Mo-doped Pr0.6Sr0.4Fe0.8Ni0.2O3-δ as potential electrodes for intermediate-temperature symmetrical solid oxide fuel cells

•Mo-doped Pr0.6Sr0.4Fe0.8Ni0.2O3-δ (PSFNM) perovskites with good redox reversibility are developed as new cobalt-free electrodes for SSOFCs.•Mo doping remarkably improves thermal expansion compatibility and hydrogen oxidation reaction (HOR) activity.•Mo doping dramatically enhances the electrochemical performance at intermediate temperatures.•Maximum power density of 500 mW/cm2 for SSOFC is obtained at 800 °C.•Mo doping leads to improved long-term stability for SSOFC after operating at 700 °C for 100 h.

Mo-doped Pr0.6Sr0.4Fe0.8Ni0.2O3-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 Pr0.6Sr0.4Fe0.8Ni0.2O3-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.