Nano-crystallite oriented self-assembled ZSM-5 zeolite and its LDPE cracking properties: Effects of accessibility and strength of acid sites

Synergistic catalysis for promoting selective C-C/C-O cleavage in plastic waste: structure-activity relationship and rational design of heterogeneous catalysts for liquid hydrocarbon production

Ever-increasing consumption of plastic products and poor waste management infrastructure have resulted in a massive accumulation of plastic waste in environments, causing adverse effects on climate and living organisms. Although contributing ∼10% towards the total plastic waste management infrastructure, the chemical recycling of plastic waste is considered a viable option to valorize plastic waste into platform chemicals and liquid fuels. Among the various chemical upcycling processes, catalytic hydroprocessing has attracted interest due to its potential to offer higher selectivity than other thermal-based approaches. Heterogeneous catalytic hydroprocessing reactions offer routes for converting plastic waste into essential industrially important molecules. However, the functional group similarities in the plastic polymers frequently constrain reaction selectivity. Therefore, a fundamental understanding of metal selection for targeted bond activation and plastic interaction on solid surfaces is essential for catalyst design and reaction engineering. In this review, we critically assess the structure-activity relationship of catalysts used in the hydroprocessing of plastic waste for the selective production of liquid hydrocarbons. We discuss the significance of C-C/C-O bond activation in plastic waste through active site modulation and surface modification to elucidate reaction networks and pathways for achieving selective bond activation and cleavage. Finally, we highlight current challenges and future opportunities in catalyst design to upcycle real-life plastic waste and produce selective liquid hydrocarbons.

Hollow Zeolite Nanoreactor with Double Shells for Methanol Aromatization: Explicit Recognition on Catalytic Function of Inverse Elemental Zone and Shell-Cavity

Core@shell catalyst composited of dual aluminosilicate zeolite can effectively regulate the distribution of acid sites to control hydrocarbon conversion process for the stable formation of target product. However, the diffusion restriction reduces the accessibility of inner active sites and affects synergy between core and shell. Herein, hollow ZSM-5 zeolite nanoreactor with inverse aluminum distribution and double shells are prepared and employed for methanol aromatization. It is demonstrated that the intershell cavity alleviated the steric hindrance from zeolites channel and provided more paths and pore entrance for guest molecule. Correspondingly, olefin intermediates generated from methanol over the external shell are easier to adsorb at internal acid sites for further reactions. Importantly, the diffusion of generated aromatic macromolecules to the external surface is also promoted, which slows down the formation of internal coke, and ensures the use of internal acid sites for aromatization. The aromatics selectivity of the nanoreactor remained at 8% after 154 h, while that of solid core@shell catalyst decreased to 2% after 75 h. This finding promises broader insight to improve internal active site utilization of core@shell catalyst at the diffusion level and can be great aid in the flexible design of multifunctional nanoreactors to enhance the relay efficiency.

Bimetallic Mn-Ce loaded on different zeolite carriers applied in the toluene abatement in air by non-thermal plasma DDBD reactor

A sequence of zeolite carriers (Carrier = ZSM-5, Small crystal ZSM-5, MCM-41, SBA-15) were used to support active metals Mn-Ce, which have presented an enormous potential for plasma oxidation of toluene in air. The prepared samples were detected by means of N2 adsorption-desorption, SEM, XPS, H2-TPR, etc. Through the activity evaluation in the Non-thermal Plasma Reactor, we found that the catalysts with different carriers showed distinct degradation activities. The performance of mesoporous supported catalysts was better than that of microporous catalysts, of which MCM-41 performed best. 96.3% of toluene can be decomposed, and 97.3% of degraded toluene converted into final products CO2 completely at the initial concentration of 1000 ppm and SIE of 9 kJ/L. From the results, we can see that the appropriate carrier is conducive to maximizing the efficiency of the active metal, and Mn-Ce/MCM-41 got the best performance in the plasma catalysis for toluene abatement.

