scholarly journals Alkaline Ionic Liquid Modified Pd/C Catalyst as an Efficient Catalyst for Oxidation of 5-Hydroxymethylfurfural

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Zou Bin ◽  
Chen Xueshan ◽  
Xia Jiaojiao ◽  
Zhou Cunshan
Keyword(s):  
Ionic Liquid ◽  
Polar Compounds ◽  
Temperature Reaction ◽  
Green Process ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Ft Ir ◽  
Redox Stability ◽  
Hydrophilicity And Hydrophobicity ◽  
Optimal Reaction

Conversion of HMF into FDCA was carried out by a simple and green process based on alkaline ionic liquid (IL) modified Pd/C catalyst (Pd/C-OH−). Alkaline ionic liquids were chosen to optimize Pd/C catalyst for special hydrophilicity and hydrophobicity, redox stability, and unique dissolving abilities for polar compounds. The Pd/C-OH− catalyst was successfully prepared and characterized by SEM, XRD, TG, FT-IR, and CO2-TPD technologies. Loading of alkaline ionic liquid on the surface of Pd/C was 2.54 mmol·g−1. The catalyst showed excellent catalytic activity in the HMF oxidation after optimization of reaction temperature, reaction time, catalyst amount, and solvent. Supported alkaline ionic liquid (IL) could be a substitute and promotion for homogeneous base (NaOH). Under optimal reaction conditions, high HMF conversion of 100% and FDCA yield of 82.39% were achieved over Pd/C-OH− catalyst in water at 373 K for 24 h.

scholarly journals Tuned Bis-Layered Supported Ionic Liquid Catalyst (SILCA) for Competitive Activity in the Heck Reaction of Iodobenzene and Butyl Acrylate

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 963
Author(s):  
Nemanja Vucetic ◽  
Pasi Virtanen ◽  
Ayat Nuri ◽  
Andrey Shchukarev ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Heck Reaction ◽  
Pd Nanoparticles ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Catalyst Synthesis ◽  
Supported Ionic Liquid ◽  
Ft Ir ◽  
The Stability ◽  
Eventual Loss

A thorough experimental optimization of supported ionic liquid catalyst (SILCA) was performed in order to obtain a stable and efficient catalyst for the Heck reaction. Out of fifteen proposed structures, propyl imidazolium bromide-tetramethylguanidinium pentanoate modified SiO2 loaded with PdCl2 appeared to be the most stable and to have a good activity in the reaction between butylacrylate and iodobezene, resulting in a complete conversion in 40 min at 100 °C, in four consecutive experiments. This study elucidated on the stability of the catalytic system with an ionic liquid layer during the catalyst synthesis but also under reaction conditions. In the bis-layered catalyst, the imidazolium moiety as a part of internal layer, brought rigidity to the structure, while in external layer pentanoic acid gave sufficiently acidic carboxylic group capable to coordinate 1,1,3,3-tetramethylguanidine (TMG) and thus, allow good dispersion of Pd nanoparticles. The catalyst was characterized by means of XPS, FT-IR, TEM, ICP-OES, ζ-potential, EDX, TGA, and 13C NMR. The release and catch mechanism was observed, whereas Pd re-deposition can be hindered by catalyst poisoning and eventual loss of palladium.

Lipase-Catalyzed Acyl-L-Carnitines Synthesis in [Bmim]PF6 Ionic Liquid

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Jin-qiang Tian ◽  
Qiang Wang ◽  
Zhong-yuan Zhang
Keyword(s):  
Ionic Liquid ◽  
Lipase Activity ◽  
Molecular Sieves ◽  
Reaction Medium ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimal Reaction ◽  
Better Than

In order to significantly improve the biosynthesis of acyl-L-carnitines catalyzed by lipase, there must be an efficient and suitable reaction medium that is not only polar but also hydrophobic. [Bmim]PF6, which satisfies the above two requirements, was applied as the medium. The optimal reaction conditions were: for isovaleryl-L-carnitine, 0.22aW, 200mg molecular sieves, 60ºC, 4:1 of molar ratio (fatty acid:L-carnitine), 150rpm and 60h; for octanoyl-L-carnitine and palmitoyl-L-carnitine, 0.22aW, 250 mg molecular sieves, 5:1 of molar ratio (fatty acid:L-carnitine), 200rpm, 48h, 60ºC (octanoyl-L-carnitine) and 65ºC (palmitoyl-L-carnitine). Their overall yields could reach 59.14%, 90.79% and 98.03%, respectively. The yields of isovaleryl-L-carnitine, octanoyl-L-carnitine and palmitoyl-L-carnitine in [Bmim]PF6 were 16.21%, 73.67% and 44.22 % more than those in acetonitrile, respectively. [Bmim]PF6 as the medium was better than acetonitrile. It could not only enhance the yields of acyl-L-carnitines, but also protect the lipase activity.

