Changes of medium-range structure in the course of crystallization of zeolite omega from magadiite

Cui, Miao; Zhang, Yifu; Liu, Xiaoyu; Wang, Lin; Meng, Changgong

doi:10.1016/j.micromeso.2014.08.025

Cited by 18 publications

(6 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The FTIR was applied to analyze the change of chemical states of laponite and the samples synthesized at 180 °C for different time. As shown in Figure , the peak at 635 cm –1 is assigned to the existing D‐6 ring,, which confirms the formation of the CHA structure. The spectrum of laponite shows the peak at 1008 cm –1 , relating to Si–O vibrations and the peak at 649 cm –1 , corresponding to the Mg–OH bending vibration .…”

Section: Resultssupporting

confidence: 57%

Synthesis of SAPO‐34 Zeolite from Laponite and Its Application in the MTO Reaction

et al. 2020

View full text Add to dashboard Cite

In this work, SAPO‐34 zeolite with high catalytic activity was successfully synthesized by hydrothermal method from laponite as the single Si source. Compared with the traditional method of synthesizing zeolites from clay, the laponite after swelling can be directly used in the synthesis process of zeolite. The crystallization behavior of SAPO‐34 synthesized from laponite was investigated by XRD, FTIR, N2 adsorption–desorption, SEM‐EDX, ICP‐MS, and DR‐UV/Vis. The process can be summarized as follows: the Si and Mg elements were produced by the depolymerization of laponite, then the primary building units of SAPO‐34 zeolite were formed under hydrothermal conditions; finally, the crystal nucleus began to form, and crystallization was triggered. Compared with the conventional SAPO‐34 synthesized from TEOS, the SAPO‐34 synthesized from laponite exhibited higher selectivity to light olefins and longer lifetime, which can be attributed to the suitable strength of acidity. This work points to a straightforward route to the synthesis of SAPO‐34 from laponite.

show abstract

Section: Resultssupporting

confidence: 57%

Synthesis of SAPO‐34 Zeolite from Laponite and Its Application in the MTO Reaction

et al. 2020

View full text Add to dashboard Cite

show abstract

“…MOR zeolite has been successfully prepared from magadiite using tetraethylammonium hydroxide as an intercalating agent and/or organic structure directing agent (OSDA). , Kooli et al successfully synthesized KLS-1, KLS-2, FLS-1, and FLS-2 via the conversion of H-magadiite. − High silica ferrierites were prepared from Al-containing hydrous magadiite in both hydrothermal and solid-state reactions. , In 2016, Kooli et al reported that RUB-15 and PLS materials could be obtained from H-magadiite by “pseudo solid-state” conversion with a drop of water added into the synthesis system. , In our pervious works, mordenite, ZSM-5, ferrierite, , offretite, and omega , were successfully obtained via the conversion of magadiite in the present of various organic templates. In our effort, we presented several reports on the role of short-chain tetraalkylammonium cations in the transformation of magadiite and the crystallization mechanism of the conversion of magadiite into zeolite L and zeolite omega was investigated in detail, − which provided a useful route to understand the zeolite formation mechanism by using magadiite as a synthetic precursor. Additionally, an OSDA-free synthesis of zeolite beta via the conversion of magadiite was carried out and we investigated the crystallization mechanism in detail.…”

Section: Introductionmentioning

confidence: 99%

Seed-Assisted Synthesis of Zeolite Beta from Solid-State Conversion of Magadiite and an Investigation on the Crystallization Mechanism

Zhang

Feng

et al. 2020

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

Pure zeolite beta was synthesized by conversion of magadiite in solid state with the assistance of seeds for the first time, and the influence of synthesis parameters was discussed in detail. To get further insights into the conversion process, changes of building units and crystallization mechanism were studied by X-ray diffraction, electron microscopy, FT-IR spectroscopy, and solid-state MAS NMR spectroscopy: most parts of 5Rs and 6Rs in magadiite were preserved in the conversion course, and the appearance of 4Rs, which could be a key to the growth of zeolite beta, was promoted by rearrangement and connection of preserved 5Rs. A trace of constitution water existing in the layer structure of magadiite would be important for a successful conversion because it could facilitate the condensation of aluminosilicate species into the beta framework.

show abstract

“…The weak bands between 820 and 722 cm -1 are assigned to the symmetric elongations of the T-O bond. The band at 619 cm -1 is characteristic of T-O vibrations rings with 6 tetrahedra, and the intense band at 435 cm -1 indicate the formation of major 4Rs [49]. The only difference between these bands is the displacement of the band at 1003 cm -1 toward the highest wavenumbers.…”

Section: Ftir Studymentioning

confidence: 97%

Structural, textural and toluene adsorption properties of microporous–mesoporous zeolite omega synthesized by different methods

Mekki

Boukoussa

2019

J Mater Sci

View full text Add to dashboard Cite

This work deals with the preparation of the zeolite omega using hydrothermal route. This zeolite was modified by acidic, basic and hydrothermal treatment (at 100°C and 150°C) using a basic/CTA ? solution. The modified zeolites were characterized by X-ray diffraction, adsorption/desorption of argon, Fourier transform infrared spectroscopy, thermogravimetric analysis TGA and scanning electronic microscopy. The obtained materials were tested for the adsorption of toluene at ambient temperature. The results showed that the zeolites modified by basic treatment showed the highest mesoporosity (* 166 Å ) and the low specific surface area and pore volume, while the one treated with an acid (dealuminated) showed a mesoporosity of * 30 Å and a higher specific surface area and porous volume. The hydrophilic character was improved after the different treatments compared to the parent material, in which the dealuminated zeolite showed the highest hydrophilic character. All modified zeolites showed a good affinity via the adsorption of toluene, and the best adsorption capacity was obtained by dealuminated zeolite. Compared to the unmodified zeolite omega (parent sample), an improvement of 68% of adsorption capacity was obtained. Finally, the dealuminated zeolite showed good stability during reuse for five cycles without loss of its adsorption capacity.

show abstract

Changes of medium-range structure in the course of crystallization of zeolite omega from magadiite

Cited by 18 publications

References 63 publications

Synthesis of SAPO‐34 Zeolite from Laponite and Its Application in the MTO Reaction

Synthesis of SAPO‐34 Zeolite from Laponite and Its Application in the MTO Reaction

Seed-Assisted Synthesis of Zeolite Beta from Solid-State Conversion of Magadiite and an Investigation on the Crystallization Mechanism

Structural, textural and toluene adsorption properties of microporous–mesoporous zeolite omega synthesized by different methods

Contact Info

Product

Resources

About