Synthesis and characterization of nanocrystalline and mesoporous zeolites

Петушков, А.А.

doi:10.17077/etd.exwgzpaa

Cited by 4 publications

(15 citation statements)

References 178 publications

(280 reference statements)

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“…(Zeolite Socony Mobil #5), which has the MFI (refers to ZSM-FIve) structure has a three dimensional structure with two kinds of intersecting channels, straight channels and zigzag channels, that are formed by 10-ring pores with pore diameters of ∼0.55 nm ( Figure 1). 3 Zeolites materials are widely used in a variety of applications in medicine, catalysis and environmental protection. 2,[4][5][6][7] Properties such as the high surface area, thermal stability, active sites, and the ability for surface functionalization make these materials highly desirable for a broad range of applications.…”

Section: Overview Of Zeolite Synthesis Methodsmentioning

confidence: 99%

Mechanochemically assisted synthesis of zeolite catalysts for biomass conversion

Nada¹

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I would like to thank Prof. Sarah Larsen and Prof. Edward Gillan for being the best research advisors and giving me the opportunity to work in their lab. I truly enjoyed being their student, and I learned a lot from their insight and advice how to be a successful research scientist. Thanks to both of them for their patience and direction throughout my graduate education experience. I would like to thank former and current graduate students in Larsen and Gillan research group for their support and advice. I learned a lot from them how to use the instruments and software in the lab and how to be a successful graduate student, and I really appreciate the time we spent together in the lab. Last but not least I would like to thank the department of chemistry and graduate college at The University of Iowa for the financial support and for giving me the opportunity to be one of their Hawkeye graduate students. It is great to be Hawkeye. Thanks iv ABSTRACT Recently, there has been growing interest in the green synthesis of zeolite (aluminosilicate) materials using solvent-free synthesis methods. Solid starting materials are typically ground for a period of time followed by thermal heating to synthesize crystalline ZSM-5 zeolite. These studies generally have focused on products formed after the thermal heating. However, very little is known about the reaction intermediates formed during the mechanochemical pre-reaction grinding step and how the pre-reaction impacts the subsequent synthetic success. In this study, the mechanochemical approach used to synthesize ZSM-5 and mordenite zeolite was investigated. Two types of solvent-free synthesis methods were investigated; templated solvent-free synthesis, and template-free and solvent-free synthesis. The effect of grinding time was investigated first to find the optimal grinding time that initiates pre-reactions between the starting materials. Controlled experiments were used to monitor chemical and physical changes occuring during the grinding step. Subsequently, the effect of different synthesis conditions such as time, temperature, template, SiO2/Al2O3, and Na2O/Al2O3 ratios, and different precursors were studied using the optimal grinding time. Both manual (mortar and pestle) and ball mill (FTS 1000) grinding were used in this study. The synthesized products were characterized using XRD, BET nitrogen adsorption, SEM, and ICP-OES. Finally, selected single-phase synthesized zeolite materials were evaluated for their catalytic performance in biomass conversion process of cellulose and glucose to useful chemicals such as hydroxymethylfurfural (HMF).

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Section: Overview Of Zeolite Synthesis Methodsmentioning

confidence: 99%

Mechanochemically assisted synthesis of zeolite catalysts for biomass conversion

Nada¹

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“…Each structure has a distinct X-ray diffraction pattern, and the pattern serves as a fingerprint of a specific type of crystalline material. 3,28,29,30 In studies of nanocrystalline ZSM-5 zeolites, the X-ray diffraction patterns of synthesized materials can be compared to the standard nanocrystalline ZSM-5 zeolite pattern to determine if the produced materials have the same pattern of peaks or not.…”

Section: Powder X-ray Diffractionmentioning

confidence: 99%

“…Another advantage of X-ray diffraction is that it can be used to determine the crystallinity of materials. By using the XRD patterns of both target and standard materials, relative crystallinity (RC) can be estimated: 3,20…”