Study on Catalytic Oxidatio Benzaldehyde to Benzoic Acid with Keggin Polyoxometalate [(CH2)5NH2]4SiW12O40

2012 ◽  
Vol 161 ◽  
pp. 185-189 ◽  
Author(s):  
Yuan Sheng Ding ◽  
Fei Lu ◽  
Xin Bao Han
Keyword(s):  
Benzoic Acid ◽  
Organic Ligand ◽  
Sodium Molybdate ◽  
Catalytic Performance ◽  
Reaction Conditions ◽  
Composition And Structure ◽  
The Matrix ◽  
Ft Ir ◽  
Keggin Polyoxometalate ◽  
Optimal Reaction

The organic–inorganic hybrid catalyst [(CH2)5NH2]4SiW12O40 was prepared by matrix acid and piperidine. The matrix acid was synthesized by sodium molybdate and sodium silicate, and the piperidine was organic ligand. The proposed composition and structure of the catalyst were evidenced by XPS, FT-IR, XRD, TG-DTA and elemental analysis. The results indicated that the heteropoly anions still reserved their Keggin structure in the compound. Its catalytic performance was evaluated in the oxidation of benzaldehyde to benzoic acid. Various reaction parameters were changed to attain the optimal conditions. The optimal reaction conditions were found to be: n(catalyst): n(benzaldehyde)=3.1×10-3:1; n(H2O2)： n(benzaldehyde)=4.5：1; reaction temperature was 80°C; reaction time was 4h. The yield of benzoic acid achieved above 85%.

scholarly journals In situ Generated Ru(0)-HRO@Na-β From Hydrous Ruthenium Oxide (HRO)/Na-β: An Energy-Efficient Catalyst for Selective Hydrogenation of Sugars

2020 ◽  
Vol 8 ◽  
Author(s):  
Sreedhar Gundekari ◽  
Heena Desai ◽  
Krishnan Ravi ◽  
Joyee Mitra ◽  
Kannan Srinivasan
Keyword(s):  
Aqueous Medium ◽  
Reaction Temperature ◽  
Energy Efficient ◽  
Ruthenium Oxide ◽  
Green Process ◽  
Sugar Alcohols ◽  
Reaction Conditions ◽  
Efficient Catalyst ◽  
Hydrogenation Reactions

A green process for the hydrogenation of sugars to sugar alcohols was designed in aqueous medium using hydrous ruthenium oxide (HRO) as a pre-catalyst supported on Na-β zeolite. Under optimized reaction conditions, sugars such as xylose, glucose, and mannose converted completely to the corresponding sugar alcohols xylitol, sorbitol, and mannitol with 100% selectivity. The pre-catalyst (HRO) is converted in situ to active Ru(0) species during the reaction under H2, which is responsible for the hydrogenation. The catalyst was recyclable up to five cycles with no loss in activity. The reduction of HRO to the active Ru(0) species is dependent on the reaction temperature and H2 pressure. Ru(0) formation increased and consequently an increased hydrogenation of sugars was observed with an increase in reaction temperature and hydrogen pressure. Further, in situ generation of Ru(0) from HRO was assessed in different solvents such as water, methanol, and tetrahydrofuran; aqueous medium was found to be the most efficient in reducing HRO. This work further demonstrates the use of supported HRO as an efficient pre-catalyst for biomass-based hydrogenation reactions.

scholarly journals A Green Synthesis of Polylimonene Using Maghnite-H+, an Exchanged Montmorillonite Clay, as Eco-Catalyst

2019 ◽  
Vol 14 (1) ◽  
pp. 69 ◽  
Author(s):  
Hodhaifa Derdar ◽  
Mohammed Belbachir ◽  
Amine Harrane
Keyword(s):  
Reaction Time ◽  
Green Synthesis ◽  
Exchange Process ◽  
Gel Permeation Chromatography ◽  
Bulk Polymerization ◽  
Montmorillonite Clay ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Ft Ir ◽  
Optimal Reaction