Isomorphous Substitution in ZSM-5 in Tandem Methanol/Zeolite Catalysts for the Hydrogenation of CO2 to Aromatics

Intensified reactors for conversion of CO2 to methanol (via hydrogenation) using metal oxide catalysts coupled with methanol conversion to aromatics in the presence of zeolites (e.g., H-ZSM-5) in a single step are investigated. Brønsted acid sites (BAS) in H-ZSM-5 are important sites in methanol aromatization reactions, and correlations of the reactivity with zeolite acid properties can guide reaction optimization. A classical way of tuning the acidity of zeolites is via the effect of the isomorphous substitution of the heteroatom in the framework. In this work, H-[Al/Ga/Fe]-ZSM-5 zeolites are synthesized with Si/T ratios = 80, 300, affecting the acid site strength as well as distribution of Brønsted and Lewis acid sites. On catalytic testing of the H-[Al/Ga/Fe]-ZSM-5/ZnO-ZrO2 samples for tandem CO2 hydrogenation and methanol conversion, the presence of weaker Brønsted acid sites improves the aromatics selectivity (CO2 to aromatics selectivity ranging from 13 to 47%); however, this effect of acid strength was not observed at low T atom content. Catalytic testing of H-[B]-ZSM-5/ZnO-ZrO2 provides no conversion of CO2 to hydrocarbons, showing that there is a minimum acid site strength needed for measurable aromatization reactivity. The H-[Fe]-ZSM-5-80/ZnO-ZrO2 catalyst shows the best catalytic activity with a CO2 conversion of ∼10% with a CO2 to aromatics selectivity of ∼51%. The catalyst is shown to provide stable activity and selectivity over more than 250 h on stream.

OSDA-Free Seeded Cu-Containing ZSM-5 Applied for NH3-SCR-DeNOx

A series of ZSM-5 zeolite materials were synthesized from organic structure-directing agent (OSDA)-free seeded systems, including nanosized silicalite-1 (12 wt % water suspension or in powder form) or nanosized ZSM-5 (powder form of ZSM-5 prepared at 100 or 170 °C). The physicochemical characterization revealed aggregated species in the samples based on silicalite-1. Contrarily, the catalysts based on ZSM-5 seeds revealed isolated copper species, and thus, higher NO conversion during the selective catalytic reduction of NOx with NH3 (NH3-SCR-DeNOx) was observed. Furthermore, a comparison of the Cu-containing ZSM-5 catalysts, conventionally prepared in the presence of OSDAs and prepared with an environmentally more benign approach (without OSDAs), revealed their comparable activity in NH3-SCR-DeNOx.

MFI Type Zeolite Aggregates with Nanosized Particles via a Combination of Spray Drying and Steam-Assisted Crystallization (SAC) Techniques

Hydrothermal synthesis is the state-of-the-art technique for the preparation of zeolites and related porous solids. However, when it comes to the preparation of nanosized zeolites, this technique is limited by low yields, separation problems and high amounts of waste. In this work, we utilized the strengths of a combination of spray drying and steam-assisted crystallization (SAC), also known as dry gel conversion, to reduce these problems. At spray drying temperatures between 300 and 400 °C, it was possible to convert all the amorphous material via SAC into zeolite particles without extra addition of template. Kinetic studies of SAC revealed that about 4 to 8 days are needed to achieve the formation of a 100% crystalline product. The newly formed crystalline phase was crystallized on the surface of the nanosized zeolites and led to a slight increase in the primary particle size while the macroscopic morphology of the spray-dried aggregates was preserved. This work demonstrates that the combination of spray drying and SAC are useful tools in supplementing the hydrothermal synthesis of nanosized zeolites.

Amorphous Aluminosilicate Nanosheets as Universal Precursors for the Synthesis of Diverse Zeolite Nanosheets for Polymer-Cracking Reactions

Zeolites catalyze some reactions in their molecular-sized pores, but large molecules can react only on their external surface. Zeolite-nanosheets (NSs) have been developed as catalysts for large molecules. The previously reported methods to synthesize zeolite-NSs are specialized for each zeolite type. Here we propose a new method to synthesize various zeolite-NSs from the same amorphous aluminosilicate NSs (AAS-NSs) as a universal precursor. We successfully synthesized the unprecedented AAS-NSs in the hydrophilic space of the stable hyperswollen lyotropic lamellar (HL) phase. The four zeolite types could be obtained from the single-species AAS-NSs. These results imply that this method enables us to synthesize almost all types of zeolite-NSs. Moreover, the synthesized CHA-NSs have great potential for various applications because of their thickness and large external surface area.

