In recent years, nanoparticle catalysts have become increasingly utilized in various processes, such as methanol conversion to light olefins (MTO), due to their higher surface area and reduced intraparticle mass/heat transfer limitation. However, these nanoparticles are not directly applicable due to the high pressure drop in the fixedbed reactors. To address this issue, this study presents, for the first time, the synthesis of fibrous composite SAPO34/Al2O3 catalysts with varying amounts of SAPO-34 nanoparticles using the electrospinning technique. These structures reduce pressure drop while maintaining the high performance of the nanoparticles. The pressure drop, calculated using the Ergun equation, and the catalytic efficiency of the fibrous catalyst were compared to those of powdered and pelletized catalysts. Results show that fibrous composite 80%SAPO-34-20%Al2O3 reduces pressure drop by 93 and 20% compared to the powdered and pelletized catalysts, respectively, and simultaneously demonstrates high catalytic activity with 88% light olefin selectivity at 561 min. This improvement results from enhanced intraparticle/interparticle mass and heat transfer due to the homogenous distribution of SAPO-34 nanoparticles with reduced agglomeration on the alumina fiber. In addition, the catalytic activity of fibrous 50%SAPO-34/50%Al2O3 and 66%SAPO-34/34% Al2O3 composite catalysts is somewhat similar to that of powder 80% SAPO-34-20%Al2O3, despite their lower SAPO-34 content. This is attributed to the positive effect of the fibrous structure.

In this attitude, a novel ZnO@CoZn-ZIF/MXene nanocomposite was constructed using an ultrafast and cost-effective method via cold plasma treatment for the degradation of methylene blue (MB). Initially, Cr2CTX nanosheets were synthesized through etching of the Cr2AlC phase. Subsequently, the bimetallic metal-organic framework CoZn-ZIF (BZIF) was prepared both individually and hybridized with MXene (BZIF/Cr2C) via a rapid nucleation approach. Thereafter, zinc oxide (ZnO) nanoparticles were deposited onto the BZIF/Cr2C surface using two methods: conventional hydrothermal/sol-gel (HS) and the novel cold plasma treatment (CP). The analyses revealed that the CP method resulted in more uniform distribution of ZnO nanoparticles, stronger chemical bonding (facilitated by APTES silane coupling agent), and reduced charge recombination compared to the HS method. FESEM images confirmed the formation of distinct phases and poor integration for the hydrothermal method, whereas the plasma-synthesized sample demonstrated a highly integrated and well-ordered structure. XPS and FTIR analyses confirmed the presence of strong bonds such as Cr-O-Si and Zn-O in the plasma-treated sample. Photocatalytic investigations demonstrated that the ZnO@BZIF/Cr2C-CP nanocomposite exhibited the highest MB degradation efficiency under both UV/Visible light (99

Post-synthetic dealumination is an effective strategy for tailoring the acidity and pore architecture of Y-type zeolites for alkylation reactions. In this study, HY zeolite was modified using mineral acids (HCl and HNO3) and organic acids (oxalic and citric acid) to investigate the influence of acid type on framework stability, acidity redistribution, and catalytic behavior in isobutane/2-butene alkylation. The resulting Pt-loaded catalysts were systematically characterized by XRD, FTIR, FESEM–EDS, N2 adsorption–desorption, NH3-TPD, and thermogravimetric analysis. The results revealed that acid treatment induced significant changes in the Si/Al ratio, pore structure, and acid-site distribution while preserving the FAU framework to different extents. Among the investigated treatments, nitric acid generated the highest concentration of moderate-strength acid sites and an optimized balance between acidity and pore accessibility, resulting in superior catalytic performance. The Pt/ HNO3HY catalyst maintained butene conversion above 85%, achieved the highest C8 selectivity (88.5%), and exhibited enhanced trimethylpentane (TMP) formation with the lowest coke selectivity. In contrast, HCl treatment increased the proportion of strong acid sites, promoting heavier hydrocarbon formation and faster deactivation. Oxalic acid induced more selective dealumination but substantially reduced the overall acidity, leading to lower catalytic activity. Notably, citric acid treatment caused severe framework degradation and partial amorphization, indicating excessive dealumination and loss of structural integrity. These findings demonstrate that catalytic performance is governed primarily by acid-site redistribution rather than surface area alone, highlighting controlled nitric-acid dealumination as an efficient route for optimizing zeolite-based alkylation catalysts.

