Highly selective production of renewable p-xylene from bio-based 2,5-dimethylfuran and ethylene over Al-modified H-Beta zeolites

Molecular sieves with beta zeolite topology are promising catalysts for various reactions as they exhibits extraordinary Lewis acidity. However, their industrial application and related research in academica is hindered because their synthesis is time consuming and typically involves toxic chemicals as hydrofluoric acid. Therefore, tetraethylammonium fluorid was tested as a non-toxic fluotide source for the synthesis of beta zeolites. In combination with the previously reported nano-seeded growth method, a fast synthesis of beta zeolites only involving non-toxic chemicals was possible. Synthesized zeolites show comparable selectivity in the Bayer-Villinger oxidation as conventional zeolites synthesized with hydrofluoric acid.<br>

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An Investigation into the Adsorption of Aniline from Aqueous Solution Using H-Beta Zeolites and Copper-Exchanged Beta Zeolites

Adsorption Science & Technology ◽

10.1260/0263617054353582 ◽

2005 ◽

Vol 23 (3) ◽

pp. 255-266 ◽

Cited By ~ 3

Author(s):

J. O'Brien ◽

T. Curtin ◽

T.F. O'Dwyer

Keyword(s):

Aqueous Solution ◽

Adsorption Process ◽

Zeolite Beta ◽

Langmuir Model ◽

Beta Zeolite ◽

Copper Leaching ◽

Beta Zeolites ◽

The Stability ◽

Ph Range ◽

Adsorbent Materials

Zeolite beta, a large-pore zeolite, was investigated in this study with a view to examining it as a potential adsorbent for the removal of aniline from aqueous solutions. Two different metal-loaded zeolites were prepared by exchanging H-beta zeolite (SiO2/Al2O3 = 75:1) with copper. The influence of exchanged copper on the uptake level was assessed. The effect of varying the silica-to-alumina ratio of the H-beta zeolite on the aniline uptake level was also examined, using three different H-beta zeolites with ratios of 25:1, 75:1 and 150:1 as adsorbents. The sorption experiments indicated an uptake level of ca. 110–120 mg/g for each zeolite and this level was also adsorbed by the copper-modified H-beta zeolites (SiO2/Al2O3 = 75:1). In all cases, the adsorption process followed the Langmuir model for adsorption and the level of aniline adsorbed was largely unaffected by a change in temperature or the presence of extra framework copper. The stability of the exchanged copper on these zeolites was then examined by measuring the quantity of copper leached from each zeolite into solution as a function of pH. Minimum copper leaching was observed in the pH range 5–11. This provided a stable pH working range for the adsorbent materials.

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Pt-Sn Supported on Beta Zeolite with Enhanced Activity and Stability for Propane Dehydrogenation

Catalysts ◽

10.3390/catal11010025 ◽

2020 ◽

Vol 11 (1) ◽

pp. 25

Author(s):

Su-Un Lee ◽

You-Jin Lee ◽

Soo-Jin Kwon ◽

Jeong-Rang Kim ◽

Soon-Yong Jeong

Keyword(s):

Catalytic Activity ◽

Surface Area ◽

High Surface ◽

Coke Formation ◽

Propane Dehydrogenation ◽

Coke Deposition ◽

Beta Zeolite ◽

Lower Amount ◽

Metal Catalyst ◽

Beta Zeolites

With the growing global propylene demand, propane dehydrogenation (PDH) has attracted great attention for on-purpose propylene production. However, its industrial application is limited because catalysts suffer from rapid deactivation due to coke deposition and metal catalyst sintering. To enhance metal catalyst dispersion and coke resistance, Pt-based catalysts have been widely investigated with various porous supports. In particular, zeolite can benefit from large surface area and acid sites, which favors high metal dispersion and promoting catalytic activity. In this work, we investigated the PDH catalytic properties of Beta zeolites as a support for Pt-Sn based catalysts. In comparison with Pt-Sn supported over θ-Al2O3 and amorphous silica (Q6), Beta zeolite-supported Pt-Sn catalysts exhibited a different reaction trend, achieving the best propylene selectivity after a proper period of reaction time. The different PDH catalytic behavior over Beta zeolite-supported Pt-Sn catalysts has been attributed to their physicochemical properties and reaction mechanism. Although Pt-Sn catalyst supported over Beta zeolite with low acidity showed low Pt dispersion, it formed a relatively lower amount of coke on PDH reaction and maintained a high surface area and active Pt surfaces, resulting in enhanced stability for PDH reaction. This work can provide a better understanding of zeolite-supported Pt-Sn catalysts to improve PDH catalytic activity with high selectivity and low coke formation.

