scholarly journals Activated Carbon as a Support of Catalysts for the Removal of Nitrogen Oxides

Mineralogia ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 9-16
Author(s):  
Anna Białas ◽  
Joanna Szlendak ◽  
Cezary Czosnek ◽  
Monika Motak
Keyword(s):  
Activated Carbon ◽  
Nitrogen Oxides ◽  
Catalytic Reduction ◽  
Textural Properties ◽  
Carbon Support ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Thermal Stability Of ◽  
Microporous Solids

Abstract Activated carbon was oxidised with concentrated nitric acid and impregnated with urea to form nitrogen-containing groups. Such a support was impregnated with cobalt, copper or silver nitrates to obtain catalysts for the selective catalytic reduction of nitrogen oxides with ammonia. Infrared spectra confirmed the formation of carboxylic and other organic oxygen-containing groups during oxidation. Nitrogen-containing species resulted from urea thermal decomposition. The metal-containing samples were hydrophilic. Cobalt and copper were present in the samples as small Co3O4 and CuO crystallites, while silver occurred in the form of large metallic crystallites, as seen from the X-ray diffraction patterns. Low temperature N2 sorption revealed that all samples were microporous solids, and the chemical and thermal treatment did not change their textural properties. The copper admixture caused the highest NO conversion, but worsened the selectivity and thermal stability of functionalised carbon support.

In Situ X-Ray Diffraction Study of Thermal Stability of Cu and Cu-Zr Samples Processed by ECAP

2013 ◽  
Vol 753 ◽  
pp. 279-284 ◽  
Author(s):  
Radomír Kužel ◽  
Zdeněk Matěj ◽  
Miloš Janeček
Keyword(s):  
In Situ Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Abnormal Growth ◽  
Angular Pressing ◽  
Dislocation Densities ◽  
Diffraction Patterns ◽  
Number Of Passes ◽  
Thermal Stability Of

X-ray diffraction (XRD) studies of ECAP (equal-channel angular pressing) materials were performed after annealing and by in-situ measurements in XRD high-temperature chamber for samples prepared by different number of passes and number of revolutions, respectively. Main attention was given to Cu and Cu-Zr samples. Significant dependence on number of passes was found for ECAP samples. In-situ measurements were focused not only on temperature dependence but also on time evolution of the diffraction line profiles. Evaluation in terms of dislocation densities, correlation and crystallite size and its distribution was performed by our own software MSTRUCT developed for total powder diffraction pattern fitting. Abnormal growth of some grains with annealing is well-known for copper and leads to the creation of bimodal microstructure. Therefore a special care must be given to the evaluation and a model of two Cu components (larger and smaller crystallites) was fitted to the data if an indication of some crystallite growth appears either in the XRD line profile shape or in two-dimensional diffraction patterns.

Massive Transformation in High Niobium Containing TiAl-Alloys

2004 ◽  
Vol 842 ◽  
Author(s):  
A. Bartels ◽  
S. Bystrzanowski ◽  
H. Chladil ◽  
H. Leitner ◽  
H. Clemens ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Sheet Material ◽  
Massive Transformation ◽  
X Ray Diffraction ◽  
Tial Alloys ◽  
X Ray ◽  
Boundary Triple ◽  
Triple Points ◽  
Diffraction Patterns ◽  
Thermal Stability Of

ABSTRACTMassive transformation in high Nb bearing γ-TiAl-based alloys, Ti-45Al-7.5Nb and Ti-46Al-9Nb (at.%), and the thermal stability of the resulting microstructure were investigated. Using a quenching dilatometer, a nearly complete massive transformation in Ti-45Al-7.5Nb was found at about 1050°C after annealing at 1305°C for 10min and subsequent cooling with a rate of 55K/s. Higher starting temperatures and higher cooling rates lead to incomplete massive transformation and small transformed areas situated at the grain-boundary triple points of the parent α-grains are observed. By means of EBSD only in one case the same orientation of the close-packed planes of parent α-grains and of massively transformed γM-areas was observed.The thermal stability of the microstructure of massively transformed Ti-46Al-9Nb sheet material was tested by annealing samples for 1 hour between 400 and 1200°C. Above 800°C a drop of hardness was measured and X-ray diffraction patterns show an increasing separation of (200)γ and (002)γ reflections as expected from a tetragonal γ-TiAl lattice. After annealing at 1100°C α2-phase segregates at grain boundaries and after 1200°C α2-lamellae appear insides the γM-grains parallel to all four {111}γ-planes.

