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  1. 14 Przemysł Chemiczny
  2. 11 Polish Journal of Chemical Technology
  3. 8 Materials Science Poland
  4. 3 Polish Journal of Chemistry
  5. 2 Prace Naukowe Politechniki Szczecińskiej. Instytut Technologii Nieorganicznej
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  1. 41 Arabczyk W.
  2. 12 Narkiewicz U.
  3. 8 Moszyński D.
  4. 8 Pelka R.
  5. 6 Jasińska I.
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  1. 3 2016
  2. 2 2015
  3. 2 2014
  4. 3 2013
  5. 2 2012
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1
Content available The activity of fused-iron catalyst doped with lithium oxide for ammonia synthesis
Jedrzejewski R., Lendzion-Bieluń Z., Arabczyk W.
Polish Journal of Chemical Technology
|
2016
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Vol. 18, nr 2
78--83
EN
The iron catalyst precursor promoted with Al2O3, CaO, and Li2O was obtained applying the fusing method. Lithium oxide forms two phases in this iron catalyst: a chemical compound with iron oxide (Li2Fe3O4) and a solid solution with magnetite. The catalyst promoted with lithium oxide was not fully reduced at 773 K, while the catalyst containing potassium was easily reducible at the same conditions. After reduction at 873 K the activity of the catalyst promoted with lithium oxide was 41% higher per surface than the activity of the catalyst promoted with potassium oxide. The concentration of free active sites on the surface of the catalyst containing lithium oxide after full reduction was greater than the concentration of free active sites on the surface of the catalyst promoted with potassium oxide.
2
Content available Adsorption of Ni2+ from aqueous solution by magnetic Fe@graphite nano-composite
Konicki W., Pelka R., Arabczyk W.
Polish Journal of Chemical Technology
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2016
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Vol. 18, nr 4
96--103
EN
The removal of Ni2+  from aqueous solution by iron nanoparticles encapsulated by graphitic layers (Fe@G) was investigated. Nanoparticles Fe@G were prepared by chemical vapor deposition CVD process using methane as a carbon source and nanocrystalline iron. The properties of Fe@G were characterized by X-ray Diffraction method (XRD), High-Resolution Transmission Electron Microscopy (HRTEM), Fourier Transform-Infrared Spectroscopy (FTIR), BET surface area and zeta potential measurements. The effects of initial Ni2+  concentration (1–20 mg L−1 ), pH (4–11) and temperature (20–60°C) on adsorption capacity were studied. The adsorption capacity at equilibrium increased from 2.96 to 8.78 mg g−1 , with the increase in the initial concentration of Ni2+  from 1 to 20 mg L−1  at pH 7.0 and 20°C. The experimental results indicated that the maximum Ni2+  removal could be attained at a solution pH of 8.2 and the adsorption capacity obtained was 9.33 mg g−1 . The experimental data fitted well with the Langmuir model with a monolayer adsorption capacity of 9.20 mg g−1 . The adsorption kinetics was found to follow pseudo-second-order kinetic model. Thermodynamics parameters, ΔHO, ΔGO and ΔSO, were calculated, indicating that the adsorption of Ni2+  onto Fe@G was spontaneous and endothermic in nature.
3
Content available remote FMR study of samples obtained by nitriding and nitrides reduction of nanocrystalline iron
Typek J., Guskos N., Zolnierkiewicz G., Guskos A., Kielbasa K., Pelka R., Arabczyk W.
Materials Science Poland
|
2016
|
Vol. 34, No. 1
6--12
EN
Samples obtained by nitriding of promoted nanocrystalline iron and the nitrides reduction at various nitriding potential in terms of thermodynamic parameters were investigated by electron paramagnetic resonance/ferromagnetic resonance (EPR/FMR) method at room temperature. Experimental FMR spectra were fitted by the Dysonian-type resonance lines arising from the presence of different Fe–N phases. The obtained FMR parameters allowed us to identify the component phases and to determine their magnetic properties. In general, the proposed simple method of decomposition of the FMR spectra produced results on the phase content in investigated samples that were consistent with XRD measurements and additionally, magnetic characteristics of the studied nanomagnets.
