A simple synthesis procedure to prepare nanosized faujasite crystals

Chaves, Thiago F.; Pastore, Heloise O.; Cardoso, Dilson

doi:10.1016/j.micromeso.2012.05.022

Cited by 64 publications

(44 citation statements)

References 39 publications

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“…This clearly shows that at any value Brij 78/SiO 2 ratio, increasing the aging time will lead to decreasing MCL. For instance, when no surfactant was used (Brij 78/SiO 2 ratio = 0), the mean crystal length is in the order M-0-5 h > M-0-24 h > M-0-48 h. Our observation is in agreement with previous reports [29,30], where increasing the aging time of precursor gel favors formation of smaller crystals (more nuclei center formation).…”

Section: Effect Of Aging Time At Fixed Brij 78/sio 2 Ratio On Mean Crsupporting

confidence: 92%

The effect of non-ionic surfactant in the microwave-assisted synthesis of MTT zeolite optimized by Taguchi method

Bakare

Muraza

Al-Amer

et al. 2015

Journal of the Taiwan Institute of Chemical Engineers

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Section: Effect Of Aging Time At Fixed Brij 78/sio 2 Ratio On Mean Crsupporting

confidence: 92%

The effect of non-ionic surfactant in the microwave-assisted synthesis of MTT zeolite optimized by Taguchi method

Bakare

Muraza

Al-Amer

et al. 2015

Journal of the Taiwan Institute of Chemical Engineers

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“…High sodium ion content in the precursor gel attributes to depressing the growth of zeolite crystals and restricts the size of the formed particles [29]. Indeed, despite the very complexity involved in the mechanisms of zeolite growth and nucleation, it is clear that alkali metal ion determines the size of the precursor particles [30,31]. Specifically, during the initial polycondensation of the aluminosilicate precursor, the high concentration of sodium ion in the synthesis solution depresses the extent of the polymerization process and results in the formation of smaller zeolite particles [29].…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

Synthesis of Wool-Ball-Like ZSM-5 with Enlarged External Surfaces and Improved Diffusion: A Potential Highly-Efficient FCC Catalyst Component for Elevating Pre-cracking of Large Molecules and Catalytic Longevity

et al. 2016

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A hierarchical ZSM-5 zeolite composed of nanosized MFI zeolite crystals was synthesized without using secondary template by a traditional hydrothermal procedure. The as-synthesized hierarchical ZSM-5 and a reference catalyst were both characterized by XRD, SEM, FT-IR, in situ infrared (IR) spectrometry of pyridine, NH 3 -TPD, N 2 adsorption-desorption, intelligent gravimetric analyzer, and by thermogravimetry analyses. After examining and comparing the results, it is discovered that the hierarchical ZSM-5 catalyst displays excellent catalytic performance with an improved conversion of isopropylbenzene and a longer catalytic life because of its dramatically enlarged external surfaces. The results also display that the shortened diffusion path length contributes to enhancing the stability of the hierarchical catalyst by depressing the coking deposit during the catalytic cracking of n-octane.Graphical Abstract A wool-ball-like zeolite composed of nano-sized MFI crystals was synthesized without a secondary template by the traditional hydrothermal procedure. Nanocrystallization of crystal particles in the hierarchical ZSM-5 zeolite gives the catalyst an improved diffusion and a dramatically enhanced external surface which contributes to elevating pre-cracking of large molecules and catalytic longevity, and to offering a potential and high-efficiency FCC catalyst component.

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“…[6][7][8][9][10] High alkalinity values tend to increase the solubility of the precursors and form a larger number of smaller crystals. 8,10 For the LTA structure, the synthesis conducted under high alkalinity leads to formation of irregular particles with spherical form.…”

Section: Introductionmentioning

confidence: 99%

Monitoring of the crystallization of zeolite LTA using Raman and chemometric tools

Chaves

Soares

Cardoso

et al. 2015

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LTA zeolite is used both in industry as well as in laboratories, because of its spatial-specific structure which is useful in gas adsorption and in ion exchange separation. At-line reaction monitoring and multivariate analysis of data, such as Principal Component Analysis (PCA), are fundamentals of the Process Analytical Technology (PAT), which consists of the use of analyzers with rapid detection and low sample preparation for analysis during the process stream. In this work, an optimization of zeolite LTA synthesis was performed aiming to obtain nanocrystals and the synthesis was monitored using Raman spectroscopy and PCA. A reaction mixture of 6.2Na2O : Al2O3 : 2SiO2 : 128H2O was used and it was possible to obtain a small particle size and high crystallinity after 72 h of synthesis at 25 °C. The synthesis was monitored at-line, using Raman spectroscopy in both liquid and solid phases. The extension of the reaction could be clearly observed by the PCA scores. As expected, the liquid phase presented changes over time, but the solid phase presented three specific stationary conditions at 0-24 h, 32-56 h and 72-80, related to the beginning of the reaction, the nucleation process, and the crystal formation, respectively. In addition, it was possible to identify the intermediates of the reaction and with the aid of PCA to monitor the reaction close to the real time.

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A simple synthesis procedure to prepare nanosized faujasite crystals

Cited by 64 publications

References 39 publications

The effect of non-ionic surfactant in the microwave-assisted synthesis of MTT zeolite optimized by Taguchi method

The effect of non-ionic surfactant in the microwave-assisted synthesis of MTT zeolite optimized by Taguchi method

Synthesis of Wool-Ball-Like ZSM-5 with Enlarged External Surfaces and Improved Diffusion: A Potential Highly-Efficient FCC Catalyst Component for Elevating Pre-cracking of Large Molecules and Catalytic Longevity

Monitoring of the crystallization of zeolite LTA using Raman and chemometric tools

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