmarking catalyst. The characterization results revealed that ie-Pd@Y had smaller Pd particle size and higher Pdn+/Pd0 ratio than im-Pd/Y. The catalytic hydrodechlorination of TCA followed a concerted dechlorination pathway and the Langmuir-Hinshelwood model. The ie-Pd@Y catalysts with different Pd loadings exhibit excellent catalytic activities with more than 95% of TCA removed within 30 min, which is far superior to the im-Pd/Y catalysts (27-70%). Moreover, due to the confinement effect of zeolite Y, ie-Pd@Y displayed enhanced catalytic stability as compared with im-Pd/Y. The initial activity of ie-Pd@Y was more than 20 times higher than that of im-Pd/Y after five reaction cycles. Additionally, with the assistance of sieving effect, ie-Pd@Y displayed much stronger capability against the interference from dissolved organic matter than im-Pd/Y. The present results demonstrate that the confined catalysts ie-Pd@Y can be applied in liquid phase catalytic hydrogenation to effectively eliminate halogenated odorants in waters.

Cellulose Nanofibrils as a Damping Material for the Production of Highly Crystalline Nanosized Zeolite Y via Ball Milling.

Nanosized zeolite Y is used in various applications from catalysis in petroleum refining to nanofillers in water treatment membranes. Ball milling is a potential and fast technique to decrease the particle size of zeolite Y to the nano range. However, this technique is associated with a significant loss of crystallinity. Therefore, in this study, we investigate the effect of adding biodegradable and recyclable cellulose nanofibrils (CNFs) to zeolite Y in a wet ball milling approach. CNFs are added to shield the zeolite Y particles from harsh milling conditions due to their high surface area, mechanical strength, and water gel-like format. Different zeolite Y to CNFs ratios were studied and compared to optimize the ball milling process. The results showed that the optimal zeolite Y to CNFs ratio is 1:1 to produce a median particle size diameter of 100 nm and crystallinity index of 32%. The size reduction process provided accessibility to the zeolite pores and as a result increased their adsorption capacity. The adsorption capacity of ball-milled particles for methylene blue increased to 29.26 mg/g compared to 10.66 mg/g of the pristine Zeolite. These results demonstrate the potential of using CNF in protecting zeolite Y particles and possibly other micro particles during ball milling.

Novel Biocomposite Films Based on High Methoxyl Pectin Reinforced with Zeolite Y for Food Packaging Applications.

Pectin is a natural biopolymer with broad applications in the food industry and it is suitable to prepare edible films to prolong food shelf-life. However, the main limitation of pectin-based films is their poor mechanical and barrier properties. Zeolite Y is a hydrophobic clay that can be used as film reinforcement material to improve its physicochemical and mechanical properties. In this work, the influence of high methoxyl citrus and apple pectin on physicochemical properties of biopolymer films modified with zeolite Y (0.05-0.2 wt%) was investigated. The films were characterized by FTIR, TGA, WAXD, mechanical analysis, and water vapor permeability analysis, and a potential film application is presented. The WAXD and FTIR analysis demonstrated that the strongest interaction between pectin chains and zeolite Y occurred when citrus high methylated pectin was used. Adding 0.2 wt% of zeolite Y into citrus high methylated pectin matrix enhanced the tensile strength by 66%, thermal stability by 13%, and water vapor barrier by 54%. In addition, fruit shelf-life test was performed, where strawberries were sealed in film. It was shown that sealed strawberries maintained a better color and healthy appearance than the control treatment after 7 days at 10 °C. This study enabled the development of biocomposite films with improved properties for potential application in food packaging.

Aminosilane-Functionalized Zeolite Y in Pebax Mixed Matrix Hollow Fiber Membranes for CO2/CH4 Separation.

Due to their interfacial defects between inorganic fillers and polymer matrices, research into mixed matrix membranes (MMMs) is challenging. In the application of CO2 separation, these defects can potentially jeopardize the performance of membranes. In this study, aminosilane functionalization is employed to improve the nano-sized zeolite Y (ZeY) particle dispersion and adhesion in polyether block amide (Pebax). The performance of CO2/CH4 separation of Pebax mixed matrix composite hollow fiber membranes, incorporated with ZeY and aminosilane-modified zeolite Y (Mo-ZeY), is investigated. The addition of the zeolite filler at a small loading at 5 wt.% has a positive impact on both gas permeability and separation factor. Due to the CO2-facilitated transport effect, the performance of MMMs is further improved by the amino-functional groups modified on the ZeY. When 5 wt.% of Mo-ZeY is incorporated, the gas permeability and CO2/CH4 separation factor of the Pebax membrane are enhanced by over 100% and 35%, respectively.

Adsorption of Toluene and Water over Cationic-Exchanged Y Zeolites: A DFT Exploration.

