Improving the oxygen permeability by a surface-coating layer

摘要

A GdBaCo_2O_(5+delta) layer was coated on the Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-delta) membranes to enhance their oxygen permeability by employing the fast oxygen adsorption/desorption surface-exchange properties of the GdBaCo_2O_(5+delta) material. The oxygen flux of the coated and uncoated Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-delta) membranes was measured in the temperature range of 600-850 deg C. The results reveal that the oxygen-permeation flux of the Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-delta) membranes coated by a GdBaCo_2O_(5+delta) layer shows significant enhancement. The GdBaCo_2O_(5+delta) layer coated on the oxygen desorption side (He side) has much effect than that coated on the oxygen adsorption side (air side). At 850 deg C, the oxygen flux with a single coating layer on the air side can rise 16 percent, while a single coating on the helium side will result into a rise of 23 percent.