Calcium cobalt zirconium perovskites as oxygen-selective sorbents for gas separation

1. A method for separating oxygen from a gas mixture which comprises

(a) preparing an oxygen-depleted perovskite from a perovskite having the formula CaCo 1-x Zr x O 3-δ wherein x is a number defined by 0.02≤x≤0.98; and δ is a number defined by 0.0≤δ≤1.0;

(b) contacting the oxygen-depleted perovskite under conditions such that the oxygen-depleted perovskite binds the oxygen from the gas mixture and generates an oxygenated perovskite with bound oxygen;

(c) treating the oxygenated perovskite under suitable conditions so as to regenerate the oxygen-depleted perovskite, release the bound oxygen from the oxygenated perovskite, and generate separated oxygen.

2. The method of claim 1 , wherein the conditions to release the bound oxygen from the oxygenated perovskite involve a pressure swing.

3. The method of claim 1 , wherein the conditions to release the bound oxygen from the oxygenated perovskite involve a temperature swing.

4. The method of claim 1 , wherein the gas mixture is air.

5. The method of claim 1 , wherein the gas mixture is a gas that is greater than 95% oxygen gas.

6. The method of claim 1 , wherein the perovskite has a formula wherein x is a number defined by 0.2≤x≤0.95.

7. The method of claim 6 , wherein the perovskite has a formula wherein x is a number defined by 0.4≤x≤0.95.

8. The method of claim 7 , wherein the perovskite has a formula wherein x is a number defined by 0.4≤x≤0.8.

9. The method of claim 1 , wherein the oxygen of step (b) is separated on a membrane comprising the perovskite.

10. The method of claim 1 , wherein the oxygen of step (b) is separated in a fluidized bed reactor.

11. The method of claim 1 , wherein the oxygen of step (b) is separated in a fixed bed reactor.

12. The method of claim 1 , wherein the oxygenated perovskite is generated at a temperature of greater than 800° C.

13. The method of claim 1 , wherein the oxygenated perovskite is generated at a pressure of about 1 bar to about 10 bar.

14. The method of claim 1 , wherein the oxygen is released from the oxygenated perovskite at a pressure of less than 1 bar.

15. The method of claim 1 , wherein the oxygen-depleted perovskite is exposed to the gas mixture for a period of time ranging from about 30 seconds to about 1 hour.

16. The method of claim 1 , wherein the oxygen-depleted perovskite is exposed to the gas mixture for a period of time ranging from about 1 minute to about 10 minutes.

17. The method of claim 1 , wherein the oxygen separation is part of a process to generate high purity oxygen.

18. The method of claim 1 , wherein the oxygen separation is utilized as part of a sensor for detecting oxygen.

19. A system for the separation of oxygen from a gas mixture, the system comprising:

(a) a reactor configured to prepare an oxygen-depleted perovskite from a perovskite having the formula CaCo 1-x Zr x O 3-δ wherein x is a number defined by 0.02≤x≤0.98; and δ is a number defined by 0.0≤δ≤1.0;

(b) a sorbent/membrane configured to contact the oxygen-depleted perovskite with the gas mixture to generate an oxygenated perovskite;

(c) a temperature-swing, pressure-swing, or combined apparatus to treat the oxygenated perovskite to release the oxygen and generate an oxygen-depleted perovskite; and

(d) a housing configured to collect the released oxygen.

20. A detector for oxygen in a gas mixture which comprises:

(a) an oxygen-depleted perovskite from a perovskite having the formula CaCo 1-x Zr x O 3-δ wherein x is a number defined by 0.02≤x≤0.98; and δ is a number defined by 0.0≤δ≤1.0;

(b) a sorbent/membrane configured to contact the oxygen-depleted perovskite with the gas mixture and, if oxygen is present, to generate an oxygenated perovskite; and

(c) a apparatus for detecting the oxygenated perovskite if present.