Effect of Zr-Doping on the Chemical Stability and Hydrogen Permeation of the Ni−BaCe_0.8Y_0.2O_3-_α Mixed Protonic−Electronic Conductor

Abstract

Successful development of hydrogen separation membranes based on mixed ionic and electronic conductors may improve the economics of hydrogen production. While high proton conductivity has been reported for many perovskite-type oxides in a humid atmosphere, materials with both high proton conductivity and good chemical stability under conditions for practical hydrogen separation are yet to be developed. In this paper, we report the effect of Zr-doping in BZCYs [Ba(Zr 0.8 - x Ce x Y 0.2 )O 3- α ] (0.4 ≤ x ≤ 0.8) on the proton conductivity and chemical stability. A novel Ni−BZCY7 [Ni−Ba(Zr 0.1 Ce 0.7 Y 0.2 )O 3- α ] cermet (metal−ceramic composite) membrane appears to have not only high proton conductivity but also adequate stability in a CO 2 - and H 2 O-containing atmosphere.