Effect of Ceria Components on Anode Performance of Ni-base Anode in Hydrocarbon Fueled SOFC

摘要

Anode performance of nickel (Ni) - scandia stabilized zirconia (ScSZ) cermet, Ni- samaria doped ceria (SDC) cermet and 1 vol% of SDC finely dispersed Ni-ScSZ cermet (SD-Ni-ScSZ) was examined at 1073 K with hydrocarbon fueled solid oxide fuel cells (SOFCs) consisting of a ScSZ electrolyte and a Ni mesh current collector. At least two anode reaction processes were observed in the impedance spectra for all tested anodes. The one corresponding to the high frequency region was enhanced in the order of the Ni-ScSZ, SD-Ni-ScSZ and Ni-SDC, whereas that observed in the low frequency region seemed to be retarded in the same order. The effect can be ascribed to changing Ni surface state by SDC component in the anode. The SD-Ni-ScSZ anode shows the best performance; that shows the smallest overall anodic resistance and the highest hydrogen content in the outlet gas under the same fuel utilization operation among the tested anodes.