Chemical, electrical, and thermal properties of strontium doped lanthanum vanadate

Strontium doped lanthanum vanadates, La1−xSrxVO3 (denoted LSV with x = 0, 0.3, 0.5, 0.7 and 1.0), were synthesized using a solid-state reaction method. The oxidation and reduction behaviors of LSV were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The chemical stability of LSV in a reducing atmosphere containing H2S up to 10 vol.% at 950 °C was investigated and their electrical conductivity at 500-1000 °C in reducing atmospheres measured with a 4-electrode technique. The coefficient of thermal expansion (CTE) was determined by dilatometry. The electrochemical catalytic activity of LSV as anodes in solid oxide fuel cells (SOFCs) was characterized using impedance spectroscopy. It was found that the La1−xSrxVO3 materials with x in the range of 0.3-0.7 exhibit good resistance to H2S, high electrical conductivity and acceptable catalytic activity at elevated temperatures in reducing atmosphere. However, the volume change associated with oxidation/reduction cycle may limit their tolerance to re-oxidation when used as anode materials for SOFCs.