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1
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Preparation of carbon nanotubes using cvd CVD method

100%
Pełech I.
Polish Journal of Chemical Technology
|
2010
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vol. 12
|
issue 3
45-49
EN
In this work preparation and characteristic of modified nanocarbons is described. These materials were obtained using nanocrystalline iron as a catalyst and ethylene as a carbon source at 700°C. The influence of argon or hydrogen addition to reaction mixture was investigated. After ethylene decomposition samples were hydrogenated at 500°C. As a results iron carbide (Fe3C) in the carbon matrix in the form of multi walled carbon nanotubes was obtained. After a treatment under hydrogen atmosphere iron carbide decomposed to iron and carbon and small iron particles agglomerated into larger ones.
2
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Removal of SO2from gases on carbon materials

51%
Narkiewicz U., Pietrasz A., Pełech I., Arabczyk W.
Polish Journal of Chemical Technology
|
2012
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vol. 14
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issue 1
41-45
EN
The aim of the work is to describe a capability of the active carbon CARBON L-2-4 (AC) and of the nanocarbon (NC) materials containing iron nanoparticles to continuously remove SO2 from air. The carbon nanomaterials (NC) containing iron nanoparticles were synthesised using a chemical vapor deposition method - through catalytic decomposition of ethylene on nanocrystalline iron.The process of SO2 removal was carried out on dry and wet with water carbon catalyst (AC or NC) and was studied for inlet SO2 concentration 0.3 vol.% in the presence of O2, N2 and H2O, in the temperature range of 40-80°C.
3
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Removal of Ni2+from Aqueous Solutions by Adsorption Onto Magnetic Multiwalled Carbon Nanotube Nanocomposite

51%
Konicki W., Pełech I., Mijowska E.
Polish Journal of Chemical Technology
|
2014
|
vol. 16
|
issue 2
87-94
EN
The removal of Ni2+ from aqueous solution by magnetic multiwalled carbon nanotube nanocomposite (MMWCNTs-C) was investigated. MMWCNTs-C was characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), surface area (BET), and Fourier Transform-Infrared Spectroscopy (FTIR). The effects of initial concentration, contact time, solution pH, and temperature on the Ni2+ adsorption onto MMWCNTs-C were studied. The Langmuir and Freundlich isotherm models were applied to fit the adsorption data. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm model with the maximum monolayer adsorption capacity of 2.11 mg g–1. The adsorption kinetics was best described by the pseudo-second-order model. The thermodynamic parameters, such as ΔHo, ΔGo and ΔSo, were also determined and evaluated. The adsorption of Ni2+ is generally spontaneous and thermodynamically favorable. The values of ΔHo and ΔGo indicate that the adsorption of Ni2+ onto MMWCNTs-C was a physisorption process.
4
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Preparation and characterization of multi-walled carbon nanotubes grown on transition metal catalysts

51%
Pełech I., Narkiewicz U., Kaczmarek A., Jędrzejewska A.
Polish Journal of Chemical Technology
|
2014
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vol. 16
|
issue 1
117-122
EN
Transition metal catalysts (mainly: iron, cobalt and nickel) on various supports are successfully used in a largescale production of carbon nanotubes (CNTs), but after the synthesis it is necessary to perform very aggressive purification treatments that cause damages of CNTs and are not always effective. In this work a preparation of unsupported catalysts and their application to the multi-walled carbon nanotubes synthesis is presented. Iron, cobalt and bimetallic iron-cobalt catalysts were obtained by co-precipitation of iron and cobalt ions followed by solid state reactions. Although metal particles were not supported on the hard-to-reduce oxides, these catalysts showed nanometric dimensions. The catalysts were used for the growth of multi-walled carbon nanotubes by the chemical vapor deposition method. The syntheses were conducted under ethylene - argon atmosphere at 700°C. The obtained catalysts and carbon materials after the synthesis were characterized using transmission electron microscopy (TEM), X-ray diffraction method (XRD), Raman spectroscopy and thermogravimetric analysis (TG). The effect of the kind of catalyst on the properties of the obtained carbon material has been described.
5
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High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide

39%
Kaszewski J., Yatsunenko S., Pełech I., Mijowska E., Narkiewicz U., Godlewski M.
Polish Journal of Chemical Technology
|
2014
|
vol. 16
|
issue 2
99-105
EN
Calcination and microwave-assisted hydrothermal processing of precipitated zirconium dioxide are compared. Characterization of synthesized products of these two technologies is presented. The infiuence of thermal treatment up to 1200oC on the structural and spectroscopic properties of the so-obtained zirconium dioxide is examined. It was found that initial crystallization of material inhibits the crystal growth up to the 800oC (by means of XRD and TEM techniques), while the material crystallized from amorphous hydroxide precursor at 400oC, exhibits 26 nm sized crystallites already. It was found using the TG technique that the temperature range 100–200oC during the calcination process is equivalent to a microwave hydrothermal process by means of water content. Mass loss is estimated to be about 18%. Based on X-ray investigations it was found that the initial hydroxide precursor is amorphous, however, its luminescence activity suggests the close range ordering in a material.
6
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Utilization of spent iron catalyst for ammonia synthesis

27%
Arabczyk W., Narkiewicz U., Lendzion-Bieluń Z., Moszyński D., Pełech I., Ekiert E., Podsiadły M., Pelka R., Jędrzejewski R., Moszyńska I., Sibera D.
Polish Journal of Chemical Technology
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2007
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vol. 9
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issue 3
108-113
EN
Several methods of the utilization of spent iron catalyst for ammonia synthesis have been presented. The formation of iron nitrides of different stoichiometry by direct nitriding in ammonia in the range of temperatures between 350°C and 450°C has been shown. The preparation methods of carbon nanotubes and nanofibers where iron catalyst catalyse the decomposition of hydrocarbons have been described. The formation of magnetite embedded in a carbon material by direct oxidation of carburized iron catalyst has been also presented.
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