Defect chemistry and oxygen permeation property of Pr2Ni0.75Cu0.25O4 oxide doped with Ga

Abstract Mixed conductivity and oxygen permeation property in Pr 2 Ni 0.75 Cu 0.25 Ga 0.05 O 4 were investigated. After examining various Ga concentrations, it was found that cation excess composition of Pr 2 Ni 0.75 Cu 0.25 Ga 0.05 O 4 achieved the highest oxygen permeability of 298 μmol·min − 1 ·cm − 2 (6.68cc·min − 1 ·cm − 2 ) at 1273 K from air to He with a 0.5 mm thickness. The oxygen permeability of Pr 2 Ni 0.75 Cu 0.25 Ga 0.05 O 4 increased with increasing the activity of surface catalyst and the highest permeation was achieved when La 0.9 Sr 0.1 Co 0.8 Fe 0.2 O 3 was used for the surface catalyst. The oxygen nonstoichiometry was further studied by using thermogravimetry. It was confirmed that the excess amount of oxygen was introduced at high P O2 range, which might be the origin of the high oxygen permeation rate in this oxide.