LaCrO3-Based Anodes for Methane Oxidation

Electrocatalytic properties of Ca, Sr, Mg, Fe, Co and Ni substituted lanthanum chromites deposited on 8YSZ lelectrolytes were studied using I/V and impedance techniques. The studied parameters were: the sintering temperature, the polarization, the gas and the anode composition. The polarization resistance depended much on these parameters. Also, a direct relationship between the electric conductivity, the catalytic and the electrocatalytic activities was evidenced. The electrocatalytic behavior followed the trend of LaCrO3 ?LaCr0.9Co0.1O3-[delta] < LaCr0.9Ni0.1O3- [delta] < La0.85Sr0.15CrO3-[delta] < La0.85Sr0.15Cr0.9Ni0.1O3-[delta] which corresponded to the measured activities for steam-reforming and oxidation catalysis of the same powders used as catalysts. The best electrochemical result was obtained with a La0.85Sr0.15Cr0.9Ni0.1O3-[delta] - anode (450 mW/cm2 in H2 and 300 mW/cm2 in CH4, T=877°C, 150 µm YSZ)