Study on optimum base-treatment of mordenite for catalytic alkylbenzene transalkylation

Tsai, Shang-Tien; Chao, Pei-Yu; Chao, Pei-Hsiun; Du, Kun-Jia; Fang, Man-Jyun; Liu, Shang-Bin; Tsai, Tseng-Chang

doi:10.1016/j.cattod.2015.04.024

Cited by 7 publications

(7 citation statements)

References 27 publications

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“…The introduction of a second level of intracrystalline porosity to the MOR pore system would be advantageous to the many acid‐catalyzed hydrocarbon conversion reactions that involve large paraffinic and aromatic molecules. A general “top‐down” approach to prepare mesoporous mordenite zeolites via desilication, dealumination or a combination of these approaches has been extensively examined. Even though these techniques are commercially available and can be scaled up, there is little control over the textural and acidic properties of the final materials.…”

Section: Introductionmentioning

confidence: 99%

Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization

et al. 2019

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We report the synthesis of hierarchical mordenite zeolite nanorods in one step using inexpensive mono‐quaternary ammonium N‐cetyl‐N‐methylpyrrolidinium (C16NMP) as mesoporogen to the synthesis gel. The presence of a small amount of C16NMP results in the formation of 0.6–1 μm rods‐like crystals oriented along the c‐axis with a high mesoporous volume (0.12 cm3 g−1) and external surface area (∼90 m2 g−1) compared to bulk mordenite. Acidity characterization shows that the presence of C16NMP during mordenite formation leads to a redistribution of aluminum in the zeolite framework: the amount of Brønsted acid sites in the side‐pockets (8MR channels) is increased at the expense of those in the 12MR main channels. As these latter acid sites are the ones involved in the conversion of alkene intermediates in bifunctional hydroconversion of alkanes, an optimized hierarchical mordenite prepared with C16NMP displays a more ideal hydrocracking selectivity than bulk MOR prepared solely with sodium.

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Section: Introductionmentioning

confidence: 99%

Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization

et al. 2019

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“…A pure alkaline treatment was performed by several groups. [262][263][264][265][266][267][268] Pastvova et al treated a parent mordenite in a 0.2 m NaOH solution. [262] This concentration, however, was varied in another study from Huang et al who concluded that extracting Si from the framework by an alkaline treatment could generate intracrystalline mesopores with diameters of 3-30 nm.…”

Section: Mordenitementioning

confidence: 99%

“…This last treatment showed to be most effective for enhancing the catalytic activity and stability. [265] A last (only) alkaline treatment from Issa et al was assisted by pyridine, which showed dual action on textural and chemical properties. This approach yielded aggregates with smaller zeolite particles with a substantially higher amount of external silanols.…”

Section: Mordenitementioning

confidence: 99%

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State of the Art and Perspectives of Hierarchical Zeolites: Practical Overview of Synthesis Methods and Use in Catalysis

et al. 2020

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Zeolites are highly crystalline aluminosilicates with welldefined pores that are constructed of SiO 2 and AlO 4 tetrahedra. These tetrahedra can be linked together in different unique ways to form various materials with a specific topology. [1] According to the International Zeolite Association (IZA), more than 250 different topologies, which are all assigned with a three-letter code, have been identified. [2] The micropores in zeolites are typically constructed from 8, 10, or 12 tetrahedral atoms

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“…The reason is the aggressive action of the solution, leading to rapid amorphization of the zeolite structure as a result of its destruction [57]. Most commonly, mordenite was alkaline treated with aqueous solutions of NaOH with a concentration of 0.05-2.5 M (pH~10) in a temperature range from RT to 90 • C with duration from 10 min to 2 h [58][59][60]. The resulting formation of mesopores is due to surface hydrolysis and dissolution of the crystals, most likely in places with accumulations of crystal defects.…”

Section: Alkaline Treatmentmentioning

confidence: 99%

Recent Progress in Synthesis and Application of Nanosized and Hierarchical Mordenite—A Short Review

2021

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Zeolites with their unique properties find applications in various fields, including medicine, agronomy, ecology, production of detergents and drying agents, and in a number of industrial processes. Among zeolites, mordenite is particularly widespread because of its high silica/alumina ratio, which allows it to resist exposure to high temperatures and to acidic gases and liquids. Mordenite is commercially available as a natural mineral and as a synthesized material. This zeolite is mostly used in its synthetic form as an acid catalyst in the petrochemical industry for the isomerization of alkanes and aromatics. In this review, we consider the scientific literature on the structure, synthesis, and two main types of modifications that solve the diffusion difficulties during catalytic processes. The first type of modifications is related to a reduction of the size of the mordenite crystals obtained to submicron or nanometric range, whereas the second ones aim to obtain hierarchical mordenite samples by appropriate post-synthetic treatments. Both types of modifications find many other applications besides solving diffusion constraints in catalytic processes. Attempts to fine-tune and control the particle size in the first type of modifications or the pore size in the second ones by adjusting various parameters during the synthesis are described.

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Study on optimum base-treatment of mordenite for catalytic alkylbenzene transalkylation

Cited by 7 publications

References 27 publications

Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization

Mordenite Nanorods Prepared by an Inexpensive Pyrrolidine‐based Mesoporogen for Alkane Hydroisomerization

State of the Art and Perspectives of Hierarchical Zeolites: Practical Overview of Synthesis Methods and Use in Catalysis

Recent Progress in Synthesis and Application of Nanosized and Hierarchical Mordenite—A Short Review

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