Synthesis and characterization of functionalized NaP Zeolite@CoFe2O4 hybrid materials: a micro–meso-structure catalyst for aldol condensation

Mortezaei, Zohreh; Zendehdel, Mojgan; Bodaghifard, Mohammad Ali

doi:10.1007/s11164-020-04085-z

Cited by 19 publications

(4 citation statements)

References 62 publications

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“…Meanwhile, there are numerous publications reporting higher yields for the di-condensation product (2,6-DBCHO). Thus, an activated fly ash catalyst [37] generated 56% yield; a ground solid NaOH led to a 2,6-DBCHO yield of over 96% [38]; NaP Zeolite/CoFe 2 O 4 /Am-Py (1:4) catalyst in free solvent condition [39] yielded 92% 2,6-DBCHO; using quaternary ammonium surfactants with n-hexadecyl group micellar system (C 16 QAS) as catalyst [40] produced a yield of 73.8% for 2,6-DBCHO; and SOCl 2 , in anhydrous ethanol (SOCl 2 /EtOH) [41] yielded more than 92%. A common feature of all the above-mentioned catalysts is the fact that they have base sites that contribute to the activation of reagent molecules.…”

Section: Introductionmentioning

confidence: 99%

An Advanced Approach for MgZnAl-LDH Catalysts Synthesis Used in Claisen-Schmidt Condensation

et al. 2022

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Using organic-base tetramethylammonium hydroxide (TMAH) is a viable, cheap, and fast option for the synthesis of MgZnAl-LDH-type materials by both co-precipitation and mechano-chemical methods. TMAH presents several advantages, such as the smaller quantity of water required in the washing step compared to the use of inorganic alkalis, the prevention of LDH contamination with alkali cations, and its action as a template molecule in texture tailoring. It also has disadvantages, such as its presence in small quantities in the resulting layered materials. Regardless of the use of organic/inorganic bases and co-precipitation/mechano-chemical methods, zincite stable phase was found in all the synthesized solids. The basicity of catalysts followed the trend: mixed oxides > reconstructed > parent LDH. The memory effect of LDH was supported only by the presence of Mg and Al cations, while Zn remained as a zincite stable phase. The catalytic activities for Claisen–Schmidt condensation of benzaldehyde with cyclohexanone provided values higher than 90% after 2 h, with a total selectivity toward 2,6-dibenzylidenecyclohexanone, while self-condensation of cyclohexanone yielded no more than 7.29% after 5 h. These behaviors depended on catalyst basicity as well as on the planar rigidity of the compound.

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Section: Introductionmentioning

confidence: 99%

An Advanced Approach for MgZnAl-LDH Catalysts Synthesis Used in Claisen-Schmidt Condensation

et al. 2022

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“…In the first step, a zeolite gel was prepared with molar composition 16 Na 2 O: Al 2 O 3 : 15 SiO 2 : 320 H 2 O, and after the aging time (5 days) based on before work [24]. Different amounts of TiO 2 (0.12, 0.24, 0.36, 0.48 g) were added to the zeolite gel.…”

Section: Synthesis and Characterization Of Nap Zeolite@ Tio 2 Nanocom...mentioning

confidence: 99%

Micro-meso structure NaP zeolite @TiO2 nanocomposite: eco-friendly photocatalyst for simultaneous removal COD and degradation of methylene blue under solar irradiation

