Thermal, electrical, and electrocatalytical properties of lanthanum-doped strontium titanate

Thermal, electrical and electrocatalytical properties of LaxSr1−xTiO3, where x=0.1, 0.2, 0.3, 0.35, and 0.4, perovskite compositions are studied in relation to their potential use as solid oxide fuel cell (SOFC) anode materials. An emphasis is made on the effect of oxidation–reduction cycling on these properties. Depending on the dopant amount, x, and the oxygen partial pressure, LaxSr1−xTiO3 possesses an electrical conductivity on the order of 0.01–500 S/cm at 800–1000 °C. The thermal expansion of LaxSr1−xTiO3 is close to that of yttria-stabilized zirconia (YSZ). No significant chemical expansion or contraction of LaxSr1−xTiO3 with x<0.4 is observed when exposed to a wide variation in pO2. LaxSr1−xTiO3 is found to be dimensionally and chemically stable when subjected to oxidation–reduction cycling. Cell tests demonstrated the potential ability of the doped titanates to be used as SOFC anodes.