Despite the critical role of composite zeolites in catalysis, the crystallization pathways of SAPO-34/ZSM-5 remain poorly understood, limiting their rational design. We describe the complex crystal growth mechanisms of SAPO-34/ZSM-5 composite zeolites by a novel combination of advanced experimental imaging and theoretical modeling, offering a time-resolved framework for their structural evolution. Using different high-resolution techniques, including SEM, TEM, AFM, XRD, FTIR, DLS, and zeta potential measurements, we observe the morphological, structural, and surface charge dynamics over a 24 h crystallization period, delineating six distinct growth stages: heterogeneous nucleation, diffusion-limited aggregation, oriented attachment, spiral growth, dissolution-recrystallization, and Ostwald ripening. Our research shows that ZSM-5 seeds act as essential nucleation sites, facilitating the initial formation of SAPO-34 nuclei. Furthermore, charge-induced transitions, indicated by significant changes in zeta potential from -50.2 mV to +134.6 mV, influence the aggregation and structural enhancement of the composite. We quantify the energy barriers governing each growth stage by applying classical nucleation theory and the Burton-Cabrera-Frank model, providing a predictive framework for crystal engineering. This thorough mechanistic comprehension connects traditional and non-classical crystallization processes and facilitates the exact synthesis of composite zeolites with enhanced efficacy in the methanol-to-olefins (MTO) reaction. By elucidating growth mechanisms, this study enables the targeted design of SAPO-34/ZSM-5 catalysts with tunable properties for enhanced performance in methanol-to-olefins (MTO) conversion.

In this study, plain zeolite (ZSM5) and hierarchical zeolite (H-ZSM5) were synthesized as efficient adsorbents for the removal of polyphenolic/antioxidant compounds from olive mill wastewater (OMW). The XRD and FTIR results confirmed the successful synthesis of ZSM5 zeolites. SEM images and BET demonstrated that H-ZSM5 possessed a markedly greater surface area of 337.99 m(2)/g in contrast to ZSM5 (162.84 m(2)/g). For H-ZSM5, the values determined for pore volume, total volume, and pore diameters are 77.655 cm(3) g(-1), 0.1844 cm(3) g(-1), and 2.1826 nm. The absolute zeta potential values varied between 5.36 +/- 1.21 and - 46.41 +/- 1.32 mV, with the peak absolute value of - 46.41 +/- 1.32 mV occurring at pH 4. The optimal conditions for the removal of phenolic compounds, achieving an efficiency exceeding 90%, were identified as a pH of 4, an adsorbent dosage of 50 mg, and a contact duration of 90 minutes. The adsorption isotherm was found to align with the Langmuir model rather than the Freundlich model, indicating a monolayer adsorption capacity of 48.7 mg/g. Kinetic studies were consistent with a pseudo-first-order model (R-2 >0.99). Ultimately, the thermodynamic analysis suggested that the adsorption of OMW onto ZSM5 is both spontaneous and governed by a physisorption mechanism.

The introduction of SAPO-34/ZSM-5 composite zeolites has significantly advanced the field of catalysis due to their unique hierarchical structure, adjustable acidity, and shape-selective properties. By combining the distinct features of ZSM-5 and SAPO-34, these composites have improved catalytic activity, stability, and selectivity in processes such as methanol-to-olefins (MTO). Since 2010, various synthesis techniques, including hydrothermal, ultrasonic-assisted, steam-assisted, microwave assisted, and solid-solid transformation methods, have been developed to optimize the textural and chemical properties of these materials. This review aims to comprehensively examine these synthesis methods, focusing on their conditions, impact on physicochemical properties, and catalytic efficiency. By highlighting recent advancements and addressing existing challenges, we hope to provide insights that will improve composite synthesis and encourage broader industrial applications in catalysis.

In this study, the gasoline yield in the methanol-to-gasoline (MTG) process was modeled using artificial neural network (ANN) and multivariate polynomial regression (MPR) techniques. The ANN trained using the Levenberg–Marquardt (LM) method and having three neurons in the hidden layer was the most accurate at predicting gasoline yield ( R 2 = 0.993 and RMSE = 0.024). Therefore, this network was used to investigate the influence of operational conditions such as pressure, weight hourly space velocity (WHSV), temperature, and the average particle size of the Zeolite Socony Mobil–5 (ZSM-5) catalyst on the gasoline yield. Then, the particle swarm optimization (PSO) and genetic algorithm (GA) were used to approach the best operating parameters and catalyst size to get the most gasoline yield. The mentioned neural network was used as a fitness function in the optimization algorithms. The optimization results showed that at a pressure of 1 bar, a temperature of 400°C, a WHSV equal to 1 h –1 , and a particle size of 1466 nm, the maximum gasoline yield is equivalent to 45.43.

