Oxygen permeation performance of Ba0.5Sr0.5Co0.8Fe0.2O3-δ membrane after surface modification

The effect of minor surface modification on the performance of Ba0.5Sr0.5Co0.8Fe0.2O3-delta membrane was evaluated in the temperature region from 700 to 850 degrees C. Oxygen permeation experiments were conducted according to membrane thickness (1.0 mm and 1.6 mm) and oxygen partial pressure (0.21, 0.42, and 0.63 atm) in the absence and in the presence of carbon dioxide (300 and 500 ppm). The oxygen permeation flux of Ba0.5Sr0.3Co0.8Fe0.2O3-delta membrane increased with increasing temperature and decreasing membrane thickness. The oxygen permeation flux through the membrane of 1.0 mm thickness with Ba0.5Sr0.5Co0.8Fe0.2O3-delta-modified surface was ca. 1.23 ml/cm(2).min at 850 degrees C under air feeding condition. It was found that the Ba0.5Sr0.5Co0.8Fe0.2O3-delta-modified Ba0.5Sr0.5Co0.8Fe0.2O3-delta membrane has better oxygen permeation flux than the pristine Ba0.5Sr0.5Co0.8Fe0.2O3-delta membrane. In summary, it has been demonstrated that the surface morphology is an important factor in determining the oxygen permeation fluxes through Ba0.5Sr0.5Co0.8Fe0.2O3-delta membrane under mixed-control conditions.