Cu 1− xPd x/CeO 2-impregnated cermet anodes for direct oxidation of methane in LaGaO 3-electrolyte solid oxide fuel cells

Abstract

A series of ceramic–metal composite anodes containing 1.0 wt.% Cu 1− x Pd x 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.% CeO 2 into a porous La 0.4Ce 0.6O 2− σ anode skeleton. The performance of these anodes was evaluated in both dry H 2 and CH 4 in the temperature range of 700–800 °C using the 300-μm thick La 0.8Sr 0.2Ga 0.83Mg 0.17O 3− 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 CH 4, with the cell maximum power density changed from 66 mW cm −2 for Cu 1.0Pd 0.0 to 345 mW cm −2 for Cu 0.0Pd 1.0 at 800 °C. In H 2, however, the performance improvement was not as significant compared to that in CH 4. In addition, carbon formation was greatly suppressed in the Cu–Pd alloy-impregnated anodes compared to that with pure Pd after exposure to dry CH 4 at 800 °C, which led to different performance stability behaviors for these cells operating with dry CH 4.