Stability of calcium substituted lanthanum chromites used as SOFC anodes for methane oxidation

La0.7Ca0.32CrO3, La0.75Ca0.15Sr0.1Cr0.95Mg0.05O3, La0.85Ca0.15CrO3 and La0. 85Ca0.15Cr0.9Mg0.1O3 compounds were studied in reducing atmospheres contain ing hydrogen, methane and CO/CO2. They were found to exhibit liquid phase s intering except for La0.85Ca0.15CrO3. Mg enhanced the densification of stoi chiometric LaCrO3. Current was found to affect the stability of the heavily doped samples, whereas the reducing atmospheres did not have a detectable impact. Calcium and or strontium and chromium enriched secondary phases wer e detected on current treated Ln(0.7)Ca(0.32)CrO(3) and La0.75Ca0.15Sr0.1Cr 0.95Mg0.05O3 samples. La0.85Ca0.15Cr0.9Mg0.1O3 did nor degrade under curren t, at least for 100 h. A current enhanced demixing could be responsable for the segregation. The solubility limit of calcium in LaCrO3 is thought to b e low at 800 degrees C (around 15%). (C) 1999 Elsevier Science Limited. All rights reserved.