Hierarchical FAU-type zeolite nanosheets as green and sustainable catalysts for benzylation of toluene

Yutthalekha, Thittaya; Wattanakit, Chularat; Warakulwit, Chompunuch; Wannapakdee, Wannaruedee; Rodponthukwaji, Kamonlatth; Witoon, Thongthai; Limtrakul, Jumras

doi:10.1016/j.jclepro.2016.08.001

Cited by 56 publications

(47 citation statements)

References 21 publications

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“…Although the solid‐state dealumination using ammonium hexafluorosilicate (AHFS) as the dealuminating agent is one of the most fascinating methods to tune acidity and stability of zeolites at low operating temperature, until now there are no reports so far on the development of acid FAU nanosheets by the solid‐state dealumination approach. Such acid‐modified FAU nanosheets would allow a straightforward increase in the catalytic performance of acid zeolites in the acid‐catalyzed reactions, such as fluid catalytic cracking (FCC), hydrocracking, and aromatics transformation …”

Section: Methodsmentioning

confidence: 99%

Tunable Acid‐Base Bifunction of Hierarchical Aluminum‐Rich Zeolites for the One‐Pot Tandem Deacetalization‐Henry Reaction

et al. 2019

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The development of bifunctional catalysts is important in the synthesis of materials for multiple sequential reactions in one‐pot tandem catalytic processes. In this context, a dealuminated acid‐base bifunctional catalyst with a hierarchical aluminum‐rich faujasite structure (zeolite Y) has been successfully prepared by the solid‐state dealumination of NaX nanosheets with ammonium hexafluorosilicate (AHFS). The characteristic properties of catalysts were examined by means of XRD, SEM, TEM, N2 physisorption technique, ICP‐OES, NH3‐TPD, CO2‐TPD, 27Al NMR, 29Si NMR, Al K‐edge XANES, and Pyridine‐FTIR. The materials exhibit a superior catalytic performance for one‐pot tandem catalysis, for example, the synthesis of trans‐β‐nitrostyrene with a yield close to 100 % in a tandem deacetalization‐Henry reaction of benzaldehyde dimethyl acetal with nitromethane. The high catalytic performance is attributed to the facile transfer of bulky molecules between acid and basic sites in the presence of hierarchical structures.

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Section: Methodsmentioning

confidence: 99%

Tunable Acid‐Base Bifunction of Hierarchical Aluminum‐Rich Zeolites for the One‐Pot Tandem Deacetalization‐Henry Reaction

et al. 2019

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“…Moreover, the synthesis of other zeolite nanosheets or nanolayers such as faujasite (FAU), ferrierite (FER) and Zeolite Socony Mobil -twelve (MTW) zeolite frameworks has been demonstrated [32][33][34][35][36][37]. TPOAC is one of the most promising mesoporogens, which is widely used in zeolite synthesis.…”

Section: Synthesis Of Hierarchical Zeolite Nanosheetsmentioning

confidence: 99%

“…For example, recently FAU zeolite nanosheets were successfully prepared by using an organosilane-surfactant, and TPOAC, as a structure-directing agent. The morphologies and textural properties can be varied by the surfactant content and the crystallization temperature [33,34]. Interestingly, the corn cob ash can also be used as the silica source instead of a commercial sodium silicate to synthesize FAU zeolite nanosheets [35].…”

Section: Synthesis Of Hierarchical Zeolite Nanosheetsmentioning

confidence: 99%

A Comprehensive Review of the Applications of Hierarchical Zeolite Nanosheets and Nanoparticle Assemblies in Light Olefin Production

