Performance of alternative oxide anodes for the electrochemical oxidation of hydrogen and methane in solid oxide fuel cells

The electrode performances of the alternative oxides: Lao _0.05Ca_0.95Cr_0.05Ti_0.95O _3-δ-8YSZ and Ce_0.8TM_0.2O _2-δ(TM=Mn, Co) for the direct electrochemical oxidation of methane are investigated to assess their potential as anode materials for efficient methane conversion in a SOFC. The electrochemical oxidation of hydrogen was also studied, for comparison. The oxides are characterised electrochemically with impedance spectroscopy in the frequency range from 10 mHz to 1MHz, using a three-electrode geometry. They are compared to a standard Ni/8YSZ anode for the electrochemical oxidation of hydrogen. It is found that La_0.05Ca_0.95Cr_0.05Ti_0.95O _3-δ-8YSZ demonstrates a poor electrochemical activity in both hydrogen and methane. However, the electrochemical activity of Ce _0.8Mn_0.2O_2-δ is promising, but the electronic conductivity needs to be increased, e.g., by adding a conducting oxide, before it can be used as an anode material in a SOFC.