Oxygen permeability and stability of dual-phase Ce0.85Pr0.15O2-δ-Pr0.6Sr0.4Fe0.9Al0.1O3-δ membrane for hydrogen production by water splitting

A series of dense xCe0.85Pr0.15O2-δ (CP) -(100-x) Pr0.6Sr0·4Fe0·9Al0·1O3-δ (PSFA) (x = 30, 40, 50, 60, 70) dual-phase oxygen transport membranes were successfully synthesized by sol-gel method. The feasibility of xCP-(100-x) PSFA membranes for hydrogen production by thermochemical water splitting was explored by testing in the thermochemical stability, oxygen permeability, hydrogen production efficiency, and performance degradation mechanism of these membranes. The results show that the thermochemical stability of xCP-(100-x) PSFA membranes is improved with the CP content increasing. The oxygen permeation model demonstrates that appropriate CP content is beneficial to reduce the permeation resistance of xCP-(100-x) PSFA membranes, and the reaction of surface exchange plays a major role in the oxygen transport process at 925 °C. The formation of Fe(SiO3) and Sr3Fe2O7 on the sweep side leads to the decline in hydrogen production rate. The 60CP-40PSFA membrane showed the best comprehensive performance with a hydrogen production retention rate of 90% and a stable hydrogen production rate of 0.99 ml cm−2 min−1 in the 100-h test cycle.