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Facile Preparation of a Binderless Hierarchical Beta Zeolite in Shaped Form and with Improved Acidity for Catalysis

10.26434/chemrxiv.13252604 ◽

2020 ◽

Author(s):

Jiaxu Liu ◽

Zhenmei Zhang ◽

Chunyan Liu ◽

Gianvito Vilé ◽

Guang Xiong ◽

...

Keyword(s):

Materials Science ◽

Zeolite Catalysts ◽

Beta Zeolite ◽

Synthetic Approach ◽

Advanced Manufacturing ◽

Hierarchical Zeolite ◽

Characterization Methods ◽

Tetraethylammonium Hydroxide ◽

Beta Zeolites ◽

Structure Properties

<div> <div> <div> <div> <p>The synthesis of a technical hierarchical nanosized zeolite catalysts without growth modifiers and binders remains a major challenge in catalysis. Herein, we report a new synthetic approach to directly produce hierarchical nanosized Beta zeolites in technical form, without any binders in the final material. The synthesis consists of two steps, where a Beta zeolite powder is first shaped using tetraethyl orthosilicate; the extrude is then recrystallized at high temperature in the presence of tetraethylammonium hydroxide solution. This transforms the SiO2 binders into zeolite framework. A variety of characterization methods were applied to unlock structure-properties relationships of the materials and demostrate their catalytic functionality. We believe that this work opens avenues for the advanced manufacturing of hierarchical zeolite materials in shaped form, and will find useful applications in catalysis and materials science. </p> </div> </div> </div> </div>

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Zeolite-templated Carbon Network: A Beta Zeolite Case Study

MRS Advances ◽

10.1557/adv.2020.183 ◽

2020 ◽

Vol 5 (14-15) ◽

pp. 751-756 ◽

Cited By ~ 1

Author(s):

Eliezer F. Oliveira ◽

Leonardo D. Machado ◽

Ray H. Baughman ◽

Douglas S. Galvao

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Beta Zeolite ◽

Beta Zeolites ◽

Preliminary Study ◽

The One ◽

Dynamics Simulations ◽

Carbon Nanotube Networks ◽

Carbon Network

ABSTRACTIn this work, we report a preliminary study, based on molecular dynamics simulations, about 3D carbon nanotube networks that could be formed inside the beta zeolites. We investigated their structural stability and mechanical properties. Our results show that from all possible carbon nanotubes that can be embedded inside the channels of the beta zeolite, the one with chirality (6,0) is the most stable. Using the carbon nanotube (6,0), it is possible to build 3D structures with both all (higher density) and only partially (lower density) filled zeolite channels. Under tensile uniaxial force, the 3D low-density carbon nanotube networks are anisotropic and can be stretched along the direction in which all nanotubes are perpendicular up to 130% of strain without fracture. Also, the porosity and network stiffness can be tuned depending on the amount of carbon nanotubes filling the channels of the zeolites.

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Understanding the roles of different acid sites in Beta zeolites with different particle sizes catalyzed liquid-phase transalkylation of diethylbenzene with benzene

Catalysis Science & Technology ◽

10.1039/d1cy01849c ◽

2021 ◽

Author(s):

Chuanyu Yang ◽

Zhongwen Dong ◽

Weifeng Chu ◽

Yanan Wang ◽

Dongpu Zhao ◽

...

Keyword(s):

Liquid Phase ◽

Acid Sites ◽

Zeolite Catalysts ◽

Beta Zeolite ◽

Particle Sizes ◽

Synthesis System ◽

Beta Zeolites

A series of Beta zeolite catalysts with controllable particle sizes and similar Si/Al ratios were prepared by introducing imidazole (IMD) into the synthesis system and used for a liquid-phase transalkylation...