A new green polymerization technique to synthesis polylimonene (PLM) is carried out in this work. This technique consists of using Maghnite-H+ as eco-catalyst to replace Friedel-Crafts catalysts which are toxics. Maghnite-H+ is a montmorillonite silicate sheet clay which is prepared through a simple exchange process. Polymerization experiments are performed in bulk and in solution using CH2Cl2 as solvent. Effect of reaction time, temperature and amount of catalyst is studied, in order to find the optimal reaction conditions. The polymerization in solution leads to the best yield (48.5%) at -5°C for a reaction time of 6 h but the bulk polymerization, that is performed at 25°C, remains preferred even if the yield is lower (40.3%) in order to respect the principles of a green chemistry which recommend syntheses under mild conditions, without solvents and at room temperature. The structure of the obtained polymer (PLM) is confirmed by FT-IR and Nuclear Magnetic Resonance of proton (1H-NMR). The glass transition temperature (Tg) of the polylimonene is defined using Differential Scanning Calorimetry (DSC) and is between 113°C and 116°C. The molecular weight of the obtained polymer is determined by Gel Permeation Chromatography (GPC) analysis and is about 1360 g/mol. Copyright © 2019 BCREC Group. All rights reservedReceived: 26th May 2018; Revised: 11st September 2018; Accepted: 22nd September 2018; Available online: 25th January 2019; Published regularly: April 2019How to Cite: Derdar, H., Belbachir, M., Harrane, A. (2019). A Green Synthesis of Polylimonene Using Maghnite-H+, an Exchanged Montmorillonite Clay, as Eco-Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 14 (1): 69-78 (doi:10.9767/bcrec.14.1.2692.69-78)Permalink/DOI: https://doi.org/10.9767/bcrec.14.1.2692.69-78 

scholarly journals Effective Depolymerization of Sodium Lignosulfonate over SO42−/TiO2 Catalyst

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 995
Author(s):  
Chengguo Mei ◽  
Chengjuan Hu ◽  
Qixiang Hu ◽  
Chang Sun ◽  
Liang Li ◽  
...  
Keyword(s):  
Calorific Value ◽  
Solvent Ratio ◽  
Sodium Lignosulfonate ◽  
Reaction Conditions ◽  
Tio2 Catalyst ◽  
Bio Oil ◽  
Ft Ir ◽  
Catalyst Dosage ◽  
Temperature Time ◽  
Optimal Reaction

In this paper, liquefaction of sodium lignosulfonate (SL) over SO42−/TiO2 catalyst in methanol/glycerol was investigated. Effects of temperature, time, the ratio of methanol to glycerol and catalyst dosage were also studied. It was indicated that optimal reaction condition (the temperature of 160 °C, the time of 1 h, solvent ratio (methanol/glycerol) of 2:1, catalyst dosage of 5 wt % (based on lignin input)) was obtained after sets of experiments. The maximum yields of liquefaction (89.8%) and bio-oil (86.8%) were gained under the optimal reaction conditions. Bio-oil was analyzed by elemental analysis, FT-IR and gas chromatogram and mass spectrometry (GC/MS). It was shown that the functional groups of bio-oil were enriched and calorific value of bio-oil was increased. Finally, it can be seen from GC/MS analysis that the type of products included alcohols, ethers, phenols, ketones, esters and acids. Phenolic compounds mainly consisted of G (guaiacyl)-type phenols.

FeCl3•6H2O Catalysed Condensation of Aldehydes and Ketones in Ionic Liquid: A Novel Green Synthesis of Chalcones

2003 ◽  
Vol 2003 (1) ◽  
pp. 33-35 ◽  
Author(s):  
Xinying Zhang ◽  
Hongying Niu ◽  
Jianji Wang
Keyword(s):  
Ionic Liquid ◽  
Green Synthesis ◽  
Green Process ◽  
Reaction Conditions ◽  
Chloride Hexahydrate ◽  
Aldehydes And Ketones ◽  
First Time

Using iron(III) chloride hexahydrate as a catalyst, chalcones were efficiently prepared from acetophenone and benzaldehyde in ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) for the first time. Compared with the known methods, this novel access to chalcones has the advantage of being a green process together with good yields and mild reaction conditions.

scholarly journals PREPARATION OF [AcMI] HSO4 AND USING AS CATALYST FOR ESTERIFICATION

