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Non‐oxidative dehydrogenation of propane is a highly efficient approach for industrial preparation of propene that is commonly catalyzed by noble Pt or toxic Cr catalysts and suffers from coking. In this work, ferric catalyst confined in a zeolite framework was synthesized by a hydrothermal procedure. The isolated Fe in the framework formed distorted tetrahedra, which were beneficial for the selective dehydrogenation of propane and reached over 95 % propene selectivity and over 99 % total olefins selectivity. This catalyst had a silanol‐free structure and was oxygen tolerant, hydrothermally stable, and coke free, with a deactivation constant of 0.01 h−1. This study provided guidance for the synthesis of structural heteroatomic zeolite and efficient propane non‐oxidative dehydrogenation over early transition metals. [ABSTRACT FROM AUTHOR]

The minimized diffusion limitation and completely exposed strong acid sites of the ultrathin zeolites make it an industrially important catalyst especially for converting bulky molecules. However, the structure-controlled and large-scale synthesis of the material is still a challenge. In this work, the direct synthesis of the single-layer MWW zeolite was demonstrated by using hexamethyleneimine and amphiphilic organosilane as structure-directing agents. Characterization results confirmed the formation of the single-layer MWW zeolite with high crystallinity and excellent thermal/hydrothermal stability. The formation mechanism was rigorously revealed as the balanced rates between the nucleation/growth of the MWW nanocrystals and the incorporation of the organosilane into the MWW unit cell, which is further supported by the formation of MWW nanosheets with tunable thickness via simply changing synthesis conditions. The commercially available reagents, well-controlled structure and the high catalytic stability for the alkylation of benzene with 1-dodecene make it an industrially important catalyst. [ABSTRACT FROM AUTHOR]

The construction of hierarchical titanosilicate beta zeolites with desirably interconnected meso-/microporosity, controllable morphology and enhanced activity of catalytic oxidation is a pervasive challenge in the zeolite community. We report here in the synthesis of the hierarchical titanosilicate beta zeolite with a three-dimensionally ordered mesoporous-imprinted structure (3DOm-i Ti-beta) through the postsynthetic treatment of the parent 3DOm-i Al-beta by successive dealumination and titanation. The highly interconnected intracrystalline meso-/microporosity derived from the well-retained 3DOm-i structure led to both enhanced diffusion property and better accessibility of active sites to the bulky substrates, which was confirmed by the improved catalytic performances in the epoxidation of cyclic olefins (cyclohexene and cyclooctene) compared with the conventional solely microporous Ti-beta and TS-1. Moreover, the demonstrated that 3DOm-i Ti-beta catalyst exhibited not only a superior stability but also a facile recyclability by simple calcination in the epoxidation reaction. [ABSTRACT FROM AUTHOR]

To improve the stability of mordenite (MOR) in the alkylation of benzene with long chain olefin, hierarchical MOR zeolites were synthesized by using organosilane surfactant [3-(trimethoxysilyl)propyl]octadecyldimethyl-ammonium chloride (TPOAC) as the mesopore structure-directing agent. Our findings reveal that the crystal size, hierarchical structure, and acidic properties of the mesoporous MOR zeolites are significantly influenced by the TPOAC/SiO2 molar ratio in the synthesis gel. Moreover, the hierarchical MOR zeolite synthesized under the optimized synthesis conditions presented the pure phase of the MOR framework and uniform mesoporous distribution. More importantly, the catalytic performance evaluated by the alkylation of benzene with 1-dodecene indicates that the optimal mesoporous MOR zeolite shows improved stability and comparable selectivity of 2-phenyl alkane (2-LAB) around 80% compared to the conventional sole microporous MOR zeolite. The improved stability of the mesoporous MOR zeolite can be attributed to the enhanced diffusivity of long chain linear alkylbenzenes and oligomers due to interconnected meso-/microporosity in the MOR. [ABSTRACT FROM AUTHOR]

