From nanoparticles to hierarchical structures: Controlling the morphology of zeolite beta

Петушков, А.А.; Merilis, Giorvanni; Larsen, Sarah C.

doi:10.1016/j.micromeso.2011.02.012

Cited by 46 publications

(42 citation statements)

References 31 publications

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“…12) shows nano-crystallites with no clear boundaries, and crystal particles clustered into agglomerates to form larger particles of different sizes. Similar observations on the CP814E morphology have been reported in the literature with the nano-sized crystals having different sizes depending on the synthesis or modification history [29,30]. Figures 13 and 14 show the solid-state NMR spectra for 27 Al and 29 Si, respectively, with the NMR spectrum showing an 27 Al peak centred at 56.08 ppm in the region corresponding to the tetrahedrally coordinated aluminium, and no additional peaks were found which could be attributed to aluminium atoms in either octahedral or pentahedral coordinated EFALs.…”

Section: Resultssupporting

confidence: 88%

“…This may be a consequence of the acid leaching treatment which followed dealumination and resulted in USY zeolite with less extra-framework aluminium (EFAL) species (the amorphous phase). Figures 3 and 4 show solid-state NMR spectra for 27 Al and 29 Si, respectively. In 27 Al MAS NMR analysis of the fresh CBV712 USY sample, as delaminated and partially acid-leached zeolites, Fig.…”

Section: Resultsmentioning

confidence: 99%

“…3 shows unique resonance spectra for three different chemical environments of aluminium. The first environment is assigned to in-framework aluminium in tetrahedral coordination Al(OSi) 4 Al MAS NMR spectra of CBV712 Figure 4 shows the 29 Si MAS NMR spectra of CBV712 USY. The 29 Si MAS NMR spectrum exhibits peaks at around -107, -102 and -95 ppm which were assigned to different configurations of SiO 4 (4Si,0Al), SiO 4 (3Si,1Al), SiO 4 (2Si,2Al), respectively.…”

Section: Resultsmentioning

confidence: 99%

“…Figures 13 and 14 show the solid-state NMR spectra for 27 Al and 29 Si, respectively, with the NMR spectrum showing an 27 Al peak centred at 56.08 ppm in the region corresponding to the tetrahedrally coordinated aluminium, and no additional peaks were found which could be attributed to aluminium atoms in either octahedral or pentahedral coordinated EFALs. The 29 Si MAS NMR spectra (Fig. 14) shows two peaks at 111.21 and 103.51 ppm, which can be assigned to the Si(0Al) and Si(1Al) configurations, respectively, and the same spectral interpretation for both 27 Al and 29 Si MAS NMR has been reported in the literature [31,32].…”

Section: Resultsmentioning

confidence: 99%

“…Characterization techniques used were: ICP optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), 27 Al and 29 Si MAS-solid-state NMR, pyridine adsorption Fourier transform infrared spectroscopy, ammonia temperature programmed desorption (NH 3 -TPD), scanning electron microscopy and energy dispersive X-ray analysis (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), hydrogen chemisorption of platinum, BET surface area analysis by nitrogen adsorption, and thermogravimetric analysis (TGA).…”

Section: Catalyst Characterizationmentioning

confidence: 99%

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The time-on-stream stability of some selected bifunctional nanoporous-based catalysts in n-heptane hydroisomerisation

et al. 2013

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In this work, some commercial nanoporousbased catalysts, such as USY, beta and mordenite zeolites loaded with Platinum metal acting as bifunctional catalysts, were used for hydroisomerisation experiments in a fixedbed reactor at the atmospheric pressure and at feed space time 5.12 h -1 to hydroisomerise n-heptane over a temperature range of 210-270°C. The study aimed to evaluate the changes with time-on-stream in the catalytic activity, product selectivity and manner of deactivation of metalloaded zeolite catalysts, at constant contact time of 5.13 h -1 and a hydrogen-to-n-heptane molar ratio fixed at 9. Various analytical techniques were used to characterise fresh and aged catalysts. Results show that pore architecture is the most important factor affecting coke formation and deactivation in zeolite catalysts, and those catalysts with three-dimensional pore structures lacking cavities or cages were best able to resist deactivation. In addition, it was found that those catalysts with high Si/Al ratios and those which had been acid-leached or steamed showed better activity, higher selectivity towards isomeric products and better time stability. Moreover, the balance between the number of metal sites and the number of acid sites played an important role in determining the activity, selectivity and stability of the bifunctional catalysts.

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Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Catalyst Characterizationmentioning

confidence: 99%

See 3 more Smart Citations

The time-on-stream stability of some selected bifunctional nanoporous-based catalysts in n-heptane hydroisomerisation

et al. 2013

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Synthesis of Engineered Zeolitic Materials: From Classical Zeolites to Hierarchical Core–Shell Materials

2018

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The term "engineered zeolitic materials" refers to a class of materials with a rationally designed pore system and active-sites distribution. They are primarily made of crystalline microporous zeolites as the main building blocks, which can be accompanied by other secondary components to form composite materials. These materials are of potential importance in many industrial fields like catalysis or selective adsorption. Herein, critical aspects related to the synthesis and modification of such materials are discussed. The first section provides a short introduction on classical zeolite structures and properties, and their conventional synthesis methods. Then, the motivating rationale behind the growing demand for structural alteration of these zeolitic materials is discussed, with an emphasis on the ongoing struggles regarding mass-transfer issues. The state-of-the-art techniques that are currently available for overcoming these hurdles are reviewed. Following this, the focus is set on core-shell composites as one of the promising pathways toward the creation of a new generation of highly versatile and efficient engineered zeolitic substances. The synthesis approaches developed thus far to make zeolitic core-shell materials and their analogues, yolk-shell, and hollow materials, are also examined and summarized. Finally, the last section concisely reviews the performance of novel core-shell, yolk-shell, and hollow zeolitic materials for some important industrial applications.

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Toward rational design of hierarchical beta zeolites: An overview and beyond

2020

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The ever‐growing need to increase the efficiency of crude oil refining raises the prospects for utilizing advanced catalytic materials to supply increasing global demands for fine chemicals and petrochemicals. Zeolites have been used as indispensable catalysts in many commercial refining processes. Among them, zeolite beta is one of the most widely produced zeolite materials with industrial significance due to its large micropores and three‐dimensional pore structures. This article discusses recent progress on hierarchical beta zeolites from various synthetic strategies. Using zeolite beta as a representative case, we provide an overview on key aspects that are applicable to different zeolites via a variety of topics, such as selection of different template materials, tailoring of mesopore sizes by base leaching, organotemplate‐free synthesis of hierarchical zeolites, and selective desilication. This article concludes with a perspective on the design of scalable hierarchical zeolites that are more relevant as industrial catalysts in commercial processes.

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From nanoparticles to hierarchical structures: Controlling the morphology of zeolite beta

Cited by 46 publications

References 31 publications

The time-on-stream stability of some selected bifunctional nanoporous-based catalysts in n-heptane hydroisomerisation

The time-on-stream stability of some selected bifunctional nanoporous-based catalysts in n-heptane hydroisomerisation

Synthesis of Engineered Zeolitic Materials: From Classical Zeolites to Hierarchical Core–Shell Materials

Toward rational design of hierarchical beta zeolites: An overview and beyond

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