Cu1−xPdx/CeO2-impregnated cermet anodes for direct oxidation of methane in LaGaO3-electrolyte solid oxide fuel cells

A series of ceramic–metal composite anodes containing 1.0 wt.% Cu1−xPdx alloys (where x = 0, 0.15, 0.25, 0.4, 0.5, 0.75 and 1.0) were prepared by impregnation of the respective metal salts and 5.0 wt.% CeO2 into a porous La0.4Ce0.6O2−σ anode skeleton. The performance of these anodes was evaluated in both dry H2 and CH4 in the temperature range of 700–800 °C using the 300-μm thick La0.8Sr0.2Ga0.83Mg0.17O3−σ (LSGM) electrolyte-supported solid oxide fuel cells (SOFCs). The addition of Pd to Cu significantly increased the performance of the single cells in dry CH4, with the cell maximum power density changed from 66 mW cm−2 for Cu1.0Pd0.0 to 345 mW cm−2 for Cu0.0Pd1.0 at 800 °C. In H2, however, the performance improvement was not as significant compared to that in CH4. In addition, carbon formation was greatly suppressed in the Cu–Pd alloy-impregnated anodes compared to that with pure Pd after exposure to dry CH4 at 800 °C, which led to different performance stability behaviors for these cells operating with dry CH4.