An Examination of SOFC Anode Functional Layers Based on Ceria in YSZ

The properties of solid oxide fuel cell (SOFC) anode functional layers prepared by impregnation of ceria and catalytic metals into porous yttria-stabilized zirconia (YSZ) have been examined for operation at . By varying the thickness of the functional layer, the conductivity of the ceria-YSZ composite was determined to be only . The initial performance of anodes made with ceria loadings of 40 or were similar but the anodes with lower loadings lost conductivity above due to sintering of the ceria. The addition of dopant levels of catalytic metals was found to be critical. The addition of Pd or Ni decreased the anode impedances in humidified dramatically, while the improvement with Cu was significant but more modest. Pd doping also decreased the anode impedance in dry much more than did Cu doping; however, addition of either Pd or Cu led to similar improvements for operation in n -butane. Based on these results, suggestions are made for ways to improve SOFC anode functional layers.