Seed-induced synthesis of ZSM-5 aggregates using the Silicate-1 as a seed: Characterization and effect of the Silicate-1 composition

Hamidzadeh, Marzieh; Komeili, Samane; Saeidi, Mohsen

doi:10.1016/j.micromeso.2018.04.016

Cited by 25 publications

(6 citation statements)

References 36 publications

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“…Such information is not easy to obtain because most experimental work was concerned with silicalite type materials with aluminum content not above one–two Al atoms in the unit cell (Si/Al ≈ 100–50). Some limited work ,,− was reported for zeolites with higher amounts of aluminum. The relevant data are shown in Figure .…”

Section: Resultsmentioning

confidence: 99%

“…values which contrast with those in Tables and . In the first group the works were conducted with unconventional synthesis procedures. − A suggestion can therefore be made that a certain crystalline material was present in the crystallization products, the signals of which were mistaken for peaks caused by the presence of ZSM-5. The second group includes an example of modeling of the aluminum framework distribution in ZSM-5 zeolites. , The exceptionally large volumes reported in these works are in a complete contrast with the experimental data available in the literature.…”

Section: Resultsmentioning

confidence: 99%

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Unit Cell Volume as a Measure of the Framework Composition of ZSM-5 Type Zeolites

Мишин

Левин

Kustov

2023

Crystal Growth & Design

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A simple X-ray powder diffraction procedure is proposed to determine the framework composition of ZSM-5 type zeolites. The procedure is based on a linear relation between the unit cell volume and the framework aluminum content found by analyzing two families of ZSM-5 zeolites with different SiO 2 /Al 2 O 3 ratios. One family consisted of products synthesized in the presence of TPA + cations while hydrogen forms were included in the second series of samples. Linear relationships between cell constants, cell volume (V u.c. ), and the framework aluminum content (N Al ) were established. For the samples synthesized in the presence of an organic template and sodium cations, the relation between N Al and V u.c. is given by N Al = (V u.c. − 5332 Å 3 )/15.13. A similar equation was computed for H-ZSM-5 zeolites: N Al = (V u.c. − 5330 Å 3 )/15.40. Equations derived can be used to evaluate the number of framework aluminum in the unit cell. In this way, the ratio of the framework and nonframework aluminum atoms in the samples of ZSM-5 type zeolites subjected to heat treatment can be estimated.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Unit Cell Volume as a Measure of the Framework Composition of ZSM-5 Type Zeolites

Мишин

Левин

Kustov

2023

Crystal Growth & Design

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“…As expected, the four XRD patterns are consistent with the MFI structure with characteristic peaks at 2θ values of 7.8 • , 8.9 • , 23.1 • , and 23.9 • . [25,36] The impregnation of zinc species has little effect on the MFI zeolites. In general, we only observed a small peak from bulk ZnO at 2θ = 36.3 • in the Zn/Silicalite-1, 5%Zn/HZSM-5, and 5%Zn/NaZSM-5 samples (JCPDS Card No.…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Catalytic dehydrogenation of ethanol over zinc-containing zeolites

2022

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“…The downside of product separation can be well solved. Moreover, ZSM-5 aggregates could support a large amount of mesopores. , A seed-induced method to synthesize ZSM-5 aggregates is supposed to be an ideal route due to its economical and environmentally friendly features, in which colloidal silicate-1 is commonly used as seed because of its advantages of high stability, tunable particle size, and high activity in inducing the formation of ZSM-5 aggregates. , But it is difficult to control the crystal growth in the direction along the channel system of interest; meanwhile, the primary nanosized crystals are often randomly stacked, both of which may be a negative effect on the transport of molecules.…”

Section: Introductionmentioning

confidence: 99%

Seed-Assisted Synthesis of ZSM-5 Aggregates Assembled from Regularly Stacked Nanosheets and Their Performance in n-Hexane Aromatization

Hou

et al. 2021

Ind. Eng. Chem. Res.

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HZSM-5 crystals with short straight channels possess the advantages of easier diffusion and less coke formation in petrochemical processes. In this work, aggregated ZSM-5 zeolite assembled by regularly stacked nanosheet-like crystals with a b-axis thickness of 60 nm was synthesized using specially designed silicate-1 as seed. Silicate-1 (S-2) was synthesized using relatively lower cost silica sol as a silica source, tetrapropylammonium bromide (TPABr) as a structure-directing agent (SDA), and ethylamine as an assistant compared with traditional silicate-1 (S-1: tetraethyl orthosilicate (TEOS) as a silica source and tetrapropylammonium hydroxide (TPAOH) as an SDA). When S-2 seeds were added into the synthesis system, the seeds could limit the crystal growth along the b-axis direction under the assistance of ethylamine. Meanwhile, the adjacent ZSM-5 nanosheet crystals would spontaneously stack together. The catalyst Zn/S-2-1 exhibited relatively higher n-hexane conversion and selectivity of benzene, toluene, ethylbenzene, and xylene (BTEX) as well as catalytic stability in contrast to the catalyst synthesized using S-1 as seed when being used in the n-hexane aromatization reaction. This work opened up a new prospective for ZSM-5 aggregates assembled from the nanosheet catalyst design in the application of hydrocarbon aromatization.

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Seed-induced synthesis of ZSM-5 aggregates using the Silicate-1 as a seed: Characterization and effect of the Silicate-1 composition

Cited by 25 publications

References 36 publications

Unit Cell Volume as a Measure of the Framework Composition of ZSM-5 Type Zeolites

Unit Cell Volume as a Measure of the Framework Composition of ZSM-5 Type Zeolites

Catalytic dehydrogenation of ethanol over zinc-containing zeolites

Seed-Assisted Synthesis of ZSM-5 Aggregates Assembled from Regularly Stacked Nanosheets and Their Performance in n-Hexane Aromatization

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