Hierarchical Low Si/Al Ratio Ferrierite Zeolite by Sequential Postsynthesis Treatment: Catalytic Assessment in Dehydration Reaction of Methanol

In contrast to high silica zeolites, it is difficult to obtain mesoporosity in zeolites with low Si/Al ratio (e.g., <20) via conventional NaOH-based treatment, making the obtainment of hierarchical zeolites with high acidity a challenging target. In this paper, we report the preparation of hierarchical FER-type zeolite at low Si/Al molar ratio (about 10) by postsynthesis etching involving a sequence of three treatments with NaAlO2, HCl, and NaOH solutions and investigate the effect of both NaAlO2 solution concentration and time of treatment on the textural properties. The obtained materials exhibit a mesoporous volume higher than the parent ferrierite with no significant effect on the sample acidity. The catalytic activity of some samples was investigated in vapour-phase methanol dehydration to dimethyl ether, revealing the superiority of hierarchical zeolites in terms of methanol conversion, although the presence of mesopores causes formation of light hydrocarbons at high temperatures.

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Paths of methanol conversion to hydrocarbons on high-silica zeolites

Bulletin of the Academy of Sciences of the USSR Division of Chemical Science ◽

10.1007/bf00956778 ◽

1985 ◽

Vol 34 (11) ◽

pp. 2251-2257

Author(s):

T. V. Vasina ◽

E. G. Khelkovskaya-Sergeeva ◽

B. K. Nefedov ◽

O. V. Bragin

Keyword(s):

Methanol Conversion ◽

High Silica ◽

High Silica Zeolites

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METHANOL CONVERSION TO OLEFINS OVER HIGH-SILICA ZEOLITES IN CONTINUOUS FLOW FIXED-BED REACTOR

Petroleum Science and Technology ◽

10.1080/10916469708949642 ◽

1997 ◽

Vol 15 (1-2) ◽

pp. 19-36 ◽

Cited By ~ 1

Author(s):

D. S. Redwan

Keyword(s):

Continuous Flow ◽

Fixed Bed ◽

Methanol Conversion ◽

Fixed Bed Reactor ◽

High Silica ◽

High Silica Zeolites

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SYNTHESIS OF In-CONTAINING HIGH-SILICA ZEOLITE OF ZSM-5 TYPE

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/tcct.2017608.5460 ◽

2017 ◽

Vol 60 (8) ◽

pp. 84

Author(s):

Khasay R. Samedov ◽

Ulviya A. Mamedova ◽

Kerim G. Ragimov ◽

Zarema A. Jabbarova

Keyword(s):

Degree Of Crystallinity ◽

Molar Ratio ◽

X Ray Diffraction ◽

Solid Product ◽

X Ray ◽

Type Zeolite ◽

High Silica ◽

Tetrabutylammonium Iodide ◽

High Degree ◽

Ratio Of Components

High silicate zeolite ZSM-5 on the basis of SiO2–In2O3–NaOH with an organic structure forming agent tetrabutylammonium iodide (TBAI) was synthesized in the temperature range of T = 150–220°C, pH = 9-12, τ = 48-240 h. As initial components, silica gel MSKO containing 86% SiO2, tetrabutylammonium iodide (TBAI), chemically pure NaOH and metallic indium (In) were used which mixed by hydrothermal synthesis. At the end of the synthesis, the solid product was separated from the mother liquor, washed on the filter with distilled water from an excess of alkali and dried at 120 °C, calcined at 550 °C (16 h). The products of hydrothermal crystallization were determined by X-ray (RFA – on the device D2-Phaser "Bruker"), differential thermal (DTA- STA-449 F3 Jupiter NETZSCH), by X-ray diffraction (XRD of brand SRM-18) and infrared spectroscopy (IR on FTIR spectroscopy, Nicolefisio VSA) analysis methods. During the synthesis, it was experimentally established that at T = 200 °C; τ = 240 h; pH≈9-10 molar ratio of components 5.78SiO2∙0.058In2O3∙0.625Na2O∙0.11H2O∙0.95 ((C4H9) 4NJ) – MFI-type zeolite is crystallized. When comparing XRF data with literature data, they were referred to a type zeolite of ZSM-5 differing in high degree of crystallinity. The following chemical composition of the synthesized zeolite (wt.%) was established by the X-ray diffraction (SRM-18) method: SiO2 – 94.01; In2O3 – 4.92; Na2O – 1.06 corresponding to the formula 0.96Na2O:In2O3:88SiO2:10H2O.Forcitation:Samedov Kh.R., Mamedova U.A., Ragimov K.G., Jabbarova Z.A. Synthesis of In-containing high-silica zeolite of ZSM-5 type.Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 8. P. 84-87.

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Methanol conversion of various cation-exchanged forms of high-silica zeolites

Reaction Kinetics and Catalysis Letters ◽

10.1007/bf02070483 ◽

1985 ◽

Vol 27 (2) ◽

pp. 403-406 ◽

Cited By ~ 2

Author(s):

S. Alcheev ◽

N. P. Samchenko ◽

Yu. N. Artyukh ◽

V. L. Struzhko

Keyword(s):

Methanol Conversion ◽

High Silica ◽

High Silica Zeolites

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Methanol conversion on high-silica zeolites with different alumosilicate modules and prepared in different ways

Theoretical and Experimental Chemistry ◽

10.1007/bf00531395 ◽

1987 ◽

Vol 23 (3) ◽

pp. 353-356

Author(s):

N. P. Samchenko ◽

I. S. Alcheev ◽

G. I. Golodets ◽

V. L. Struzhko

Keyword(s):

Methanol Conversion ◽

High Silica ◽

High Silica Zeolites

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98/02828 Methanol conversion to olefins over high-silica zeolites in continuous flow fixed-bed reactor

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(98)96353-6 ◽

1998 ◽

Vol 39 (4) ◽

pp. 262

Keyword(s):

Continuous Flow ◽

Fixed Bed ◽

Methanol Conversion ◽

Fixed Bed Reactor ◽

High Silica ◽

High Silica Zeolites

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Gas Permeation Properties of High-Silica CHA-Type Zeolite Membrane

Membranes ◽

10.3390/membranes11040249 ◽

2021 ◽

Vol 11 (4) ◽

pp. 249

Author(s):

Yasuhisa Hasegawa ◽

Chie Abe ◽

Mayumi Natsui ◽

Ayumi Ikeda

Keyword(s):

Molecular Size ◽

Gas Permeation ◽

Zeolite Membrane ◽

Type Zeolite ◽

High Silica ◽

Separation Of Co2 ◽

Α Al2o3 ◽

Separation Performances ◽

Molecular Sieving ◽

Permeation Properties

The polycrystalline CHA-type zeolite layer with Si/Al = 18 was formed on the porous α-Al2O3 tube in this study, and the gas permeation properties were determined using single-component H2, CO2, N2, CH4, n-C4H10, and SF6 at 303–473 K. The membrane showed permeation behavior, wherein the permeance reduced with the molecular size, attributed to the effect of molecular sieving. The separation performances were also determined using the equimolar mixtures of N2–SF6, CO2–N2, and CO2–CH4. As a result, the N2/SF6 and CO2/CH4 selectivities were as high as 710 and 240, respectively. However, the CO2/N2 selectivity was only 25. These results propose that the high-silica CHA-type zeolite membrane is suitable for the separation of CO2 from CH4 by the effect of molecular sieving.

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