Spatial sulfur poisoning behavior associated with in‐plane electrochemical performance variation of solid oxide fuel cells

Abstract

AbstractIn this study, sulfur poisoning behavior is investigated on a 5 × 5 cm2 anode‐supported cell as a function of H2S concentration, cell voltage, and in‐plane region. At a lower cell voltage, the 1st drop % in the current density decreases by promoting sulfur desorption while the 2nd drop % increases slightly. The outlet regions with poor performance show a lower drop % owing to the water vapor effect, while the inlet regions with superior performance show a higher drop %, especially at high H2S concentrations. Ni oxidation in the inlet regions is caused by the substantial 2nd drop under the combined conditions of high current density and H2S concentration, whereas that in the outlet region is caused by the high H2O concentration. The results indicate that in‐plane performance variation may aggravate sulfur poisoning in the inlet regions, whereas it may lead to Ni oxidation in the outlet regions.