Enhanced electrode reaction for La0.8Sr0.2FeO3-δ-Sm0.2Ce0.8O1.9 composite cathode by barium carbonate nanoparticles as a synergistic catalyst

BaCO 3 nanoparticles are demonstrated as outstanding catalysts for high-temperature oxygen reduction reaction on the La 0.8 Sr 0.2 FeO 3-δ (LSF)-Sm 0.2 Ce 0.8 O 2−δ (SDC) cathode for solid oxide fuel cells (SOFCs). X-ray diffraction shows that BaCO 3 is chemically compatible with LSF and SDC under the fabrication and operation conditions of intermediate-temperature SOFCs. The BaCO 3 nanoparticles can greatly reduce the interfacial polarization resistance; from 1.65 to 0.35 Ω cm 2 at 700 °C when 7.6wt% BaCO 3 is infiltrated to the porous LSF-SDC electrode. Electrochemical impedance spectra also show that there are both significantly decrease in high- and low-frequency resistance, indicating that BaCO 3 nanoparticles can greatly enhance the oxygen ions transfer and surface reaction steps in LSF-SDC composite cathode. In addition, LSF-SDC cathodes with infiltrated BaCO 3 nanoparticles have shown excellent stability and substantially enhanced single-cell performance, suggesting BaCO 3 nanoparticles are very effective as a catalytic phase for LSF-SDC cathode.