Mo-doped Pr_0.6Sr_0.4Fe_0.8Ni_0.2O_3-δ as potential electrodes for intermediate-temperature symmetrical solid oxide fuel cells

Mo-doped Pr_0.6Sr_0.4Fe_0.8Ni_0.2O_3-δ (PSFNM) perovskites are synthesized by a modified Pechini method and evaluated as both anode and cathode for intermediate-temperature symmetrical solid oxide fuel cell (SSOFC). The influence of Mo-doping on structure, conductivity, thermal expansion coefficient and electrochemical performance of Pr_0.6Sr_0.4Fe_0.8Ni_0.2O_3-δ (PSFN) electrode are investigated. The results indicate that PSFNM exhibits a cubic perovskite structure and shows a good reversibility. After heated at 800 °C for 10 h in humidified H₂, some new phases of SrPrFeO₄, Pr₂O₃, and Fe-Ni alloy in PSFNM are identified by powder X-ray diffraction analysis. Although the conductivity of Mo-doped sample is slightly decreased, the thermal expansion compatibility and hydrogen oxidation reaction (HOR) activity are gradually improved. The maximum power density of SSOFC increase from 435 mW/cm² to 500 mW/cm² at 800 °C, and the corresponding polarization resistance decrease from 0.102 Ω.cm² to 0.070 Ω.cm², respectively. In addition, the SSOFC with PSFNM electrode shows a robust stability after operating at 700 °C for 100 h. These results demonstrate that PSFNM is a promising electrode for SSOFC at intermediate temperatures.