4
Content available remote Katalizatory kobaltowo-molibdenowe domieszkowane cezem do syntezy amoniaku
Moszyński D., Adamski P., Pełech I., Arabczyk W.
Przemysł Chemiczny
|
2015
|
T. 94, nr 8
1399-1403
PL
Badano katalizatory kobaltowo-molibdenowe domieszkowane cezem (0,25–3% mas. Cs) w procesie syntezy amoniaku. W katalizatorach tych zidentyfikowano dwie fazy krystaliczne azotków kobaltu i molibdenu: Co₂Mo₃N oraz Co₃Mo₃N. Wykazano, że materiały te charakteryzują się dużą aktywnością w procesie syntezy amoniaku. Optymalną aktywność katalityczną uzyskano dla katalizatorów zawierających 1,7% mas. cezu. Na podstawie testu starzenia termicznego wykazano, że dochodzi do częściowego spiekania krystalitów fazy repeatedly detd. Thermal treatment resulted in sintering of crystallite Co₃Mo₃N phase and decreasing the activity of catalysts.N oraz zmniejszenia powierzchni właściwej. W rezultacie zmniejsza się aktywność katalizatorów.
EN
Co-Mo catalysts contg. Cs (0.25–3.0% by mass) were obtained by redn. of precursors with NH₃ at 700°C. The precursors were derived from aq. solns. of (NH₄)₆Mo₇O₂₄, Co(NO₃)₂ and CsOH. The anal. of catalysts by X-ray diffraction and anal. of the diffraction profiles by Rietveld method showed the presence of Co₂Mo₃N and Co₃Mo₃N phases depending on the content of Cs in the catalyst. Activities of the catalysts were tested under lab. Conditions of the synthesis of NH₃ at 400°C and 10 MPa. The reaction rate const. was detd. by measuring the flow of the reaction gases and NH₃ concns. The highest activity was achieved for the catalyst contg. Cs 1.7% by mass. The catalysts used for the activity detns. were then subjected to aging (650°C, 18 h) and their activity was repeatedly detd. Thermal treatment resulted in sintering of crystallite Co₃Mo₃N phase and decreasing the activity of catalysts.
5
Content available remote Azotowanie nanokrystalicznego żelaza mieszaniną amoniaku i wodoru w temperaturze 300°C
Wilk B., Kiełbasa K., Arabczyk W.
Przemysł Chemiczny
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2015
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T. 94, nr 10
1816-1820
PL
Przedstawiono wyniki badań procesu azotowania nanokrystalicznego żelaza oraz redukcji uzyskanych nanokrystalicznych azotków żelaza mieszaninami azotującymi o różnym składzie chemicznym w temp. 300°C w stanach stacjonarnych. Stwierdzono istnienie histerezy zależności stopnia zaazotowania żelaza od potencjału azotującego stosowanej mieszaniny NH3+H2. Zaprezentowano przebieg zmian składu fazowego próbki podczas azotowania nanokrystalicznego żelaza i redukcji otrzymanych nanokrystalicznych azotków żelaza. Wykazano znaczne odstępstwa zachowania układu nanokrystaliczne żelazo-amoniak-wodór od otrzymanych przez Lehrera zależności dla materiałów grubokrystalicznych. W układzie nanokrystaliczne żelazo-amoniak-wodór stwierdzono występowanie mieszanin azotków żelaza i żelaza w szerokim zakresie potencjałów azotujących.
EN
Spent nanocryst. Fe catalyst for NH3 synthesis was nitrided and reduced with NH3+H2 mixt. at 300°C to a mixt. of nanocryst. α-Fe(N) + γ’-Fe4N and γ’-Fe4N + ε-Fe3-2N phases and a ternary α-Fe(N) + γ’-Fe4N + ε-Fe3-2N system. The chem. and phase compn. was confirmed by X-ray diffractometry and at. emission spectroscopy. The nitriding degree increased with increasing nitriding potential of the NH3+H2 mixt.
