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

A porous PrBaCO2O5+delta or Ce0.8Sm0.2O2-delta-50 vol.% PrBaCO2O5+delta (SDC-PBCO (5/5)) layer was deposited on dense Ce0.8Sm0.2O2-delta-40 vol.% PrBaCo2O5+delta (SDC-PBCO (6/4)) membrane (450 mu m) 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 degrees C. The results revealed that the oxygen permeation performance of Ce0.8Sm0.2O2-delta-PrBaCO2O5+delta 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 degrees C, the oxygen permeation flux of dense SDC-PBCO (6/4) membrane modified by porous SDC-PBCO (5/5) layer is 3.56 x 10(-7-) mol cm(-2) s(-1), 26% higher than that of the unmodified one. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.