Fine-tuning the surface acidity of hierarchical zeolite composites for methanol-to-olefins (MTO) reaction

Suttipat, Duangkamon; Saenluang, Kachaporn; Wannapakdee, Wannaruedee; Dugkhuntod, Pannida; Ketkaew, Marisa; Pornsetmetakul, Peerapol; Wattanakit, Chularat

doi:10.1016/j.fuel.2020.119306

Cited by 21 publications

(15 citation statements)

References 67 publications

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“…In the core−shell structure, the formed nonacidic shell layer restrains the side reactions induced by the abundant external surface acid sites. 16,17 In addition, introducing mesopores by an alkaline solution to reduce coke formation in micropores and to increase coke capacity has been demonstrated as an effective strategy to improve the product selectivity and catalytic stability in many catalytic reactions, such as methanol to hydrocarbon (MTH), methanol to olefin (MTO), and methanol to propylene (MTP) reactions. 18−20 In most cases, NaOH has been used to obtain a mesoporous zeolite via post-treatment.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Recently, coating catalysts with a passivated shell to control their deactivation in catalytic reactions has attracted research interest. , For ZSM-5 zeolite, covering the external surface with a silicalite-1 shell is an efficient way to modify the external surface acid site. In the core–shell structure, the formed nonacidic shell layer restrains the side reactions induced by the abundant external surface acid sites. , In addition, introducing mesopores by an alkaline solution to reduce coke formation in micropores and to increase coke capacity has been demonstrated as an effective strategy to improve the product selectivity and catalytic stability in many catalytic reactions, such as methanol to hydrocarbon (MTH), methanol to olefin (MTO), and methanol to propylene (MTP) reactions. − In most cases, NaOH has been used to obtain a mesoporous zeolite via post-treatment . However, the control of the desilication depth of catalysts when NaOH is used is difficult because of its strong dissolution capability and easy diffusion into the channels of zeolites.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous Enhancement of Aromatic Products and Catalytic Lifetime for Catalytic Re-forming of Lignite Pyrolysis Volatiles over a Self-Assembled Hierarchical Core–Shell ZSM-5@Silicalite-1 Zeolite

Feng

Cao

Yao

et al. 2021

ACS Sustainable Chem. Eng.

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Catalytic re-forming of lignite pyrolysis volatiles to aromatics over zeolites is a promising method for value-added utilization of coal tar. However, to achieve a significant enhancement in both the yields of light aromatics and the catalytic lifetime by adjusting the structure of ZSM-5 zeolite and to understand its catalytic mechanism comprehensively are still great challenges. Herein, a self-assembled hierarchical core−shell ZSM-5@silicalite-1 with controlled mesopores and acidity as well as an ultrathin nonacidic protective shell was synthesized through a mild hydrothermal method of alkaline treatment with tetrapropylammonium hydroxide or tetraethylammonium hydroxide (TPAOH or TEAOH). Both the number and pore size distribution of mesopores can be regulated by adjusting the hydrothermal treatment time. These generated mesopores not only facilitate the mass transfer of reactants and products but also improve the utilization efficiency of the acid site. In addition, the newly fabricated nonacidic shell, which coats on the surface of ZSM-5 as a chain mail, plays a critical role in suppressing the coke formation by passivation of the acid sites on the external surface. In this work, the pore properties and acid distribution of ZSM-5 zeolite can be regulated synchronously through a desilication−recrystallization process. In addition, enhanced yields of light aromatics and catalytic lifetime were obtained simultaneously. The construction of this hierarchical core−shell zeolite with redistributed acid sites contributes to the highly efficient catalytic upgrading of macromolecular reactants.

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Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Simultaneous Enhancement of Aromatic Products and Catalytic Lifetime for Catalytic Re-forming of Lignite Pyrolysis Volatiles over a Self-Assembled Hierarchical Core–Shell ZSM-5@Silicalite-1 Zeolite

Feng

Cao

Yao

et al. 2021

ACS Sustainable Chem. Eng.