ZSM-5 nanoparticles are widely used as the catalyst in the methanol conversion to olefins (MTO) process due to their high surface area and short diffusion path length. However, agglomerate formation is a challenge for this catalyst. To address this issue, in this study, electrospinning was used for the first time to synthesize fibrous catalysts comprised of ZSM-5 nanoparticles embedded in the alumina nanofibers. The catalysts were charac-terized using XRD, FTIR, SEM, TEM, EDX-map, BET, and NH3-TPD analyses. In the synthesized samples, ZSM-5 nanoparticles with an average particle size of 683 nm are uniformly and homogeneously dispersed over alumina nanofibers with a 300 nm diameter. These composites form core-shell structures and have a reactor porosity of 0.85, which is higher than that of parent ZSM-5. In the MTO process, electrospun catalysts demonstrate superior catalytic activity and a longer lifespan than powder catalysts. 80 wt% ZSM-5-20 wt% Al2O3 with 47.76 % light olefin selectivity and complete methanol conversion after 321min on stream performed better than 50 wt% ZSM-5-50 wt% Al2O3. Moreover, a lower coke formation of about 3.28 % was achieved for the 80 wt% ZSM-5-20 wt% Al2O3 sample. The reduced bulk density of the electrospun samples increases the probability of reactant and catalyst contact. Additionally, electrospinning is an effective method for reducing particle aggregation and improving catalytic process efficiency.

The ultrasound-assisted preparation of UiO-66 was carried out at T = 80–220 °C, and the catalytic performances were evaluated in methanol conversion. Also, physicochemical properties were assessed by XRD, SEM, PSD, FTIR, N2 adsorption–desorption, TG-DTG, and NH3-TPD analysis. The characterization proved that increasing the synthesis temperature positively affected the crystallinity, specific surface area, thermal stability, and acidity of the catalysts. Besides, the catalysts' performance was investigated in the methanol conversion reaction (T = 350–450 °C, P = 1 atm, and WHSV = 5 h−1), leading to the DME (Dimethyl Ether) production. Rising reaction temperature increased the methanol conversion and DME yield. The synthesized sample at 220 °C had the best properties and performance with conversion and yield of about 38% and 51%, respectively. The stability test for the UiO-66-220 (University of Oslo 66) catalyst was performed at 450 °C for 12 h, and the activity remained stable for about 5 h. Furthermore, the used catalyst was characterized via XRD and TG analysis.

In response to the increasing concerns about climate change and the depletion of fossil fuel reserves, the application of zeolite ZSM-5 as a catalyst in the methanol to olefin (MTO) process is considered a promising chemical technique. It holds the potential to produce essential chemical building blocks, such as light olefins, using sustainable raw materials. In this study, electrospun MgO/ZSM-5 nanofibers were synthesized to enhance mass/heat transfer limits during the MTO process and improve catalyst stability. In this synthesis, ZSM-5 nanoparticles with a mean diameter of 600 nm were arranged on magnesium oxide nanofibers with a mean diameter of 200 nm. The catalysts were characterized using various techniques, including XRD, SEM, TEM, EDX-Mapping, NH3-TPD, BET, and TGA. The electrospinning technique prevented nanoparticle accumulation and improved the morphology of the catalyst. In an isothermal fixed-bed reactor, the catalysts were tested at 450 degrees C, 1 atm, WHSV = 4.5 hr-1, with a methanol-water solution in a 1:1 (v/v) ratio as the feed. The stability of the nanofibers was found to be enhanced compared to ZSM-5 nanoparticles. MgO/ZSM-5-50 nanofibers (50 wt% zeolite), MgO/ZSM-5-80 nanofibers (80 wt% zeolite), and ZSM-5 nanoparticles exhibited methanol conversion rates of 99 %, 88 %, and 76 %, respectively, after 430 min of continuous operation. Furthermore, the amount of coke formed after 10 h for MgO/ZSM-5-50, MgO/ZSM-5-80, and ZSM-5 was 11.83 wt%, 13.63 wt%, and 20.98 wt%, respectively. The reduced coke formation on the electrospun samples compared to ZSM-5 nanoparticles demonstrates improved performance and stability for nanofiber catalysts.