Hierarchical SAPO-34 zeolites with a special nanosheet-assembled morphology were hydrothermally synthesized under dynamic condition by using the commercial quaternary ammonium-type organosilane surfactant [3-(trimethoxysilyl) propyl] octadecyldimethyl-ammonium chloride (TPOAC) for the mesoscopic aggregation and tetraethylammonium hydroxide as the micropore structure-directing agent. The growth evolution during the crystallization process and governing factors including TPOAC content and dynamic hydrothermal condition in the synthesis were discussed in detail, and the possible nucleation and growth process were proposed as well. With a systematic structure characterization by XRD, FTIR, N2 adsorption-desorption, ICP, SEM, TEM, NH3-TPD and pyridine-adsorbed IR measurements, the nanosheet-assembled SAPO-34 (NA-SP34) prepared under the optimized synthesis condition presented the pure phase of CHA framework, high degree of crystallinity, interconnected hierarchical meso-/microporosity and relatively weak acidity comparing with the conventional microporous SAPO-34 (CM-SP34) with micron size and the nanosheet-like SAPO-34 (NL-SP34) synthesized in the absence of TPOAC. Moreover, the catalytic performances evaluated by the methanol-to-olefin reaction indicated that the optimal NA-SP34 catalyst presented remarkable improvements of not only much longer catalytic lifetime (300 min) and slower coke formation rate (0.24 mg g−1 min−1) but also higher ethylene and propylene selectivity (81.93%) comparing with those (95 min, 0.55 mg g−1 min−1 and 80.75%, respectively) of CM-SP34, which can be attributed to the integrated balance of well-remained microporosity, considerable mesoporosity and suitable weak acidity. [ABSTRACT FROM AUTHOR]

Abstract: Siliceous zeolites are ideally suited for emerging applications in gas separations, sensors, and the next generation of low‐k dielectric materials, but the use of fluoride in the synthesis significantly hinders their commercialization. Herein, we show that the dry gel conversion (DGC) technique can overcome this problem. Fluoride‐free synthesis of two siliceous zeolites—AMH‐4 (CHA‐type) and AMH‐5 (STT‐type), has been achieved for the first time using the method. Siliceous *BEA‐, MFI‐, and *MRE‐type zeolites have also been synthesized to obtain insights into the crystallization process. Charge‐balancing interactions between the inorganic cation, organic structure‐directing agent (OSDA), and Si−O− defects are found to be an essential aspect. We quantify this factor in terms of the “OSDA charge/silica ratio” of the as‐made zeolites and demonstrate that the DGC technique is broadly applicable and opens up new avenues for fluoride‐free siliceous zeolite synthesis. [ABSTRACT FROM AUTHOR]

Confined synthesis of three-dimensionally ordered mesoporous-imprinted (3DOm-i) zeolites within three-dimensionally ordered mesoporous (3DOm) carbons prepared from silica colloidal crystals was achieved through multiple hydrothermal (MHT) synthesis and steam-assisted crystallization (SAC). The transition of ordered mesoporous structures, starting from silica colloidal crystal to resulting 3DOm-i zeolites including the intermediate 3DOm carbon templates, and the correlations among the confined synthesis methods, crystal growth nature of different zeolites, and the sintering of the templates were studied. An imperfect replication was found in 3DOm-i zeolite when it compared to silica colloidal crystals regardless the synthesis methods (MHT or SAC), which might be originated from combination effects of sintering of the silica colloidal crystals and partial filling of cavities of the 3DOm carbon template during the confined synthesis, and the degree of the structure replication was notably influenced by microstructures of zeolite as well. A thorough investigation of the growth development of 3DOm-i BEA zeolites with various Si/Al ratios ranging from 14 to 27 through the MHT method confirmed that the crystallization takes place in the carbon template by a cage-to-cage propagation growth process. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZSM-xD zeolite with yolk-shell structure was prepared by Oswald ripening. • The performance of ZSM-xD for CCO aromatization to produce BTEX was evaluated. • The structure–activity relationship between ZSM-xD structure and catalytic products. • The excellent mass transfer ability of ZSM-xD promotes the alkylation of aliphatics. • Micro-mesoporous structure resists carbon deposition and aids catalyst regeneration. Aiming to improve the catalytic performance of HZSM-5 in the catalytic conversion of coal-oil co-refining oil, a range of zeolite catalysts (HZ5-xD) were prepared by adjusting the recrystallization times of dissolution–recrystallization of HZSM-5 basing on the Oswald ripening mechanism. The results show that HZ5-xD processes more easily accessible active sites and mixed microporous-mesoporous structures. Larger pore size and moderate acidity were beneficial for the generation of benzene, toluene, ethylbenzene and xylene (BTEX). The selectivity and yield of reached as high as 29.76 % and 236.83 mg·g−1 over HZ5-2D at 700 °C, respectively. Both HZSM-5 and HZ5-xD demonstrate high selectivity to C3 gaseous hydrocarbons, likely due to the obedience of the carbenium ion mechanism. HZ5-2D still demonstrated more excellent catalytic performance than HZSM-5 after five regenerations. Collectively, these finding illustrates the broad application potential of Oswald ripening in special morphologies of zeolite to improve the conversion efficiency of coal tar to BTEX. [ABSTRACT FROM AUTHOR]