Microwave-responsive SiC foam@zeolite core-shell structured catalyst for catalytic pyrolysis of plastics

Catalytic pyrolysis is a promising chemical recycling technology to supplement mechanical recycling since plastics can be broken down into monomers or converted to the required fuels and chemicals. In this study, a microwave (MW) -responsive SiC foam@zeoltie core-shell structured catalyst was proposed for the catalytic pyrolysis of polyolefins. Under microwave irradiation, the SiC foam core works as both microwave adsorber and catalyst support, thus concentrating the generated heat energy on the ZSM-5 zeolite shell, where the catalytic reaction takes place. SiC foam with an open cellular structure can also improve the global transport of mass and heat during plastics pyrolysis. In this work, the effects of the SiO₂/Al₂O₃ ratio and alkaline treatment of ZSM-5 zeolite coated SiC foam under MW irradiation on the variations in product distribution from low-density polyethylene (LDPE) pyrolysis were investigated at 450 °C. The results indicated that the appropriate acidity and pore structure were crucial to upgrading gas and liquid products. Particularly, the creation of a mesoporous structure in ZSM-5 zeolite via alkaline treatment could improve the diffusion of large molecules and products, thus significantly increasing the selectivity of high-valued light olefins and aromatics while inhibiting the formation of unwanted alkanes, which are expected in the chemical industry. Concretely, the concentration of olefins in gas increased to 51.0 vol% for ZSM-5(50)-0.25AT, and 65.6 vol% for ZSM-5 (50)-0.50AT, compared with 45.2 vol% for the parent ZSM-5(50). The relative concentration of aromatics in liquid decreased from 96.6% for ZSM-5(50) to 75.9% for ZSM-5(50)-0.25AT, and 71.1% for ZSM-5(50)-0.50AT. Given the respective yield of gas and liquid, the total selectivity of C2-C4 olefins and aromatics for mesoporous ZSM-5 zeolites could reach 58.6-64.9% during LDPE pyrolysis, which were higher than that for the parent ZSM-5 zeolite.

Facile Morphology and Porosity Regulation of Zeolite ZSM-5 Mesocrystals with Synergistically Enhanced Catalytic Activity and Shape Selectivity

The morphology and mesoporosity of zeolite are two vital properties to determine its performance in diverse applications involving adsorption and catalysis; while it remains a big challenge for the synthesis and regulation of zeolites with exceptional morphology/porosity only through inorganic-ions-based modification. Herein, by simply optimizing the alkali metal type (K⁺ or Na⁺), as well as alkali/water ratio and crystallization temperature, the zeolite ZSM-5 mesocrystals with diverse mesostructures are simply and controllably prepared via fine-tuning the crystallization mechanism in an organotemplate-free, ions-mediated seed-assisted system. Moreover, the impacts of these key parameters on the evolution of seed crystals, the development and assembly behavior of aluminosilicate species and the solution-phase process during zeolite crystallization are investigated by means of directional etching in NH₄F or NaOH solutions. Except for the morphology/mesoporosity modulation, their physical and chemical properties, such as particle size, microporosity, Si/Al ratio and acidity, can be well maintained at a similar level. As such, the p/o-xylene adsorption and catalytic performance of o-xylene isomerization are used to exhaustively evaluate the synergistically enhanced catalytic activity and shape selectivity of the obtained products. This work demonstrates the possibility of effectively constructing novel zeolite mesostructures by simply altering parameters on simple ions-controlled crystallization and provides good models to inspect the impacts of mesoporosity or morphology on their catalytic performances.

Facile Synthesis of Nanosheet-Stacked Hierarchical ZSM-5 Zeolite for Efficient Catalytic Cracking of n-Octane to Produce Light Olefins

The development of an effective strategy for synthesizing two-dimensional MFI zeolites has attracted more and more attention. Herein, nanosheet-stacked hierarchical ZSM-5 zeolite was obtained by a seed-assisted hydrothermal synthesis route using a small amount of [C18H37-N+(CH3)2-C6H12-N+(CH3)2-C6H12]Br2 (C18-6-6Br2) as a zeolite structure-directing agent and triethylamine (TEA) as a zeolite growth modifier. By varying the molar ratio of C18-6-6Br2/TEA from 2.5/0 to 2.5/40, the morphologies and textural properties of the resultant HZ5-2.5/x catalysts were finely modulated. By increasing x from 5 to 40, the morphology of the HZ5-2.5/x changed from unilamellar assembly with narrow a–c plane to intertwined nanosheets with wide a–c plane and multilamellar nanosheets with house-of-cards morphology. The thickness of these nanosheets was almost 8–10 nm. In addition, selectivity to light olefins reached 70.7% for the HZ5-2.5/10 catalyst, which was 6.6% higher than that for CZSM-5 (64.1%). Furthermore, the MFI zeolite nanosheets exhibited better anticoking stability within the 60 h reaction time compared to conventional ZSM-5 zeolite, which could be attributed to the short diffusion path and hierarchical porosity. This work will provide valuable insights into the rational design of novel zeolite catalysts for the efficient cracking of hydrocarbons.

