scholarly journals Palladium(0) Nanoparticles Immobilized onto Silica/Starch Composite: Sustainable Catalyst for Hydrogenations and Suzuki Coupling

2019 ◽  
Vol 14 (3) ◽  
pp. 586
Author(s):  
Ravinderpal Kour Sodhi ◽  
Satya Paul
Keyword(s):  
Electron Microscopy ◽  
Carbonyl Compounds ◽  
Active Catalyst ◽  
Suzuki Coupling ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
Transmission Electron ◽  
Metal Acetylacetonate ◽  
Work Up ◽  
Insight Into

The present paper aims to give insight into the art in the field of the synthesis, characterization and applications of Pd(0) nanoparticles immobilized onto silica/starch composite (SS-PdNPs) for hydrogenations and Suzuki coupling. Metal(0) nanoparticles immobilized onto silica/starch composite [SS-MNPs] were prepared from different metal acetylacetonate complexes [Co(acac)2], [Cu(acac)2], [Pd(acac)2],  [Ru(acac)3], [Mn(acac)3], [Co(acac)3] by immobilizing onto silica/starch composite, followed by reduction with NaBH4. Excellent yield of the products, reusability and the facile work-up makes SS-PdNPs a unique catalyst for the reduction of nitroarenes/carbonyl compounds, a,b unsaturated carbonyl compounds and Suzuki coupling under environmentally benign reaction conditions. All the catalysts were characterized by Fourier Transform Infra Red (FTIR), Atomic Absorption Spectroscopy (AAS) analyses,  while the most active catalyst [SS-PdNPs] was further characterized by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Copyright © 2019 BCREC Group. All rights reserved

Evolution of Crystalline Phase and Morphology of the Products Formed during the Hydrothermal Synthesis of Y2O3 Powders

2011 ◽  
Vol 189-193 ◽  
pp. 1275-1279
Author(s):  
Ying Wang ◽  
Gao Yang Zhao ◽  
Li Yuan
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Treatment ◽  
Crystalline Phase ◽  
Hydrothermal Reaction ◽  
Yttrium Nitrate ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron

The crystalline phase and morphology of the products formed during the synthesis of yttrium oxide via the hydrothermal treatment yttrium nitrate were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Products with high OH/NO3ratios are formed with the increasing of hydrothermal treatment. The crystalline phases are evolved from Y2(OH)5.14(NO3)0.86•H2O toY4O(OH)9(NO3) and finally Y(OH)3. The hydrothermal reaction conditions play an important role in the synthesis of the microstructures. Results show the particle size and final morphology of samples could be controlled by reaction temperature, reaction time, and OH-concentration. Sheets, hexagonal and needle-like Y2O3powders are obtained with the hydrothermal treatment of yittrium nitrate at 180 oC to 200oC for 2-8 hours at pH 9-13.

scholarly journals Nanocrystalline alloys: synthesis and characterization of non-stoichiometric Co2FeAl nanocrystals

2016 ◽  
Vol 94 (4) ◽  
pp. 367-372 ◽  
Author(s):  
Lana T. Huynh ◽  
Stephanie N. Bonvicini ◽  
Arthur C. Pinon ◽  
Simon Trudel
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Magnetic Measurements ◽  
Size Control ◽  
Synthesis And Characterization ◽  
Spintronic Devices ◽  
Transmission Electron ◽  
Metal Acetylacetonate ◽  
Capping Ligands

Non-stoichiometric Co2FeAl nanoparticles are formed by the in-solution thermal decomposition of the corresponding metal acetylacetonate complexes in the presence of capping ligands followed by reduction of the obtained material under an H2-containing atmosphere. Transmission electron microscopy indicates that sub-100 nm nanoparticles are obtained, with reasonable size control. Magnetic measurements indicate that the saturation magnetization, Bloch behavior, magnetization reversal, spin-wave stiffness, and exchange stiffness are all comparable to those observed for bulk and thin-film Co2FeAl, indicating that these nanomaterials are promising for use in nanoparticle-based spintronic devices.

