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 Ru0. The SSOFC with Ce/Ru codoped SrFeO3 on a Sr- and Mg-doped LaGaO3 electrolyte showed a small Rp value (0.12 Ω cm2) when H2 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 °C using H2 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 Ru0 nanoparticles.