6
Content available remote Badanie procesów azotowania i redukcji w układzie nanokrystaliczne żelazo-amoniak-wodór
Wilk B., Arabczyk W.
Przemysł Chemiczny
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2014
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T. 93, nr 6
1036-1040
PL
Badano procesy azotowania nanokrystalicznego żelaza oraz redukcji otrzymanych nanokrystalicznych azotków żelaza mieszaninami azotującymi o różnym składzie chemicznym w temp. 350°C w stanach kwazirównowagowych. Wykazano znaczne odstępstwa zachowania nanokrystalicznego układu Fe-NH3-H2 od otrzymanych przez Lehrera zależności dla materiałów grubokrystalicznych. Stwierdzono istnienie zjawiska histerezy dla zależności stopnia zaazotowania żelaza od potencjału azotującego w stałej temperaturze. Izoterma procesu redukcji nanokrystalicznych azotków żelaza przebiega powyżej izotermy procesu azotowania nanokrystalicznego żelaza w obszarze potencjałów azotujących, w których zachodzi reakcja chemiczna. W tych obszarach azotujących w procesach azotowania i redukcji trwale istnieją obok siebie dwie fazy stałe: α-Fe(N) + γ’-Fe4N lub γ’-Fe4N + ε-Fe3-2N. W redukcji nanokrystalicznego azotku żelaza w temp. 350°C w obszarze potencjałów azotujących 0,0036-0,0020 Pa-0,5 stwierdzono współistnienie 3 faz stałych: α-Fe(N) + γ’-Fe4N + ε-Fe3-2N.
EN
Com. Fe catalyst for NH3 synthesis was nitrided with NH3-H2 mixts. at 350°C. The nitriding resulted in formation of stable Fe(N), Fe4N and Fe2-3N phases. After redn., the area of the Fe2-3N phase was extended.
7
Content available remote Magnetic characterization of nanocrystalline iron samples with different size distributions
Typek J., Zolnierkiewicz G., Pelka R., Kielbasa K, Arabczyk W, Guskos N.
Materials Science Poland
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2014
|
Vol. 32, No. 3
423—429
EN
Nanocrystalline iron was obtained by fusing magnetite and promoters. The oxidized form was reduced with hydrogen and passivated (sample P0). The average nanocrystallite size in sample P0 was d(P0) =16 nm and the width of size distribution was s(P0) = 18 nm. Samples of nanocrystalline iron with narrower diameter ranges and larger and smaller average crystallite sizes were also synthesized. They were: sample P1 (d(P1) = 28 nm, s(P1) = 5 nm), sample P2 (d(P2) = 22 nm, s(P1) = 5 nm), sample P3 (d(P3) = 12 nm, s(P1) = 9 nm). These four samples were studied at room temperature by dc magnetization measurements and ferromagnetic resonance at microwave frequency. Correlations between samples sizes distributions (average size and width of the sizes) and magnetic parameters (effective magnetization, anisotropy field, anisotropy constant, FMR linewidth) were investigated. It was found that the anisotropy field and effective magnetization determined from FMR spectra scale linearly with nanoparticle sizes, while the effective magnetic anisotropy constant determined from the hysteresis loops decreases with nanoparticle size increase.
8
Content available remote Badanie procesu azotowania katalizatora żelazowego
Kiełbasa K., Wilk B., Arabczyk W.
Przemysł Chemiczny
|
2013
|
T. 92, nr 5
859-861
9
Content available Studies of the Ammonia Decomposition over a Mixture Of α - Fe(N) And γ' - Fe4n
Kiełbasa K., Arabczyk W.
