Pr-Doped SrTi_0.5Mn_0.5O_3-δ as an Electrode Material for a Quasi-Symmetrical Solid Oxide Fuel Cell Using Methane and...

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 SrTiO₃ is explored in this study as both the cathode and the anode for an SSOFC. Though the limit of Mn doping in SrTiO₃ is generally low, the additional Pr^3+/4+ donor on the Sr site of SrTi_0.5Mn_0.5O₃ was found to enhance the structure stability, electric conductivity, and electrocatalysis. The cell with Pr_0.5Sr_0.5Ti_0.5Mn_0.5O₃ electrodes excels under H₂, propane, or CH₄/H₂ fuel, providing the cocatalyst was infiltrated on the anode side. The polarization resistance value of Pr_0.5Sr_0.5Ti_0.5Mn_0.5O₃ was 0.27 Ω·cm² as the cathode and 0.33 Ω·cm² for the SSOFC using H₂ fuel. The performance under CH₄/H₂ 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 SrTiO₃ for application in SSOFC for natural gas with renewable H₂ injection.