Patent ID: 7556676

Claim:
A composite oxygen ion transport membrane comprising: a dense layer having an electronic phase and an ionic phase; said electronic phase is (La u Sr v Ce 1−u−v ) w Cr x Mn y V z O 3−5 , where u is from about 0.7 to about 0.9, v is from about 0.1 to about 0.3 and (1−u−v) is greater than or equal to zero, w is from about 0.94 to about 1, x is from about 0.67 to about 0.77, y is from about 0.2 to about 0.3, z is from about 0.015 to about 0.03, and x+y+z=1; said ionic phase is Zr x′ Sc y′ A z′ O 2−δ , where y′ is from about 0.08 to about 0.15, z′ is from about 0.01 to about 0.03, x′+y′+z′=1 and A is Y or Ce or mixtures of Y and Ce; a porous support layer, said porous support layer formed of Zr x″ A y″ O 2−δ , where y″ is from about 0.03 to about 0.05, x″+y″=1, A is Y or Sc or Al or Ce or mixtures of Y, Sc, Al and Ce.