Abstract: The Sm0.5Sr0.5CoO3-δ(SSC) cathode was fabricated under slightly overfired condition and was in situ treated with 25%CO2 (V/V) under single cell operating circumstance. XRD and TG analysis demonstrated that some SrCO3 and Co3O4 appeared on the SSC surface after CO2 treatment at 600 ℃. The existence of SrCoO3-δand Co3O4 under air sweep condition resulted in the changes of physicochemical properties of cathode surface to some extent. The acceleration of oxygen reduction rate of the cathode electrocatalyst evidently decreased the polarization resistance and consequently yielded about 20% higher cell performance than the untreated one.

Key words: samarium, strontium, cobalt, carbon dioxide, polarization resistance, cathode electrocatalyst, solid oxide fuel cell