Rapid solvent-free synthesis of nano-sized ZSM-5 with low Si/Al ratio at 90 °C

Nano-sized ZSM-5 zeolites with wide framework Si/Al ratios are highly desired in petrochemical and other fields, whereas the synthesis suffers from cost, efficiency and environmental issues. Herein, a new protocol...

c-Axis-penetrated mesoporous MWW zeolite nanosheets: preparation by H2O2-induced micro-explosion and their enhanced properties

A series of highly dispersed and c-axis-penetrated mesoporous MWW oligolayers with enhanced properties was prepared via an efficient, green, and controllable method through H2O2-induced micro-explosion.

Tandem catalysts for the conversion of methanol to aromatics with excellent selectivity and stability

A schematic diagram of the construction methods and reaction paths of different catalysts.

Synthesis, characterization, and catalytic application of hierarchical nano-ZSM-5 zeolite

Hierarchical nano-ZSM-5 zeolites (Z5-X) with different grain sizes were synthesized by varying amounts of 3-glycidoxypropyltrimethoxysilane (KH-560) in the hydrothermal synthesis strategy. Moreover, the conventional ZSM-5zeolite(Z5), which was prepared without KH-560, was used as the reference sample. The crystalline phases, morphologies, porous characteristics, Si/Al molar ratios and acidic properties of all fresh catalysts were characterized using the X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), scanning electron microscopy (SEM), N₂ adsorption–desorption, inductively coupled plasma atomic emission spectroscopy (ICP) and temperature programmed desorption of ammonia (NH₃-TPD) techniques. Results show that the grain size and strong acid amount of zeolite decreased with the increasing amount of KH-560. The micropore surface areas and the corresponding volume of Z5-X changed less compared with Z5. Consequently, the high shape-selectivity of zeolite was preserved well under the addition of KH-560. However, the mesopore surface areas and the corresponding volume increased significantly with the increasing amount of KH-560. Benefiting from the abundant hierarchical structure, the Z5-X catalysts exhibited a larger coke capacity than the Z5 catalyst. The coke depositions of all the deactivated catalysts were characterized by the thermogravimetric technique (TG), and the results are indicative of the decreased average rate of coke deposition with an increasing amount of KH-560, which could result from the gradually reduced strong acid amount and the nano-sized crystallites. The catalytic performance of methanol-to-aromatics (MTA) indicates that the Z5-0.12 catalyst exhibited higher catalytic activity and selectivity of BTX as the reaction was prolonged, which could result from the synergistic effect among the proper strong acid amount, the smaller zeolite grain size, and the abundant hierarchical structure.

The crystal size and strong acid amounts of ZSM-5 decrease and the mesopores increase with increasing of KH-560. High MTA catalytic performance could be obtained under synergistic effect of proper strong acid amount, smaller crystal size and abundant hierarchical structure.

Co-hydrolysis and Seed-Induced Synthesis of Basic Mesoporous ZSM-5 Zeolites with Enhanced Catalytic Performance

For zeolite catalysts, the regulation of active site and pore structure plays an important role in the enhancement of their catalytic performance. In this work, a one-pot and organic template-free co-regulation route is proposed to straightforwardly synthesize basic mesoporous ZSM-5 zeolites with adjustable alkaline-earth metal species. The synthesis pathway combines two decisive strategies: 1) the seed-induced interface assembly growth method and 2) the acidic co-hydrolysis/condensation of aluminosilicate species and alkaline-earth metal (e.g., Mg, Ca, Sr, or Ba) sources. It is interesting that the mesoporous structure was self-evolved through particle-attached seed-interfacial crystallization without the assistance of any template. Meanwhile, the incorporation of alkaline-earth metals species is homogeneous and highly dispersed in the solid products during the whole crystallization process, and finally generate the superior basicity. Catalysis tests of the as-synthesized samples displayed their novel performance in the typical base reaction of Knoevenagel condensation, even for bulky substrates owing to the enhanced diffusion arising from the meso/microporous network. This finding opens new possibilities for facile, cost-effective, and environmentally friendly synthesis of mesoporous high-silica zeolites with tunable acid/base properties, and deepens our understanding of the particle-attached crystallization.

