Tailoring the Stability of Ti-Doped SrFeTiMoO Electrode Materials for Solid Oxide Fuel Cells.

In this work, the stability of Sr(FeMo)O-type perovskites was tailored by the substitution of Mo with Ti. Redox stable SrFeTiMoO (x = 0.1, 0.2 and 0.3) perovskites were successfully obtained and evaluated as potential electrode materials for SOFCs. The crystal structure as a function of temperature, microstructure, redox stability, and thermal expansion properties in reducing and oxidizing atmospheres, oxygen content change, and transport properties in air and reducing conditions, as well as chemical stability and compatibility towards typical electrolytes have been systematically studied. All SrFeTiMoO compounds exhibit a regular crystal structure with -3 space group, showing excellent stability in oxidizing and reducing conditions. The increase of Ti-doping content in materials increases the thermal expansion coefficient (TEC), oxygen content change, and electrical conductivity in air, while it decreases the conductivity in reducing condition. All three materials are stable and compatible with studied electrolytes. Interestingly, redox stable SrFeTiMoO, possessing 1 μm grain size, low TEC (15.3 × 10 K), large oxygen content change of 0.72 mol·mol between 30 and 900 °C, satisfactory conductivity of 4.1-7.3 S·cm in 5% H at 600-800 °C, and good transport coefficients and , could be considered as a potential anode material for SOFCs, and are thus of great interest for further studies.