A Ce/Ru Codoped SrFeO3-δ Perovskite for a Coke-Resistant Anode of a Symmetrical Solid Oxide Fuel Cell

Employment of identical oxides for the cathode and anode in a symmetrical solid oxide fuel cell (SSOFC) is beneficial for decreasing the fabrication costs of a robust cell. Ce doping on the A site of SrFeO3 increased the structural stability in a reducing atmosphere, but ceria was found to exsolve from the perovskite during the cooling process in the air if the doping level reached 20 atom %. The additional doping of 5 atom % Ru in Sr0.8Ce0.2FeO3 on the Fe site could prevent the ceria segregation in air and induce the surface decomposition under fuel conditions for the formation of nanoscale SrO, CeO2, and Ru-0. The SSOFC with Ce/Ru codoped SrFeO3 on a Sr- and Mg-doped LaGaO3 electrolyte showed a small R-p value (0.12 Omega cm(2)) when H-2 and ambient air were used as fuel and oxidant, respectively. The peak power densities of 846 and 310 mW cm(-2) were achieved at 800 degrees C using H-2 and C3H8 as fuel, respectively. The excellent coke resistance of the anode could be related to the simultaneous in situ exsolution of CeO2, SrO, and Ru-0 nanoparticles.