Synthesis and characterization of a silylated Brazilian clay mineral surface

2014 ◽  
Vol 68 (7) ◽  
Author(s):  
Márcia Silva ◽  
Saloana Gomes ◽  
Maria Fonseca ◽  
Kaline Sousa ◽  
José Espínola ◽  
...  
Keyword(s):  
Clay Mineral ◽  
Solid State Nmr ◽  
Textural Properties ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Diffraction Patterns ◽  
Trimethoxy Silane

AbstractClay mineral containing kaolinite, illite and montmorillonite was organofunctionalized with silylating agents: (3-aminopropyl)triethoxysilane, 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane and (3-mercaptopropyl)trimethoxy-silane, to yield three hybrids labelled Clay1, Clay2 and Clay3, respectively. These solids were characterized using elemental analysis, thermogravimetry, X-ray diffractometry, infrared spectroscopy, scanning electron micrograph, and 29Si and 27Al solid state NMR. Immobilized quantities of the organic groups were 0.66 mmol g−1, 0.48 mmol g−1 and 0.88 mmol g−1 for Clayx (x = 1–3), respectively. X-ray diffraction patterns confirmed the immobilization of silanes onto the surface without changes in the textural properties of the clay mineral as noted from the SEM images. Spectroscopic measurements were in agreement with the covalent bonding between the silanes and the hydroxyl groups deposited on the surface. The new hybrids were utilized as adsorbents of cobalt in aqueous solution, with retention values of 0.78 mmol g−1, 1.1 mmol g−1 and 0.70 mmol g−1 for Clayx (x = 1–3), respectively.

Thermal decomposition of magnesium sesquicarbide

1983 ◽  
Vol 48 (7) ◽  
pp. 1963-1968 ◽  
Author(s):  
Bohumil Hájek ◽  
Pavel Karen ◽  
Vlastimil Brožek
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Data ◽  
Arrhenius Equation ◽  
Kinetic Equations ◽  
Decomposition Reaction ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Thermal Stability Of

The structure of Mg2C3 and the course of its decomposition were studied. The powder X-ray diffraction patterns were analyzed to obtain the lattice parameters for hexagonal Mg2C3, a = 743.4 ± 0.5 pm, c = 1 056.4 ± 1.6 pm. Thermal decomposition data were obtained for temperatures 670-740 °C and pressure 130 Pa; they could be fitted satisfactorily by kinetic equations for various processes, including the 1 st order decomposition reaction, and so the controlling phenomenon of the reaction cannot be deduced based on the kinetic data. The 1 st order rate constants and reaction halflives were evaluated for various temperatures and approximated by the Arrhenius equation to calculate the parameters AA = 1.97 . 1014 s-1, EA = 333 kJ mol-1. The conditions of synthesis of Mg2C3 are discussed from the point of view of the choice of a suitable hydrocarbon for the reaction with magnesium. The thermal stability of the sesquicarbide increases with increasing pressure; it could be formed from dicarbide and sustained even at a temperature of 1 450 °C by applying a pressure as high as 6 GPa.

scholarly journals Synthesis and Characterization of Dodecylbenzene Sulfonic Acid doped Tetraaniline via Emulsion Polymerization

2012 ◽  
Vol 9 (3) ◽  
pp. 1342-1346 ◽  
Author(s):  
K. Basavaiah ◽  
K. Tirumala Rao ◽  
A. V. Prasada Rao
Keyword(s):  
Sulfonic Acid ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Molar Ratios ◽  
Uv Visible ◽  
Dodecylbenzene Sulfonic Acid ◽  
Diffraction Patterns ◽  
Thermal Stability Of

In this work, we report preparation and characterization of dodecylbenzene sulfonic acid (DBSA) doped tetraaniline via micelles assisted method using ammonium per sulphate (APS) as an oxidant. Here, DBSA act as dopant as well as template for tetraaniline nanostructures. The synthesized DBSA doped tetraaniline have been well characterized by X-ray diffraction patterns, Fourier transform infrared spectroscopy, UV-Visible spectroscopy, Scanning electron microscopy and thermogravimetry. The morphologies of tetraaniline were found to be dependent on molar ratios of N-phenyl-1, 4-phenylenediamine to DBSA. The spectroscopic data indicated that DBSA doped tetraaniline. Thermogravimetry studies revealed that the DBSA doping improved the thermal stability of tetraaniline.

