This title appears in the Scientific Report : 2013 

Synthesis and Characterization of Nonsubstituted and Substituted Proton-Conducting La6−xWO12−y
Seeger, J. (Corresponding author)
Ivanova, Mariya / Meulenberg, W. A. / Sebold, D. / Stöver, D. / Scherb, T. / Schumacher, G. / Escolástico, S. / Solís, C. / Serra, J. M.
Werkstoffsynthese und Herstellungsverfahren; IEK-1
Inorganic chemistry, 52 (2013) 18, S. 10375−10386
Washington, DC American Chemical Society 2013
Journal Article
Solid Oxide Fuel Cell
Power Plants
Please use the identifier: in citations.
Mixed proton−electron conductors (MPEC) can be used as gas separation membranes to extract hydrogen from a gas stream, for example, in a power plant. From the different MPEC, the ceramic material lanthanum tungstate presents an important mixed protonic−electronic conductivity. Lanthanum tungstate La6−xWO12−y (with y = 1.5x + δ and x =0.5−0.8) compounds were prepared with La/W ratios between 4.8 and 6.0 and sintered at temperatures between 1300 and 1500 °C in order to study the dependence of the single-phase formation region on the La/W ratio and temperature. Furthermore, compounds substituted in the La or W position were prepared. Ce, Nd, Tb, and Y were used for partial substitution at the La site, while Ir, Re, and Mo were applied for W substitution. All substituents were applied in different concentrations. The electrical conductivity of nonsubstituted La6−xWO12−y and for all substituted La6−xWO12−y compounds was measured in the temperature range of 400−900 °C in wet (2.5% H2O) and dry mixtures of 4% H2 in Ar. The greatest improvement in the electrical characteristics was found in the case of 20 mol % substitution with both Re and Mo. After treatment in 100% H2 at 800 °C, the compounds remained unchanged as confirmed with XRD, Raman, and SEM.