Coompositions capable of operating under high carbon dioxide partial

Abstract

The present invention presents a new class of multicomponent metallic oxides which are particularly suited toward use in fabricating components used in solid-state oxygen separation devices. The compositions of the present invention are represented by the formula Ln.sub.x A'.sub.x' A'.sub.x' B.sub.y B'.sub.y' B'.sub.y' O.sub.3-z, wherein Ln is an element selected from the f block lanthanides, A' is selected from Group 2, A' is selected from Groups 1, 2 and 3 and the f block lanthanides, and B,B',B' are independently selected from the d block transition metals, excluding titanium and chromium, wherein 0.ltoreq.x<1, 0<x'<1, 0.ltoreq.x'<1, 0<y<1.1, 0<y'<1.1, 0<y'<1.1, x+x'+x'=1.0, 1.1>y+y'+y'>1.0 and z is a number which renders the compound charge neutral wherein such elements are represented according to the Periodic Table of the Elements adopted by IUPAC. These compositions provide superior resistance to degradation when employed in such devices under process conditions of high carbon dioxide and water partial pressures.