A CO2-Stable K2NiF4-Type Oxide(Nd0.9La0.1)2(Ni0.74Cu0.21Al0.05)O4+δfor Oxygen Separation.

A K2NiF4-type oxide (Nd0.9La0.1)2(Ni0.74Cu0.21Al0.05)O4+δ(NLNCA) has been successfully synthesizedby a sol–gel method. The oxygen permeation and stability ofthe NLNCA membrane under CO2atmosphere were systematicallystudied. A steady oxygen permeation flux of 0.39 mL/(min·cm2) was obtained through the NLNCA membrane with a membranethickness of 0.6 mm at 975 °C when CO2was used asthe sweep gas. More importantly, the oxygen permeation flux has nosignificant decrease during 250 h operation, which indicates thatthe NLNCA membrane is stable under CO2. X-ray diffractionanalysis of the spent membrane shows that the membrane retains K2NiF4-type structure and no carbonate was formedeven exposed to CO2after 250 h operation. The resultsindicate that the NLNCA membrane has a great potential applicationin supplying oxygen for oxyfuel combustion with CO2capture.Moreover, the cost of the NLNCA is low, and it is beneficial for industrialapplication. [ABSTRACT FROM AUTHOR]