Characteristics and performance of electrolyte-supported solid oxide fuel cells under ethanol and hydrogen

A direct ethanol solid oxide fuel cell (SOFC) fabricated from conventional materials is described. The performance of Ni-cermet anodes with zirconia and ceria as the ceramic phase in SOFCs operating on hydrogen and ethanol is compared by means of current-voltage and impedance spectroscopy measurements in the 700-900 degrees C temperature range. The experimental data indicate that the studied ethanol-fueled SOFCs have comparable performance. However, different ceramic matrix and metallic phase composition of cermets result in different behavior of the ethanol direct oxidation. Below 800 degrees C, the performance of fuel cells is relatively more stable as compared to higher temperatures, but the catalytic activity for ethanol conversion of doped ceria is insufficient to prevent carbon formation. The experimental results provide evidence for the importance of an appropriate combination of fuel, operating conditions, and anode materials in designing SOFCs for direct operation using ethanol as fuel. (C) 2008 The Electrochemical Society.