Selection and study of basic layered cobaltites as mixed ionic–electronic conductors for proton conducting fuel cells

Abstract High Temperature Steam Electrolysis using Proton Conducting Cells is a promising method for large-scale hydrogen production, but such system requires the development of new electrode materials ideally presenting Mixed Proton and Electron Conductivity. Different cobaltites were investigated in terms of durability and compatibility with the BaZr 0.9 Y 0.1 O 3 proton conducting electrolyte. REBaCo 2 O 5+ δ (RE = Pr, Nd, Sm, Gd, Y), YBaCo 4 O 7 , Ca 3 Co 4 O 9 and Ca 3 Co 2 O 6 , were considered, among which the vacancy ordered perovskites were found to be the most stable in wet air. Oxygen vacancy formation and hydration properties of REBaCo 2 O 5+ δ were studied by iodometry and TGA in dry and wet atmospheres, respectively.