Catalytic Olefin Hydroalkoxylation by Nano Particles of Pollucite

2015 ◽  
Vol 68 (6) ◽  
pp. 981 ◽  
Author(s):  
Sara Zamanian ◽  
Ali Nemati Kharat
Keyword(s):  
Nitrogen Adsorption ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Catalyst ◽  
Aromatic Alcohols ◽  
Electron Microscopy Analysis ◽  
Adsorption Surface ◽  
Microscopy Analysis ◽  
Temperature Programmed

The catalytic hydroalkoxylation of α,β-unsaturated esters, nitriles, and ethers with aliphatic and aromatic alcohols over pollucite using thermal and microwave-assisted methods was investigated. To study the effect of the alcohol structures on the mechanism of the hydroalkoxylation reaction, different alcohols, such as methanol to butanol, cyclohexanol, phenol, and 2-ethylhexanol were used. The activities of pollucite, in contrast to other basic solids, were scarcely affected by the presence of air and moisture. The correlation between alcohol acidity and reaction activity is discussed. The prepared pollucite was characterized by X‐ray diffraction, volumetric nitrogen adsorption surface area analysis, and CO2 temperature‐programmed desorption. Scanning electron microscopy analysis revealed that the size of the modified nano catalyst particles was under 40 nm.

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

Ethylenediamine Processed Cu2SnS3 Nano Particles via Mild Solution Route

2016 ◽  
Vol 19 (1) ◽  
pp. 001-005 ◽  
Author(s):  
Paul Nesamony Prathiba Jeya Helan ◽  
Kannusamy Mohanraj ◽  
Sethuramachandran Thanikaikarasan ◽  
Thaiyan Mahalingam ◽  
Ganesan Sivakumar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Techniques ◽  
Scanning Electron

Copper tin sulphide nanoparticles have been prepared by solution growth technique at various ethylenediamine concentrations. Prepared samples have been characterized using x-ray diffraction, fourier transform infrared, Raman and scanning electron microscopy techniques. x-ray diffraction results revealed that the prepared samples are nanocrystalline in nature with tetragonal structure. Fourier transform infrared spectroscopy analysis results showed the presence of Cu-O, Sn-O and Sn-S vibrations in the wavenumber range between 450 and 620 cm-1. Vibrational symmetry of prepared samples have been analyzed using Raman spectroscopy. Scanning electron microscopy analysis indicated the formation of flower like nanocrystals for samples prepared at various Ethylenediamine concentrations.

scholarly journals Photocatalytic degradation of tartrazine dye using CuO straw-sheaf-like nanostructures

2017 ◽  
Vol 75 (6) ◽  
pp. 1421-1430 ◽  
Author(s):  
Martha Purnachander Rao ◽  
Jerry J. Wu ◽  
Abdullah M. Asiri ◽  
Sambandam Anandan
Keyword(s):  
Photocatalytic Degradation ◽  
Photocatalytic Performance ◽  
Chemical Precipitation ◽  
Degradation Pathway ◽  
Gas Chromatography Mass Spectrometry ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

Straw-sheaf-like CuO nanostructures were fruitfully synthesized using a chemical precipitation approach for the photocatalytic degradation assessment of tartrazine. Phase identification, composition, and morphological outlook of prepared CuO nanostructures were established by X-ray diffraction and scanning electron microscopy analysis. The photocatalytic performance of the synthesized CuO nanostructures was appraised in the presence of visible light and the possible intermediates formed during the photocatalytic degradation were analyzed by gas chromatography–mass spectrometry. A suitable degradation pathway has also been proposed.

Preparation of Al2O3/MgO Nano-Composite Particles for Bio-Applications

2020 ◽  
Vol 38 (4A) ◽  
pp. 586-593
Author(s):  
Hayder A. Sallal ◽  
Alla A. Abdul-Hameed ◽  
Farhad. M. Othman
Keyword(s):  
Composite Materials ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Composite Particles ◽  
X Ray Diffraction ◽  
Nano Composite ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

This study describes the preparation and study of the properties of Nano composite particles prepared in a sol-gel method which consists of two materials (Αl2Ο3-MgΟ). The powder was evaluated by x-ray diffraction analysis, scanning electron microscopy analysis (SEM), particle size analysis, and energy dispersive x-ray analysis (EDX) and antibacterial test. The evaluation results of the nanocomposite particles shows a good distribution of the chemical composition between aluminum oxide and magnesium oxide, smoothness in particles  size where it reached to (54.9, 59.8) nm at calcination in (550 0C and 850 0C) respectively, formation of different shapes of nanoparticles and different  phases of the Αl2Ο3 particles (kappa and gamma) and nanopowder have well antibacterial action, Therefore, this reflects the efficiency of the proposed method to manufacture the nanocomposite powder and the possibility of using this powder as a strengthening material for the composite materials and using these composite materials in bio applications, especially in the fabrication of artificial limbs.

