Effect of mechanical treatment on properties of zeolites with chabazite structure

Buzimov, A Y; Кулъков, С. Н.; Eckl, Wilhelm; Pappert, Sandra; Gömze, László A.; Kurovics, Emese; Kocserha, István; Géber, Róbert

doi:10.1088/1742-6596/790/1/012004

Cited by 10 publications

(16 citation statements)

References 7 publications

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“…Of course, as already commented, after surpassing certain milling conditions, amorphization of the seed may happen. [48][49][50][51] This seems to be case for the zeolites milled at the H2O/SiO2=1.7 molar ratio, Figure 13.…”

Section: Crystallinitymentioning

confidence: 82%

“…Some authors have proposed that this is due to the fact that the energy supplied in the milling stage generates a reduction in the size of the seed which leads to a dispersion of nucleation centers, hence producing smaller crystals and, under some conditions, even leading to some degree of amorphization of the seed during ball milling. [48][49][50][51] Results from SEM-EDS are reported in Table 2. The materials synthesized with the mechanochemical method had a rather constant Si/Al molar ratio of ~ 8.5 which was lower than the one of the seed.…”

Section: Analysis Of the Morphology And Chemicalmentioning

confidence: 99%

“…The results of the experimental design were statistically analyzed by both graphical and numerical methods. Main effects and interaction plots 31,51 were built to analyze the effect of the synthesis variables on the physicochemical properties of the synthesized zeolites. A quantitative statistical assessment of the observed effects was further achieved by carrying out analysis of variance (ANOVA) tests with the aid of a Microsoft Excel® 2016 spreadsheet.…”

Section: Funding Sourcesmentioning

confidence: 99%

“…A quantitative statistical assessment of the observed effects was further achieved by carrying out analysis of variance (ANOVA) tests with the aid of a Microsoft Excel® 2016 spreadsheet. In every instance, an analysis of residuals was performed for checking the validity of the assumptions of normality, constant variance and independence of the ANOVA model following the procedures presented in textbooks 51,52 and in previous works. 53 The effect of the milling speed and time, and H2O/SiO2 molar ratio was assessed from a statistical analysis for the corresponding block of experiments of the singly replicated 2 3 full factorial design.…”

Section: Funding Sourcesmentioning

confidence: 99%

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Key Factors During the Milling Stage of the Seed‐assisted and Solvent‐free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert‐butyl Alcohol

et al. 2021

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The so-called mechanochemical method for the synthesis of zeolites reduces the generation of liquid residues and gaseous pollutants as compared to the conventional solvothermal method. Different types of zeolites have been synthesized at the laboratory scale with this method using mostly pestle and mortar. However, such an approach hinders both the systematic comprehension of the effects of the input variables of the milling process and its further scale-up towards the synthesis of the zeolites and their catalytic application. This work investigates the influence of key factors involved in the ball milling stage of the mechanochemical route for the synthesis of MFI done with the assistance of a commercial MFI seed and in the absence of solvents over the most salient physicochemical properties of this type of materials, i.e. the recovery percentage, production cost, morphology, surface area and porosity, crystallinity, acidity of the protonated MFI and catalytic performance. The synthesis of the materials was planned and executed following a full 2 4 factorial experiment whose input variables were the Na2O/SiO2 and H2O/SiO2 molar ratios and the milling time and speed. The effects of both main and interaction factors over key physicochemical properties, and catalytic behavior of the synthesized materials on the alkylation of phenol with tert-butyl alcohol were established within the explored sampling space. Results showed that the Na2O/SiO2 molar ratio plays a key role for the mechanochemical synthesis of MFI, since this variable may direct the synthesis to the preferential production of MOR instead of MFI. On the other hand, it was found that the milling time and speed and their interactions markedly impact the textural properties of MFI. Furthermore, the triple interaction between the input variables affected the concentration of Lewis acid sites of the produced materials. These effects were rationalized by considering that sodium can act as a structure directing agent during the mechanochemical synthesis of MFI and also can promote the incorporation of aluminum to its structure. On the other hand, the milling time and speed are non-linearly correlated to the milling energy required for forming the aluminosilicate precursor that crystallizes during the hydrothermal stage of the process. Overall, all the zeolites synthesized by the mechanochemical route were less crystalline than both the MFI used as seed and an MFI synthesized by solgel. This was associated to the formation of amorphous agglomerates around the zeolitic crystals. Finally, the catalytic behavior of the mechanochemical MFI zeolites in the studied reaction was found to be linearly and positively correlated with both the concentration of BrØnsted of sites and with the density of acid sites. The catalytic tendencies were consistent with the proposal of a stepwise Langmuir-Hinshelwood mechanism for the alkylation of phenol with tert-butyl alcohol.

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Section: Crystallinitymentioning

confidence: 82%

Section: Analysis Of the Morphology And Chemicalmentioning

confidence: 99%

Section: Funding Sourcesmentioning

confidence: 99%

Section: Funding Sourcesmentioning

confidence: 99%

See 2 more Smart Citations

Key Factors During the Milling Stage of the Seed‐assisted and Solvent‐free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert‐butyl Alcohol

et al. 2021

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“…Zeolites are fragile materials undergoing amorphization during dry ball milling [14,15,17,18]. In some instances, a partially amorphizised zeolite shows enhanced selectivity by the alteration of the acid-base properties [19].…”

Section: Introductionmentioning

confidence: 99%

Catalytic activation of all-silica COK-14 zeolite through alumination and particle size reduction using wet ball milling

et al. 2019

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Ball milling as an important pretreatment technique in lignocellulose biorefineries: a review

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Gebreyohannes

et al. 2021

Biomass Conv. Bioref.

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Effect of mechanical treatment on properties of zeolites with chabazite structure

Cited by 10 publications

References 7 publications

Key Factors During the Milling Stage of the Seed‐assisted and Solvent‐free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert‐butyl Alcohol

Key Factors During the Milling Stage of the Seed‐assisted and Solvent‐free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert‐butyl Alcohol

Catalytic activation of all-silica COK-14 zeolite through alumination and particle size reduction using wet ball milling

Ball milling as an important pretreatment technique in lignocellulose biorefineries: a review

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