Activation of persulfate by heterogeneous catalyst ZnCo2O4–RGO for efficient degradation of bisphenol A

2020 ◽  
Vol 98 (12) ◽  
pp. 771-778
Author(s):  
Xin Chang ◽  
Xiangyang Xu ◽  
Zhifeng Gao ◽  
Yingrui Tao ◽  
Yixuan Yin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bisphenol A ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
One Step ◽  
Application Potential

A nanocomposite, reduced graphene oxide (RGO) modified ZnCo2O4 (ZnCo2O4–RGO) was synthesized via one-step solvothermal method for activating persulfate (PS) to degrade bisphenol A (BPA). The morphology and structure of the nanocomposite were identified by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. RGO provides nucleation sites for ZnCo2O4 to grow and inhibits the agglomeration of the nanoparticles. The influence of different reaction conditions on the oxidation of BPA catalyzed by ZnCo2O4–RGO was investigated, including the content of RGO, the dosage of catalyst, the concentration of humic acid (HA), anions in the environment, the reaction temperature, and pH. BPA can be totally degraded within 20 min under optimized reaction conditions. The presence of HA, Cl−, and NO3− only has a slight effect on the oxidation of BPA, whereas the presence of either H2PO4− or HCO3− can greatly inhibit the reaction. ZnCo2O4–RGO shows good cycling stability and practical application potential. A reaction mechanism of the degradation of BPA was also explored.

scholarly journals Synthesis of Pyrazolo-Fused 4-Azafluorenones in an Ionic Liquid. Mechanistic Insights by Joint Studies Using DFT Analysis and Mass Spectrometry

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 820
Author(s):  
Efraín Polo ◽  
Valentina Arce-Parada ◽  
Xaviera A. López-Cortés ◽  
Jesús Sánchez-Márquez ◽  
Alejandro Morales-Bayuelo ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Density Functional ◽  
Room Temperature ◽  
Theoretical Study ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Three Component Reaction ◽  
Work Up

A series of pyrazolo-fused 4-azafluorenones (indeno[1,2-b]pyrazolo[4,3-e]pyridines, IPP) were synthesized via the three-component reaction between arylaldehydes, 3-methyl-1H-pyrazol-5-amine and 1,3-indanedione in an ionic liquid as a catalyst at room temperature. The applied synthetic route has the advantages of easy work-up under mild reaction conditions presenting moderate yields and an environmentally benign procedure. A theoretical study based on conceptual-density functional theory has been done, bond reactivity indices have been calculated and an electrophilic and nucleophilic character of localized orbitals has been determined to analyze the possible electronic mechanisms.

SYNTHESIS OF ZnS:Mn/SILICA CORE/SHELL MICROSPHERES WITH A COMBINATION OF SOL–GEL AND SELF-TEMPLATING TECHNIQUES

NANO ◽  
2014 ◽  
Vol 09 (03) ◽  
pp. 1450028
Author(s):  
QING ZHANG
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Fluorescence Emission ◽  
Core Shell ◽  
Reaction Conditions ◽  
Whole Process ◽  
Transmission Electron ◽  
Novel Method ◽  
Nanosilica Particles

Core/shell microspheres with functional Mn -doped ZnS microspheres ( ZnS : Mn ) as core and with nanosilica particles as shell were prepared by a combination of sol–gel and self-templating techniques. The characteristic of this novel method was that the whole process required neither additional surfactant nor stabilizer, which exempted from removing the template and reduced reaction steps compared to the conventional process. The morphologies, structure and particle size distribution of the resulting ZnS : Mn / SiO 2 microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively. Surface chemical composition and optical properties were determined with X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy, respectively. In addition, the effects of reaction conditions on the structure and morphologies were investigated. Experimental results indicated that the resulting ZnS : Mn / SiO 2 microspheres were perfectly spherical with distinct core/shell structures, and exhibited stronger fluorescence emission.

scholarly journals ZnO-beta zeolite mediated simple and efficient method for the one-pot synthesis of quinoxaline derivatives at room temperature

2010 ◽  
Vol 8 (2) ◽  
pp. 320-325 ◽  
Author(s):  
Santosh Katkar ◽  
Pravinkumar Mohite ◽  
Lakshman Gadekar ◽  
Balasaheb Arbad ◽  
Machhindra Lande
Keyword(s):  
Efficient Method ◽  
Room Temperature ◽  
Environmentally Benign ◽  
Beta Zeolite ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Quinoxaline Derivatives ◽  
The One ◽  
Work Up

AbstractA rapid and an efficient one-pot method for the synthesis of quinoxalines catalysed by ZnO-beta zeolite at room temperature is described. This environmentally benign method provides several advantages over methods that are currently employed such as a simple work-up, mild reaction conditions, good to excellent yields, and a process to recover and reuse the catalyst for several cycles with consistent activity.