Dugkhuntod

Wattanakit

2020

Catalysts

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Light olefins including ethylene, propylene and butylene are important building blocks in petrochemical industries to produce various chemicals such as polyethylene, polypropylene, ethylene oxide and cumene. Traditionally, light olefins are produced via a steam cracking process operated at an extremely high temperature. The catalytic conversion, in which zeolites have been widely used, is an alternative pathway using a lower temperature. However, conventional zeolites, composed of a pure microporous structure, restrict the diffusion of large molecules into the framework, resulting in coke formation and further side reactions. To overcome these problems, hierarchical zeolites composed of additional mesoporous and/or macroporous structures have been widely researched over the past decade. In this review, the recent development of hierarchical zeolite nanosheets and nanoparticle assemblies together with opening up their applications in various light olefin productions such as catalytic cracking, ethanol dehydration to ethylene, methanol to olefins (MTO) and other reactions will be presented.Catalysts 2020, 10, 245 2 of 15 windows, they can be divided into three different categories including large porous, medium porous and small porous zeolites, which are composed of a different number of tetrahedral units, or T atoms of 12, 10 and 8 membered rings, respectively. These behaviors make each zeolite serving unique shape selective properties, which are very important for the appropriate applications.Although there are several above-mentioned promising properties of zeolites, they are typically composed of a very small microporous structure, eventually resulting in some disadvantages of the diffusion limitation of guest molecules inside the framework. Some bulky molecules cannot easily penetrate into active sites located at microporous channels, and therefore a poor catalytic performance due to a very low reaction rate and a fast deactivation of catalysts is observed. To overcome these limitations and to improve the accessibility of molecules into active sites, in recent years modified zeolites obtained by introducing additional larger porous structures have been extensively developed [5][6][7][8].It is well known that hierarchical zeolites, composed of at least two levels of porous structures such as microspores and mesopores, microspores and macropores, and micropores/mesopores and macropores have been extensively studied and developed. Their microporous (<2 nm), mesoporous (2-50 nm) and/or macroporous (>50 nm) structures are well connected to each other. In this case, the additional larger porous structures can improve diffusion limitation, molecular transportation and coke deposition [9]. In the past decade, there have been several studies regarding the synthesis of hierarchical zeolites to overcome these problems. Herein, this comprehensive review opens up perspectives of the recent synthesis approaches of hierarchical zeolite nanosheets and nanoparticle assemblies, as well as the successful production of light olef...

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“…Interestingly, the natural amino acids directed the biomimetic mineralization of core‐shell mesoporous Y zeolites, as shown in Figure , which possessed an ant‐nest like hollow interior and a mechanically strong thin microporous shell. The core‐shell zeolite Y samples exhibit superior crystallinity and enhanced catalytic activity for Friedel‐Crafts benzylation of toluene, affording a yield twice that obtained over conventional zeolite Y, and also much higher than that of FAU nanosheets …”

Section: Roles Of Organic Small Moleculesmentioning

confidence: 99%

“…The core-shell zeolite Y samples exhibit superior crystallinity and enhanced catalytic activity for Friedel-Crafts benzylation of toluene, affording a yield twice that obtained over conventional zeolite Y, and also much higher than that of FAU nanosheets. [36] Amino acids typically contain multiple functional groups. For example, L-alanine contains an α-carboxylic acid group, a side chain methyl group, and an α-amino group connected to a chiral carbon atom leading to the absolute S configuration.…”

Section: Organic Mesopore Generating Agentmentioning

confidence: 99%

Organic Mesopore Generating Agents (OMeGAs) for Hierarchical Zeolites: Combining Functions on Multiple Scales

2019

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In the synthesis of porous zeolites, small organic molecules usually function as organic structure‐directing agents (OSDAs) or zeolite growth modifiers (ZGMs), while mesoporous zeolites are typically synthesized by employing the physical space‐filling strategy with mesoscale templates including carbons, surfactants, and polymers. Recently, we discovered that a class of small organic molecules including the common amino acids could mediate the formation of zeolite mesopores based on a chemical bond‐breaking mechanism. This class of organic mesopore generating agents (OMeGAs) are distinguished by their ability to form organic anions in situ. In this minireview, we briefly introduce the widely recognized role of OSDA and ZGM, and then focus on the interesting function of OMeGA for the intracrystalline void generation. Comparison of OMeGA with the mesoscale templates especially surfactants are made in terms of their mesopore‐forming mechanisms, and the potential implications on a possible dissociative‐associative crystallization pathway are discussed. We end this review with the prospects of future research on the small molecule OMeGA, such as function integration and structure optimization.

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Hierarchical FAU-type zeolite nanosheets as green and sustainable catalysts for benzylation of toluene

Cited by 56 publications

References 21 publications

Tunable Acid‐Base Bifunction of Hierarchical Aluminum‐Rich Zeolites for the One‐Pot Tandem Deacetalization‐Henry Reaction

Tunable Acid‐Base Bifunction of Hierarchical Aluminum‐Rich Zeolites for the One‐Pot Tandem Deacetalization‐Henry Reaction

A Comprehensive Review of the Applications of Hierarchical Zeolite Nanosheets and Nanoparticle Assemblies in Light Olefin Production

Organic Mesopore Generating Agents (OMeGAs) for Hierarchical Zeolites: Combining Functions on Multiple Scales

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