|
| |
|
|
Activity of K-Promoted Co-Mn-Al Mixed in Direct Decomposition of No and Deep Oxidation of Ethanol.
Jirátová, Květa ; Balabánová, Jana ; Pacultová, K. ; Karásková, K. ; Klegová, A. ; Obalová, L.
In this study, Co-Mn-Al mixed oxides modified by K were prepared by co-precipitation of a solution of metal nitrates with the aqueous solution of K2CO3 and KOH, washing the precipitates to different level of K concentrations and finally calcined at chosen temperature, usually 500 °C. The catalysts were characterized by AAS, nitrogen physisorption (Sbet), TPR-H2, XRD, and TPD- CO2. In case of direct NO decomposition, the catalysts pre-calcined at 700 °C were tested for direct NO decomposition in inert gas (650 °C, 0.5 g, 1000 ppm NO/N2, 49 ml min"1). Deep oxidation of ethanol was carried out under following conditions: 0.2 g, 760 ppm of ethanol in air, 4 000 ml h'1, the temperature ramp of 2 °C min'1.
Fulltext:  PDF
|
|
| |
|
|
Magnetic properties of doped CeO.sub.2./sub. nanoparticles and CeO.sub.2./sub.-Fe.sub.2./sub.O.sub.3./sub. mixed oxides
Mantlíková, Alice ; Bittová, Barbara ; Burianová, Simona ; Vejpravová, Jana ; Nižňanský, D. ; Holec, Petr
We have investigated magnetic properties of CeO2 nanoparticles and CeO2/SiO2 nanocomposites doped by various magnetic metal oxide ions (Fe, Gd, Sm, Nd). Samples were obtained by co-precipitation and sol-gel method. Particle size has been obtained as 5 - 25 nm for nanocomposite and 25 - 100 nm for nanoparticles increasing with the increase of the annealing temperature. Detailed measurements of magnetization demonstrate paramagnetic state in the majority of the doped samples with maximum magnetization decreasing with the decrease of effective magnetic moment of the dopant ions from Gd3+ to Nd3+. It has been also observed, that the high-coercivity ε-Fe2O3 forms in CeO2-Fe2O3/SiO2 nanocomposite for higher concentration of the Fe ions (Ce/Fe/Si ratio equal to 1/2/9) and for the highest annealing temperature.
|
|
|
Total Oxidation of Organic Compounds in Air over Oxide Catalysts
Ludvíková, Jana ; Jirátová, Květa ; Kovanda, F. ; Klempa, Jan
The aim of this work was investigation of the influence of various combinations of metals, Cu, Co, Ni, Mn or Al on properties of LDH (layered double hydroxides)-precursors and their calcined forms, examination of formation of these layered double hydroxides on a model support (anodized aluminum foil), and determination of catalytic activity of the calcined precursors in oxidation of ethanol as model compound.
Fulltext: PDF
|
|
| |
|
| |
guest ::