Defect engineering of UiO-66 metal-organic frameworks offers promising opportunities to develop catalytic applications. Recently, the methanol conversion reaction has been used to quantitatively investigate the catalytic properties of defective UiO-66. In this contribution, the role of synthesis temperature in creating structural defects of UiO-66 was evaluated. First, the catalysts were synthesized using the solvothermal method at various temperatures (100-220 degrees C). The XRD, SEM-PSD, FTIR, TG-DTG, BET, TPD-NH3, and TPD-CO2 techniques were used to study the characteristics. The findings suggested that raising the synthesis temperature enhanced the crystallinity, surface area, thermal stability, and acidity of catalysts. Following that, activity tests were performed at P = 101.3 kPa and T = 300-450 degrees C, and increasing the reaction temperature improved the catalyst's performance. As a result, UiO-66 produced at 220 degrees C had the best performance (conversion = 51 %, yield DME = 81 %), and its activity remained stable at 450 degrees C for 6 h.

In this study, metal-organic frameworks (MOFs) based on zirconium which are called MOF-808 were synthesized by solvothermal method. A series of Zr-MOF were synthesized at different temperatures and reaction times to find the best synthesis samples to produce dimethyl ether from dehydration of methanol. As synthesized MOFs were characterized with x-ray diffraction, standard electron microscopy, and BET, they showed high methanol conversion and selectivity for methanol oxidation. The relationship between crystallinity, reactivity and relation catalysts life was discussed. For the first time, this MOF was used as a solid catalyst in the conversion of methanol to dimethyl ether due to its thermal stability and moderate acidity. The results show that all samples had a crystalline structure and were properly synthesized. The performance of the synthesized catalysts, the selectivity, and the effect of reactor temperature in the conversion of methanol to dimethyl ether in a tubular reactor with weight hourly space velocity = 5 h(-1) were investigated. The highest surface area is nearly 1360 m(2)/g, size dimension of samples is in the range of 200-800 nm, and the highest Langmuir surface area is 1530 m(2)/g.

The present study aims at investigating sonochemically synthesized MIL-53(Al) and its applications in adsorption lead ions from aqueous solution. XRD, FESEM, BET, and FTIR analyses were employed to identify and characterize MIL-53(Al). The ultrasonic-assisted synthesis procedure results in reducing the synthesis time to 24 h; however, the conventional synthesis of MIL-53(Al) takes 3 days. Applying ultrasonic waves also leads to increase of the specific surface area up to 50% more than that of synthesized by the conventional method, as well as creating the hierarchical MIL-53(Al) structure which reduces the mass transfer limitation of ions into internal micropores. The optimum conditions for removing lead ions are pH of 6, Pb +2 ion concentration of 20 mg/L, contact time of 60 min, adsorbent dose of 0.04 g, and temperature of 318 K with the removal efficiency of 97.63%. The experimental adsorption equilibrium and kinetic data fit the Langmuir isotherm and pseudo-second-order kinetic models, respectively. Moreover, the usage of sonochemically synthesized MIL-53(Al), for the first time as an adsorbent in heavy metal removal points to the great potential of this new environmentally-friendly adsorbent in removing lead ions from aqueous solutions

The use of ultrasonic waves was developed for synthesis of zeolites at shorter crystallization time with improving their desirable properties. A series of nanostructured ZSM-5/ZSM-12 composite zeolites with different Si/Al ratios and alkalinity using organic templates were prepared by hydrothermal and sonochemical synthesis methods. The physicochemical properties of synthesized nanocatalysts such as structure, morphology, textural, and acidity were characterized via XRD, FESEM, N-2 physisorption, FTIR, TPD-NH3, TGA-DTG techniques. The results revealed that increasing the Si/Al ratio and alkalinity in the hydrothermal samples enhanced the crystallization, formation of amorphous microcrystals, and dominant phase of MFI with decreasing MTW competitive phase. Zeolites synthesized by high-temperature and short-time sonochemical method had higher crystallinity, less dominant phase of ZSM-5, smaller crystals, greater surface areas, higher concentration of Bronsted acid sites, and stronger strength of moderate/strong acid sites. The catalytic performance of the zeolites for MTH conversion was evaluated under a reaction temperature of 450 degrees C at different times on stream. The results showed that the sonochemical zeolite had a higher methanol conversion (100%), higher selectivity toward olefins (28% vs. 19%) with more C-3(=)/C-2(=) ratio (0.79 vs. 0.58), and lower alkanes selectivity (66% vs. 72%) after 240 min TOS. (C) 2022 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

