Synthesis and Application of Silver and Cobalt Nanoparticles Immobilized on Ionic Liquid-Functionalized Halloysite Nanotubes in the Reduction of 4-Nitrophenol in Aqueous Solution

NANO ◽  
2021 ◽  
pp. 2150089
Author(s):  
Khadijeh Yavari ◽  
Bagher Eftekhari-Sis ◽  
Ali Akbari
Keyword(s):  
Catalytic Activity ◽  
Catalytic Reduction ◽  
Human Life ◽  
Halloysite Nanotubes ◽  
Significant Loss ◽  
Point Of View ◽  
Molar Ratios ◽  
Toxic Pollutant ◽  
Ft Ir ◽  
Co Nanoparticles

4-nitrophenol (4-NP) is a highly toxic pollutant for aquatic ecosystem and human life. Therefore, the catalytic reduction of 4-NP into useful 4-aminophenol (4-AP) is of interest. In this regard, two heterogeneous nanocatalysts, including Ag@HNTs-ILs and Co@HNTs-ILs were prepared by grafting imidazolium-based ionic liquids (ILs) onto the halloysite nanotubes (HNTs), followed by immobilization of Ag and Co nanoparticles (NPs), and characterized by means of FT-IR, SEM, EDX, TEM and XRD. The catalytic activity of the prepared nanocatalysts was evaluated for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) under environmentally friendly condition. A set of time, temperature, nanocatalyst amount and NaBH4/4-NP molar ratios was screened. The reusability experiments demonstrated that Ag@HNTs-ILs and Co@HNTs-ILs were highly reusable, up to five reduction cycles without considerable changes in the reaction time. As the synthesized hybrid nanocatalysts could be re-collected and reused for various catalytic runs without any significant loss in their catalytic activity, they could be considered very promising nanomaterials from sustainability point of view.

Halloysite Nanotubes Functionalized Sulfonic Acid: Synthesis, Spectroscopic Characterization, Computational Studies and Application for the Synthesis of 1,4-Dihydropyridines

2021 ◽  
Vol 18 ◽  
Author(s):  
Princy Gupta ◽  
Nayan Prakash ◽  
Yogeshwar Ramawat ◽  
Palvi Rajput ◽  
Amir Fayaz ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Sulfonic Acid ◽  
Spectroscopic Characterization ◽  
Acid Synthesis ◽  
Halloysite Nanotubes ◽  
Spectroscopic Studies ◽  
Significant Loss ◽  
One Pot ◽  
Solvent Free Conditions ◽  
Chemical Studies

: Naturally occurring clay halloysite is used to synthesize novel halloysite functionalized sulfonic acid in two steps; functionalization followed by oxidation and its catalytic activity is estimated for one-pot synthesis of Hantzsch 1,4-dihydropyridines under green solvent-free conditions. Spectroscopic studies such as FTIR, TGA, elemental analysis and first-principles based quantum chemical studies are used to characterize the catalyst. Recyclability without significant loss of catalytic activity is observed for several runs.

Cobalt(II), copper(II), and iron(II) tetrasulfophthalocyanines covalently supported on wool: Synthesis, characterization and catalytic activity

2016 ◽  
Vol 20 (06) ◽  
pp. 677-688 ◽  
Author(s):  
Ahmad Shaabani ◽  
Zeinab Hezarkhani
Keyword(s):  
Catalytic Activity ◽  
Carbonyl Compounds ◽  
Aerobic Oxidation ◽  
Significant Loss ◽  
X Ray Diffraction ◽  
Flame Atomic Absorption Spectroscopy ◽  
X Ray ◽  
Flame Atomic Absorption ◽  
Eds Analysis ◽  
Ft Ir

Functionalized wool with cobalt(II), copper(II), and iron(II) tetrasulfophthalocyanine (CoTSPc@wool, CuTSPc@wool, and FeTSPc@wool) have been synthesized and their structures characterized by flame atomic absorption spectroscopy (FAAS), FT-IR, UV-vis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the energy dispersive spectroscopy (EDS) analysis. The catalytic activity of the synthesized catalysts was investigated for the aerobic oxidation of alkyl arenes and alcohols to their corresponding carbonyl compounds in the absence of any co-promoter and additional oxidizing reagent. We found the best catalyst for the mentioned reactions is the CoTSPc@wool from the solvent, conversion, temperature, and reaction time point of views. The synthesized catalysts can be readily recycled and reused for several runs without significant loss of efficiency.

scholarly journals Silver Coordination-Polymer based of 4,6-Diamino-2-pyrimidinethiol as Organic Ligand: a Highly Reusable Heterogeneous Nanocatalyst for the Asymmetric Hantzsch Synthesis of Polyhydroquinolines under Green Conditions