Abstract We reported a strategy to synthesize MFI zeolites with tunable properties by tailoring organic structure-directing agents (OSDAs) under the hydrothermal conditions. The tailored surfactants were obtained by tuning the structure of Gemini-type C ph-10-6-6 and Bola-type BC ph-10-6-6 , including alkyl tail chains, ammonium groups and alkyl middle chains. The textural property, morphology and acidity of resulting MFI zeolites were characterized by a complementary combination of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption isotherms and FTIR spectra of pyridine adsorption. Moreover, the correlation between the OSDAs' composition and the inorganic precursor in the fabrication of zeolite framework was investigated by DFT calculations in this study. The catalytic performance of the resulting MFI samples was investigated by the alkylation of mesitylene with benzyl alcohol. The results revealed that the OSDAs without ammonium groups only leaded to form the micro-structure of zeolites, but the OSDAs with ammonium groups can induce the formation of micro- and meso-structure simultaneously, regardless the OSDAs ended with or without alkyl tail chains. In addition, the resulting MFI zeolites showed an improved catalytic activity in alkylation of mesitylene with benzyl alcohol due to the enhanced pore accessibility, the acidity (Brønsted/Lewis) controlled the activation of benzyl alcohol, and the ratio of external surface area (S ext /S BET) governed the selectivity of alkylation reaction. As a result, tailoring the structure of OSDAs can pick another strategy to synthesize MFI zeolites with tunable zeolite structure and catalytic performance. Graphical abstract The morphology and textural property of MFI zeolites were systematically tailored by tuning the molecular structure of organic templates. Image 1 Highlights • The morphology of MFI zeolites can be tuned by changing the structure of amphiphilic molecules. • The MFI zeolites can be synthesized without utilization of quaternary ammonium surfactant. • The structure-directing ability of amphiphilic molecules was investigated by DFT calculation. • The condensed structure of MFI zeolites was unfavorable for alkylation of mesitylene. [ABSTRACT FROM AUTHOR]

Abstract The pillared MWW (PMWW or MCM-36) and pillared MFI (PMFI) are two prominent representatives of meso-/microporous lamellar zeolites, which are made by pillaring of layered MCM-22(P) and multilamellar MFI precursors, respectively. They both consist of a 10-membered ring sinusoidal micropore channel within each zeolitic layer and mesopore voids created by pillars between two adjacent zeolitic layers. Although catalytic activities of PMWW and PMFI have been compared, identification of mesopore differences between these two pillared lamellar zeolites has not been attempted. In this work, we report the differences in mesopore characteristics between PMWW and PMFI zeolites probed by atomic layer deposition (ALD) of titania (ALD-TiO 2) species and a combination of structural, textural, composition and catalytic property analyses of the samples before and after ALD treatment, respectively. The results suggest PMFI has cylindrical mesopores with uniform sizes from pore entrance to main body, while PMWW has ink-bottle mesopores with the neck size much smaller than pore body. The communication between micropore and mesopore in PMFI is direct, but no communication exists in PMWW zeolites. The ALD-TiO 2 process considerably modified external surface composition of PMFI and PMWW zeolites, which consequently led to a new application of the pillared lamellar zeolite materials, i.e., photo-catalytically active meso-/microporous zeolites for environmental remedy reactions. Graphical abstract Image 1 Highlights • Identification of mesopore differences between PMFI and PMWW was attempted. • Atomic layer deposition of titania was used as probe for mesopore differences. • PMFI has more uniform mesopores compared to PMWW zeolite. • Atomic layer deposition of titania enabled photocatalytic activity. [ABSTRACT FROM AUTHOR]