One Pot Three Component Synthesis of 9-arylpolyhydroacridine Derivatives in an Ionic Liquid Medium

2005 ◽  
Vol 2005 (9) ◽  
pp. 600-602 ◽  
Author(s):  
Yu-Ling Li ◽  
Mei-Mei Zhang ◽  
Xiang-Shan Wang ◽  
Da-Qing Shi ◽  
Shu-Jiang Tu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ammonium Acetate ◽  
Aromatic Aldehydes ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
One Pot ◽  
High Yields ◽  
Work Up ◽  
Ionic Liquid Medium

In this paper the preparation of 3,3,6,6-tetramethyl-9-aryl-1,2,3,4,5,6,7,8,9,10- decahydroacridin-1,8-dione derivatives from aromatic aldehydes, 5,5-dimethyl-1,3- cyclohexanedione and ammonium acetate in ionic liquids [bmim+][BF4-] is described. This new method has the advantages of easier work-up, milder reaction conditions, high yields and an environmentally benign procedure compared with other methods.

One-step synthesis of Sb2O3 broom-like belts with controllable morphology

2005 ◽  
Vol 83 (8) ◽  
pp. 1093-1097 ◽  
Author(s):  
Qingrui Zhao ◽  
Xuanjun Zhang ◽  
Qing Yang ◽  
Yi Xie
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Solvothermal Reaction ◽  
Antimony Trioxide ◽  
Reactant Ratio ◽  
Reaction Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
One Step ◽  
Template Free

A direct and simple surfactant- and template-free route has been developed for the controlled synthesis of Sb2O3 belt-like microstructures. By adjusting the reactant ratio between SbCl3 and urea under solvothermal reaction conditions, broom-like belts and rods of Sb2O3 have been successfully prepared. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS) has been used to characterize the phases and morphologies of the as-prepared products. A possible formation mechanism is also discussed.Key words: antimony trioxide, solvothermal synthesis, broom-like belts.

Resolving the Morphology of Niobium Carbonitride Nano-Precipitates in Steel Using Atom Probe Tomography

2014 ◽  
Vol 20 (4) ◽  
pp. 1100-1110 ◽  
Author(s):  
Andrew J. Breen ◽  
Kelvin Y. Xie ◽  
Michael P. Moody ◽  
Baptiste Gault ◽  
Hung-Wei Yen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Atom Probe Tomography ◽  
Atom Probe ◽  
Niobium Carbonitride ◽  
Surrounding Matrix ◽  
Transmission Electron ◽  
A New Technique ◽  
Insight Into ◽  
Reconstructed Data ◽  
Magnification Effect

AbstractAtom probe is a powerful technique for studying the composition of nano-precipitates, but their morphology within the reconstructed data is distorted due to the so-called local magnification effect. A new technique has been developed to mitigate this limitation by characterizing the distribution of the surrounding matrix atoms, rather than those contained within the nano-precipitates themselves. A comprehensive chemical analysis enables further information on size and chemistry to be obtained. The method enables new insight into the morphology and chemistry of niobium carbonitride nano-precipitates within ferrite for a series of Nb-microalloyed ultra-thin cast strip steels. The results are supported by complementary high-resolution transmission electron microscopy.

scholarly journals Polystyrene-supported aluminum chloride as an efficient and reusable catalyst for condensation of indole with various carbonyl compounds

2010 ◽  
Vol 75 (4) ◽  
pp. 423-431 ◽  
Author(s):  
Bahman Tamami ◽  
Nasrolahi Shirazi ◽  
Parvanak Borujeni
Keyword(s):  
Aluminum Chloride ◽  
Carbonyl Compounds ◽  
Low Cost ◽  
Reaction Times ◽  
Reusable Catalyst ◽  
Reaction Conditions ◽  
Crosslinked Polystyrene ◽  
Aldehydes And Ketones ◽  
Polymeric Catalyst ◽  
Work Up

Crosslinked polystyrene-supported aluminum chloride (Ps-AlCl3) is a stable, recyclable and environmental friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford bis-indolylmethanes. In addition, (Ps-AlCl3) shows satisfactory selectivity in the reaction of mixtures of an aldehyde and a ketone with indole. Although AlCl3 is a water sensitive, corrosive and environmentally harmful compound, Ps-AlCl3 is a stable and water-tolerant species. The mild reaction conditions, short reaction times, easy work-up, high to excellent yields, chemoselectivity, reuse of the catalyst for at least ten times without significant change in its catalytic activity, low cost, and easy preparation and handling of the polymeric catalyst are obvious advantages of the present method.

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