Synthesis Of Zeolite Research Articles

Direct Synthesis of Highly Siliceous Faujasite-type Zeolite Enabled by Low Charge Density Organic Structure-directing Agents.

Ultrastable Y (USY) zeolites (Faujasite-type, FAU) with high SiO2/Al2O3 ratios (SARs) have been widely applied in fluidized catalytic cracking and hydrocracking processes. However, their preparation typically involves labor-intensive post-treatments that inevitably introduce defects, extra-framework species, and compositional gradients. Herein, we report the direct synthesis of FAU-type zeolite with a record-high SAR up to 21.28, which shows superior catalytic performance in the catalytic cracking of cumene and straight-run diesel. This was achieved by using a highly siliceous initial gel and seed, together with low charge-density organic structure-directing agents (OSDAs) of tetramethylammonium (TMA+) and tetrabutylammonium (TBA+) cations, while minimizing the use of high charge-density inorganic Na+ cations. Comprehensive NMR analyses, including two-dimensional (2D) heteronuclear correlation (HETCOR) experiments (1H-13C, 1H-27Al, 1H-29Si), and synchrotron radiation X-ray diffraction-based Rietveld refinements, revealed that (1) TMA+ and TBA+ preferentially interact with Si species over Al species in the initial gel, promoting Si incorporation into the FAU structure's long-range order; and (2) TMA+ cations were tightly confined within the sodalite (sod) cages, while TBA+ cations occupied the faujasite (fau) supercages, adopting folded butyl chain configurations. The encapsulation of low charge-density OSDA cations, coupled with the exclusion of high charge-density Na+ cations, resulted in a highly siliceous Y zeolite with a SAR of 21.28. The synthesized Y zeolite exhibited improved durability and enhanced activity in cumene cracking and comparable selectivity for the target products [liquefied petroleum gas (LPG) and gasoline] while reducing coke formation by 28% in straight-run diesel catalytic cracking compared to conventional USY zeolites.

Efficient synthesis of smaller crystal ZSM-5 zeolite in low TPAOH-to-silica ratio dry-gel hydrothermal system

Efficient synthesis of smaller crystal ZSM-5 zeolite in low TPAOH-to-silica ratio dry-gel hydrothermal system

An efficient approach for template free synthesis of Silicalite-1 zeolite: Effect of seed nature and NH4F

An efficient approach for template free synthesis of Silicalite-1 zeolite: Effect of seed nature and NH4F

Economically and eco-friendly synthesis of SSZ-13 zeolite using choline chloride as template with the investigation effects of sodium ion and aging

Economically and eco-friendly synthesis of SSZ-13 zeolite using choline chloride as template with the investigation effects of sodium ion and aging

Seed-assisted zeolite interconversion synthesis of fly ash-based ZSM-5 zeolite

Seed-assisted zeolite interconversion synthesis of fly ash-based ZSM-5 zeolite

Precipitation Method for LTA Zeolite Synthesis and Structural Characterization

The demand for large-scale industrial applications of zeolite has driven the development of synthetic zeolite as an alternative to natural zeolite, which is limited by availability and production constraints. This study investigates the synthesis of LTA (Linde Type A) zeolite using a precipitation method, focusing on the effects of stirring time and aging time on zeolite yield and crystallinity. The synthesis process involved preparing sodium aluminate and sodium silicate solutions, followed by controlled crystallization at 80°C for 8h. The resulting zeolite was analyzed using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to determine its phase purity, morphology, and Si/Al ratio. The results showed that optimal zeolite yield (24.75%) was obtained with 3h of stirring and 24h of aging. SEM analysis confirmed the cubic morphology characteristic of LTA zeolite, while EDS analysis determined an Si/Al ratio of 1.44, classifying the product as LTA zeolite. These findings highlight the significance of controlled stirring and aging conditions in optimizing zeolite synthesis for industrial applications.

In Situ Synthesis of Magnetic Zeolite A From Coal Gangue and Its Adsorption Properties for Cu2+

ABSTRACTDue to the abundant SiO2 and Al2O3 content in coal gangue (CG), the synthesis of zeolite from CG has become a route to realize the high‐value utilization of CG. However, some impurities contained in CG, such as iron oxide and carbon, have an adverse impact on the crystallization and application of zeolites. In this work, we propose a strategy to directly convert CG into magnetic zeolite without the need for an external magnetic source. Carbon in CG is calcined to in situ reduce iron oxide to magnetite. This is followed by the hydrothermal reaction to synthesize magnetic zeolite A. Effects of m (NaOH)/m (CG), alkali fusion temperature, crystallization temperature, and time on the synthesis of zeolites are investigated. The synthesized zeolite A is magnetic and exhibits the cubic morphology with rounded corners, having a particle size of about 2 μm. The maximum adsorption capacity and removal ratio of magnetic zeolite A for Cu2+ are 91.74 mg/g and 98.50%, respectively. The solid–liquid separation test after adsorption shows that the magnetic zeolite A could achieve the accelerated solid–liquid separation within 15 min. This work provides a pathway to realize comprehensive utilization of CG and demonstrates a good adsorbent for practical application of highly efficient adsorption separation.