Abstract Hierarchical lamellar zeolites, comprised of both micro- and mesoporosity, afford high active site accessibility and mass transport in processing of bulky molecules. Here, we report the synthesis of hierarchical lamellar MFI zeolites with sequential intergrowth that is induced by composition variation in the standard recipe of 100SiO 2 /0.5Al 2 O 3 /3C 22-6-6 /18.5Na 2 O/4000H 2 O, where C 22-6-6 stands for the diquaternary ammonium surfactant ([C 22 H 45 N+(CH 3) 2 C 6 H 12 N+(CH 3) 2 C 6 H 13 ]Br− 2) template. The influences of C 22-6-6 concentration, alkalinity, and aluminum amount on the intergrowth of hierarchical lamellar MFI zeolites were investigated. The consequences of intergrowth on mesoporosity were analyzed. In all studied synthesis conditions except for very low alkalinity, hierarchical lamellar MFI zeolites were successfully crystallized. The increasing template concentration in the synthesis gel resulted in an increase in intergrowth and thus mesoporsotiy in the hierarchical MFI products. The increasing alkalinity led to an increase and then a decrease in mesoporosity in the hierarchical MFI products, which reflects the same trend in intergrowth in the hydrothermal synthesis process. The aluminum concentration, however, did not significantly affect the intergrowth and mesoporosity of the resultant hierarchical MFI zeolites. The sequential intergrowth achieved by simple variation in the synthesis composition for lamellar MFI zeolites resulted in higher structure hierarchy, mesoporosity, and acid site accessibility in one-step. Graphical abstract Image 1 Highlights • Hierarchical lamellar MFI zeolites were synthesized in one-step. • Intergrowth enhanced mesoporosity in hierarchical lamellar MFI zeolites. • Intergrowth increased with increasing surfactant template content in synthetic gel. • Intergrowth increased and then decreased with alkalinity in synthetic gel. • Aluminum content in synthetic gel did not influence intergrowth noticeably. [ABSTRACT FROM AUTHOR]

Researches in the synthesis of zeolite molecular sieves main focus on manipulating the properties of zeolite particles by adjusting their size, composition and morphology. Especially, the "core and shell concept" particles, which realize the integration of two or more functions into a single geometric shape, have been extensively studied. The "core and shell concept" particles related to zeolite are synthesized with core-shell structure, hollow structure, and yolk-shell structure through bottom-up and top-down methods. The multifunctionality of a single material is achieved through the formation of multiple shells and the manipulation of core or shell materials. This article presents novel design strategies for numerous zeolite-related "core and shell concept" particles, being introduced to the study of their application among conventional thermal catalysis. However, the high cost associated with preparing such catalysts and the need for deeper research into their application present significant challenges. The "core and shell concept" encompasses three types of materials: core-shell, hollow, and Yolk-shell structures. This paper provides a detailed introduction to the design strategy of zeolite-related "core and shell concept" particles and its application in the field of traditional catalysis, and discusses the prospects of this field. [Display omitted] • Reviewed the conventional preparation of "core and shell concept" zeolite-based catalysts. • Elucidation of the anti-sintering mechanism of "core and shell concept" materials. • Exposition of the hollow and Yolk-shell mechanism of Oswald ripening preparation. • Hollow zeolite and yolk-shell zeolite is mostly MFI structure zeolite and practical application is few. • Summarizes the research and development trends in the past five years. [ABSTRACT FROM AUTHOR]

Abstract The MFI zeolites with nanosheet assemblies morphology were prepared by a seed-assisted strategy using specially designed bolaform surfactant [C 6 H 13 -N+(CH 3) 2 -C 6 H 12 -N+(CH 3) 2 -(CH 2) 12 -O-(p-C 6 H 4) 2 -O-(CH 2) 12 -N+(CH 3) 2 -C 6 H 12 -N+(CH 3) 2 -C 6 H 13 ] [Br−] 4 (C 6-12-diphe) as a structure-directing agent. The MFI zeolite nanosheet assemblies were composed of MFI nanosheets with randomly organized structure, exhibiting a narrow mesopore distribution. By tuning the Si/Al ratios of MFI zeolite nanosheet assemblies from 60 to 10, the morphology of resultant zeolites changed from nanosheet stacks to house-of-cards-like structures, and to nanosponges. In addition, the porosity and Brønsted acid/Lewis acid ratio exhibited a parabola-type dependence on the Si/Al ratios of obtained zeolites, indicating that meso-/microporosity and acidity of MFI nanosheet assemblies can be systematically tailored by changing the constituents of zeolites. Catalytic performance of MFI zeolite nanosheet assemblies was investigated in the benzylation of benzyl alcohol with mesitylene. The results revealed that MFI zeolite nanosheet assemblies exhibited extraordinary catalytic activity compared to conventional ZSM-5 zeolite. The conversion of benzyl alcohol and selectivity (1,3,5-trimethyl-2-benzylbenzene vs dibenzyl ether) of zeolite catalysts were linearly dependent on the Brønsted acid/Lewis acid ratio, and they exhibited a parabola-type dependence on the S ext /S BET , indicating that a balance between acidity and porosity of zeolites can be realized to modulate the catalytic properties of MFI zeolite nanosheet assemblies guided by C 6-12-diphe. Graphical abstract Fabrication of 2D MFI zeolite nanosheet assemblies with tailored catalytic activity for benzylation of mesitylene and benzyl alcohol. Image 1 Highlights • MFI zeolite nanosheet assemblies were prepared through seed-assisted approach. • The porosity and acidity of the zeolites can be tailored by tuning the Si/Al ratios. • MFI nanosheet assemblies exhibited enhanced catalytic property due to additional mesoporosity. • The synergy between Brønsted acid and Lewis acid sites was key factor to determine the catalytic activity. [ABSTRACT FROM AUTHOR]