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

SYNTHESIS AND CHARACTERIZATION OF HG-BASED SUPERCONDUCTING THIN FILMS PRODUCED STARTING FROM LASER-DEPOSITED PRECURSORS

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2731-2736 ◽  
Author(s):  
M. BINDI ◽  
F. FUSO ◽  
N. PUCCINI ◽  
E. ARIMONDO ◽  
A. TAMPIERI ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Deposition ◽  
Precursor Film ◽  
Superconducting Thin Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Zero Resistance ◽  
Microscopy Analysis

Correctly c-axis oriented HgBa 2 CaCu 2 O 6+δ thin films have been produced on (100) MgO single crystal substrates and characterized. Pulsed laser deposition has been exploited to deposit Hg-free Re-doped precursor which then underwent synthesis in evacuated and sealed quartz tubes. X-ray diffraction pattern of the precursor target shows the expected composition of oxides. Scanning electron microscopy analysis have been performed on the surface of the precursor film. Hg-1212 films have been analyzed by θ-2θ Bragg-Brentano X-ray diffractometry. The patterns show little contributions in composition of Hg-1223 phase. The films exhibit a transition temperature >120 K with zero-resistance at around 115 K.

scholarly journals Study of dielectric behavior and electrical properties of hematite α-Fe2O3 doped with Zn

2012 ◽  
Vol 44 (3) ◽  
pp. 307-321 ◽  
Author(s):  
M.V. Nikolic ◽  
M.P. Slankamenac ◽  
N. Nikolic ◽  
D.L. Sekulic ◽  
O.S. Aleksic ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Spinel Phase ◽  
Dielectric Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Zn Content ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Two Phases

The effects of Zn-doping on the dielectric behavior and electrical properties of bulk ?-Fe2O3 have been studied. X-ray diffraction analysis revealed the presence of two phases in all samples: hematite and spinel ZnFe2O4, with the amount of spinel phase increasing with increasing Zn content. Scanning electron microscopy analysis combined with energy dispersive X-ray spectroscopy showed that the Zn-bearing phase occurred in the form of individual spinel ZnFe2O4 grains in a hematite matrix. DC conductivity was measured in the temperature range 25-225oC (298-498 K). Impedance spectroscopy measurements in the same temperature range were carried out in the frequency range 100Hz to 10 MHz. Increase in the Zn content resulted in increased electrical conductivity and higher values of the dielectric constant. The resistance and capacitance of grains and grain boundaries were analyzed by modeling the experimental results using an equivalent circuit.

A COMPARISON OF THE X-RAY DIFFRACTION AND NITROGEN ADSORPTION SURFACE AREAS OF CARBON BLACKS AND CHARCOALS

1948 ◽  
Vol 26a (4) ◽  
pp. 236-242 ◽  
Author(s):  
J. C. Arnell ◽  
W. M. Barss
Keyword(s):  
Carbonaceous Material ◽  
Nitrogen Adsorption ◽  
Activation Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Crystallite Surface ◽  
Adsorption Surface ◽  
Order Of Magnitude

The surface areas, as determined from X-ray diffraction and low temperature nitrogen adsorption data, were compared for a number of carbon blacks and activated charcoals. Comparative data were also obtained on samples of charcoal at various stages of activation and after calcination. The X-ray diffraction data indicated that all the samples examined were composed of small graphitelike crystallites of the same order of magnitude, which had specific surfaces of about 2500 to 3000 sq. m. per cc. The nitrogen adsorption surface of a highly activated charcoal was found to be about equal to the X-ray surface. It is suggested that the crystallite surface represents the potential adsorption surface of a carbonaceous material and, providing that crystal growth does not occur during activation, the activation process makes these surfaces available to external adsorbate.

scholarly journals Study of the effect of Ca/Mg alkali-oxides ratio on the structure of a glass-ceramic based on an aluminosilicated glass containing 2wt.% of zirconolite crystalline phase

2014 ◽  
Vol 46 (3) ◽  
pp. 377-383
Author(s):  
R. Souag ◽  
N. Kamel ◽  
Y. Mouheb ◽  
M. Hammadi ◽  
Z. Kamel ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Aluminosilicate Glass ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Alkali Oxides ◽  
Scanning Electron

New nuclear glass-ceramics are extensively studied for the radioactive waste confinement, due to the double confinement conferred by the glass-ceramics. In this study, a glass-ceramic constituted by an aluminosilicate glass in the system: SiO2-Al2O3-CaO-MgOZrO2-TiO2, containing 2wt.% of Ca0.83Ce0.17ZrTi1.66Al0.34O7 zirconolite, has been synthesized by the discontinuous method. Cerium, an actinide surrogate is introduced both in the glass and ceramic phases. The synthesis is performed by a double melting at 1350?C, followed by a nucleation at 564?C, during 2 h, and a crystal growth at 1010?C during 3 h. Then effect of Ca/Mg ratio on the distribution of the crystalline network in the material was studied for Ca / Mg ratios ranging from 0.4 to 5.5. For the whole of the materials, Archimedes density is about 2.80 g/cm3. X-ray diffraction (XRD) analysis shows that the increase of Ca/Mg ratio leads to the increase of aluminosilicated crystalline phases with high Ca contents; the materials molar volumes remaining constant. The zirconolite phase is not affected by these additive aluminosilicated phases. The scanning electron microscopy analysis (SEM) coupled with energy dispersive X-ray (EDX) analysis confirmed these results; and shows the uniformity of distribution of the ceramics in the bulk of the materials.

Sign in / Sign up

Export Citation Format

Share Document