Synthesis and structural characterization of Co-doped lanthanum strontium titanates

NAPOLITANO, FEDERICO; LAMAS, DIEGO; SOLDATI, ANALIA L.; SERQUIS, ADRIANA C.

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2012 vol. 37 p. 18302 - 18309

0360-3199

Lanthanum strontium titanates based oxides, materials with perovskite-type crystalstructure, are good candidates for symmetrical fuel cell electrodes. They can become goodmixed conductors (electronic and ionic) and reach adequate electrocatalytic activity forboth oxygen reduction and fuel oxidation reactions if the right doping or structuralmodification of the (La,Sr)TiO3 compound is performed. However, the crystallographicinformation reported in the literature indicates a noticeable lack of reproducibility, since itis strongly dependent on synthesis conditions. In this work, La0.4Sr0.6Ti1
yCoyO3-d(0.0  y  0.5) synthesis by a low-temperature chemical route and its structural characterizationby X-ray powder diffraction and transmission electron microscopy are reported.From Rietveld refinements results, charge compensation mechanisms are studied andtheir correlation with synthesis parameters is discussed. We show that the creation of Srvacancies at the A-site of the perovskite-type structure is the main compensation mechanismand their concentration decreases with the incorporation of Co in the crystalstructure.