Effect of silica source on zeolite MFI crystallization in fluoride media and its physicochemical and catalytic properties

Павлов, В. С.; Bruter, D. V.; Коннов, С. В.; Ivanova, I. I.

doi:10.1016/j.micromeso.2022.112088

Cited by 9 publications

(9 citation statements)

References 35 publications

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“…As a result, large crystals (Figure b) with the core enriched in Al and the shell enriched with Si are formed. The core enrichment with Al in the zeolites obtained from silica hydrogel was confirmed by various techniques, including TEM combined with EDS, XPS, and FTIR studies in our previous contributions. , …”

Section: Resultsmentioning

confidence: 99%

“…The core enrichment with Al in the zeolites obtained from silica hydrogel was confirmed by various techniques, including TEM combined with EDS, XPS, and FTIR studies in our previous contributions. 32,42 A different picture is observed in the case of the CS reaction mixture (Figure 6a,c,e). No solid products are recovered at the initial steps of synthesis in this case.…”

Section: Preparation Of Precursor Mixtures With Differentmentioning

confidence: 99%

“…An analysis of the literature data shows that many variables can impact the crystallization process and the final product formed. These variables include the synthesis temperature − and crystallization time, − the type of raw materials, , order of mixing, , agitation, − and aging. , Among the most important parameters controlling the crystal size and morphology of the final product is the silica source. − Silica sources with different specific surface areas and ability to dissolve in alkaline mixtures are shown to dramatically affect the state of precursor mixtures from the colloidal (clear) suspensions to dense amorphous gels . The state of aluminosilicate particles in the precursor mixtures further determines the mechanism of nucleation and crystal growth and properties of the final product, including the crystal size and morphology of the final product.…”

Section: Introductionmentioning

confidence: 99%

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Multinuclear MAS NMR Monitoring of the Effect of Silicate Speciation on the Mechanism of Zeolite BEA Formation: Toward Engineering of Crystal Size and Morphology

Ivanova

Andriako

Kostyukov

et al. 2023

Crystal Growth & Design

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Time-resolved in situ 13C, 27Al, and 29Si MAS NMR and ex situ XRD, X-ray fluorescence, and TG studies have been applied for the elucidation of the mechanisms of hydrothermal synthesis of zeolite BEA from a clear solution and a dense hydrogel. Isotopic labeling with 29Si and 13C isotopes has been used to follow the fate of siliceous species and structure-directing agent ((13CH3-CH3)4NOH)). The results point to different mechanistic pathways depending on silicate speciation in the initial reaction mixture: (i) an aggregation/nucleation process for the reaction mixture prepared from a colloidal silica source and (ii) solution-mediated crystallization for the reaction mixture prepared from a dense silica hydrogel. The products obtained have been characterized using a set of physicochemical methods including XRD, X-ray fluorescence analysis, TEM, low-temperature nitrogen adsorption–desorption, and NH3-TPD. The results demonstrate that the crystallization mechanism affects the crystal size and morphology: the aggregation/nucleation process leads to very tiny crystals with a size of 5–15 nm, whereas solution-mediated crystallization results in dense polycrystals with a size of 300–700 nm with the core enriched with Al. The evaluation of the catalysts in liquid-phase alkylation of benzene with propylene points to the higher activity of zeolite BEA obtained from a colloidal silica source.

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Section: Resultsmentioning

confidence: 99%

Section: Preparation Of Precursor Mixtures With Differentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Multinuclear MAS NMR Monitoring of the Effect of Silicate Speciation on the Mechanism of Zeolite BEA Formation: Toward Engineering of Crystal Size and Morphology

Ivanova

Andriako

Kostyukov

et al. 2023

Crystal Growth & Design

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“…This research was carried out at UIN Mataram Physics Laboratory. The synthesis method used in this research was the Sol-Gel method (Hou et al, 2018;Pavlov et al, 2022). Iron sand samples were taken from Sompang river sand in East Lombok and Coastal Sand from Gading in Mataram City.…”

Section: Methodsmentioning

confidence: 99%

“…The areas which has more iron sands in Indonesia is Lombok island (Asri et al, 2021;Pavlov et al, 2022;Susilawati et al, 2018). Lombok Island is located in the central part of Indonesia and has abundant natural resources.…”

Section: Introductionmentioning

confidence: 99%

Morphological characteristics and electrical properties analysis of silica based on river and coastal iron sand

Meiliyadi¹,

Wahyudi²,

Damayanti

et al. 2022

jipfalbiruni

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This study aims to analyze silica's morphological characteristics and electrical properties based on the river and coastal sand. Iron samples were taken from Sompang river sand, East Lombok and Coastal Sand from Gading, Mataram City. The silica was synthesized using the sol-gel method with a sintering temperature variation of 100 to 175 ℃. Morphological characteristics samples analysis was done using SEM-EDX. The electrical properties of iron sand included measuring the dielectric constant using the parallel plate method. Furthermore, the resistivity was measured using the two-point probe method. In the silica-based on river sand sample, the resistivity value was inversely proportional to the sintering temperature. In contrast, the resistivity value of silica based on the coastal sand sample was directly proportional to the sintering temperature. Silica-based on river sand has a resistivity of about 7.1'104 Wm at a sintering temperature of 100℃ and 3.5'104 Wm at a sintering temperature of 175℃. Silica-based on river sand has a resistivity of about 1.8'104 Wm at a sintering temperature of 100℃ and 7.1'104 Wm at 175℃. This research is a preliminary study on the electrical properties of natural sand-based silica to improve understanding of the physical properties of silica to be used in technological applications, such as sensors. Furthermore, the dielectric constant value in the river sand sample was directly proportional to the sintering temperature. However, the dielectric constant in the coastal sand sample was inversely proportional to the sintering temperature. Silica-based on river sand has a dielectric constant of about 1.02'102 at a sintering temperature of 100℃ and 1.18'102 at 175℃. Silica-based on coastal sand has a dielectric constant of about 1.97'102 at a sintering temperature of 100℃ and 1.15'102 at 175℃.

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Mechanistic investigation of methanol-to-olefins conversion catalyzed by H-ZSM-5 zeolite: a DFT study

Pang,

Ren,

et al. 2024

J Mol Model

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Effect of silica source on zeolite MFI crystallization in fluoride media and its physicochemical and catalytic properties

Cited by 9 publications

References 35 publications

Multinuclear MAS NMR Monitoring of the Effect of Silicate Speciation on the Mechanism of Zeolite BEA Formation: Toward Engineering of Crystal Size and Morphology

Multinuclear MAS NMR Monitoring of the Effect of Silicate Speciation on the Mechanism of Zeolite BEA Formation: Toward Engineering of Crystal Size and Morphology

Morphological characteristics and electrical properties analysis of silica based on river and coastal iron sand

Mechanistic investigation of methanol-to-olefins conversion catalyzed by H-ZSM-5 zeolite: a DFT study

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