Y0.08Sr0.92FexTi1−xO3−δ perovskite for solid oxide fuel cell anodes

A single phase perovskite Y0.08Sr0.92FexTi1−xO3−δ (x = 0.05, 0.1,0 0.20, 0.25, 0.40, and 0.50) was fabricated at 1400 °C in air by a solid state reaction method and its electrical conductivity and electrochemical properties as an anode were investigated as a function of the Fe content. Doping with Y for Sr allowed the SrFexTi1−xO3−δ perovskite to be stable at 800 °C in a reducing atmosphere. At 900 °C, metallic Fe precipitated and the stability of the perovskite phase under a reducing atmosphere decreased as the Fe content increased. The conductivity of Y0.08Sr0.92FexTi1−xO3−δ (x = 0.40) was greater than that of the x = 0.20 sample. The conductivity of Y0.08Sr0.92FexTi1−xO3−δ was found to be 2 × 10−1 Scm−1 at 800 °C in H2. Sintering the Y0.08Sr0.92FexTi1−xO3−δ anode at 1200 °C was found to be optimum to obtain not only good interfacial adhesion, but also a fine grain structure. The Y0.08Sr0.92Fe0.25Ti0.75O3−δ anode exhibited the lowest polarization resistance (0.7 and 1.8 Ωcm2 at 800 and 700 °C).