A new symmetric solid oxide fuel cell with a samaria-doped ceria framework and a silver-infiltrated electrocatalyst

A new symmetric SOFC with an SDC framework and a silver-infiltrated electrocatalyst is presented for the first time in this paper. A three-electrode polarization test shows that the Ag–SDC has a low area specific resistance of 1.07   Ω   cm 2 at 600   °C, a low activation energy of 85   kJ   mol −1 and high exchange current densities of 428.2 and 129.0   mA   cm −2 at 750 and 650   °C, respectively, when it is used as an oxygen reduction electrode. It also exhibits low polarization resistance in a humidified hydrogen atmosphere. A symmetric single cell is used in real fuel cell conditions to deliver peak power densities of 200 and 84   mW   cm −2 at 750 and 650   °C, respectively, when humidified hydrogen is used as a fuel and ambient air is used as the cathode atmosphere. The cell still reaches a peak power density of 81   mW   cm −2 at 750   °C when operating on CO. O 2 -TPO analysis demonstrates that the Ag–SDC electrode has even better coking resistance than the pure SDC scaffold. The results indicate that Ag–SDC|SDC|Ag–SDC symmetric cells with an infiltrated silver electrocatalyst are a promising new type of fuel cell for use with both hydrogen fuel and carbon-containing fuels.