Synthesis and studies of advanced adsorbent zeolites by using red mud and rice husk ash as a thermal insulation agent

Synthesis and studies of advanced adsorbent zeolites by using red mud and rice husk ash as a thermal insulation agent

Nanoporous Zeolite Anchored Cellulose Nanofiber Aerogel for Safe and Efficient Hemostasis

AbstractClay‐based hemostatic materials are commercially available devices designed to control massive bleeding. However, their widespread application is hindered by concerns related to material safety and hemostatic efficacy. In this study, a hemostatic aerogel composed of cellulose nanofibers (CNFs) and Calcium ion‐exchanged nanoporous zeolite is developed. CNFs facilitate the in‐situ synthesis of nanoporous zeolites, and the zeolites are firmly embedded within the aerogel through abundant hydrogen bonds. Notably, the zeolite loading in the aerogel is only 2.89 wt.%, significantly lower than the 18.76 wt.% kaolin content in QuikClot combat gauze. Despite the low loading, the nanoporous zeolites exhibit high efficiency in promoting prothrombin‐to‐thrombin conversion and accelerating blood clotting. The reduced zeolite content, combined with its strong binding to the aerogel matrix, minimizes the risks of exothermic burns and detached particle‐induced distal thrombosis. The animal experiments reveal that the aerogel rapidly controls severe femoral artery bleeding and substantially reduces blood loss. This study presents a novel formulation of zeolite‐based hemostatic materials, offering remarkable improvements in both safety and efficacy.

Thermodynamics and Adsorption of Fe2+ from Oilfield Produced Water using Clay-derived Zeolite

The study explored the potential of clay-derived zeolite (CDZ) as an adsorbent for the removal of Fe2+ ions from produced water generated from oil fields. The clay was sourced from the Ikepshi Community in the Akoko-Edo Local Government Area of Edo State, Nigeria. The zeolite was produced through a calcination process at a temperature of 600 °C, followed by dealumination and zeolite synthesis prior to its application for adsorption of Fe2+ from produced water. A variety of operational parameters were evaluated to understand their impacts on the adsorption process. These included different dosages of the adsorbent, contact time, temperature, agitation speed, and pH levels. The thermodynamics parameters were evaluated over a temperature range of 303 K to 343 K. Scanning Electron Microscopy (SEM) images displayed the characteristic silicate flakes of kaolinite clay, while Fourier Transform Infrared Spectroscopy (FTIR) results identified specific functional groups. Particularly, the presence of O-H and Si-O stretching vibrations confirmed the clay kaolinite composition. The analysis of adsorption outcomes across varying temperatures revealed negative values for Gibbs free energy ( ), and a positive entropy value ( , this indicates that the adsorption process is spontaneous and feasible, along with an increase in degree of randomness of adsorption process. The process of Fe2+ uptake on CDZ was considered as endothermic, as shown by the positive enthalpy values ( obtained thus shows a strong Vander Waal forces between the adsorbent and adsorbate.

Dual organic structure-directing agents in zeolite synthesis: cooperation or competition?

Organic structure-directing agents (OSDAs) play a vital role in the structural arrangement and compositional diversity of zeolites. The synthesis procedure and properties of zeolites can be improved through the "dual-OSDA" approach, which involves cooperation and/or competition of different OSDAs in the synthesis media. Two OSDAs achieving results that neither of the OSDAs can deliver on its own is referred to as the "cooperative OSDA" approach. In this manner, one can enhance zeolite properties by stabilizing different parts of the framework and altering the synthesis outcome, such as acidity and/or Al distribution. However, cooperation can easily be disrupted, and one of the challenges in dual-OSDA zeolite synthesis is determining the conditions under which OSDA molecules can function in harmony to affect zeolite properties and control phase selection. On the other hand, competition does not always result in negative outcomes (e.g., intergrowth materials). In this review, we discussed the importance of cooperative dual-OSDA synthesis in certain cases, explained the outcomes of this approach, and described the different behaviors key to cooperative systems.

