Improving the oxygen permeability of Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes by a surface-coating layer of GdBaCo2O5+δ

A GdBaCo2O5+δ layer was coated on the Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes to enhance their oxygen permeability by employing the fast oxygen adsorption/desorption surface-exchange properties of the GdBaCo2O5+δ material. The oxygen flux of the coated and uncoated Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes was measured in the temperature range of 600–850 °C. The results reveal that the oxygen-permeation flux of the Ba0.5Sr0.5Co0.8Fe0.2O3−δ membranes coated by a GdBaCo2O5+δ layer shows significant enhancement. The GdBaCo2O5+δ layer coated on the oxygen desorption side (He side) has much effect than that coated on the oxygen adsorption side (air side). At 850 °C, the oxygen flux with a single coating layer on the air side can rise 16%, while a single coating on the helium side will result into a rise of 23%.