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  1. Article ; Online: Effect of interlayer anions on the catalytic activity of Mg-Al layered double hydroxides for furfural and acetone aldol condensation reaction

    Said Arhzaf / Jamal Houssaini / Mohammed Naciri Bennani / Marwa Alaqarbeh / Mohammed Bouachrine

    Arabian Journal of Chemistry, Vol 17, Iss 1, Pp 105412- (2024)

    1481  

    Abstract: The aldol condensation reaction between furfural (F) and acetone (A), which typically produces 4-(2-Furyl)-3-buten-2-one (FA), is a critical reaction due to the application of the final product as a flavoring agent in various food items. Traditionally, ... ...

    Abstract The aldol condensation reaction between furfural (F) and acetone (A), which typically produces 4-(2-Furyl)-3-buten-2-one (FA), is a critical reaction due to the application of the final product as a flavoring agent in various food items. Traditionally, this reaction is catalyzed by liquid-based catalysts. However, homogeneous liquid-base catalysis often leads to environmental damage. Solid-base catalysis is highly desirable to address the environmental issue due to liquid-base catalysis as it reduces the need for excessive solvents and reagents, thus preserving the environment. In this study, a series of Mg-Al hydrotalcites (HT) intercalated with nitrate ion (HT-NO3), carbonate ion (HT-CO3), or acetate ion (HT-CH3COO) were prepared using three different coprecipitation procedures. Upon calcination at 450 °C, the solids were transformed into mixed metal oxides. Among the calcined hydrotalcites, the catalysts with acetate anion (cHT-CH3COO) or carbonate anion (cHT-CO3) exhibited the highest basicity and thus showed superior catalytic activity for the aldol condensation reaction. Optimal conversion and selectivity were achieved at 90 °C for 2 h using the most basic catalysts (cHT-CO3 and cHT-CH3COO). These catalysts yielded over 98 % conversion with FA selectivity of 76 % for cHT-CO3 and 65 % for cHT-CH3COO, respectively. Notably, the catalyst cHT-CH3COO exhibited higher selectivity towards F2A (32 %) than the cHT-CO3 catalyst (18 %). The effect of interlayer anions on the structural properties of the Mg-Al hydrotalcites was analyzed using X-ray diffraction. Fourier-transform infrared spectroscopy (FT-IR) was employed to investigate the interactions corresponding to different types of anions. The specific surface area and pore volume of the calcined Mg-Al hydrotalcites were determined using nitrogen adsorption (BET), while their total basicity was evaluated through acid-base titration. The reaction kinetics were monitored using gas chromatography.
    Keywords Mg-Al Hydrotalcite ; Mixed metal oxides ; Aldol condensation ; Furfural ; Acetone ; Chemistry ; QD1-999
    Subject code 540 ; 660
    Language English
    Publishing date 2024-01-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Effect of microwave method on jasminaldehyde synthesis using solvent-free over Mg–Al–NO3 hydrotalcite catalyst

    Jamal Houssaini / Mohammed Naciri Bennani / Said Arhzaf / Hamid Ziyat / Marwa Alaqarbeh

    Arabian Journal of Chemistry, Vol 16, Iss 12, Pp 105316- (2023)

    2023  

    Abstract: Jasminaldehyde is a widely used starting material in the chemical industry. One method for synthesizing jasminaldehyde is through the aldol condensation of benzaldehyde with 1–heptanal, using a heterogeneous catalyst called hydrotalcite Mg–Al–NO3. The ... ...

    Abstract Jasminaldehyde is a widely used starting material in the chemical industry. One method for synthesizing jasminaldehyde is through the aldol condensation of benzaldehyde with 1–heptanal, using a heterogeneous catalyst called hydrotalcite Mg–Al–NO3. The synthesized catalyst was characterized using various techniques, including XRD, FT–IR, TGA, DTA, SEM, EDX, and N2 adsorption–desorption isotherm (BET) to determine its structure, morphology, thermal stability, and properties. This catalyst was tested in the studied reaction under solvent-free conditions, using both microwave and conventional heating methods (in an oil bath) to evaluate the efficiency of each method in producing jasminaldehyde. The results showed that the use of microwave heating in this reaction is particularly advantageous. It allowed for the highest conversion (>99%) of 1–heptanal, with a good selectivity (80%) towards jasminaldehyde, after only 50 min of reaction time. In contrast, conventional heating required a longer reaction time of about 8 h to achieve similar conversion and selectivity values. Furthermore, Mg–Al–NO3 demonstrated nearly sustained activity in three consecutive reuse experiments, and the durability of this catalyst was characterized using several techniques.
    Keywords Microwave ; Conventional Heating ; Aldol–condensation ; Mg–Al–NO3 Catalyst ; Jasminaldehyde ; Chemistry ; QD1-999
    Subject code 660
    Language English
    Publishing date 2023-12-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Solvent-free synthesis of jasminaldehyde over chitosan–layered double hydroxide catalyst assisted by microwave irradiation

    Jamal Houssaini / Mohammed Naciri Bennani / Said Arhzaf / Chadia Mounir / Marwa Alaqarbeh / Hammou Ahlafi / Abdellatif Amhoud

    Arabian Journal of Chemistry, Vol 16, Iss 12, Pp 105326- (2023)

    2023  

    Abstract: This research paper reports on the use of chitosan-modified layered double hydroxide (LDH) composite catalysts (CS/MgAl–NO3) for the synthesis of jasminaldehyde under microwave irradiation. The catalysts were prepared by co-precipitation in an inert ... ...

