National Repository of Grey Literature 19 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Co-Mn-Al mixed oxides promoted for direct NO decomposition: preparation and properties.
Jirátová, Květa ; Pacultová, K. ; Balabánová, Jana ; Karásková, K. ; Klegová, A. ; Bílková, T. ; Jandová, Věra ; Koštejn, Martin ; Martaus, A. ; Kotarba, A. ; Obalová, L.
The catalysts investigated in this work were prepared by co-precipitation of nitrates with aqueous K2CO3/KOH solution, followed by washing the precipitates to varying degrees of potassium content and calcining the precursors at 500 °C for 4 h. Mn-Al potassium salt followed by calcination at 500 °C. Before the catalytic reaction, they were calcined at 700 °C. The catalysts and their precursors were characterized by the following measurement techniques: ICP, DTG, XRD, N2 physisorption, FTIR, H2-TPR, CO2-TPD, XPS, and thermal alkali metal desorption (SR-TAD).\n\n
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Co-Mn Mixed Oxides Preared by Magnetron Sputtering on Meshes as Catalysts for Oxidation of Organic Compounds.
Jirátová, Květa ; Perekrestov, Roman ; Dvořáková, M. ; Balabánová, Jana ; Koštejn, Martin ; Topka, Pavel ; Kšírová, Petra ; Čada, Martin ; Hubička, Zdeněk ; Kovanda, F.
The catalysts with various Mn content were examined by XRD, SEM, FUR. XPS, and Ih-TPR. tested in the gas-phase oxidation of model organic compound (ethanol) and compared with pelletized commercial Co-Mn- Al mixed oxide catalyst (Astin 2-100, Czech Republic, Co:Mn:Al molar ratio of 4:1:1 ).
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Pulsed Laser Deposition under Low Background Gas Pressure.
Koštejn, Martin ; Fajgar, Radek ; Dřínek, Vladislav ; Jandová, Věra ; Klementová, Mariana ; Bakardjieva, Snejana
The nucleation of nanoparticles was applied during gold deposition onto TiO2 layers. For nucleation, up to 10 Pa of inert gas (argon) was used. Argon molecules efficiently helped to cool temperature of evolving plume and initiated the nucleation which resulted in deposition of gold nanoislands. Gold nanoparticles incorporated in TiO2 layers provided plasmonic properties. Au/TiO2 layers were used for water splitting as proved by photoelectrochemical measurements.
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The Novel Preparation of Hydrotreating Catalysts Using Machanochemical Activation of Aluminum Nitrate and NiMo Complexes.
Kaluža, Luděk ; Jirátová, Květa ; Tyuliev, G. ; Gulková, Daniela ; Balabánová, Jana ; Palcheva, R. ; Koštejn, Martin ; Spojakina, A.
The novel Al2O3 synthesis by mechanochemical activation of aluminum nitrate hydrate was applied to prepare hydrodesulfurization (HDS) NiMo catalysts. Impregnation techniques using the complex made by dissolution of nitrilotriacetic acid (NTA), ammonium heptamolybdate and nickel nitrate and the Anderson-type heteropolyoxymolybdate ((NH4)4Ni(OH)6Mo6O18) complex were compared with conventional impregnation using subsequent deposition of ammonium heptamolybdate (first) and nickel nitrate (second) with calcination in between. Properties of the support and HDS catalysts were studied by N2 physisorption, Raman spectroscopy, H2 temperature-programmed reduction (H2-TPR), O2 chemisorption and X-ray photoelectron spectroscopy (XPS).
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Regeneration of TFC PA Membrane Used for Permation of Hexane Vapours.
Petrusová, Zuzana ; Morávková, Lenka ; Štefková, V. ; Machanová, Karolina ; Jandová, Věra ; Koštejn, Martin ; Izák, Pavel ; Jansen, J.
This contribution is accomplished by the study of the membrane affinity via contact angle measurements and by structural analysis via electron he transport properties of the TFC PA were studied at various experimental conditions and the obtained results will be discussed.
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Hydrodesulfurization NiMo Catalysts over Mechanochemically Prepared Gamma-Alumina.
Kaluža, Luděk ; Jirátová, Květa ; Tyuliev, G. ; Palcheva, R. ; Koštejn, Martin ; Spojakina, A.
The aim of the present work is to explore optimum preparation route of NiMo catalysts for the novel mechanochemically prepared Al2O3 in order to achieve high HDS activity. Specifically, the goals are: i) to up-scale the support synthesis to provide sufficient amount ofAl2O3, ii) to deposit NiMo from solutions of highly soluble precursors by conventional impregnation techniques (I), i.e. sequential impregnation using Mo (first) and Ni (second), and by co-impregnation (Ni+Mo together), i.e. using chelating agent NTA or nickel heteropolyoxomolybdate (HPO), iii) to deposit NiMo from solutions ofslightly soluble precursors by slurry impregnation (SI).\n
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Preparation of Magnesium Silicide from Recycled Materials for Energy Storage.
Bumba, Jakub ; Dytrych, Pavel ; Šolcová, Olga ; Koštejn, Martin ; Fajgar, Radek ; Maléterová, Ywetta ; Kaštánek, František
Recycling technologies help to save energy, materials and environment. This is the main reason of their popularity. The recovery of semiconductors and metals depends on recycling treatment. A new multi-step technology, which enables to obtain pure silicon and hydrogen from waste materials,is reported in this study. The only by-product is magnesium phosphate, which is a desired fertilizer. Magnesium silicide was successfully prepared from milled silicon photovoltaic (PV) panels and milled Mg obtained from the scrap. The formed magnesium silicide was then hydrolysed by phosphoric acid to form a mixture of silanes. Gaseous products (silanes) were separated by cooling below their boiling temperature by liquid nitrogen and then thermally decomposed by a hot wire, e.g. Pt.This treatment leads to pure silicon and hydrogen release. In this study a deep-in characterization by various methods spectroscopy, Scanning Electron Microscopy (SEM) with Energy Dispersive X- Ray spectroscopy (EDX), etc.) of prepared samples was also done to explain the individual influences, e.g. reaction temperature and atmosphere.
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Generation of TiO2 Nanoparticles for Follow-Up Inhalation Experiments with Laboratory Animals
Moravec, Pavel ; Schwarz, Jaroslav ; Vodička, Petr ; Koštejn, Martin
A method of TiO2 nanoparticle generation appropriate for follow-up long lasting inhalation experiments with laboratory animals was tested. Nanoparticles were synthesized in an externally heated tube reactor using titanium tetraisopropoxide as a precursor. Total 264 hours of particle generation in four experimental campaigns was performed with one batch of precursor without observable decrease of precursor volatility. Particle production was studied in wide range of experimental conditions such as reactor temperature, reactor flow rate and precursor vapor pressure by pyrolysis, using nitrogen as a carrier gas, and also in oxidizing atmosphere (10 vol. % of oxygen in the reaction mixture). Particle characteristics were investigated by scanning/transmission electron microscopy, energy dispersive spectroscopy, inductively coupled plasma optical emission spectrometry, elemental and organic carbon analyzer, X-ray diffraction and X-ray photoelectron spectrometry. As a result, particle production with number concentration high above 1.0 x 10(7) #/cm(3) and with primary particle size well below 50 nm can be easily achieved in most of investigated experimental conditions. Particles are free of elemental carbon, content of organic carbon is less than 10 weight %, detected crystalline phase is typically anatase, Ti is present in bonds Ti-O (TiO2) and total Ti concentration recalculated on TiO2 is approximately 80 mass %.
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1 Kostejn, M.
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