Recent advances in hierarchically structured zeolites: synthesis and material performances

Hua, Zi Le; Zhou, Jian; Shi, Jian Lin

doi:10.1039/c1cc10261c

Cited by 135 publications

(89 citation statements)

References 82 publications

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“…However, utilization of powdered zeolites for the industrial applications is often limited because of diffusion and access problems arising from the small zeolites pore size ranging of 0.3-1 nm which is similar to the dimensions of molecules [3,4]. The poor diffusion of relatively large reactant molecules or ions to the active sites present in the zeolite micropores may lead to the underutilization of the available zeolite internal surface area and volume, frequent blocking of the diffusion path and rapid zeolites deactivation [3,5]. The catalysis and uptake activity of zeolite is related to both the length of diffusion path and the diffusion coefficient.…”

Section: Introductionmentioning

confidence: 99%

Hierarchically porous zeolite X composites for manganese ion-exchange and solidification: Equilibrium isotherms, kinetic and thermodynamic studies

Al‐Jubouri

Holmes

2017

Chemical Engineering Journal

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This paper deals with the kinetic and isotherm studies of manganese ion removal by zeolite X and its hierarchically porous composites as ion-exchange materials. A hydrothermal treatment was applied to grow a layer of zeolite X over diatomite and carbon surfaces. The hierarchically porous composites used for Mn 2+ ion removal showed higher ion-exchange capacity when compared to pure zeolite X under same conditions. A thermodynamic study of the rate of ion-exchange revealed that the intra-particle diffusion rate constant of zeolite X/carbon and zeolite X/diatomite was higher than that of pure zeolite X indicating that the intra-particle diffusion was enhanced when zeolite was prepared in form of hierarchically porous composites. The study showed that the thickness of boundary film of zeolite X/carbon and zeolite X/diatomite was less than that of pure zeolite X indicating ion diffusion resistance to the active sites was reduced when the composites were utilised. The experimental data showed good agreement with Freundlich model. The calculated thermodynamic parameters such as ΔG°, ΔH° and ΔS° indicated the ion-exchange process of Mn 2+ ion by zeolite X and its composites was spontaneous, endothermic and the randomness increased at the liquid/solid interface under the conditions studied. The results of kinetic study showed that the ion-exchange of Mn 2+ ion by zeolite X and its composites followed a pseudo second order

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Section: Introductionmentioning

confidence: 99%

Hierarchically porous zeolite X composites for manganese ion-exchange and solidification: Equilibrium isotherms, kinetic and thermodynamic studies

Al‐Jubouri

Holmes

2017

Chemical Engineering Journal

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“…3 and 4) is probably an artefact. It was outlined by Groen et al [25,26] that a peak with mean pore radius at around 10 Å , observed in pore radius distributions of ZSM-5 obtained from nitrogen isotherms by the BJH method [19], is caused by phase transition (solidification) of the nitrogen adsorbed in the ZSM-5 micropores and not by the presence of real mesopores. Fig.…”

Section: Zeolitization Of Preformed Mesoporous Materialsmentioning

confidence: 99%

“…In recent years, there has been a rapid development in synthesis and applications of hierarchical zeolitic materials. Many excellent reviews highlighting various aspects of the latest progress in this field have been published [6,[8][9][10]13,14,[16][17][18][19][20][21][22][23][24][25][26][27][28][29]. It should be noted that most of them have focused on hierarchical zeolites (HZs).…”

Section: Direct-synthesis Using Zeolite Precursorsmentioning

confidence: 99%

Micro/Mesoporous Zeolitic Composites: Recent Developments in Synthesis and Catalytic Applications

Armbruster

Martin

2016

Catalysts

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Micro/mesoporous zeolitic composites (MZCs) represent an important class of hierarchical zeolitic materials that have attracted increasing attention in recent years. By introducing an additional mesoporous phase interconnected with the microporosity of zeolites, a hierarchical porous system of MZCs is formed which facilitates molecular transport while preserving the intrinsic catalytic properties of zeolites. Thus, these materials offer novel perspectives for catalytic applications. Over the years, numerous synthesis strategies toward the formation of MZCs have been realized and their catalytic applications have been reported. In this review, the three main synthesis routes, namely direct synthesis using zeolite precursors, recrystallization of zeolites, and zeolitization of preformed mesoporous materials are thoroughly discussed, with focus on prior works and the most recent developments along with prominent examples given from the literature. In addition, the significant improvement in the catalytic properties of MZCs in a wide range of industrially relevant reactions is presented through several representative cases. Some perspectives for the future development of MZCs are also given.

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“…Furthermore, some works have also noted that these materials improve the performance of heterogeneous catalysts when used as supports instead of classical zeolites in hydrodesulfuration reactions [328].…”

Section: Synthesis and Structurementioning

confidence: 99%

Ordered Porous Nanomaterials: The Merit of Small

Murcia

2013

ISRN Nanotechnology

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This paper will introduce the reader to some of the “classical” and “new” families of ordered porous materials which have arisen throughout the past decades and/or years. From what is perhaps the best-known family of zeolites, which even now to this day is under constant research, to the exciting new family of hierarchical porous materials, the number of strategies, structures, porous textures, and potential applications grows with every passing day. We will attempt to put these new families into perspective from a synthetic and applied point of view in order to give the reader as broad a perspective as possible into these exciting materials.

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Recent advances in hierarchically structured zeolites: synthesis and material performances

Cited by 135 publications

References 82 publications

Hierarchically porous zeolite X composites for manganese ion-exchange and solidification: Equilibrium isotherms, kinetic and thermodynamic studies

Hierarchically porous zeolite X composites for manganese ion-exchange and solidification: Equilibrium isotherms, kinetic and thermodynamic studies

Micro/Mesoporous Zeolitic Composites: Recent Developments in Synthesis and Catalytic Applications

Ordered Porous Nanomaterials: The Merit of Small

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