Zendehdel

Cruciani

Barghi

2022

Photochem Photobiol Sci

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A low-cost NaP zeolite@TiO 2 nanocomposite catalyst with zeolite Si/Al ratio lower than three were synthesized for the first time under hydrothermal condition. The nanocomposites were characterized by different methods such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), N 2 physisorption, NH 3 temperature-programmed desorption (NH 3 -TPD), fluorescence microscopy, thermal analysis (TGA/DTA) and zeta potential analysis. The results showed that a micro-meso structure NaP zeolite with higher surface area and acidity with respect to pure zeolite was prepared. TiO 2 nanoparticle was dispersed over the whole of zeolite without aggregation. A reduction of the TiO 2 bandgap nanoparticle was observed from DRS spectra. The photocatalytic activity of low-cost NaP zeolite@TiO 2 nanocomposite was tested for simultaneous methylene blue dye (MB) and chemical oxygen demand (COD) under solar and ultraviolet light. The result showed that the nanocomposite catalyst has great potential (above 90%) for COD removal discolouring of MB (about 99.6%) at room temperature. The optimum amount of some parameters such as the loaded amount of TiO 2 (0.36 g), catalyst dosage (0.1 g), time (2 h), initial dye concentration (100 mg/L), solution pH value (about 7) under solar light were considered. In addition, present negative charge in the surface that show in zeta potential confirm the high activity of catalyst to interaction with cationic dye. As a further advantage, the NaP zeolite@TiO 2 nanocomposite was easier to be separated in aqueous media than the pure TiO 2 powders, making possible the reuse several times (over five runs) without using oxidant. Finally, the NaP zeolite@TiO 2 nanocomposite was used for COD abatement in wastewater from two real industrial streams. The MB degradation kinetics were fitted by a pseudo-first-order model with K = 0.534 h −1 .

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“…Specifically, Claisen–Schmidt condensation [ 37 , 38 ] is dedicated to the formation of new C–C bonds. The condensation of cyclohexanone and benzaldehyde to mono -, 2-benzylidene-cyclohexanone, or di -condensation, 2,6-dibenzylidene-cyclohexanone, is also an important subject [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ]. However, the Claisen–Schmidt condensation has some limitations due to the possibility of the appearance of side reactions, such as self-condensation, as an effect of the additional presence of the acid sites.…”

Section: Introductionmentioning

confidence: 99%

New MgFeAl-LDH Catalysts for Claisen–Schmidt Condensation

et al. 2022

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A rapid, cheap and feasible new approach was used to synthesize the Mg0.375Fe0.375Al0.25-LDH in the presence of tetramethylammonium hydroxide (TMAH), as a nontraditional hydrolysis agent, applying both mechano-chemical (MC) and co-precipitation methods (CP). For comparison, these catalysts were also synthesized using traditional inorganic alkalis. The mechano-chemical method brings several advantages since the number of steps and the energy involved are smaller than in the co-precipitation method, while the use of organic alkalis eliminates the possibility of contaminating the final solid with alkaline cations. The memory effect was also investigated. XRD studies showed Fe3O4 as stable phase in all solids. Regardless of the alkalis and synthesis methods used, the basicity of catalysts followed the trend: mixed oxides > parent LDH > hydrated LDH. The catalytic activity of the catalysts in the Claisen–Schmidt condensation between benzaldehyde and cyclohexanone showed a linear dependence to the basicity values. After 2 h, the calcined sample cLDH-CO32−/OH−-CP provided a conversion value of 93% with a total selectivity toward 2,6-dibenzylidenecyclohexanone. The presence of these catalysts in the reaction media inhibited the oxidation of benzaldehyde to benzoic acid. Meanwhile, for the self-condensation of cyclohexanone, the conversions to mono- and di-condensed compounds did not exceed 3.8%.

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Synthesis and characterization of functionalized NaP Zeolite@CoFe2O4 hybrid materials: a micro–meso-structure catalyst for aldol condensation

Cited by 19 publications

References 62 publications

An Advanced Approach for MgZnAl-LDH Catalysts Synthesis Used in Claisen-Schmidt Condensation

An Advanced Approach for MgZnAl-LDH Catalysts Synthesis Used in Claisen-Schmidt Condensation

Micro-meso structure NaP zeolite @TiO2 nanocomposite: eco-friendly photocatalyst for simultaneous removal COD and degradation of methylene blue under solar irradiation

New MgFeAl-LDH Catalysts for Claisen–Schmidt Condensation

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