Preparation of Hierarchical Porous Zeolite Particles with Multiscale Pore Architectures through a Template-Assisted Spray Process for Enhanced Toluene Adsorption Rate.

Hierarchical porous zeolite particles featuring multiscale pore architectures have gained significant attention due to their enhanced mass transfer properties and superior adsorption capabilities. This study reports the first successful synthesis of hierarchical porous zeolites with integrated micropores, mesopores, and macropores using a template-assisted spray process, addressing the limitations of conventional zeolites in adsorbing large organic molecules such as toluene. By employing poly(methyl methacrylate) (PMMA) particles (about 350 nm in size) as a template, we achieved precise control over macropore formation, providing a new level of flexibility in tailoring zeolite pore architectures. The effect of the PMMA/zeolite mass ratio on the resulting macroporous structures and their toluene adsorption performance was systematically investigated. The results revealed that the hierarchical porous zeolite exhibited a significantly enhanced toluene adsorption rate compared to samples synthesized without the PMMA template. This improvement is attributed to the optimized macroporous structure, which facilitates efficient mass transfer. Importantly, this study addresses a critical gap in the literature by demonstrating the successful integration of macropores into zeolites through an environmentally friendly process, with significant implications for applications in volatile organic compound removal. This advancement in porous zeolite design could enable more efficient and practical solutions for industrial air purification and environmental remediation.

Synthesis of zeolite from biomass power plant ash for removal of Pb2+ from solution: Performance and mechanism

Synthesis of zeolite from biomass power plant ash for removal of Pb2+ from solution: Performance and mechanism

Nanoscale Fe(0)-zeolite composite derived from coal bottom ash for efficient treatment of Cr(VI)-contaminated groundwater: Unveiling the importance of locations for surface-bound Fe(II) and Fe(0) passivation products.

Nanoscale Fe(0)-zeolite composite derived from coal bottom ash for efficient treatment of Cr(VI)-contaminated groundwater: Unveiling the importance of locations for surface-bound Fe(II) and Fe(0) passivation products.

Synthesis of chabazite zeolite: a dual-function material for high-performance carbon capture and para-nitrophenol removal from synthetic wastewater with comprehensive characterization and modeling

Synthesis of chabazite zeolite: a dual-function material for high-performance carbon capture and para-nitrophenol removal from synthetic wastewater with comprehensive characterization and modeling

Electrolytic manganese residue and red mud co-treatment: Synthesizing zeolite X and adsorbing leaching solution from electrolytic manganese residue

Electrolytic manganese residue and red mud co-treatment: Synthesizing zeolite X and adsorbing leaching solution from electrolytic manganese residue

Molecular descriptor-assisted interpretable machine learning: A scheme for guiding the synthesis of zeolites with target structures

Molecular descriptor-assisted interpretable machine learning: A scheme for guiding the synthesis of zeolites with target structures

A green red mud utilization process for Fe, Al, and Si extraction and NaA–zeolite synthesis for wastewater treatment

A green red mud utilization process for Fe, Al, and Si extraction and NaA–zeolite synthesis for wastewater treatment

Green Synthesis of Coal Gangue-Derived NaX Zeolite for Enhanced Adsorption of Cu2+ and CO2

The accumulation of coal gangue (CG), a byproduct of coal mining, poses severe environmental challenges. This study presents a green strategy to convert CG into high-value NaX zeolite via an alkali fusion–hydrothermal method. Through orthogonal experiments, the optimal synthesis conditions (solid–liquid ratio 1:8, crystallization temperature 110 °C, time 12 h) were identified, yielding NaX zeolite with exceptional crystallinity (98%), specific surface area (703.5 m2/g), and pore volume (0.28 cm3/g). Comprehensive characterization (XRD, SEM-EDS, BET, etc.) confirmed its structural integrity and thermal stability. The synthesized zeolite exhibited remarkable adsorption capacities for Cu2+ (185.35 mg/g) and CO2 (5.51 mmol/g), following the Langmuir isotherm model. This work not only addresses gangue disposal challenges but also demonstrates a cost-effective route for producing high-performance adsorbents, aligning with circular economy and carbon neutrality goals.

Synthesis of MOR Zeolite from Natural Stellerite and Clinoptilolite for Efficient Pb2+ and Cd2+ Removal from Aqueous Solutions

Synthesis of MOR Zeolite from Natural Stellerite and Clinoptilolite for Efficient Pb²⁺ and Cd²⁺ Removal from Aqueous Solutions