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Andrzejczuk M.,Warsaw University of Technology | Vasylyev O.,Frantcevych Institute for Problems of Materials Science | Brychevskyi M.,Frantcevych Institute for Problems of Materials Science | Dubykivskyi L.,Frantcevych Institute for Problems of Materials Science | And 6 more authors.
Materials Science- Poland | Year: 2012

The structure of Ceria doped Scandia Stabilized Zirconia (1Ce10ScSZ) electrolyte film deposited by EB-PVD (Electron Beam-Physical Vapour Deposition) technique on NiO-ZrO 2 substrate was characterized by electron microscopy. The highly porous substrate was densely covered by deposited film without any spallation. The produced electrolyte layer was of a columnar structure with bushes, bundles of a diameter up to 30 um and diverse height. Between the columns, delamination cracks of few microns length were visible. The annealing of zirconia film at 1000 °C resulted in its densification. The columnar grains and delaminating cracks changed their shape into a bit rounded. High magnification studies revealed nanopores 5-60 nm formed along the boundaries of the columnar grains during annealing. High-quality contacts between the electrolyte film and anode substrate ensured good conductivity of the electrolyte film and high efficiency of SOFC. © 2012 Wroclaw University of Technology.

Brodnikovskyi I.,Frantcevych Institute for Problems of Materials Science | Chedryk V.,Pisarzhevsky Institute for Physical Chemistry | Vasyliv B.,Karpenko Physical and Mechanical Institute | Ostash O.,Karpenko Physical and Mechanical Institute | Vasylyev O.,Frantcevych Institute for Problems of Materials Science
ECS Transactions | Year: 2010

Long-term operation of the solid oxide fuel cell (SOFC) depends strongly on reliability of its components. In the case of SOFCs incorporating Ni-ScCeSZ anodes, hydrogen reduction of Ni results in changes in the chemistry, microstructure and properties of the Ni-ZrO2 anode material. In this work, the influence of microstructure of non-reduced (NiO-ScCeSZ) and reduced (Ni-ScCeSZ) anodes on their strength were studied. It was found considerable deterioration in mechanical behavior of Ni-ScCeSZ anodes after reduction comparing to initial state. Biaxial strength of anode samples decrease from ∼100 MPa in air at ambient temperature to -20 MPa after reduction in hydrogen atmosphere at 600°C. Reduced anode samples were used for studying its catalytic activity for conversion of methane into CO. The degradation of anode structures during reduction decreases its catalytic activity. © The Electrochemical Society.

Sadykov V.A.,RAS Boreskov Institute of Catalysis | Mezentseva N.V.,RAS Boreskov Institute of Catalysis | Bunina R.V.,RAS Boreskov Institute of Catalysis | Alikina G.M.,RAS Boreskov Institute of Catalysis | And 6 more authors.
Journal of Fuel Cell Science and Technology | Year: 2010

Ni/YSZ or Ni/ScCeSZ cermets were promoted by up to 10 wt % of fluoritelike (Pr-Ce-Zr-O, La-Ce-Zr-O, and Ce-Zr-O) or perovskitelike (La-Pr-Mn-Cr-O) oxides and small (up to 1.4 wt %) amounts of Pt group metals (Pd, Pt, or Ru). Reactivity of samples, their lattice oxygen mobility, and their ability to activate methane were characterized by temperature-programed reduction by CH4. The catalytic properties of these samples in methane steam reforming were studied at 500-850°C and short contact times (10 ms) in feeds with 8 mol % of CH4 and steam/methane ratio of 1:3. Oxide promoters ensure stable performance of cermets in stoichiometric feeds at T>650°C by suppressing carbon deposition. Copromotion with precious metals enhances performance in the intermediate temperature (450-600°C) range due to more efficient activation of methane. Factors determining specificity of these cermet materials' performance (chemical composition, microstructure, oxygen mobility in oxides, interaction between components, and reaction media effect) are considered. The most promising systems for practical application are Pt/Pr-Ce-Zr-O/Ni/YSZ and Ru/La-Pr-Mn-Cr-O/Ni/YSZ cermets demonstrating a high performance in the intermediate temperature range under broad variation in steam/CH4 ratio.). Copyright © 2010 by ASME.

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