Alexander Karl Opitz

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In the search for optimized cathode materials for high-temperature electrolysis, mixed conducting oxides are highly promising candidates. This study deals with fundamentally novel insights into the relation between surface chemistry and electrocatalytic activity of lanthanum ferrite based electrolysis cathodes. For this means, near-ambient-pressure X-ray(More)
The oxygen exchange activity of mixed conducting oxide surfaces has been widely investigated, but a detailed understanding of the corresponding reaction mechanisms and the rate-limiting steps is largely still missing. Combined in situ investigation of electrochemically polarized model electrode surfaces under realistic temperature and pressure conditions by(More)
An array of analytical methods including surface area determination by gas adsorption using the Brunauer, Emmett, Teller (BET) method, combustion analysis, XRD, ToF-SIMS, TEM and impedance spectroscopy has been used to investigate the interaction of gadolinia doped ceria (GDC) with hydrogen sulphide containing reducing atmospheres. It is shown that sulphur(More)
A solid oxide electrolysis cell (SOEC) with a model-type La 0.6 Sr 0.4 FeO 3-d thin-film cathode (working electrode) on an yttria-stabilized zirconia electrolyte and a porous La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-d counterelectrode was operated in wet argon gas at the cathode. The hydrogen formation rate in the cathode compartment was quantified by mass(More)
Cation diffusion was investigated in La0.6Sr0.4CoO3-δ (LSC) thin films on (100) yttria stabilized zirconia in the temperature range 625-800 °C. Isotopic ((86)Sr) and elemental tracers (Fe, Sm) were used to establish diffusion profiles of the cations in bi- and multi-layered thin films. The profiles were analyzed by time of flight-secondary ion mass(More)
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