US 5,580,497 A · Oxygen ion-conducting dense ceramic

Abstract

Preparation, structure, and properties of mixed metal oxide compositions containing at least strontium, cobalt, iron and oxygen are described. The crystalline mixed metal oxide compositions of this invention have, for example, structure represented by Sr.sub..alpha. (Fe.sub.1-x Co.sub.x).sub..alpha.+.beta. O.sub..delta. where x is a number in a range from 0.01 to about 1, .alpha. is a number in a range from about 1 to about 4, .beta. is a number in a range upward from 0 to about 20, and .delta. is a number which renders the compound charge neutral, and wherein the composition has a non-perovskite structure. Use of the mixed metal oxides in dense ceramic membranes which exhibit oxygen ionic conductivity and selective oxygen separation, are described as well as their use in separation of oxygen from an oxygen-containing gaseous mixture.

Claims12

Dependent claims

A crystalline mixed metal oxide composition represented by

Sr.sub..alpha. (Fe.sub.1-x Co.sub.x).sub..alpha.+.beta. O.sub..delta.
where x is a number in a range from 0.01 to about 1, .alpha. is a number in a range from about 1 to about 4, .beta. is a number in a range from 0 to about 20, wherein
<
(.alpha.+.beta.)/.alpha.<6,
and .delta. is a number which renders the compound charge neutral, and wherein the composition has a powder X-ray diffraction pattern as follows:
______________________________________ Principal XRD Lines Interplanar Assigned Spacing d, .ANG. Strength ______________________________________ 9.52 .+-. .05 Weak 3.17 .+-. .05 Weak 2.77 .+-. .05 Medium-Strong 2.76 .+-. .05 Medium-Strong 2.73 .+-. .03 Very Strong 2.08 .+-. .03 Weak-Medium 1.96 .+-. .02 Medium 1.90 .+-. .02 Weak-Medium 1.592 .+-. .009 Weak-Medium 1.587 .+-. .009 Medium 1.566 .+-. .009 Weak. ______________________________________

3 more elements

Dependencies are inferred from the claim text.

Oxygen ion-conducting dense ceramic

Life of this patent

Oxygen ion-conducting dense ceramic

Life of this patent

Abstract

Claims12