    Abstract This research paper reports on the use of chitosan-modified layered double hydroxide (LDH) composite catalysts (CS/MgAl–NO3) for the synthesis of jasminaldehyde under microwave irradiation. The catalysts were prepared by co-precipitation in an inert nitrogen atmosphere. The resulting samples were characterized by mean of X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric/differential thermal analysis (TGA/DTA), scanning electron microscope (SEM) with energy-dispersive X–ray (EDX), and N2 adsorption/desorption isotherm (BET) analysis. The basicity of each catalyst was determined by the acid-base titration method. The performance of the catalysts was evaluated in the solvent-free synthesis of jasminaldehyde from aldol by condensation reaction between benzaldehyde and 1–heptanal in a microwave oven at P = 100 W and T = 90 °C. The effects of different parameters that are involved in the reaction, such as the catalyst amount and the benzaldehyde to 1–heptanal molar ratio, and reaction temperature, are investigated in detail. The results showed that the CS-functionalization of the catalyst leads to the enhancement of its basic sites making it more efficient than the naked MgAl–NO3 catalyst, in terms of the initial reaction rate, the conversion of the reactants and the selectivity toward the jasminaldehyde. The CS/MgAl–NO3 catalyst was also evaluated in successive regeneration reaction cycles.
    Keywords Chitosan ; Layered double hydroxide ; Microwave irradiation ; Catalytic activity ; Aldol condensation ; Jasminaldehyde ; Chemistry ; QD1-999
    Subject code 540
    Language English
    Publishing date 2023-12-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Study of the Catalytic Activity of the Compounds Hydrotalcite Type Treated by Microwave in the Self-Condensation of Acetone

    Jamal Houssaini / Mohammed Naciri Bennani / Hamid Ziyat / Said Arhzaf / O. Qabaqous / Abdellatid Amhoud

    International Journal of Analytical Chemistry, Vol

    2021  Volume 2021

    Abstract: The self-condensation reaction of acetone, producing diacetone alcohol (DAA), is of great industrial importance. It was used to study the catalytic activity of Mg-Al catalysts synthesized by the coprecipitation method. For this purpose, we synthesized Mg- ...

    Abstract The self-condensation reaction of acetone, producing diacetone alcohol (DAA), is of great industrial importance. It was used to study the catalytic activity of Mg-Al catalysts synthesized by the coprecipitation method. For this purpose, we synthesized Mg-Al based hydrotalcite with a molar ratio of 3, obtained either after conventional heating or after microwave irradiation with of 100 W for three minutes. Structural and chemical properties of the obtained catalysts were characterized, using different techniques: X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), equipped with energy dispersive X-ray (EDX), and specific surface area of the catalysts were determined by the methylene blue (MB) adsorption method. Also, these catalysts were tested in the self-condensation reaction of acetone at 273 K in the liquid phase without solvent, a reaction which requires very high catalytic activity. The microwave treatment improves the catalyst activity, and the conversion of acetone to diacetone alcohol increases from 13.2 to 18.3% after 8 h of reaction. Moreover, the microwave-treated hydrotalcite catalyst, calcined at 723 K and rehydrated under a flow of N2, is the most active and gives conversion of acetone of 52% under the same reaction conditions.
    Keywords Analytical chemistry ; QD71-142
    Subject code 660 ; 540
    Language English
    Publishing date 2021-01-01T00:00:00Z
    Publisher Hindawi Limited
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article ; Online: Adsorption of Thymol onto Natural Clays of Morocco

    Hamid Ziyat / Mohammed Naciri Bennani / Hassan Hajjaj / Omar Qabaqous / Said Arhzaf / Soumiya Mekdad / Safae Allaoui

    Journal of Chemistry, Vol

    Kinetic and Isotherm Studies

    2020  Volume 2020

    Abstract: The present work aims to study the affinity of a component of the thyme essential oil “thymol” to natural Moroccan clay “Rhassoul” using the adsorption technique. The physicochemical characterizations of the purified and modified clay were carried out by ...

    Abstract The present work aims to study the affinity of a component of the thyme essential oil “thymol” to natural Moroccan clay “Rhassoul” using the adsorption technique. The physicochemical characterizations of the purified and modified clay were carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DTA/TGA, and SEM-EDX. Thymol adsorption tests on the purified Rhassoul (Rh-P) and the modified one by CTAB (Rh-CTAB) were followed by UV-visible spectroscopy. They show that the adsorption isotherms can be described by the Freundlich model and that the kinetics of adsorption is in accordance with the pseudo-second-order model for the two clays. Adsorption capacities obtained were of the order of 6 mg/g for the purified Rhassoul and 16 mg/g for the modified Rhassoul by cetyltrimethylammonium bromide (CTAB). These values show that the modified Rhassoul has a better adsorption capacity compared to the purified Rhassoul.
    Keywords Chemistry ; QD1-999
    Subject code 660
    Language English
    Publishing date 2020-01-01T00:00:00Z
    Publisher Hindawi Limited
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

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    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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