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

Zhang, Lejian; Wang, Xinping; Shi, Chuan

doi:10.1039/d2qi00298a

Cited by 15 publications

(4 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…n(Si/Al) has a significant impact on the preparation of ZSM-5 molecular sieves. Different n(Si/Al) directly lead to the crystallinity, morphology, and pore size characteristics of ZSM-5 molecular sieves [ 49 , 50 ]. The influence of n(Si/Al) on the preparation of ZSM-5 molecular sieves was investigated using acid leaching samples with different n(Si/Al) as raw materials.…”

Section: Resultsmentioning

confidence: 99%

Preparation of a High-Silicon ZSM-5 Molecular Sieve Using Only Coal Gangue as the Silicon and Aluminum Sources

Zheng

Zhou

et al. 2023

Materials

View full text Add to dashboard Cite

The traditional preparation of ZSM-5 molecular sieves relies on chemical reagents to provide silicon and aluminum sources, which are limited as raw materials and cannot be commonly used in production practice. Using coal gangue as the raw material and using medium-temperature chlorination roasting and the pressure acid leaching process to control the silicon–aluminum ratio [n(Si/Al)] of coal gangue, a ZSM-5 molecular sieve was prepared using the alkali melting hydrothermal method. The pressure acid leaching process solved the limitation that kaolinite and mica cannot simultaneously be activated. Under optimal conditions, the n(Si/Al) of the coal gangue increased from 6.23 to 26.14 and complied with the requirements for the synthesis n(Si/Al) of a ZSM-5 molecular sieve. The effect of n(Si/Al) on the preparation of the ZSM-5 molecular sieve was studied. Finally, spherical granular ZSM-5 molecular sieve material with a microporous specific surface area of 169.6329 m2/g, an average pore diameter of 0.6285 nm, and a pore volume of 0.0988 cm3/g was prepared. Providing ideas for the high-value utilization of coal gangue, it is significant for solving the problem of coal gangue solid waste, as well as the problem of ZSM-5 molecular sieve feed stock.

show abstract

Section: Resultsmentioning

confidence: 99%

Preparation of a High-Silicon ZSM-5 Molecular Sieve Using Only Coal Gangue as the Silicon and Aluminum Sources

Zheng

Zhou

et al. 2023

Materials

View full text Add to dashboard Cite

show abstract

“…16,17 In fact, the water content has been demonstrated to significantly affect the crystal size of zeolites. 18,19 Importantly, a concentrated hydrated gel system should lead to a fast acceleration of the nucleation rate in the synthesis, achieving nanosized zeolite crystals. 20,21 Xiao et al came up with a simple route to prepare nanosized ZSM-5 zeolites by increasing the nutrient concentration in the starting gels (H 2 O/SiO 2 = 2).…”

Section: Introductionmentioning

confidence: 99%

“…Since Xiao group − pioneered a solvent-free synthetic method through simply manually grinding the solid raw materials without additional water in zeolite synthesis, the solvent-free method has drawn increasing interest due to the advantages of high zeolite yields, short synthesis time, few amounts of water pollution, as well as low structure-directing agent (SDA) consumption . However, for solvent-free synthesis, the zeolites are always present in an aggregated state, leading to large particle sizes of zeolites (>1 μm). , In fact, the water content has been demonstrated to significantly affect the crystal size of zeolites. , Importantly, a concentrated hydrated gel system should lead to a fast acceleration of the nucleation rate in the synthesis, achieving nanosized zeolite crystals. , Xiao et al came up with a simple route to prepare nanosized ZSM-5 zeolites by increasing the nutrient concentration in the starting gels (H 2 O/SiO 2 = 2) . Nonetheless, the drawback of this method is that the obtained products are small particle aggregates (100–200 nm).…”

Section: Introductionmentioning

confidence: 99%

Rapid and Facile Synthesis of Nanosized Silicalite-1 Zeolites from Solid Silica in a Semisolid-like System via a Two-Step Crystallization Method

Zheng,

Zhang,

Tan

et al. 2024

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Nanosized zeolites have been found in extensive applications. Herein, a rapid two-step crystallization process (8 h) in a semisolid-like gel system, constructed by simply mixing and grinding solid silica gel, NaOH with TPAOH aqueous solution without extra water addition and any other additives, for the first time is demonstrated to synthesize nanosized silicalite-1 zeolites (∼66 nm) with high crystallinity and high product yield (>90%). The obtained nanosized silicalite-1 zeolites exhibit a large BET surface area (418 m 2 g −1 ), a high micropore surface area (316 m 2 g −1 ), and a rich micropore volume (0.14 cm 3 g −1 ). The rapid evolution process of nanosized zeolites could be decoupled into the nucleation stage at low temperatures and the crystallization stage at high temperatures during the two-step crystallization process. Importantly, the semisolid-like gel ensures fast nucleation. Moreover, in the later crystallization period, the fast crystal growth and inhibited ripening endow nanosized zeolite crystals with good crystallinity through a mass transfer-confined space. The obtained silicalite-1 zeolites were successfully applied in the preparation of (h0h)-oriented MFI zeolite membranes on hollow fibers, showing the flux up to 5.44 kg m −2 h −1 and the separation factor of 70 during the pervaporation test (5 wt % ethanol/water solution, 60 °C). This research develops a state-of-the-art synthetic approach for the efficient preparation of high-quality MFI-type nanozeolites.

show abstract

“…MFI-type ZSM-5 zeolites with robust structures, unique channels, modulable acidic sites, and high thermal stability have been widely used as heterogeneous acid catalysts in petrochemical and refining processes. [1][2][3][4] Two intersected 10-membered ring channels of ZSM-5 provide its unique shape selectivity in catalytic processes. 5,6 However, the sole presence of micropores (<2 nm) imposes a significant limitation on the intracrystalline diffusion of bulk reactant molecules, causing side reactions as well as subsequent coke formation and eventual catalyst deactivation.…”

Section: Introductionmentioning

confidence: 99%

Anisotropic ZSM-5 nanorod assemblies: facile synthesis, epitaxial growth, and strikingly enhanced stability in benzene alkylation

Zhu,

Yu,

Gao

et al. 2024

Inorg. Chem. Front.

View full text Add to dashboard Cite

show abstract

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

Abstract: 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...

Cited by 15 publications

References 51 publications

Preparation of a High-Silicon ZSM-5 Molecular Sieve Using Only Coal Gangue as the Silicon and Aluminum Sources

Preparation of a High-Silicon ZSM-5 Molecular Sieve Using Only Coal Gangue as the Silicon and Aluminum Sources

Rapid and Facile Synthesis of Nanosized Silicalite-1 Zeolites from Solid Silica in a Semisolid-like System via a Two-Step Crystallization Method

Anisotropic ZSM-5 nanorod assemblies: facile synthesis, epitaxial growth, and strikingly enhanced stability in benzene alkylation

Contact Info

Product

Resources

About