Pr-Doped SrTi0.5Mn0.5O3−δ as an Electrode Material for a Quasi-Symmetrical Solid Oxide Fuel Cell Using Methane and Propane Fuel

The use of identical electrodes for both the cathode and the anode in a symmetrical solid oxide fuel cell (SSOFC) can simplify the preparation process and increase the durability of the cell, but it is also demanding on the properties of the electrode including stability, electric conductivity, and electrocatalysis. The doping of variable-valence Mn 4+/3+2+ on the B site of stable SrTiO 3 is explored in this study as both the cathode and the anode for an SSOFC. Though the limit of Mn doping in SrTiO 3 is generally low, the additional Pr 3+/4+ donor on the Sr site of SrTi 0.5 Mn 0.5 O 3 was found to enhance the structure stability, electric conductivity, and electrocatalysis. The cell with Pr 0.5 Sr 0.5 Ti 0.5 Mn 0.5 O 3 electrodes excels under H 2, propane, or CH 4 /H 2 fuel, providing the cocatalyst was infiltrated on the anode side. The polarization resistance value of Pr 0.5 Sr 0.5 Ti 0.5 Mn 0.5 O 3 was 0.27 Ω·cm 2 as the cathode and 0.33 Ω·cm 2 for the SSOFC using H 2 fuel. The performance under CH 4 /H 2 fuel can be boosted to above 0.9 W cm –2 if Ni/ceria was loaded onto the anode to enhance the methane reforming. This work contributes to a perovskite anode with high Mn doping in SrTiO 3 for application in SSOFC for natural gas with renewable H 2 injection.