Oxygen permeable mixed conductor membranes

Abstract

The present invention relates to novel solid state mixed conductor membranes and their use for separating oxygen from oxygen-containing feeds at elevated temperatures. The membranes comprise a multicomponent metallic oxide of substantially cubic perovskite structure, stable in air over the temperature range of 25.degree.-950.degree. C., having no connected through porosity wherein the membrane is of a composition represented by the formula ›A.sub.1-x A'.sub.x !›Co.sub.1-y-z B.sub.y B'.sub.z !O.sub.3-.delta., where A.tbd.Ca, Sr, Ba, and mixtures thereof; A'.tbd.La, Y, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, U, and mixtures thereof; B.tbd.Fe, Mn, Cr, V, Ti, and mixtures thereof; B'.tbd.Cu, Ni, and mixtures thereof; .about.0.0001.ltoreq.x.ltoreq..about.0.1; .about.0.002.ltoreq.y<0.05; .about.0.0005.ltoreq.z.ltoreq..about.0.3; .delta. is determined by the valence of the metals.

Dependencies are inferred from the claim text.