Novel catalytic aspects of beta zeolite for alkyl aromatics transformation

Halgeri, A. B.; Das, Jagannath

doi:10.1016/s0926-860x(98)00395-0

Cited by 83 publications

(40 citation statements)

References 10 publications

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“…Better Beta-SDS 120 samples with good thermal stability, high surface area, large micropore volume, and stable tetrahedral aluminum species compared to those of Beta-SDS 140 have been rationally synthesized at 120°C in the presence of 1.4-8.7% Beta-L seeds. The improved properties of Beta-SDS 120 are explained by the fact that defects such as terminal Si-OH groups in Beta-SDS 120 samples should be much less frequent than those in Beta-SDS 140 , which are supported by 29 Si NMR spectroscopy and TG analysis. The Beta-SDS 120 samples with improved quality should be important for developing efficient Beta zeolite catalysts in the future.…”

Section: Discussionmentioning

confidence: 83%

“…Nuclear magnetic resonance (NMR) spectra were recorded on a Varian Infinityplus-400 spectrometer. 29 Si MAS NMR spectra were obtained at 79.4 MHz using 7.5-mm MAS probe with a spinning rate of 4 KHz. Chemical shifts were referenced to 4,4-dimethyl-4-silapentane sulfonate sodium (DSS).…”

Section: Characterizationmentioning

confidence: 99%

“…Fig. 7 shows 29 Si NMR spectra of as-synthesized Beta-SDS 120-1 and Beta-SDS 140 samples. Both samples show bands at around À115, À110, À105, and À100 ppm.…”

Section: Rational Synthesis Of Beta-sds Zeolitementioning

confidence: 99%

“…In order to understand the contribution of terminal Si-OH groups in the zeolite framework, 1 H ? 29 Si CP/MAS NMR spectra of Beta-SDS 120-1 and Beta-SDS 140 samples were measured, and the results exhibit that the band intensity at ca. À102 ppm is greatly increased (Fig.…”

Section: Rational Synthesis Of Beta-sds Zeolitementioning

confidence: 99%

“…Beta zeolite with unique three-dimensional network of large pores (12MR) exhibits excellent properties in a series of catalytic reactions such as the petroleum refining and fine chemical synthesis [28][29][30][31][32][33][34]. However, its wide applications are still challenging by the use of organic templates such as tetraethylammonium hydroxide (TEAOH).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Rational synthesis of Beta zeolite with improved quality by decreasing crystallization temperature in organotemplate-free route

Zhang

Xie

Meng

et al. 2013

Microporous and Mesoporous Materials

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Section: Discussionmentioning

confidence: 83%

Section: Characterizationmentioning

confidence: 99%

“…Fig. 7 shows 29 Si NMR spectra of as-synthesized Beta-SDS 120-1 and Beta-SDS 140 samples. Both samples show bands at around À115, À110, À105, and À100 ppm.…”

Section: Rational Synthesis Of Beta-sds Zeolitementioning

confidence: 99%

Section: Rational Synthesis Of Beta-sds Zeolitementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Rational synthesis of Beta zeolite with improved quality by decreasing crystallization temperature in organotemplate-free route

Zhang

Xie

Meng

et al. 2013

Microporous and Mesoporous Materials

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Preparation and permeation characterization of β‐zeolite‐incorporated composite membranes

Huang

et al. 2008

J of Applied Polymer Sci

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In this work, several b-zeolite-incorporated polymer composite membranes were fabricated with the solution-casting method. The zeolite loadings were 10, 20, and 30 wt %, respectively. Scanning electron microscopy characterization showed that the zeolite particles could be uniformly distributed in the whole polymer matrix. Gas permeation results demonstrated that after the incorporation of the same b-zeolite, the polyimide exhibited a significant increase in gas permeability but a decrease in permselectivity, and both were quite pronounced at high zeolite loadings; this resulted from the loose structure that formed. The poly(ether sulfone) composite membranes showed obvious increases in both permeability and selectivity, and the permeability increase was considerably greater at higher zeolite loadings. The permselectivity increase could possibly be attributed to the pore sieving and preferential adsorption of b-zeolite entities for the test gases as the heat treatment may have resulted in the formation of a defect-free microstructure. However, breakthrough of the upper-bound line was not achieved for these composite membranes, as reflected by Robeson plots. Our results suggest that changes in membrane performance not only are attributable to the properties and content of b-zeolite particles but also depend on the heterogeneous microstructure created by zeolite entities.

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Production of Xylenes from Toluene and 1,2,4‐Trimethylbenzene over ZSM‐5 and Mordenite Catalysts in a Fluidized‐Bed Reactor

2010

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The production of various xylenes from toluene, heavy aromatics such as 1,2,4-trimethylbenzene (1,2,4-TMB) and their mixture was investigated over H-ZSM-5 (H-Z), H-mordenite (H-M) and a dual zeolitic catalyst comprising ZSM-5 and mordenite (H-ZM). The experiments were conducted in a riser-simulator reactor under different operating conditions to study the effect of temperature, reaction time and feed composition on conversion and product yields. At 400°C, the conversion of toluene over the three catalysts yielded mainly benzene and xylenes with maximum conversion at 25 % and a xylene yield of 12.5 wt % over the H-M catalyst. The transformation of 1,2,4-TMB doubled the conversion level and xylene yield and suppressed benzene formation. However, a considerable portion of the 1,2,4-TMB feed was isomerized into 1,2,3-TMB and 1,3,5-TMB accompanied by the formation of tetramethylbenzenes (TeMBs). The conversion of an equimolar mixture of toluene and 1,2,4-TMB over the three catalysts resulted in higher toluene conversion and double xylene yield in comparison with 1,2,4-TMB alone. The advantage of using a dual zeolitic catalyst was observed at an equimolar feed of toluene and 1,2,4-TMB, exhibiting maximum toluene conversion, higher xylene yield and the formation of lower levels of undesirable products.

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Novel catalytic aspects of beta zeolite for alkyl aromatics transformation

Cited by 83 publications

References 10 publications

Rational synthesis of Beta zeolite with improved quality by decreasing crystallization temperature in organotemplate-free route

Rational synthesis of Beta zeolite with improved quality by decreasing crystallization temperature in organotemplate-free route

Preparation and permeation characterization of β‐zeolite‐incorporated composite membranes

Production of Xylenes from Toluene and 1,2,4‐Trimethylbenzene over ZSM‐5 and Mordenite Catalysts in a Fluidized‐Bed Reactor

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