Method for producing an electrode catalyst from a perovskite metal oxide

Patent metadata

Field	Value
Publication number	US-11271216-B2
Application number	US-201716316250-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 8, 2016
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The invention relates to a method of producing electrode materials for solid oxide cells which comprises applying an electric potential to a metal oxide which has a perovskite crystal structure. The resultant electrode catalyst exhibits excellent electrochemical performance. The invention extends to the electrode catalyst itself, and to electrodes and solid oxide cells comprising the electrode catalyst.

First claim

The invention claimed is:

1. A method of producing an electrode catalyst comprising:
applying an electric potential to a perovskite metal oxide lattice;
causing one or more metals from the perovskite metal oxide lattice to exsolve while applying the electric potential; and
forming metal particles of the one or more metals on a surface of the perovskite metal oxide lattice.

2. A method according to claim 1 , wherein the perovskite metal oxide has the formula:
(M 1 x1 M 2 x2 )(M 3 y M 4 z M 5 a M 6 b )O 3-δ

wherein
M 1 is a rare earth metal,
M 2 is an alkaline earth metal,
M 3 , M 4 , M 5 and M 6 are each independently Al or a transition metal, and M 3 is
different from at least one of M 4 , M 5 and M 6 ,
0≤x1+x2≤1,
0<y≤1,
0<z≤1,
0≤a≤1,
0≤b≤1,
y+z+a+b=1, and
0≤γ≤0.1.

3. A method according to claim 2 , wherein M 1 is selected from the group consisting of La, Ce and Pr; M 2 is selected from the group consisting of Ca, Sr and Ba; M 3 is selected from the group consisting of Ti, Cr, Fe, Al and Sc; M 4 , M 5 and M 6 are each independently chosen from the group consisting of Ti, Sc, V, Mn, Cr, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Cd, Ag, Pt, Au and Al; and M 3 is different from at least one of M 4 , M 5 and M 6 .

4. A method according to claim 2 , wherein M 2 is Ca.

5. A method according to claim 3 , wherein M 2 is Ca.

6. A method according to claim 1 comprising applying an electrical potential of from 1.5 to 2.5 volts to the perovskite metal oxide.

7. An electrode catalyst obtained or obtainable by the method of claim 1 .

8. An electrode comprising the electrode catalyst of claim 7 .

9. A solid oxide cell comprising an electrode according to claim 8 .

10. A method of operating the solid oxide cell of claim 9 in fuel cell mode comprising combining H 2 and O 2 electrochemically to produce power.

11. A method of regenerating an electrode catalyst according to claim 7 , which method comprises applying an electrical potential to the electrode catalyst.

12. A method according to claim 11 , comprising applying an electrical potential to an electrode comprising said electrode catalyst, which electrode is in a solid oxide cell, under solid oxide cell operating conditions.

13. A method according to claim 1 , wherein the metal particles have a population of from 100 to 600 particles μm −2 .

14. A method of of producing an electrode catalyst comprising:
applying an electric potential to a perovskite metal oxide lattice;
causing one or more metals from the perovskite metal oxide lattice to exsolve while applying the electric potential; and
forming metal particles of the one or more metals on a surface of the perovskite metal oxide lattice, wherein the perovskite metal oxide lattice has the formula:
(M 1 x1 M 2 x2 )(M 3 y M 4 z M 5 a M 6 b )O 3-δ

wherein
M 1 is a rare earth metal,
M 2 is calcium,
M 3 , M 4 , M 5 and M 6 are each independently Al or a transition metal, and M 3 is
different from at least one of M 4 , M 5 and M 6 ,
0≤x1+x2≤1,
0<y≤1,
0<z≤1,
0≤a≤1,
0≤b≤1,
y+z+a+b=1, and
0≤γ≤0.1.

15. A method according to claim 14 , wherein the population of the metal particles is from 100 to 600 particles μm −2 .

16. A method of producing an electrode catalyst comprising:
applying an electric potential to a perovskite metal oxide lattice;
causing one or more metals from the perovskite metal oxide lattice to exsolve while applying the electric potential; and
forming metal particles of the one or more metals on a surface of the perovskite metal oxide lattice;
wherein the perovskite metal oxide has the formula:
(M 1 x1 M 2 x2 )(M 3 y M 4 z M 5 a M 6 b )O 3-δ

wherein
M 1 is a rare earth metal,
M 2 is an alkaline earth metal,
M 3 , M 4 , M 5 and M 6 are each independently aluminum (Al) or a transition metal,
and M 3 is different from at least one of M 4 , M 5 and M 6 ,
0≤x1+x2≤1,
0<y≤1,
0<z≤1,
0≤a≤1,
0≤b≤1,
y+z+a+b=1, and
0≤γ≤0.1.

Assignees

• Univ Court Univ St Andrews

Inventors

• Irvine John T S
• Myung Jae-Ha
• Neagu Dragos
• Miller David

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/186

  by electrolytic decomposition of the electrolytic solution or the formed water product · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/1213

  characterised by the electrode/electrolyte combination or the supporting material · CPC title

• H01M8/04223

  during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells · CPC title