Polish Journal of Chemical Technology
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2013
|
Vol. 15, nr 1
97-101
EN
An industrial pre-reduced iron catalyst for ammonia synthesis was nitrided in a differential reactor equipped with the systems that made it possible to conduct both the thermogravimetric measurements and hydrogen concentration analyser in the reacting gas mixture. The nitriding process, particularly the catalytic ammonia decomposition reaction, was investigated under an atmosphere of ammonia-hydrogen mixtures, under the atmospheric pressure, at 475oC. The nitriding potentials were changed gradually in the range from 19.10-3 to 73.10-3 Pa-0.5 in the reactor for an intermediate area where two phases exist simultanously: Fe(N) and γ’-Fe4. In the area wherein P > 73.10-3 Pa-0.5, approximately stoichiometric composition of γ’ - Fe4N phase exists and saturating of that phase by nitrogen started. The rate of the catalytic ammonia decomposition was calculated on the basis of grain volume distribution as a function of conversion degree for that catalyst. It was found that over γ’ - Fe4N phase in the stationary states the rate of catalytic ammonia decomposition depends linearly on the logarithm of the nitriding potential. The rate was decreasing along with increase in the nitriding potential. For the intermediate area, the rate of ammonia decomposition is a sum of the rates of reactions which occur on the surfaces of both Fe(N) and γ’ - Fe4N.
10
Content available remote Characterization of carbon deposit with controlled carburization degree
Helminiak A., Mijowska E., Arabczyk W.
Materials Science Poland
|
2013
|
Vol. 31, No. 1
29-35
EN
Promoted nanocrystalline iron was carburized in a differential tubular flow reactor with thermogravimetric measurement of mass changes. The carburization process was carried out in the presence of pure methane under atmospheric pressure at 650 °C to obtain different carburization degrees of the sample. The carburized iron samples were characterized by the X-ray diffraction, high-resolution transmission electron microscope in the energy-dispersive X-ray spectroscopy mode, thermoprogrammable oxidation, and Raman spectroscopy. As a result of the methane decomposition on the nanocrystalline iron the following nanocrystalline products were observed: iron carbide Fe3C, graphite, iron and nanotubes. The crystallinity of the samples increased with the carburization degree.
11
Content available Removal of SO2 from gases on carbon materials
Narkiewicz U., Pietrasz A., Pełech I., Arabczyk W.
Polish Journal of Chemical Technology
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2012
|
Vol. 14, nr 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.
12
Content available remote Elastomery uretanowe o zwiększonej odporności na zużycie ścierne napełniane gradientowe
Nachman M., Michalski P., Hełminiak A., Arabczyk W., Rosłaniec Z.
Elastomery
|
2012
|
T. 16, nr 2
11-15
PL
Zsyntezowa.no termoplastyczne, multiblokowe elastomery uretanowe (PUR) różniące się zawartością segmentów giętkich, napełnione gradientowa napełniaczem nanokrystalicznym o właściwościach magnetycznych. Materiały uzyskano metodą prepolimerową z oligomerycznego polieteru (PTMO) zakończonego grupami hydroksylowymi, glikolu butylenowego i 4,4'-duzocyjanianu difenylometanu, a następnie odlano w formach. W celu zwiększenia jednostronnie odporności na zużycie ścierne użyto dwóch rodzajów nanokrystalicznych napełniaczy. Gradientowy rozkład napełniacza magnetycznego uzyskano dzięki zastosowaniu silnego magnesu pod dnem formy. Na aparacie Schoppera wyznaczono wielkość zużycia ściernego napełnionych elastomerów uretano-wych. Otrzymane wyniki porównano z pomiarami uzyskanymi dla nienapełnionych PUR, syntezowa-nych w tych samych warunkach. W artykule określono strukturę oraz ivpływ rodzaju nanokrystaliczne-go napełniacza na poziom zużycia ściernego otrzymanych materiałów.
EN
Gradient-filled thermoplastic multiblock polyurethane elastomers (PUR with a nanocrystaline filler, containing different concentration ofpolyether soft segments were synthesized to prepare an nanocompo-site with high abrasive tuear resistance. The materials were obtained by the prepolymer methode with oligomeric polyether (PTh/lO), butylene glycol and methylenediphenyl-4,4'-diisocyanate, then cast into molds. Magnet was placed under a molds to obtain the gradient distribution of filler in polyurethane. Used two types of nanocrystalline fillers with magnetic properties. Abrasive wear resistance and density were analyzed.
