Observation of Oxide Development from Room Temperature (RT) to 700 °C Demonstrated by In Situ XPS of Crofer 22 APU Alloy

The planar-type solid oxide fuel cell (SOFC) owes its design to the interconnector section which enables units of fuel cells to be stacked together. High operating temperature of SOFCs coupled with the gaseous environment, subjects this part to corrosion. To maintain its structural integrity, Fe-Cr alloy-based interconnector materials, such as Crofer 22 APU, rely on the formation of a protective layer which is directly affected by the alloy composition. In situ X-ray photoelectron spectroscopy (XPS) was used to study the surface composition and compounds of Crofer 22 APU from room temperature (RT) to 700 °C.