2021 ◽  
Author(s):  
Noorullah Hussain-Khil ◽  
Arash Ghorbani-Choghamarani ◽  
Masoud Mohammadi
Keyword(s):  
Catalytic Activity ◽  
Coordination Polymer ◽  
Organic Ligand ◽  
Reaction Times ◽  
Nitrogen Adsorption ◽  
Significant Loss ◽  
Hantzsch Synthesis ◽  
Reaction Conditions ◽  
Ft Ir ◽  
Adsorption Desorption

Abstract A highly efficient and stable heterogeneous coordination polymer (CP) was successfully prepared by hydrothermal combination of silver and 4,6-diamino-2-pyrimidinethiol. The prepared coordination polymer was characterized by FT-IR, XRD, TGA, SEM, EDX, X-ray mapping and Nitrogen adsorption-desorption analysis. The prepared Ag-CP exhibit excellent catalytic activity in multicomponent Hantzsch synthesis of polyhydroquinolines under mild reaction conditions in relatively short reaction times. The heterogeneity of the catalyst was confirmed by the hot filtration test; also, the catalyst was reused for at least four times under the optimized reaction conditions without any significant loss of its catalytic activity.

scholarly journals A new silver coordination polymer based on 4,6-diamino-2-pyrimidinethiol: synthesis, characterization and catalytic application in asymmetric Hantzsch synthesis of polyhydroquinolines

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Noorullah Hussain-Khil ◽  
Arash Ghorbani-Choghamarani ◽  
Masoud Mohammadi
Keyword(s):  
Catalytic Activity ◽  
Coordination Polymer ◽  
Reaction Times ◽  
Nitrogen Adsorption ◽  
Significant Loss ◽  
Hantzsch Synthesis ◽  
Reaction Conditions ◽  
Catalytic Application ◽  
Ft Ir ◽  
Adsorption Desorption

AbstractA highly efficient and stable heterogeneous coordination polymer (CP) was successfully prepared by hydrothermal combination of silver and 4,6-diamino-2-pyrimidinethiol. The prepared coordination polymer was characterized by FT-IR, XRD, TGA, SEM, EDX, X-ray mapping and Nitrogen adsorption–desorption analysis. The prepared Ag–CP exhibit excellent catalytic activity in multicomponent Hantzsch synthesis of polyhydroquinolines under mild reaction conditions in relatively short reaction times. The heterogeneity of the catalyst was confirmed by the hot filtration test; also, the catalyst was reused for at least four times under the optimized reaction conditions without any significant loss of its catalytic activity.

scholarly journals Efficient Catalytic Reduction of 4-Nitrophenol Using Copper(II) Complexes with N,O-Chelating Schiff Base Ligands

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5876
Author(s):  
Hassan Wafi Garba ◽  
Muhammad Sabiu Abdullahi ◽  
Mohamad Shazwan Shah Jamil ◽  
Nor Azam Endot
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Catalytic Reduction ◽  
Schiff Base Ligands ◽  
Paramagnetic Resonance ◽  
Nitrophenol Reduction ◽  
Ft Ir ◽  
Uv Visible ◽  
Electron Paramagnetic ◽  
Excellent Reproducibility

The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride was used as a model to test the catalytic activity of copper(II) complexes containing N,O-chelating Schiff base ligands. In this study, a series of copper(II) complexes containing respective Schiff base ligands, N′-salicylidene-2-aminophenol (1), N′-salicylidene-2-aminothiazole (2), and N,N′-bis(salicylidene)-o-phenylenediamine (3), were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR), and UV-Visible (UV-Vis) and electron paramagnetic resonance (EPR) spectroscopies. The results from the 4-nitrophenol reduction showed that 3 has the highest catalytic activities with 97.5% conversion, followed by 2 and 1 with 95.2% and 90.8% conversions, respectively. The optimization of the catalyst amount revealed that 1.0 mol% of the catalyst was the most optimized amount with the highest conversion compared to the other doses, 0.5 mol% and 1.5 mol%. Recyclability and reproducibility tests confirmed that all three complexes were active, efficient, and possess excellent reproducibility with consistent catalytic performances and could be used again without a major decrease in the catalytic activity.

scholarly journals Polyvinylpolypyrrolidone Supported Brønsted Acidic Catalyst for Esterification

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Song Wang ◽  
Chengcheng Tian
Keyword(s):  
Catalytic Activity ◽  
Sulfuric Acid ◽  
Elemental Analysis ◽  
Catalytic Performance ◽  
Significant Loss ◽  
High Catalytic Activity ◽  
Acidic Catalyst ◽  
Ft Ir ◽  
Esterification Reactions