Hierarchical SAPO-34 zeolites with three-dimensionally ordered mesoporous-imprinted structure (3DOm-i SAPO-34) were first confined synthesized within three-dimensionally ordered mesoporous carbons by multiple hydrothermal (MHT) treatments. With perfect structure replication, the obtained 3DOm-i SAPO-34 zeolite particles exhibited unique ordered structures consisting of primary spherical elements of sizes determined by mesopore cages of the corresponding carbon templates, and the sizes of mesopores constituted by the adjacent spherical elements can be precisely tuned from 5.5 to 13.0 nm by varying the 3DOm carbon. The as-synthesized hierarchical 3DOm-i SAPO-34 catalysts showed superior catalytic performance in the MTO reaction with prolonged catalytic lifetime and significant improvement of selectivity for light olefins (ethylene and propylene) compared to the conventional microporous SAPO-34. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acylation of anisole is solely carried out on the external surface of MWW zeolites. • Acylation of anisole on MWW zeolites follows Langmuir-Hinshelwood mechanism. • Strong adsorption of product in 12-MR pockets results in low rate constant of single-layer MWW. • High mass transfer property of single-layer MWW was restrained in batch reaction. • Single-layer MWW exhibits long lifetime in fixed bed reactor at higher temperature. Numerous efforts have been dedicated to develop solid acid catalysts with higher activity and stability replacing the homogeneous catalysis for Friedel-Crafts (FC) acylation reaction. In this study, single- to multiple-layer MWW zeolites are employed as well-defined model catalysts to investigate the influencing mechanism of microscale structure of MWW zeolites on the kinetics for acylation of anisole with acetic anhydride. It is found that the acylation of anisole is solely carried out on the external acid sites of MWW zeolites and follows Langmuir-Hinshelwood mechanism. The single-layer MWW (SL-MWW) with more external acid sites exhibits lower catalytic activity for acylation of anisole in batch reaction, whereas the recycle stability of SL-MWW is clearly higher than that of multiple-layer MWW (ML-MWW). Kinetics results reveal that a large equilibrium constant of product adsorption together with the confinement effect within 12MR pockets on surface of SL-MWW results in difficult desorption of product and small rate constant. Therefore, the favorable mass-transfer and diffusion of SL-MWW is restrained in batch reaction and at low temperature condition. Based on these findings, the continuous flow fixed-bed process under an elevated temperature (493 K) was conducted to underline the structural advantages of SL-MWW zeolite. The lifetime of SL-MWW can reach to 300 h in the optimal reaction conditions, which is potential catalyst for industrial application in the field of FC acylation reactions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Hydrothermal synthesis can be combined with confined synthesis to prepare mesoporous zeolites. [•] Repeating the incipient wetness can improve the structure of 3DOm carbon. [•] Ordered mesoporous zeolites with well-controlled morphology and acidity were synthesized. [•] The 3DOm-i structure can significantly improve the catalyst performance. [ABSTRACT FROM AUTHOR]

