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

BaCO3 nanoparticles are demonstrated as outstanding catalysts for high-temperature oxygen reduction reaction on the La0.8Sr0.2FeO3-delta (LSF)-Sm0.2Ce0.8O2-delta (SDC) cathode for solid oxide fuel cells (SOFCs). X-ray diffraction shows that BaCO3 is chemically compatible with LSF and SDC under the fabrication and operation conditions of intermediate-temperature SOFCs. The BaCO3 nanoparticles can greatly reduce the interfacial polarization resistance; from 1.65 to 0.35 Omega cm(2) at 700 degrees C when 7.6wt% BaCO3 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 BaCO3 nanoparticles can greatly enhance the oxygen ions transfer and surface reaction steps in LSF-SDC composite cathode. In addition, LSF-SDC cathodes with infiltrated BaCO3 nanoparticles have shown excellent stability and substantially enhanced single-cell performance, suggesting BaCO3 nanoparticles are very effective as a catalytic phase for LSF-SDC cathode.