A polyvinylpolypyrrolidone (PVPP) supported Brønsted acidic catalyst ([PVPP-BS]HSO4) was prepared by coupling SO3H-functionalized polyvinylpolypyrrolidone with H2SO4in this work. After the characterization through FT-IR, FESEM, TG, BET, and elemental analysis, it was found that 1,4-butane sultone (BS) and sulfuric acid reacted with PVPP and were immobilized on PVPP surface. The prepared[PVPP-BS]HSO4catalyst shows high catalytic activity for a series of esterification reactions and could be separated from the reacted mixture easily. Moreover, this catalyst could be recycled and reused for six times without significant loss of catalytic performance.

Thanato-Laboratorien. Theorien von Tod und Sterben und Elias Canettis Buch gegen den Tod

2020 ◽  
Vol 4 (1) ◽  
pp. 67-86
Author(s):  
Elisabeth Heyne
Keyword(s):  
Human Life ◽  
Death And Dying ◽  
Point Of View ◽  
Visual Images ◽  
Elias Canetti ◽  
History Of ◽  
Series Of Experiments ◽  
First Time ◽  
Textual Form ◽  
Or History

AbstractAlthough visual culture of the 21th century increasingly focuses on representation of death and dying, contemporary discourses still lack a language of death adequate to the event shown by pictures and visual images from an outside point of view. Following this observation, this article suggests a re-reading of 20th century author Elias Canetti. His lifelong notes have been edited and published posthumously for the first time in 2014. Thanks to this edition Canetti's short texts and aphorisms can be focused as a textual laboratory in which he tries to model a language of death on experimental practices of natural sciences. The miniature series of experiments address the problem of death, not representable in discourses of cultural studies, system theory or history of knowledge, and in doing so, Canetti creates liminal texts at the margins of western concepts of (human) life, science and established textual form.

Synthesis and Evaluation of Levulinic Ester as Biodiesel Additives

2020 ◽  
Vol 71 (8) ◽  
pp. 21-26
Author(s):  
Elena-Emilia Oprescu ◽  
Cristina-Emanuela Enascuta ◽  
Elena Radu ◽  
Vasile Lavric
Keyword(s):  
Maximum Yield ◽  
Strength Distribution ◽  
Point Of View ◽  
Reaction Parameters ◽  
X Ray ◽  
Ethyl Levulinate ◽  
Ft Ir ◽  
Ir Analysis ◽  
Biodiesel Blend ◽  
Acid Strength Distribution

In this study, the SO42-/TiO2-La2O3-Fe2O3 catalyst was prepared and tested in the conversion of fructose to ethyl levulinate . The catalyst was characterized from the point of view of the textural analysis, FT-IR analysis, acid strength distribution, X-ray powder diffraction and pyridine adsorption IR spectra. The influence of the reaction parameters on the ethyl levulinate yield was study. The maximum yield of 37.95% in levulinate esters was obtained at 180 �C, 2 g catalyst and 4 h reaction time. The effect of ethyl levulinate addition to diesel-biodiesel blend in different rates, i.e, 0.5, 1, 2.5, 5 (w.t %) on density, kinematic viscosity and flash point was evaluated and compared with the European specification.

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

Chiral Mn(III) Salen Complex Immobilized on CuFe2O4@SiO2-NH2 NPs: A Cheap and Efficient Catalyst for N-arylation of Aryl Halides and Phenylboronic Acid Under Mild Conditions

2020 ◽  
Vol 17 (11) ◽  
pp. 857-863
Author(s):  
Mohammad Ali Nasseri ◽  
Seyyedeh Ameneh Alavi ◽  
Milad Kazemnejadi ◽  
Ali Allahresani
Keyword(s):  
Phenylboronic Acid ◽  
Significant Loss ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Efficient Catalyst ◽  
Aryl Chlorides ◽  
Mild Conditions ◽  
Cross Coupling Reactions ◽  
Salen Complex ◽  
Ft Ir

A convenient and efficient chiral CuFe2O4@SiO2-Mn(III) Ch.salen nanocatalyst has been developed for the C-N cross-coupling reactions of aryl halides/ phenylboronic acid with N-heterocyclic compounds in water and/or DMSO under mild conditions. The catalyst could be applied for the N-arylation of a variety of nitrogen-containing heterocycles with aryl chlorides, bromides, iodides and phenylboronic acid under mild conditions. Moderate to good yields were achieved for all substrates. The structure of catalyst was characterized using various techniques including FT-IR, FE-SEM, EDX, XRD, TEM and TGA. The catalyst can be simply recovered and reused for several times without significant loss of activity.

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