Oxygen permeation through a CO 2 ‐tolerant mixed conducting oxide (Pr 0.9 La 0.1 ) 2 (Ni 0.74 Cu 0.21 Ga 0.05 )O 4+δ

A novel K 2 NiF 4 ‐type oxide based on (Pr 0.9 La 0.1 ) 2 (Ni 0.74 Cu 0.21 Ga 0.05 )O 4+δ (PLNCG) dense mixed conducting ceramic membrane was successfully prepared through a sol–gel route. The oxygen permeation flux through the membrane swept by pure CO 2 was comparative to that swept by He. The oxygen permeation and the stability of PLNCG under pure CO 2 were investigated in detail. A membrane with a thickness of 0.8 mm was steadily operated for 230 h with a constant oxygen permeation flux of 0.32 mL/(min cm 2 ) at 975 ° C using pure CO 2 as sweep gas. X‐ray diffraction shows that PLNCG can maintain its fluorite phase, and no carbonates were observed, even when it was exposed to pure CO 2 for a long time. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2473–2478, 2012