Cathode materials for solid oxide electrolysis cells

The cathode in solid oxide electrolysis cells is the electrode at which water and carbon dioxide can be split into hydrogen, carbon monoxide, and oxygen ions. The state-of-the-art material is a Ni cermet, as developed for solid oxide fuel cells. This electrode shows promising electrolysis rates and compatibility with adjacent cell components, and a basic understanding of its electrode processes has also been gained. However, stability issues have recently triggered a search for alternative materials. Electronically conducting oxides, with or without activation by submicron-scale electrocatalysts, are of interest because of their stability in high water contents, as described in the last part of this chapter.