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“…Moreover, the strong acidity dramatically decreased after the steam treatment at higher than 450 • C. The decrease of strong acid sites is caused by the dealumination process and the conversion of framework tetrahedral Al sites to aluminum hydroxide, resulting from the steam treatment procedure. Recently, the acidic properties of isolated ZSM-5 zeolite, hierarchical ZSM-5@Silicalite-1 nanosheet coreshell material, and conventional ZSM-5@Silicalite-1 composite samples were examined by the NH 3 -TPD technique, and the results are shown in Figure 6 [75]. The NH 3 -TPD profiles displayed two main desorption peaks at low and high desorption temperatures, which are attributed to the weak and strong acid sites, respectively.…”

Section: Acid-base Properties and Active Speciesmentioning

confidence: 99%

“…terial, and conventional ZSM-5@Silicalite-1 composite samples were examined by the NH3-TPD technique, and the results are shown in Figure 6 [75]. The NH3-TPD profiles displayed two main desorption peaks at low and high desorption temperatures, which are attributed to the weak and strong acid sites, respectively.…”

Section: Acid-base Properties and Active Speciesmentioning

confidence: 99%

“…The catalytic activity over Ag-3.5%Zr/BEA zeolite (Ag/Zr(3.5)BEA( 75)) was compared to that of the parent BEA zeolite (BEA(75)), dealuminated BEA zeolite (DeAlBEA(75)), and Ag doped dealuminated BEA zeolite (Ag/DeAlBEA(75)) as shown in Figure 12. The BEA (75) and the DeAlBEA(75) produced only diethyl ether and ethylene, which are ethanol dehydration products. After the introduction of Ag into the dealuminated BEA (Ag/DeAlBEA(75)), a high amount of ethanol dehydrogenation product (acetaldehyde) and low amount of butadiene were observed, indicating the change of reaction pathway towards butadiene production.…”

Section: Bioethanol To Butadienementioning

confidence: 99%

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Bioethanol Upgrading to Renewable Monomers Using Hierarchical Zeolites: Catalyst Preparation, Characterization, and Catalytic Studies

Iadrat

Wattanakit

2021

Catalysts

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Bioethanol is one of the most promising renewable resources for the production of important monomers. To date, there have been various processes proposed for bioethanol conversion to renewable monomers. In this review, the catalytic bioethanol upgrading to various types of monomers using hierarchical zeolites as catalysts is illustrated, including the recent design and preparation of hierarchical zeolites for these catalytic processes. The characterizations of catalysts including textural properties, pore architectures, acidic properties, and active species are also exemplified. Moreover, the catalytic studies with various processes of monomer production from bioethanol including bioethanol dehydration, bioethanol to hydrocarbons, and bioethanol to butadiene are revealed in terms of catalytic activities and mechanistic studies. In addition, the future perspectives of these catalytic circumstances are proposed in both economic and sustainable development contexts.

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Ultra‐small PtNi bimetallic encapsulated in silicalite‐1 zeolite with fine‐tuned surface acidity for selective conversion of levulinic acid

Wang

Bao

Zuo

et al. 2022

Applied Organom Chemis

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Exploration of levulinic acid (LA) hydrogenation to γ‐valerolactone (GVL) contributes to the conversion from carbohydrates to valuable fuels and chemicals. Here, we obtained a series of ultra‐small PtNix bimetallic composite catalysts encapsulated in silicalite‐1 zeolite (S‐1) via a one‐pot synthesis strategy protected by tetra(p‐carboxyphenyl)porphyrin (TCPP) ligands. The catalytic results showed that PtNi3@S‐1 (TCPP) exhibited the most active catalytic performance (95.7% LA conversion and 93.8% GVL selectivity) under optimized conditions. The characterization results indicate that ligand modification and bimetallic synergy play an important role in enhancing the catalytic activity. The introduction of TCPP provides a guarantee for the homogeneous encapsulation of PtNi3 in S‐1 zeolite at sub‐nanometer size. The electronic interaction of PtNi bimetallic, high dispersibility of active components, improved surface acidity and excellent stability co‐contribute to the satisfactory hydrogenation activity.

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Fine-tuning the surface acidity of hierarchical zeolite composites for methanol-to-olefins (MTO) reaction

Cited by 21 publications

References 67 publications

Simultaneous Enhancement of Aromatic Products and Catalytic Lifetime for Catalytic Re-forming of Lignite Pyrolysis Volatiles over a Self-Assembled Hierarchical Core–Shell ZSM-5@Silicalite-1 Zeolite

Simultaneous Enhancement of Aromatic Products and Catalytic Lifetime for Catalytic Re-forming of Lignite Pyrolysis Volatiles over a Self-Assembled Hierarchical Core–Shell ZSM-5@Silicalite-1 Zeolite

Bioethanol Upgrading to Renewable Monomers Using Hierarchical Zeolites: Catalyst Preparation, Characterization, and Catalytic Studies

Ultra‐small PtNi bimetallic encapsulated in silicalite‐1 zeolite with fine‐tuned surface acidity for selective conversion of levulinic acid

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