2011 ◽  
Vol 14 (4) ◽  
pp. 61-73
Author(s):  
Thu Ngoc Ha Le ◽  
Thach Ngoc Le
Keyword(s):  
Ionic Liquid ◽  
Chloroacetic Acid ◽  
Molar Ratio ◽  
Hydrogen Sulfate ◽  
Reaction Conditions ◽  
Brønsted Acidic Ionic Liquid ◽  
Acidic Sites ◽  
Concentrated Sulfuric Acid ◽  
Zwitter Ion ◽  
Optimal Reaction

New Bronsted acidic ionic liquid, 1-carboxymethyl-3-methylimidazolium hydrogen sulfate [AcMI]HSO4, has two acidic sites -COOH and HSO4 -. It has been synthesized by three steps. First, 1-carboxymethyl-3-methylimidazolium chloride [AcMI]Cl was prepared by alkylation of 1- methylimidazole with chloroacetic acid (molar ratio is 1.5:1) under microwave irradiation in 6 min (84 % isolated yield). Then, zwitter ion 1-carboxylatmethyl-3-methylimidazolium was obtained by using Ag2O to remove ion chloride Cl- from [AcMI]Cl. At last, concentrated sulfuric acid (98 %) was added into zwitter ion to give 1-carboxymethyl-3-methylimidazolium hydrogen sulfate (yield 96 %). This ionic liquid used as a recyclabe catalyst for the esterification of isopropanol and chloroacetic acid. The optimal reaction conditions were obtained as follows: isopropanol: chloroacetic acid:[AcMI]HSO4 are 1.3:1:0.2, reaction time for 10 min at 60 oC under microvave irradiation. The yield of isopropyl chloroacetate was 86 %. This ionic liquid was removed from ester easily, recovered and recycled without loss of activity.

Preparation and Characterization of PA6-PEG/Li High Performance Static Dissipation Composites

2017 ◽  
Vol 70 (6) ◽  
pp. 669
Author(s):  
Chongling Yang ◽  
Shouzai Tan ◽  
Gengen Chen ◽  
Litao Guan
Keyword(s):  
High Performance ◽  
Condensation Reaction ◽  
Polyamide 6 ◽  
Decomposition Temperature ◽  
Reaction Conditions ◽  
Comprehensive Properties ◽  
Ft Ir ◽  
Optimal Reaction ◽  
Resistivity Testing

A copolymer of PA6 (polyamide 6) and PEG (polyethylene glycol) was synthesized by a condensation reaction. The optimal reaction conditions were determined as the following: a reaction temperature of 255°C, –0.04 MPa vacuum, and a condensation time of 40 min. A series of novel PA6-PEG/Li composites were developed by melt blending the PA6-PEG copolymer (10 wt-% PEG) with three different kinds of colourless lithium salts (LiCl, C18H35LiO2, LiAc). FT-IR, NMR, thermogravimetric (TGA), electronic universal testing, and resistivity analyses were employed to investigate the comprehensive properties of the copolymers and composites. The results of FT-IR and 1H NMR analyses revealed that the PEG was copolymerized with PA6 successfully. TGA results indicated that the decomposition temperature of the PA6-PEG copolymer was above 350°C. Resistivity testing revealed that the surface resistivity (Rs) of the copolymer decreased from 1 × 1014 to 5.67 × 109 Ω square–1 with an increase of the content of PEG. The PA6-PEG/LiCl composite showed an excellent static dissipation performance of 2.71 × 108 Ω square–1.

Alkylation of Phenol with Cyclohexanol Catalyzed by Acidic Ionic Liquid

2011 ◽  
Vol 233-235 ◽  
pp. 188-193 ◽  
Author(s):  
Hai Bing Yu ◽  
Jun Nan ◽  
Jing Cheng Zhang ◽  
Jian Zhou Gui
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Reactant Ratio ◽  
Temperature Reaction ◽  
Reaction Conditions ◽  
Acidic Ionic Liquid ◽  
Optimum Reaction

Alkylation of phenol with cyclohexanol catalyzed by acidic ionic liquid has been investigated. The influences of reaction temperature, reaction time, reactant ratio (mol ratio of phenol to cyclohexanol), the amount and the recycle of ionic liquid on catalytic activity were studied. The conversion of phenol and the selectivity of paracyclohexylphenol were 75.5% and 61.6%, respectively, under optimum reaction conditions. The ionic liquid was utilized repeatedly over three times without remarkable loss of catalytic activity．

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