Protonic conduction in oxides at elevated temperatures and their possible applications

Protonic conduction in oxide ceramics under hydrogen-containing atmosphere at elevated temperatures is reviewed with respect to oxide materials, their electrochemical properties, conduction mechanism and possible applications . These oxides are unique in respect of the fact that they have no protons as a host component hut incorporate protons via reactions with the atmosphe re. The materials of this class are some perovskite-type oxides and other o xides which contain crystal defects. Defect equilibria for proton formation in these kinds of oxides are discussed citing some experimental results. P ossible electrochemical devices using proton conducting ceramics are briefl y introduced.