Novel CO2-tolerant dual-phase Ce0.9Pr0.1O2-d - La0.5Sr0.5Fe0.9Cu0.1O3-d membranes with high oxygen permeability

A series of novel dense, CO2-tolerant, oxygen permeable, dual-phase membranes made of Ce0.9Pr0.1O2-d - La0.5Sr0.5Fe0.9Cu0.1O3-d (CPO-LSFCO) with different CPO : LSFCO weight ratios (2:8, 4:6, 6:4 and 8:2) was prepared by an one-pot EDTA-citric acid method. Their chemical compatibility, oxygen permeability, CO2 tolerance and long-term stability regarding the phase structure and composition in different atmospheres were studied. A direct dependency of the oxygen permeation flux through the membranes on the CPO : LSFCO weight ratio was obtained. The highest permeation fluxes of 0.93 mL min−1 cm−2 and 0.71 mL min−1 cm−2 under an air/He and an air/CO2 gradient, respectively, through a 0.5 mm thick membrane at 1173 K were measured for a weight ratio of 4:6. Especially, the membranes showed excellent chemical resistance towards CO2 for more than 2050 h and CO2 plasma for more than 20 h. This work demonstrates that dual-phase CPO-LSFCO membranes are promising, chemically stable candidates as oxygen suppliers or oxygen distributors for industrial applications.