Ordered mesoporous γ-Al 2 O 3 as highly efficient and recyclable catalyst for the Knoevenagel reaction at room temperature

Bhanja, Piyali; Kayal, Utpal; Bhaumik, Asim

doi:10.1016/j.mcat.2018.01.019

Cited by 13 publications

(4 citation statements)

References 46 publications

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“…Mesoporous alumina (Al 2 O 3 ) materials with high chemical, mechanical, and thermal stability have been widely adapted in many industrial applications such as high-temperature catalysis and adsorption. − Improving mesoporous Al 2 O 3 with structural and textural features such as periodicity and long range order, uniform pore size and good connectivity, high surface area and pore volume, acidic/basic surface characteristics, and addition of metal components can further enhance their physical and chemical functionalities and expand the application space into energy conversion, size-selective separation and sensing of environmental pollutants, and enrichment of biomacromolecules. − …”

Section: Introductionmentioning

confidence: 99%

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO₂ Capture and Dye Separation

Seah

Wang

Tan

et al. 2021

ACS Appl. Mater. Interfaces

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We describe a versatile and scalable strategy toward long-range and periodically ordered mesoporous alumina (Al 2 O 3 ) structures by evaporationinduced self-assembly of a structure-directing ABA triblock copolymer (F127) mixed with aluminum tri-sec-butoxide-derived sol additive. We found that the separate preparation of the alkoxide sol−gel reaction before mixing with the block copolymer enabled access to a relatively unexplored parameter space of copolymerto-additive composition, acid-to-metal molar ratio, and solvent, yielding ordered mesophases of two-dimensional (2D) lamellar, hexagonal cylinder, and 3D cage-like cubic lattices, as well as multiscale hierarchical ordered structures from spinodal decomposition-induced macro-and mesophase separation. Thermal annealing in air at 900 °C yielded well-ordered mesoporous crystalline γ-Al 2 O 3 structures and hierarchically porous γ-Al 2 O 3 with 3D interconnected macroscale and ordered mesoscale pore networks. The ordered Al 2 O 3 structures exhibited tunable pore sizes in three different length scales, <2 nm (micropore), 2−11 nm (mesopore), and 1−5 μm (macropore), as well as high surface areas and pore volumes of up to 305 m 2 /g and 0.33 cm 3 /g, respectively. Moreover, the resultant mesoporous Al 2 O 3 demonstrated enhanced adsorption capacities of carbon dioxide and Congo red dye. Such hierarchically ordered mesoporous Al 2 O 3 are well-suited for green environmental solutions and urban sustainability applications, for example, hightemperature solid adsorbents and catalyst supports for carbon dioxide sequestration, fuel cells, and wastewater separation treatments.

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Section: Introductionmentioning

confidence: 99%

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO₂ Capture and Dye Separation

Seah

Wang

Tan

et al. 2021

ACS Appl. Mater. Interfaces

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“…Bhanja et al [ 42 ] have synthesized p -chlorobenzylidene-malononitrile in high yields (98 %) using ethanol as solvent at room temperature. Therefore, based on its availability, less toxicity and less cost, ethanol was chosen as a solvent to validate and optimize the remaining parameters like the amount of catalyst, malononitrile quantity for the Knoevenagel condensation reaction.…”

Section: Resultsmentioning

confidence: 99%

“…In practical terms, the surface atoms operate as Lewis acid-base centers, allowing chemical reactions to be catalytically activated. The key mechanism for catalyzing the reactions is the incidence of strong Lewis acid and base sites on the catalyst surface and the catalyst's high specific surface area [ 42 ]. The mechanism using the as-synthesized nanocatalyst illustrated in Fig.…”

Section: Resultsmentioning

confidence: 99%

Highly efficient CdS/CeO2/Ag3PO4 nanocomposite as novel heterogenous catalyst for Knoevenagel condensation and acetylation reactions

Zenebe,

Taddesse,

Sivasubramanian

et al. 2024

Heliyon

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“…Although this strategy is helpful, leaching of heteropolyacids from the support is still a challenging issue. Knoevenagel condensation, on the other hand, can be promoted by various catalysts [17][18][19] , such as metal-organic frameworks (MOFs) and chitosan (CS) [20][21][22] . MOFs…”

mentioning

confidence: 99%

Chitosan bead containing metal–organic framework encapsulated heteropolyacid as an efficient catalyst for cascade condensation reaction

Sadjadi

Abedian-Dehaghani

Heydari

et al. 2023

Sci Rep

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Using cyclodextrin and chitosan that are bio-based compounds, a novel bi-functional catalytic composite is designed, in which metal–organic framework encapsulated phosphomolybdic acid was incorporated in a dual chitosan-cyclodextrin nanosponge bead. The composite was characterized via XRD, TGA, ICP, BET, NH3-TPD, FTIR, FE-SEM/EDS, elemental mapping analysis and its catalytic activity was examined in alcohol oxidation and cascade alcohol oxidation–Knoevenagel condensation reaction. It was found that the designed catalyst that possess both acidic feature and redox potential could promote both reactions in aqueous media at 55 °C and various substrates with different electronic features could tolerate the aforementioned reactions to furnish the products in 75–95% yield. Furthermore, the catalyst could be readily recovered and recycled for five runs with slight loss of the catalytic activity. Notably, in this composite the synergism between the components led to high catalytic activity, which was superior to each component. In fact, the amino groups on the chitosan served as catalysts, while cyclodextrin nanosponge mainly acted as a phase transfer agent. Moreover, measurement of phosphomolybdic acid leaching showed that its incorporation in metal–organic framework and bead structure could suppress its leaching, which is considered a drawback for this compound. Other merits of this bi-functional catalyst were its simplicity, use of bio-based compounds and true catalysis, which was proved via hot filtration.

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Ordered mesoporous γ-Al 2 O 3 as highly efficient and recyclable catalyst for the Knoevenagel reaction at room temperature

Cited by 13 publications

References 46 publications

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO₂ Capture and Dye Separation

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO₂ Capture and Dye Separation

Highly efficient CdS/CeO2/Ag3PO4 nanocomposite as novel heterogenous catalyst for Knoevenagel condensation and acetylation reactions

Chitosan bead containing metal–organic framework encapsulated heteropolyacid as an efficient catalyst for cascade condensation reaction

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Ordered mesoporous γ-Al 2 O 3 as highly efficient and recyclable catalyst for the Knoevenagel reaction at room temperature

Cited by 13 publications

References 46 publications

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO2 Capture and Dye Separation

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO2 Capture and Dye Separation

Highly efficient CdS/CeO2/Ag3PO4 nanocomposite as novel heterogenous catalyst for Knoevenagel condensation and acetylation reactions

Chitosan bead containing metal–organic framework encapsulated heteropolyacid as an efficient catalyst for cascade condensation reaction

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Product

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About

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO₂ Capture and Dye Separation

Ordered Mesoporous Alumina with Tunable Morphologies and Pore Sizes for CO₂ Capture and Dye Separation