Klementina Zupan, Stane Pejovnik, Jadran Maček

Faculty of Chemistry and Chemical Technology, University of Ljubljana
 

ABSTRACT

Lanthanum chromite-based materials have a great potential for use in various high temperature applications and as SOFC (solid oxide fuel cell) separators. Submicron crystalline lanthanum chromite was prepared by the autoignition of a citrate- nitrate gel. The effect of the fuel- oxidant molar ratio and sample form prior to combustion was investigated in terms of phase formation, particle size, morphology, and agglomerate formation. Various characterization methods, including X-ray powder diffraction and thermal analysis, scanning electron microscopy and BET measurement, were used to evaluate powder characteristics. It was shown that the reaction period depends on the fuel/oxidant ratio and reaction mixture packing. The lanthanum chromite powders prepared via the combustion route exhibited surface areas of about 12 m²/g for the loose packed layer prepared samples and 8.8 to 13 m²/g for the samples prepared from a pellet.