scholarly journals Synthesis and Characterization of Activated Carbon from Sago Waste (Metroxylon sagu) with ZnCl2 Activation and HNO3 Modification

2019 ◽  
Vol 2 (1) ◽  
pp. 48
Author(s):  
Yanti Kiding Allo ◽  
Sudarmono ◽  
Octolia Togibasa
Keyword(s):  
Activated Carbon ◽  
Raw Materials ◽  
Silica Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Structures ◽  
Sago Waste ◽  
Diffraction Patterns ◽  
Metroxylon Sagu

Previous researches have shown that activated carbon could be made from various raw materials which contain lignocellulose. The aims of this research were to synthesis and characterize the activated carbon obtained from lignocellulose contained in sago waste. The synthesis was conducted through multiple stages of dehydration, carbonization, silica extraction with NaOH, activation by ZnCl2 10%, and surface modification using HNO3 65%, successively. From X-ray fluorescence, it was confirmed that treatment with NaOH removed practically all silica content from the sample with only 1 wt% left. The X-ray diffraction patterns showed that the samples have amorphous structures before the modification and started to form exfoliated graphite crystals, as shown by the peaks at 2θ 30.27° and 35.10°. The significant result was obtained from the series of processes of carbonization, extraction, activation, and modification using 1.5 mL of HNO3 (CEA 1.5), which produced nanoporous particles with regular homogeneous shapes in the range of 200 nm in size as shown by scanning electron images. Finally, the infrared spectra from activated and modified samples confirmed that the oxygen-containing groups had increased.

Experimental Study on Simultaneous Desulfurization and Denitrification over Activated Carbon Carried Catalyst under Microwave Irradiation

2011 ◽  
Vol 347-353 ◽  
pp. 3540-3544
Author(s):  
Shuang Chen Ma ◽  
Wei Liu ◽  
Xin Jin ◽  
Yi Jing Jin
Keyword(s):  
Experimental Study ◽  
Activated Carbon ◽  
Sulfur Dioxide ◽  
Nitrogen Oxides ◽  
Removal Efficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Effects ◽  
Simultaneous Desulfurization And Denitrification ◽  
Reducing Energy

The influences of different catalysts added to the activated carbon were studied for reducing energy consumption and enhancing reaction selectivity while microwave irradiate activated carbon for removal of sulfur dioxide and nitrogen oxides. It was found that the addition of catalyst can lower the power of microwave needed for the same sulfur dioxide and nitrogen oxides removal efficiency to a large extent; moreover, different catalysts introduced would cause different effects, in which the zincous catalyst and manganese catalyst had more apparent catalytic effects, about 95% removal efficiency could be achieved under microwave power 420W. X-ray diffraction (XRD) was adopted to have a study of the microstructure of the activated carbon, and it is shown that some catalyst components do exist on the surface of the activated carbon

Preparation and characterization of poly(2-hydroxyethyl methacrylate)/ Na-montmorillonite intercalated nanocomposites

2013 ◽  
Vol 33 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Zafer Koç ◽  
Meltem Çelik ◽  
Müşerref Önal ◽  
Yüksel Sarıkaya ◽  
Yesim Mogulkoc
Keyword(s):  
Interlayer Spacing ◽  
Hydroxyethyl Methacrylate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Monomer Content ◽  
Diffraction Patterns ◽  
Thermal Stability Of

Abstract A series of intercalated nanocomposites were prepared via in situ polymerization of 2-hydroxyethyl methacrylate (HEMA) between the interlayer spacing of hydrous Na-montmorillonite (Na-MMT) using benzoyl peroxide (Bz2O2) as a radical initiator. X-ray diffraction patterns showed the absence of any intercalation up to 61.7 mass% of HEMA, but anhydrous Na-MMT formed by the hydrophilic effect of HEMA. The interlayer spacing (d001) values of hydrous and anhydrous Na-MMT were calculated as 1.19 and 1.03 nm, respectively. At higher monomer contents, the increase in the value of d001 from 1.19 to 2.01 nm indicated intercalation of polymer in the interlayer spacing of Na-MMT. Besides, transmission electron microscopy results supported the formation of the intercalated nanocomposites. Thermogravimetric analysis showed that the thermal stability of the nanocomposites increased considerably by intercalation of pure poly-HEMA. Specific surface area and specific nanopore volume of the nanocomposites decreased with the increasing of the monomer content taken by the preparations. The decrease is due to the nonporous nature of the polymer matrix.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

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