A preliminary study of a CH₄ / O₂ solid oxide fuel cell

Abstract

Lanthanum calcium chromite (LCC) supported on yttria stabilized zirconia (YSZ) prepared in this laboratory exhibits very good performances both as anode and cathode in a fuel cell when operated in the range of 1023 to 1173 K. In the anodic mode it shows reactivities towards H₂, CO and CH₄ oxidation with the products being CO₂ and H₂O. Current density of -100 mA cm^-2 at the cell potential of 900 mV is achieved while the maximum output power is obtained at ~ 200 mA cm^-2, and 400 mV cell voltage and corresponds to 140 mW cm^-2. In the experiments the theoretical cell voltage at the open circuit condition is not achieved. Very interestingly, under moderate loads the anodic selectivity is switched to CO and H₂ rather than CO₂ and H₂O and under high drain currents the cell behaves as an oxygen pump.