A one-pot facile route for preparing hierarchically layered titanosilicate-1 (LTS-1) zeolites with stable interlayered mesopores was proposed by integrated using bolaform surfactant (BC ph-12-6-6) and tetrapropyl ammonium hydroxide (TPAOH) as dual templates. By tuning the molar ratios of BC ph-12-6-6 /TPAOH from 5/0 to 5/9, the corresponding LTS-1 samples showed continuous transformations in morphology and intensified degrees of intergrowth by TS-1 nanosheets, resulting in an effective interlayer self-pillaring to avoid the excessive collapse after the removal of the occupied templates by calcination. Moreover, the LTS-1 samples by dual-template synthesis manifested enriched contents of mononuclear octahedrally coordinated Ti species ("TiO 6 "). Benefitted by the highly patulous structure and more accessible Ti active sites predominated with high-performance "TiO 6 " species, the LTS-1 catalysts by dual-template synthesis exhibited a superior catalytic activity in the epoxidation of cyclooctene compared with the layered TS-1 directed by sole template of BC ph-12-6-6 and the conventional bulk TS-1. It is reasonable to expect that the demonstrated work has important implications for the design and facile synthesis of layered titanosilicate zeolite catalysts with a stably hierarchical structure and tunable catalytic oxidation activities by an optimized distribution of titanium coordination states containing the coordinated "TiO 4 " and "TiO 6 " species. [Display omitted] • One-pot dual-template synthesis of hierarchically layered titanosilicate-1 (LTS-1). • Effective interlayer self-pillaring by integrated templating of BC ph-12-6-6 and TPAOH. • LTS-1 manifests enriched contents of mononuclear octahedrally coordinated Ti species ("TiO 6 "). • Improved catalytic epoxidation performances by the highly patulous structure and more accessible Ti active sites. [ABSTRACT FROM AUTHOR]

Hierarchical two-dimensional (2D) lamellar zeolites represent a young emerging field and a novel expression of the zeolite frameworks. Accompanied with synthesis and catalytic performance investigation, assessment on the local environment and catalytic behavior of acid sites in 2D zeolites are needed. Here, we described the local environment of Lewis acid sites and evaluated catalytic activities of external acid sites (i.e. sites on external surface and in mesopores) in 2D lamellar titanium silicalite-1 (TS-1) zeolites. For comparison purpose, four TS-1 zeolites, including 3D TS-1, multilamellar 2D TS-1 without pillarization and with pillarization by silica and silica/titania, respectively, were prepared. The local environment of Ti-sites, including coordination status of Ti-atom, speciation of hydroxyl (-OH) group that hints degree of confinement, acid site strength and accessibility, was collectively assessed by spectroscopic and organic base titration measurements. Kinetic studies of cyclooctene (C 8 H 14) epoxidation with hydrogen peroxide (H 2 O 2) discerned catalytic activity of external Ti-sites that decreased with increasing mesoporosity due to decrease in site confinement. Image 1 • External Lewis acid sites in 2D TS-1 zeolites were quantified. • 2D TS-1 zeolites have high density of isolated surface silanol and titanol groups. • Reactivity of external sites decreases with increasing mesoporosity in 2D TS-1. • Decrease in reactivity of external sites is caused by loss of partial confinement. • Kinetic decoupling of epoxidation pathways enabled catalytic behavior assessment. [ABSTRACT FROM AUTHOR]

• Dual-templating synthesis of gallium-substituted mesoporous ZSM-5 (Ga-MZ5). • Ga-MZ5 exhibited superior performances with high aromatic-yield and effective phenol-reduction in CFP. • Dehydrogenation/cracking ratio decided by zeolite acidity. • Deoxygenation of phenols dominated by non-framework Ga x O y species. • Diffusion superiority contributed by hierarchical meso-/microporosity. Five MFI-type zeolite catalysts, which were aluminosilicate ZSM-5 (Z5), gallium-substituted silicalite-1 (Ga-S1), mesoporous ZSM-5 (MZ5), gallium-substituted mesoporous silicalite-1 (Ga-MS1) and gallium-substituted mesoporous ZSM-5 (Ga-MZ5), were hydrothermally synthesized with combined using of TPAOH and TPOAC as micropore and mesopore structure-directing agents respectively, followed by the application in the catalytic upgrading of volatiles from low-rank coal fast pyrolysis. The obtained results indicated that significant improvements with the yield of high value-added products of BTEXN (benzene, toluene, ethylbenzene, xylene and naphthalene) increased from 5.4 mg.g−1 to 11.9–26.4 mg.g−1, as well as the content of light fractions (<300 °C) in coal tars increased from 51% to 65–88% were realized by using the representative MFI-type zeolite catalysts in contrast to non-catalyst pyrolysis. Moreover, the possible mechanism for catalytic upgrading over the best-performing catalyst of gallium-substituted mesoporous ZSM-5 (Ga-MZ5) with the highest yield of aromatics and effective reduction of phenols was proposed on the basis of systematic comparison of structural features and catalytic performances of various MFI-type zeolite catalysts and fundamental study of the synergetic effects dominated by acidity, ratio of Brønsted/Lewis acid sites, intra-/extra-framework gallium species and hierarchical meso-/microporosity. [ABSTRACT FROM AUTHOR]