In this literature, it was successfully prepared metal-organic framework MIL-53(Al) for the first time at convenient conditions using sonication irradiation. Comparison of Sonochemical-assisted hydrothermal synthesis with conventional hydrothermal method had been investigated. Suitable morphology and unique porosity properties were obtained through Sonochemical-assisted approach, which has presented excellent features and good thermal stability for crystals samples with nano-sized particles versus the conventional hydrothermal method. Low reaction temperature of 150 degrees C and short time of synthesis 6 h investigated pure crystallinity of MIL-53(Al) via Sonochemical-assisted synthesis due to its ability to supply controlled amounts of energy to the solution that leads to increase nucleation rate and crystal growth. The characterization of samples was specified using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Nitrogen Adsorption Technique (BET) and Thermal Gravimetric Analysis (TGA). Highest surface area is nearly to 1363.5 m2/g, best thermal stability up to 600 degrees C, more uniform and narrower size distribution in the range of 0.7-0.93 mu m at short sonication time 24 h and low temperature at 150 degrees C were observed.

Phosphorus, boron and fluorine were employed as promoters to synthesize the optimized gamma-Al2O3 support and NiMo/gamma-Al2O3 catalyst. Based on Response Surface Methodology, supports were synthesized with specified contents of promoters using wet impregnation method. Characterization and properties of the samples were determined through BET, TPD, XRD, TGA and EDX analyses. Moreover, the catalytic performance of the NiMo/gamma-Al2O3 catalysts was evaluated at the temperature, pressure and LHSV of 350 ?, 4.5 MPa and 1.1 h( - 1) , respectively. The results of experimental design indicated the effects of the promoters on the responses including pore volume, BET surface area and acidity. Based on the results, a model was designed to predict the optimal condition of synthesis. Then, the optimal support was synthesized using 3.99 wt.% of fluorine, 1.7 wt.% of phosphorus and its properties including acidity, BET surface area and pore volume were 1.28 mmolNH(3)/g, 276.95 m(2)/g and 0.63 cm(3)/g, respectively. Based on the developed model, it was concluded that boron-fluorine and phosphorus-fluorine interactions mostly affected the acidity and BET surface area, respectively. Then, properties and catalytic performance of catalyst were evaluated in the HDS process through diesel fuel feeding (sulfur content: 12,100 ppm) and its acidity was 2.2 mmolNH(3)/g and the efficiency of desulfurization and the coke of catalyst were 81% and 3%, respectively, which confirms better performance in comparison to a commercial catalyst. (c) 2022 Elsevier B.V. All rights reserved.

Reducing synthesis costs in the petrochemical industry leads to decreasing financial value of final products from raw materials. In this paper, SAPO-34 molecular sieve as a main catalyst of methanol-to-olefin process is newly synthesized by rice husk. The silica source of SAPO-34 synthesis is achieved from this agricultural waste material by calcination and leaching methods with the purity of 97% based on XRF analysis. Between the series of samples synthesized, the sample with the highest crystallinity and textural properties is obtained by Si = 0.6 M concentration and hydrothermal synthesis at 200 degrees C for 18 h which has been proved by XRD, SEM, BET, EDX and NH3-TPD analyses. Also, this sample showed that has relatively higher selectivity toward light olefins compared to other samples. In the case of operating conditions, using methanol/water (20 wt%) instead of pure methanol as feed increased light olefins selectivity and reached the maximum value of 83.5% at 375 degrees C, however, highest light olefins mass (26 wt%) from the consumed feed acquired at 425 degrees C.

Recently, many studies are dealing with developments of Metal-Organic Frameworks (MOFs), especially MIL-53(Al), which shows high thermal and mechanical stability. Among these, optimizing the synthesis condition of MIL-53(Al) to obtain appropriate characteristics has attracted much attention in academia and the industry. Here, the effect of synthesis time and ligand to metal molar ratio on the hydrothermal synthesis of MIL-53(Al) are pursued. The synthesized MIL-53(Al) samples are characterized by X-ray diffraction (XRD), the Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), thermal gravimetric analysis (TGA), and nitrogen adsorption-desorption technique (BET). The present study shows that MIL-53(Al) can be conventionally synthesized with a high yield within a shorter reaction time than the previous studies. Furthermore, the catalytic activity of the optimized MIL-53(Al) in the pure and Mn-doped form is studied in a methanol dehydration reaction. It is thus inferred that this popular MOF in the Mn/MIL-53(Al) form has a high activity and DME selectivity during methanol conversion. Our present results confirm the merits of employing the MIL-53(Al) as a catalyst in methanol to DME conversion, which can be an avenue for the practical application of acidic catalyst.