Mesoporous ZSM-5 zeolite catalysts prepared by desilication with organic hydroxides and comparison with NaOH leaching

Abelló, Sònia; Bonilla, Adriana; Pérez‐Ramírez, Javier

doi:10.1016/j.apcata.2009.05.055

Cited by 282 publications

(131 citation statements)

References 31 publications

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“…These results are attributed to the dissolution of Si and Al in the aqueous phase [60][61][62]. In addition, acidities of BS On the other side, the bimetallic catalyst forms Ni-Co alloy which stabilizes small Ni particles and is more resistant to leaching.…”

Section: Catalystmentioning

confidence: 92%

Understanding the Performance and Stability of Supported Ni-Co-Based Catalysts in Phenol HDO

Huynh¹,

Armbruster

Kreyenschulte

et al. 2016

Catalysts

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Performances of bimetallic catalysts (Ni-Co) supported on different acidic carriers (HZSM-5, HBeta, HY, ZrO 2 ) and corresponding monometallic Ni catalysts in aqueous phase hydrodeoxygenation of phenol were compared in batch and continuous flow modes. The results revealed that the support acidity plays an important role in deoxygenation as it mainly controls the oxygen-removing steps in the reaction network. At the same time, sufficient hydrothermal stability of a solid catalyst is essential. Batch experiments revealed 10Ni10Co/HZSM-5 to be the best-performing catalyst in terms of conversion and cyclohexane yield. Complementary continuous runs provided more insights into the relationship between catalyst structure, efficiency and stability. After 24 h on-stream, the catalyst still reveals 100% conversion and a slight loss (from 100% to 90%) in liquid hydrocarbon selectivity. The observed alloy of Co with Ni increased dispersion and stability of Ni-active sites, and combination with HZSM-5 resulted in a well-balanced ratio of metal and acid sites which promoted all necessary steps in preferred pathways. This was proved by studies of fresh and spent catalysts using various characterization techniques (N 2 physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and infrared spectroscopy of adsorbed pyridine (pyr-IR)).

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Section: Catalystmentioning

confidence: 92%

Understanding the Performance and Stability of Supported Ni-Co-Based Catalysts in Phenol HDO

Huynh¹,

Armbruster

Kreyenschulte

et al. 2016

Catalysts

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“…This is an evidence of the protective role of TBA + cations during desilication. They are attached at the external surface of the Beta zeolite, since has strong diffusional limitations, and force NaOH to enter pores and then attack the zeolite from inside the structure [39,40]. This resulted in more homogeneous desilication across the zeolite particle, being the external and bulk Si/Al ratios very similar (Table 1).…”

Section: Bulk and Surface Chemical Compositions: Chemical Analyses Anmentioning

confidence: 95%

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

Tarach

Góra‐Marek

Tekla

et al. 2014

Journal of Catalysis

161

111

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The zeolite Beta is considered as a promising additive for FCC catalyst in diesel oil production. In this article, it is shown that hierarchical zeolite Beta obtained by an optimized desilication procedure increases Diesel and propylene yields during gas-oil cracking reaction.The alkaline treatment of zeolite Beta (Si/Al = 22) by desilication with NaOH and NaOH&TBAOH was investigated. The catalytic performance improvement of desilicated zeolite Beta has been rationalized by deep characterization of the samples including X-ray diffraction, low temperature adsorption of nitrogen, solid-state 29 Si MAS NMR and IR studies of acidity. Finally, the catalytic performance of the zeolites Beta was evaluated in the cracking of n-decane, 1,3,5-tri-iso-propylbenzene and vacuum gas oil. It was found that desilication with NaOH&TBAOH ensures the more uniform intracrystalline mesoporosity with the formation of narrower mesopores, while preserving full crystallinity resulting in catalysts with the most appropriated acidity and then, with better catalytic performance.

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“…Particularly desilication, typically with aqueous NaOH solutions, seems attractive due to extensive mesopore formation and easy scale-up [24]. Besides NaOH, several other strong bases of inorganic (LiOH, KOH, and Na 2 CO 3 ) or organic (TMAOH, TPAOH) nature have been used as desilicating agents to generate mesopores in zeolites [25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Mesoporous ZSM-5 Zeolites in Acid Catalysis: Top-Down vs. Bottom-Up Approach

et al. 2017

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Abstract:A top-down desilication of Al-rich ZSM-5 zeolites and a bottom-up mesopores creating method were evaluated in this study. Three liquid-solid and one gas-solid heterogeneously-catalysed reactions were chosen to establish relationships between zeolites textural properties and their catalytic behavior in acid-catalysed model reactions that are influenced by shape selectivity: Diels-Alder cyclization between isoprene and methylacrylate, Methanol-to-Olefins (MTO) reaction, chlorination of iodobenzene with trichloroisocyanuric acid (TCCA), and Friedel-Crafts acylation of anisole by carboxylic acids with differing sizes. It is found amongst others that no optimal mesoporosity for all the different reactions can be easily obtained, but depending on the chosen application, a specific treatment has to be set to achieve high activity/selectivity and stability.

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Mesoporous ZSM-5 zeolite catalysts prepared by desilication with organic hydroxides and comparison with NaOH leaching

Cited by 282 publications

References 31 publications

Understanding the Performance and Stability of Supported Ni-Co-Based Catalysts in Phenol HDO

Understanding the Performance and Stability of Supported Ni-Co-Based Catalysts in Phenol HDO

Catalytic cracking performance of alkaline-treated zeolite Beta in the terms of acid sites properties and their accessibility

Mesoporous ZSM-5 Zeolites in Acid Catalysis: Top-Down vs. Bottom-Up Approach

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