Impedance spectra were recorded on electrolyte based symmetric cells Cu/BCZY/Cu in the temperature range 750-600°C, in dry and moist reducing atmospheres. The area specific resistances (ASR) of these three electrodes were found to be lower in moist gases and were two orders of magnitude lower than that measured on painted Cu electrodes (see figure) . At 700°C, in 3% moist forming gas, ASR of 2.9, 3.8 and 22.7 Ω∙cm2 were calculated on the Cu electrodes with the Pd, Ru and Cu activation catalyst respectively.
The microstructure of the electrodes was evaluated before and after electrochemical testing. In all cases, nano-pores were present on the as-deposited electrodes. After exposure to dry and moist reducing atmosphere at high temperatures, the microstructure of the Pd/Cu and Ru/Cu did not change significantly while major reorganisation was observed for the Cu/Cu electrode.
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