New basic catalysts obtained from layered double hydroxides nanocomposites

Chebout, Redouane; Tichit, Didier; Layrac, Géraldine; Barama, Akila; Coq, Bernard; Cota, Iuliana; Ramírez, Eliana; Medina, Francisco

doi:10.1016/j.solidstatesciences.2009.11.007

Cited by 22 publications

(25 citation statements)

References 22 publications

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“…In these samples, the lattice parameter a differs largely from those stated for the Mg,Al-LDHs as the presence of the larger calcium cations, if compared to the magnesium counterparts, in the main layer of the LDHs result in increased distances between neighbouring atoms in the brucite-like layers [20,22]. For the Ca,Al-LDHs samples, a values of 5.73 Å (CA-MnO4) and 5.75 Å (CA-S2O8) were observed, which were in very good agreement with the values reported in the literature [20,[26][27][28][29][30][31][32].…”

Section: Powder X-ray Diffractionsupporting

confidence: 89%

“…Data from the literature regarding MgAl-LDHs confirm that the well-formed hydrotalcite-like structure can already be formed with aging times of one day or less [18,25,26]. The synthesis of hydrocalumite-like materials using co-precipitation is usually carried out at higher temperatures [27,28]. In this study, as the aging of the samples was carried out at room temperature to avoid the formation of undesired side products, a longer aging time was selected.…”

Section: Preparation Of Samplesmentioning

confidence: 99%

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Layered Double Hydroxides with Intercalated Permanganate and Peroxydisulphate Anions for Oxidative Removal of Chlorinated Organic Solvents Contaminated Water

et al. 2020

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The contamination by chlorinated organic solvents is a worldwide problem as they can deeply penetrate aquifers, accumulating in the sub-surface as lenses of highly hazardous pollutants. In recent years, so called in situ oxidation processes have been developed to remediate chlorinated organic solvents from groundwater and soil by injecting solutions of oxidising agents such as permanganate or peroxydisulphate. We here present modified layered double hydroxides (LDHs) with intercalated oxidising agents that might serve as new reactants for these remediation strategies. LDHs might serve as support and stabiliser materials for selected oxidising agents during injection, as the uncontrolled reaction and consumption might be inhibited, and guarantee that the selected oxidants persist in the subsurface after injection. In this study, LDHs with hydrotalcite- and hydrocalumite-like structures intercalated with permanganate and peroxydisulphate anions were synthesised and their efficiency was tested in batch experiments using trichloroethene or 1,1,2-trichloroethane as the target contaminants. All samples were characterised using powder X-ray diffraction, thermal analysis coupled with mass spectrometry to directly analyse evolving gases, and Fourier-transform infrared spectroscopy. Additionally, particle size distribution measurements were carried out on the synthesised materials. Results of the batch experiments confirmed the hypothesis that oxidising agents keep their properties after intercalation. Permanganate intercalated LDHs proved to be most efficient at degrading trichloroethene while peroxydisulphate intercalated Ca,Al-LDHs were the most promising studied reactants degrading 1,1,2-trichloroethane. The detection of dichloroethene as well as the transformation of the studied reactants into new LDH phases confirmed the successful degradation of the target contaminant by oxidation processes generated from the intercalated oxidising agent.

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Section: Powder X-ray Diffractionsupporting

confidence: 89%

Section: Preparation Of Samplesmentioning

confidence: 99%

Layered Double Hydroxides with Intercalated Permanganate and Peroxydisulphate Anions for Oxidative Removal of Chlorinated Organic Solvents Contaminated Water

et al. 2020

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“…After completing the addition, the samples were aged in the parent solution for 1 day (Mg,Al-LDH) or six days (Ca,Al-LDHs) at room temperature under constant magnetic stirring. Based on the literature [32][33][34][35][36] and our previous results about the synthesis of the materials studied here [8,14,[37][38][39], different aging times were selected to optimize the procedure. The literature confirms the successful synthesis of rather well-formed hydrotalcite-like structures using aging times shorter than 24 h [8,32,33].…”

Section: Preparation Of Samplesmentioning

confidence: 99%

Fluorescing Layered Double Hydroxides as Tracer Materials for Particle Injection during Subsurface Water Remediation

et al. 2020

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Nowadays, the contamination of groundwater and soils by highly hazardous and toxic chlorinated solvents is a global issue. Over the past years, different remediation strategies have been developed, involving injection of reactive solutions and/or particles. However, a major difficulty is the monitoring of injected particles during the injection and after secondary mobilisation by groundwater flow. This study is focussed on the development of directly traceable particles by combining fluorescein with Layered Double Hydroxides (LDHs). We present here the facile and easily tuneable synthesis of fluorescing LDHs (Fluo-LDH) via co-precipitation under supersaturation conditions. Their ability to mimic particle sizes of previously studied reactive LDHs, which proved to be able to adsorb or degrade chlorinated organic solvents from aqueous solutions, was investigated as well. Tests using a novel Optical Image Profiler (OIP) confirmed that the fluorescent LDHs can be easily detected with this tool. Even LDHs with the lowest amount of fluorescent dye were detectable. Together with the use of an OIP, which is capable of exciting the fluorescent material and collecting real-time pictures, this can provide a new, efficient, and cost-effective method for in situ tracing of injected particles in the subsurface.

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“…As it has been reportedt hat homogeneous bases can catalyze the cyclization of 2'-aminochalcones, heterogeneous basic catalysts such as MgO and Al/Mg mixed oxides [33,34] werea lso tested as they showed high activity for performing the intramolecular Michael addition of 2'-hydroxychalcones into flavanones. [35,36] We have also studied the aza-Michaelc yclization of trans-2'-aminochalcone by using aM gO sample with Lewis basic sites and high surface area (660 m 2 g À1 ).…”

Section: Catalysis By Solid Basesmentioning

confidence: 99%

Use of Mesoporous Molecular Sieves in the Production of Fine Chemicals: Preparation of Dihydroquinolinones of Pharmaceutical Interest From 2′‐Aminochalcones

et al. 2016

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Product desorption has been controlled by optimizing catalyst pore structure and surface composition, together with a proper selection of solvent and reaction temperature.Process intensification for the synthesis of aryl-2,3-4(1H)-quinolinones of pharmaceutical interest has been achieved by preparing catalysts that allow the one pot synthesis of the dihydroquinolinones starting from 2'-nitrochalcones with excellent yields.

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New basic catalysts obtained from layered double hydroxides nanocomposites

Cited by 22 publications

References 22 publications

Layered Double Hydroxides with Intercalated Permanganate and Peroxydisulphate Anions for Oxidative Removal of Chlorinated Organic Solvents Contaminated Water

Layered Double Hydroxides with Intercalated Permanganate and Peroxydisulphate Anions for Oxidative Removal of Chlorinated Organic Solvents Contaminated Water

Fluorescing Layered Double Hydroxides as Tracer Materials for Particle Injection during Subsurface Water Remediation

Use of Mesoporous Molecular Sieves in the Production of Fine Chemicals: Preparation of Dihydroquinolinones of Pharmaceutical Interest From 2′‐Aminochalcones

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