Lower olefins from methane: recent advances

Modern methods for methane conversion to lower olefins having from 2 to 4 carbon atoms per molecule are generalized. Multistage processing of methane into ethylene and propylene via syngas or methyl chloride and methods for direct conversion of CH4 to ethylene are described. Direct conversion of syngas to olefins as well as indirect routes of the process via methanol or dimethyl ether are considered. Particular attention is paid to innovative methods of olefin synthesis. Recent achievements in the design of catalysts and development of new techniques for efficient implementation of oxidative coupling of methane and methanol conversion to olefins are analyzed and systematized. Advances in commercializing these processes are pointed out. Novel catalysts for Fischer – Tropsch synthesis of lower olefins from syngas and for innovative technique using oxide – zeolite hybrid catalytic systems are described. The promise of a new route to lower olefins by methane conversion via dimethyl ether is shown. Prospects for the synthesis of lower olefins via methyl chloride and using non-oxidative coupling of methane are discussed. The most efficient processes used for processing of methane to lower olefins are compared on the basis of degree of conversion of carbonaceous feed, possibility to integrate with available full-scale production, number of reaction stages and thermal load distribution.

The bibliography includes 346 references.

Construction of a tandem HZSM-5 with CuZnAl catalyst for alkylation of benzene with syngas

A bifunctional catalyst composed of ZSM-5 and Cu–Zn–Al shows an outstanding catalytic performance in the alkylation reaction of benzene with syngas.

Mesoporogen-free synthesis of hierarchical HZSM-5 for LDPE catalytic cracking

We show how Stöber silica spheres can be transformed into hierarchical HZSM-5 by a mesoporogen-free and modified SAC route.

Comparison and assessment of zeolite catalysts performance dimethyl ether and light olefins production through methanol: a review

The present review focuses on a comparison and assessment of zeolite catalyst performance of dimethyl ether and light olefin production through methanol. Dimethyl ether is a clean fuel which needs diverse processes to be produced. Methanol to dimethyl ether is a very novel process which offers considerable advantages versus additional processes for the production of dimethyl ether. The corresponding fixed-bed reactors compose the most important section of such a process. Production of dimethyl ether by the mentioned process is of high importance since it can be catalytically transferred to a substance with the value of propylene. Furthermore, in case of capability to transfer low-purity methanol into dimethyl ether, less expensive methanol can be consequently achieved with higher value added. In the petrochemical industry, light olefins, for example, ethylene and propylene, can be used as raw materials for the production of polyolefin. The present review aims to produce dimethyl ether in order to reach olefin substances, initially conducting a compressive assessment on production methods of olefin substances.

Chemical Crosslinking Assembly of ZSM-5 Nanozeolites into Uniform and Hierarchically Porous Microparticles for High-Performance Acid Catalysis

Hierarchically porous zeolites combining the advantages of desirable mass transport of nanozeolites and easy separation and handling of micro-zeolites are ideal candidates in catalytic applications. Facile routes for the assembly of zeolite microparticles with hierarchical porosity and high mechanical strength are much expected. Herein, based on a microfluidic jet spray drying technology, we report a facile and scalable chemical crosslinking assembly strategy for the synthesis of hierarchical zeolite microparticles by directly using the conventional as-synthesized nanozeolite suspension as a precursor. This route not only avoids the energy-intensive centrifugal separation process of nanozeolites but also significantly increases the uniformity and mechanical strength of the microparticles. The soluble aluminosilicate species act as a stabilizer to improve the droplet stability during the drying process and then as a "cross-linker" to chemically bind and interconnect zeolite nanoparticles to form robust bodies after drying and calcination. Zeolite microparticles with variable morphologies (spherical, bowl-like, and dimpled) and uniform and controllable sizes (from 70 to 108 μm) can be obtained by adjusting the experimental parameters. The particle formation mechanism is discussed based on the zeolite microparticles obtained from the purified nanozeolite suspension as a control. The zeolite microparticles possess emerged uniform mesopores (∼6 nm) and a well-maintained high surface area, large pore volume, high microporosity, and strong acidity of the original nanozeolites. As a result, they exhibit excellent acid catalytic performances in acetolysis of epichlorohydrin and catalytic cracking of low-density polyethylene, far better than those of the commercial ZSM-5.

