The influence of normalH2S fuel impurity on power generation characteristics of solid oxide fuel cells (SOFCs) has been analyzed by measuring cell voltage at a constant current density, as a function of normalH2S concentration, operational temperature, and fuel gas composition. Reversible cell voltage change was observed around 1000°C , while fatal irreversible degradation occurred at a lower operational temperature, at a higher normalH2S concentration, and at a lower fuel normalH2∕CO ratio. Sulfur tolerance of SOFCs was improved by using normalSc2normalO3 -doped ZrnormalO2 instead of normalY2normalO3 -doped ZrnormalO2 as electrolyte and/or as electrolyte component in the anode cermets. It has been found that normalH2S poisoning consists of at least two stages, i.e., an initial cell voltage drop within a short time period to a metastable cell voltage, followed by a gradual larger cell voltage drop. Possible normalH2S poisoning processes are discussed.

No abstract

No abstract

No abstract

No abstract