Evaluation of the Effect of Sulfur on the Performance of Nickel/Gadolinium‐Doped Ceria Based Solid Oxide Fuel Cell Anodes

The focus of this study is the measurement and understanding of the sulfur poisoning phenomena of Ni/gadolinium‐doped ceria (CGO) based solid oxide fuel cells (SOFC). Cells with Ni/CGO10 and NiCu5/CGO40 anodes were characterized by using impedance spectroscopy at different temperatures and H(2)/H(2)O fuel ratios. The short‐term sulfur poisoning behavior was investigated systematically at temperatures of 800–950 °C, current densities of 0–0.75 A cm(−2), and H(2)S concentrations of 1–20 ppm. A sulfur poisoning mitigation effect was observed at high current loads and temperatures. The poisoning behavior was reversible for short exposure times. It was observed that the sulfur‐affected processes exhibited significantly different relaxation times that depend on the Gd content in the CGO phase. Moreover, it was demonstrated that the capacitance of Ni/CGO10 anodes is strongly dependent on the temperature and gas‐phase composition, which reflects a changing Ce(3+)/Ce(4+) ratio.