Boosting the turnover number of core–shell Al-ZSM-5@B-ZSM-5 zeolite for methanol to propylene reaction by modulating its gradient acid site distribution and low consumption diffusion

Hierarchical Al-ZSM-5@B-ZSM-5 core–shell zeolite was prepared to boost turnover number of MTP reaction.

Synthesis and Characterization of Hierarchical ZSM-5 Zeolites with Outstanding Mesoporosity and Excellent Catalytic Properties

A novel soft-template (ST) is fabricated and successfully employed as mesoporogen to synthesis hierarchical ZSM-5 zeolites with outstanding mesoporosity and high hierarchy factors. The as-produced soft-template can connect steadily with the MFI frameworks by covalent bonds of -Si-O-Si- during the high-temperature hydrothermal crystallization process. This type of connection mode can effectively avoid the formation of amorphous materials, and the specific structure of this soft-template can efficiently introduce plentiful of mesopores with few micropores being consumed. The particles of as-synthesized hierarchical ZSM-5 zeolites are in size of about 1 μm, which are made up of nanocrystals of 60-150 nm. The structure parameters of these samples are characterized with the techniques of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nitrogen sorption, scanning electron microscope (SEM), transmission electron microscope (TEM), NH₃ temperature-programmed desorption (NH₃-TPD) and thermogravimetric (TG). Due to the nature of zeolites and great microporosity, these hierarchical samples present great tolerance of hydrothermal treatment. And because of the intracrystalline mesopores, large external surface areas, and abundant accessible acid sites, whether in conversion rate of reactants or selectivity of products, the hierarchical samples exhibit excellent catalytic performance in the reactions of alkylation between benzene and benzyl alcohol, cracking of 1,3,5-tri-isopropylbenzene, and thermal cracking of low-density polyethylene (LDPE), respectively.

Seed-induced synthesis of multilamellar ZSM-5 nanosheets directed by amphiphilic organosilane

Multilamellar ZSM-5 nanosheets formed by the transformation of ordered MCM-41-like mesophases.

Graphene oxide-assisted synthesis of core–shell structured ZSM-5 zeolites and their catalyst texture effect on the catalytic performance in the acid-catalyzed o-methylation of cyclohexanone with methanol

Tailoring the crystallization process to realize targeted material texture/porosity is a major challenge in zeolite synthesis, which facilitates the practical application of zeolites.

Seed-induced and additive-free synthesis of oriented nanorod-assembled meso/macroporous zeolites: toward efficient and cost-effective catalysts for the MTA reaction

A general seed-induced strategy is reported for the synthesis of meso/macroporous zeolites with high catalytic efficiencies for the MTA reaction.

Acidity and accessibility studies of desilicated ZSM-5 zeolites in terms of their effectiveness as catalysts in acid-catalyzed cracking processes

The structural, textural and acidic characteristics of hierarchical ZSM-5 (Si/Al = 18–32), obtained with two desilication approaches, and the effect of these treatments on the reactivity in various cracking reactions of variable feedstock size and severity have been investigated.

Synthesis of microscale and nanoscale ZSM-5 zeolites: effect of particle size and acidity of Zn modified ZSM-5 zeolites on aromatization performance

Zn/NZ5 zeolite exhibits a higher BTX yield because of the higher mesoporosity and strong Lewis acid sites formed by [ZnOZn]²⁺ species.

Controllable fabrication of single-crystalline, ultrafine and high-silica hierarchical ZSM-5 aggregates via solid-like state conversion

Single-crystalline, ultrafine and high-silica HA-ZSM-5 aggregates were directly synthesizedviaSSC method using HTAB as the mesoporogen through a S-1 seed-induced route.

Precise control of the size of zeolite B-ZSM-5 based on seed surface crystallization

A unified functionD³=d³D₀³/[xD₀³+ (1 −x)d³] is established to precise control and predict the particle size of B-ZSM-5 from 153 nm to 14.2 μm in the TPABr and/or TPAOH synthetic systems.