13
Content available remote Wpływ wielkości nanokrystalitów żelaza na proces azotowania stopowego katalizatora żelazowego
Pelka R., Kiełbasa K., Arabczyk W.
Przemysł Chemiczny
|
2010
|
T. 89, nr 4
509-511
14
Content available remote Wpływ dyfuzji międzyziarnowej na aktywność katalizatorów żelazowych do syntezy amoniaku
Jasińska I., Lendzion-Bieluń Z., Arabczyk W.
Przemysł Chemiczny
|
2010
|
T. 89, nr 4
406-409
15
Content available remote Badanie właściwości katalizatora żelazowego pobranego z różnych części wlewka
Jędrzejewski R., Ekiert E., Lendzion-Bieluń Z., Arabczyk W.
Przemysł Chemiczny
|
2010
|
T. 89, nr 4
410-412
16
Content available Kinetics of nanocrystalline iron nitriding
Arabczyk W., Zamłynny J., Moszyński D.
Polish Journal of Chemical Technology
|
2010
|
Vol. 12, nr 1
38-43
EN
Nitriding of nanocrystalline iron was studied under the atmosphere of pure ammonia and in the mixtures of ammonia - hydrogen - nitrogen at temperatures between 350°C and 500°C using thermogravimetry and x-ray diffraction. Three stages of nitriding were observed and have been ascribed to the following schematic reactions: (1) α-Fe → γ-Fe4N, (2) γ- Fe4N → ε - Fe3N and (3) ε - Fe3N → ε - Fe2N. The products of these reactions appeared in the nitrided nanocrystalline iron not sequentially but co-existed at certain reaction ranges. The dependence of a reaction rate for each nitriding stage on partial pressure of ammonia is linear. Moreover, a minimal ammonia partial pressure is required to initiate the nitriding at each stage.
17
Content available remote Zjawisko histerezy procesów azotowania i redukcji w układzie nanokrystaliczne żelazo-amoniak-wodór
Moszyńska I., Moszyński D., Arabczyk W
Przemysł Chemiczny
|
2009
|
T. 88, nr 5
526-529
18
Content available remote Utlenianie a pasywacja materiałów nanokrystalicznych
Jasińska I., Ekiert E., Pelka R., Lubkowski K., Arabczyk W.
Przemysł Chemiczny
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2009
|
T. 88, nr 5
462-467
19
Content available The possibility of implementation of spent iron catalyst for ammonia synthesis
Ekiert E.A., Pelka R., Lubkowski K., Arabczyk W.
Polish Journal of Chemical Technology
|
2009
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Vol. 11, nr 1
28-33
EN
An iron catalyst used in the ammonia synthesis is pyrophoric in its reactive, reduced form. Before further use the catalyst has to be passivated. Results of the research on the iron catalyst - its passivation, re-use as a catalyst in other processes and implementation as a substrate to obtain new nanocrystalline materials have been presented in the paper.
20
Catalytic Decomposition of Ethylene on Iron - the Effect of Process Conditions on the Yield and Morphology of Nanocarbon Products
Narkiewicz U., Pełech I., Arabczyk W., Biedermann K., Tüschner Ch.
Polish Journal of Chemistry
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2008
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Vol. 82, nr 9
1743-1752
EN
The catalytic decomposition of ethylene on nanocrystalline iron was investigated. The processes were carried out in a horizontal tube reactor under atmospheric pressure and in the temperature range of 500-800°C. Various process parameters such as: reaction time, temperature, C2H4:H2 ratio, C2H4:Arratio have been examined to determine the effect of these parameters on both the yield of carbon and the morphology of products. The quality of the products was characterized by means of transmission electron microscopy (TEM). According to the observed results, ethylene can be used as a very effective carbon source for growing multi-walled carbon nanotubes (MWCNTs). The meandiameter of the obtained MWCNTs was 20-30 nm. The length of carbon nanotubes in creased with reaction time. The carbon nanotubes obtained in presence of hydrogen or argon in reaction mixture were straighter and less entangled than carbon nanotubes obtained through de composition of pure ethylene.
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