Enhanced stability of perovskite Pr0.6Sr0.4Fe0.9Nb0.1O3-δ oxygen transport membrane for water splitting

The development of a perovskite-type oxygen transport membrane with high stability is desirable to meet the application of thermochemical water splitting to hydrogen production. The effect of stability enhancement of doped high valence ions of Nb 5+ in Pr 0.6 Sr 0.4 Fe 0.9 Nb 0.1 O 3- δ (PSFN) oxygen transport membrane was studied systematically, which is influenced by the crystal structure, thermal expansion property, and roles of Fe 3+/4+ ions. The introduction of Nb inhibits the high-temperature phase transition, thermal expansion, and lattice oxygen release, enhancing the structural stability even in a reducing atmosphere. Furthermore, the decrease in the average valence of Fe ions also enhances the chemical stability of PSFN. The relative proportion of Fe 3+ and Fe 4+ closer to 2:1, a considered steady status for the oxygen permeation process, contributes to the long-term stability of H 2 production performance from water splitting.