Section: Powder X-ray Diffractionmentioning

confidence: 99%

“…The pore size and the pore volume can be determined by collecting the full isotherm (adsorption/desorption isotherm). 3,10,12,31,32,33…”

Section: Nitrogen Adsorption Isotherm By Betmentioning

confidence: 99%

“…The structure of ZSM-5 is a three dimensional structure with two kinds of intersecting channels, straight channels and zigzag channels, that are formed by 10-ring pores with pore diameters of ∼0.55 nm. 3 Because the activity of ZSM-5 zeolites involves the active surface sites, , the performance of ZSM-5 will depend on the total accessible surface area of the structure and the diffusion path lengths. 4,5,6,7,8 In other words, increasing the total surface area of the ZSM-5 crystalline will increase its efficiency as a catalyst because the number of active sites on the surface will increase as well.…”

Section: Introductionmentioning

confidence: 99%

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Greener synthesis of nanocrystalline ZSM-5

Nada¹

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Nanocrystalline ZSM-5 zeolite, which is a well-known catalyst used in a variety of applications in industry, environment, and medicine, can be synthesized using different methods. However, a big challenge in synthesizing nanocrsytalline ZSM-5 is the use of an organic template such as TPAOH, which is very expensive. The template is required to facilitate the growth of the nanocrsytalline ZSM-5 during the synthesis. However, to use the nanocrsytalline ZSM-5, the template has to be removed by a calcination process to open the pores and reveal the active surface of the nanocrystalline ZSM-5. The calcination process requires a high temperature for a long time to remove the organic template. Consequently, synthesizing nanocrystalline ZSM-5 by using a templated method is considered to be time, energy, and materials inefficient. In addition, the production of CO2 from the calcination process is a negative impact on the environment. Therefore, finding another method to synthesize nanocrystalline ZSM-5 without using an organic template would be beneficial. Here, nanocrystalline ZSM-5 was synthesized successfully in high yield and quality by using a seed-assisted method and without using the organic template. In addition, the effect of synthesis temperature, synthesis time, basic environment, amount of seeds, size of seeds, aging time, and use of calcined and uncalcined seeds are investigated in this study. The synthesized nanocrystalline ZSM-5 materials were characterized by using X-ray diffraction (XRD), gas adsorption isotherm (BET/BJH), and transmission electron microscopy (TEM). v

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Synthesized 2nd Generation Zeolite as an Acid-Catalyst for Esterification Reaction

Alfattal¹,

Abbas²

2019

IJCPE

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MCM-48 zeolites have unique properties from the surfaces and structure point of view as it’s shown in the results ,and unique and very sensitive to be prepared, have been experimentally prepared and utilized as a second-generation/ acid - catalyst for esterification reactions of oleic acid as a model oil for a free fatty acid source with Ethanol. The characterization of the catalyst used in the reaction has been identified by various methods indicating the prepared MCM-48 is highly matching the profile of common commercial MCM-48 zeolite. The XRF results show domination of SiO2 on the chemical structure with 99.1% and agreeable with the expected from MCM-48 for it's of silica-based, and the SEM results show the cubic crystallographic space group compatible with Ia3d space group giving the hexagonal surface structure. The AFM test gave an average particle diameter of 97.51 nm and an average catalyst roughness of 0.855 nm. Esterification reaction of oleic acid with ethanol on MCM-48 has been carried in a batch reactor with 5% the prepared MCM-48 zeolite catalyst loading gives 81% of conversion after one hour at 353K

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Synthesis and characterization of nanocrystalline and mesoporous zeolites

Cited by 4 publications

References 178 publications

Mechanochemically assisted synthesis of zeolite catalysts for biomass conversion

Mechanochemically assisted synthesis of zeolite catalysts for biomass conversion

Greener synthesis of nanocrystalline ZSM-5

Synthesized 2nd Generation Zeolite as an Acid-Catalyst for Esterification Reaction

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