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Facile Preparation of a Binderless Hierarchical Beta Zeolite in Shaped Form and with Improved Acidity for Catalysis

10.26434/chemrxiv.13252604.v1 ◽

2020 ◽

Author(s):

Jiaxu Liu ◽

Zhenmei Zhang ◽

Chunyan Liu ◽

Gianvito Vilé ◽

Guang Xiong ◽

...

Keyword(s):

Materials Science ◽

Zeolite Catalysts ◽

Beta Zeolite ◽

Synthetic Approach ◽

Advanced Manufacturing ◽

Hierarchical Zeolite ◽

Characterization Methods ◽

Tetraethylammonium Hydroxide ◽

Beta Zeolites ◽

Structure Properties

<div> <div> <div> <div> <p>The synthesis of a technical hierarchical nanosized zeolite catalysts without growth modifiers and binders remains a major challenge in catalysis. Herein, we report a new synthetic approach to directly produce hierarchical nanosized Beta zeolites in technical form, without any binders in the final material. The synthesis consists of two steps, where a Beta zeolite powder is first shaped using tetraethyl orthosilicate; the extrude is then recrystallized at high temperature in the presence of tetraethylammonium hydroxide solution. This transforms the SiO2 binders into zeolite framework. A variety of characterization methods were applied to unlock structure-properties relationships of the materials and demostrate their catalytic functionality. We believe that this work opens avenues for the advanced manufacturing of hierarchical zeolite materials in shaped form, and will find useful applications in catalysis and materials science. </p> </div> </div> </div> </div>

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Skeletal Isomerization of n-Butane Over Mordeniteand Beta Zeolites

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19980042 ◽

1998 ◽

Vol 63 (1) ◽

pp. 42-52

Author(s):

Evžen Babůrek ◽

Jana Nováková

Keyword(s):

Structural Features ◽

Skeletal Isomerization ◽

Beta Zeolite ◽

Total Conversion ◽

Total N ◽

Beta Zeolites ◽

Butane Conversion

It was found that the addition of platinum (3 wt.%) substantially increases the total n-butane conversion and selectivity to isobutane over H-Beta zeolite. The same holds for H-Mordenite; however, the conversion significantly decreases in time at 350 °C due to the coking of the catalyst. The selectivity to isobutane is the highest at 300 °C over both zeolite types with platinum (over Pt/H-Beta 1.8 times higher than over Pt/H-Mordenite at almost the same conversion levels of 30 and 36%, respectively). The H-forms of both zeolite types are most selective at 250 °C, but the total conversion is low. The results obtained are related to the structural features of both zeolite types.

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The Steric Effect in Green Benzylation of Arenes with Benzyl Alcohol Catalyzed by Hierarchical H-beta Zeolite

Catalysts ◽

10.3390/catal9100869 ◽

2019 ◽

Vol 9 (10) ◽

pp. 869

Author(s):

Xinyu Liu ◽

Meihuan Lu ◽

Xuan Wang ◽

Juyou Lu ◽

Jianxin Yang

Keyword(s):

Benzyl Alcohol ◽

Steric Effect ◽

Beta Zeolite ◽

Aromatic Molecules ◽

Beta Zeolites ◽

Silica Alumina ◽

Molecular Sizes ◽

Adsorption Desorption ◽

First Time ◽

Relative Adsorption

For decades the steric effect was still ambiguously understood in catalytic benzylation reactions of arenes with benzyl alcohol, which limited the green synthesis of phenylmethane derivates in industrial scale. This research applies a series of silica–alumina beta zeolites to systematically evaluate factors like catalyst porosity, reactants molecule size, and reaction temperature on catalytic benzylation. First, a suitable hierarchical beta zeolite catalyst was screened out by X-ray powder diffraction, N2 adsorption−desorption, and probe benzylation with p-xylene. In the following substrates expanding study, for a typical benzylation of benzene, it showed extraordinary performance among literature reported ones that the conversion was 98% while selectivity was 90% at 353 K only after 10 min. The steric effect of aromatics with different molecular sizes on benzylation was observed. The reaction activities of four different aromatics followed the order: benzene > toluene > p-xylene > mesitylene. Combined with macroscopic kinetic analysis, this comprehensive study points out for the first time that the nature of this steric effect was dominated by the relative adsorption efficiency of different guest aromatic molecules on the host zeolite surface.

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