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Preparation of CoMo/MgO Catalysts for Hydrodesulfurization
Gulková, Daniela ; Kaluža, Luděk ; Zdražil, Miroslav ; Vít, Zdeněk
The aim of the present work was to elucidate the possibility of deposition of molybdenyland cobalt- acetylacetonates on the high surface area MgO by impregnation from solutions of these compounds in methanol. Furthermore, non-aqueous solutions of MoO3 and CoCO3, (NH4)6Mo7O24 and Co(NO3)2, MoO2(C5H7O2)2 and Co(C5H7O2)2 with chelating agent nitrilotriacetic acid (NTA) were studied for CoMo deposition in one impregnation step.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22014082908311 - PDF
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Highly Loaded Carbon Black Supported Pt Catalysts for Fuel Cells
Kaluža, Luděk ; Zdražil, Miroslav ; Gulková, Daniela ; Vít, Zdeněk ; Šolcová, Olga ; Soukup, Karel ; Maixnerová, Lucie
The aim of this work was to elucidate on the methods of Pt deposition on carbon black to achieve high loadings of Pt of about 60 wt.% in highly dispersed form. The carbon black supports were characterized by nitrogen physisorption. Platinum was deposited on the supports: from true solutions of H2PtCl6, Pt(C5H7O2)2, Pt(NH3)4(NO3)2, or Pt(NH3)2(NO2)2, and from fine dispersions of Pt(C5H7O2)2, PtO2, Pt(NH3)4(OH)2. Atomic adsorption spectroscopy, AAS, and scanning electron microscopy, SEM, were used for elemental analysis and determination of Pt content. The deposited Pt species were dried, calcined or reduced and were subjected to temperature programmed reduction, TPR. After degassing at increased temperature, the Pt dispersion was determined by hydrogen chemisorption at -60 C.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22014082908313 - PDF
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Hydrodesulfurization CoMo/Al2O3 and CoMo/C Catalysts Prepared with Nitrilotriacetic Acid without Use of NH4OH
Kaluža, Luděk ; Zdražil, Miroslav ; Vít, Zdeněk
We have calculated and experimentally confirmed that in the catalysts without NTA before sulfidation, the deposited phase takes up only about 5% of the pore volume of Al2O3 support. The deposited Co-Mo-O phase forms a monolayer and all Co-Mo-species are in physical and chemical contact with the support surface. In NTA catalysts before sulfidation, the deposited NTA-Co-Mo phase takes up about 60% of the pore volume of Al2O3. During sulfidation, the metal-support interaction of the majority of the Co and Mo species is blocked not only chemically by their own NTA ligands, but also physically by the surrounding supported solid. The majority of deposited solid in dried NTA catalysts is sulfided as if it were in the unsupported form. This leads to different morphology and structure of Co-Mo sulfides as compared with the catalysts without NTA. It was concluded that the overall NTA action is a combination of not only chemical effects described in the literature, but also of the above physical effect.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22014082908312 - PDF
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