In this study, density functional theory (DFT) calculations have been performed to investigate the adsorption mechanisms of toluene and water onto various cationic forms of Y zeolite (LiY, NaY, KY, CsY, CuY and AgY). Our computational investigation revealed that toluene is mainly adsorbed via π-interactions on alkalis exchanged Y zeolites, where the adsorbed toluene moiety interacts with a single cation for all cases with the exception of CsY, where two cations can simultaneously contribute to the adsorption of the toluene, hence leading to the highest interaction observed among the series. Furthermore, we find that the interaction energies of toluene increase while moving down in the alkaline series where interaction energies are 87.8, 105.5, 97.8, and 114.4 kJ/mol for LiY, NaY, KY and CsY, respectively. For zeolites based on transition metals (CuY and AgY), our calculations reveal a different adsorption mode where only one cation interacts with toluene through two carbon atoms of the aromatic ring with interaction energies of 147.0 and 131.5 kJ/mol for CuY and AgY, respectively. More importantly, we show that water presents no inhibitory effect on the adsorption of toluene, where interaction energies of this latter were 10 kJ/mol (LiY) to 47 kJ/mol (CsY) higher than those of water. Our results point out that LiY would be less efficient for the toluene/water separation while CuY, AgY and CsY would be the ideal candidates for this application.

Porosity, Powder X-Ray Diffraction Patterns, Skeletal Density, and Thermal Stability of NIST Zeolitic Reference Materials RM 8850, RM 8851, and RM 8852.

This paper reports the powder X-ray diffraction patterns, argon isotherms at 87 K, Brunauer-Emmett-Teller surface areas, pore size distributions, pore volumes, skeletal densities, and thermal gravimetric analyses for three National Institute of Standards and Technology zeolitic reference materials, RM 8850 (zeolite Y), RM 8851 (zeolite A), and RM 8852 (ZSM-5).

Deposition of NiO Nanoparticles on Nanosized Zeolite NaY for Production of Biofuel via Hydrogen-Free Deoxygenation.

Nickel-based catalysts play an important role in the hydrogen-free deoxygenation for the production of biofuel. The yield and quality of the biofuel are critically affected by the physicochemical properties of NiO supported on nanosized zeolite Y (Y65, crystal size of 65 nm). Therefore, 10 wt% NiO supported on Y65 synthesized by using impregnation (IM) and deposition-precipitation (DP) methods were investigated. It was found that preparation methods have a significant effect on the deoxygenation of triolein. The initial rate of the DP method (14.8 goil·h-1) was 1.5 times higher than that of the IM method (9.6 goil·h-1). The DP-Y65 showed the best deoxygenation performance with a 80.0% conversion and a diesel selectivity of 93.7% at 380 °C within 1 h. The outstanding performance from the DP method was due to the smaller NiO particle size (3.57 ± 0.40 nm), high accessibility (H.F value of 0.084), and a higher Brönsted to Lewis acidity (B/L) ratio (0.29), which has improved the accessibility and deoxygenation ability of the catalyst. The NH4+ released from the decomposition of the urea during the DP process increased the B/L ratio of zeolite NaY. As a result, the pretreatment to convert Na-zeolite to H-zeolite in a conventional zeolite synthesis can be avoided. In this regard, the DP method offers a one-pot synthesis to produce smaller NiO-supported nanosized zeolite NaY with a high B/L ratio, and it managed to produce a higher yield with selectivity towards green diesel via deoxygenation under a hydrogen-free condition.

Experimental dataset investigating the effect of temperature in the presence or absence of catalysts on the pyrolysis of plantain and yam peels for bio-oil production.

More than 1.3 billion tons, a third of the total food produced, is wasted annually, and it has been predicted to increase in the coming years. Food waste significantly contributes to greenhouse gas (GHG) emissions resulting in the release of about 3.3 billion tonnes of CO2 into the environment yearly. Hence this large amount of wastes, with adverse environmental effects, needs to be appropriately managed. New technologies such as Anaerobic digestion, fermentation, and gasification are being used to produce renewable energy, which in turn reduces the increasing level of food wastes in the environment. Pyrolysis of biomass materials or food wastes produces high-value energy products or bio-oil that can possibly replace non-renewable fossil fuels when it is upgraded. In this study, pyrolysis (thermal treatment in the absence of oxygen) of plantain and yam peels to produce bio-oil, was investigated. The pyrolysis conditions, wide temperature ranges at an interval of 100 °C (200-700 °C), absence of a catalyst (AOC), the use of zeolite -Y catalyst using two separate heterogeneous catalysis procedures were imposed and used to produced bio-oil. In the first procedure, the pyrolysis gases were allowed to rise through a zeolite-Y catalyst bed (HTC). And in the second procedure, the plantain or yam peel feedstock was first mixed uniformly with the zeolite-Y catalyst before pyrolysis (HMC). The GC-MS machine was used to analyze or characterize the obtained bio-oil while proximate analysis and XRF machine were used to characterize the plantain and yam peels feed. The residue, biochar, from the pyrolysis process, was also characterized using the XRF machine.

Effect of dealumination on the acidity of zeolite Y and the yield of glycerol mono stearate (GMS).

Research on the production of Glycerol Monostearate from glycerol using dealuminated Zeolite Y catalysts has been carried out. Optimization of the dealumination process is conducted using the help of statistical software 10, where the variables used are acid concentration (5-7 M), temperature of dealumination (55-70 °C) and time of dealumination (2-6 h). The acidity characterization test of dealuminated Zeolite Y using ammonia and pyridine solution. Glycerol Monostearate yield was obtained by GC-MS test that was carried out on 2 samples zeolite Y catalyst with the highest value of total and surface acidity of zeolite Y which produced 2.18% and 4% yield of Glycerol Monostearate. The two samples showed that the greater the acidity, the GMS yield was also greater. Compared to previous studies it was found that ZSM-5 catalyst has a higher acidity value than zeolite Y so that the yield of Glycerol Monostearate is higher with the use of ZSM-5 than Zeolite Y.