Improved oxygen permeability of Ce0.8Sm0.2O2−δ–PrBaCo2O5+δ dual-phase membrane by surface-modifying porous layer

A porous PrBaCo2O5+δ or Ce0.8Sm0.2O2−δ–50 vol.% PrBaCo2O5+δ (SDC–PBCO (5/5)) layer was deposited on dense Ce0.8Sm0.2O2−δ–40 vol.% PrBaCo2O5+δ (SDC–PBCO (6/4)) membrane (450 μm) to enhance the oxygen permeability by increasing the surface area contacting with air. The oxygen permeation flux was measured in the temperature range of 825–945 °C. The results revealed that the oxygen permeation performance of Ce0.8Sm0.2O2−δ–PrBaCo2O5+δ membranes can be significantly enhanced by coating SDC–PBCO (5/5) porous layer alone on the surface of feed side. The thickness of modification layer has obvious effect on the permeability of surface modified membrane. The modification on the feed side has much better effect than that on the permeate side. At 945 °C, the oxygen permeation flux of dense SDC–PBCO (6/4) membrane modified by porous SDC–PBCO (5/5) layer is 3.56 × 10−7 mol cm−2 s−1, 26% higher than that of the unmodified one.

► SDC–PBCO porous layer can enhance the oxygen permeability of SDC–PBCO membrane.
► The modification on the feed side has better effect than that on both sides.
► SDC–PBCO layer exhibits better modification performance than pure PBCO layer.
► The thickness of modification layer has significant impact on the permeability.