Copper doped lanthanum strontium ferrite for reduced temperature solid oxide fuel cells

Copper doped lanthanum strontium ferrite showed superior kinetics for the electro-reduction of oxygen. The generic formulation was La1−xSrxCu1−yFeyO3 (LSCuF) where x ranged from 0.2 to 0.3 and y varied from 0 to 0.4. Doping with copper improved the electrocatalytic activity compared with undoped material. In oxygen, the La0.7Sr0.3Cu0.2Fe0.8O3 sample showed current densities approximately 2–3 times that of La0.7Sr0.3FeO3 and 10 times that of La0.8Sr0.2FeO3. This improvement was confirmed with cyclic voltammetric studies on half cells and on full fuel cell tests. Copper doped materials have unusual electrochemical characteristics and copper apparently undergoes a one electron reduction at overpotentials less than −0.1 V. This occurred only in air but not in oxygen.