Efficient water oxidation catalysts and methods of oxygen and hydrogen production by photoelectrolysis

Patent metadata

Field	Value
Publication number	US-10208384-B2
Application number	US-201113207998-A
Country	US
Kind code	B2
Filing date	Aug 11, 2011
Priority date	Aug 11, 2011
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

Processes for the liberation of oxygen and hydrogen from water are provided allowing for mass scale production using abundant sources of catalyst materials. A metal oxide based anode is formed by the simple oxidation of metal in air by heating the metal for a specified time period. The resultant anode is then contacted with water and subjected to a voltage from an external source or driven by electromagnetic energy to produce oxygen at the surface of the anode by oxidation of water. These processes provide efficient and stable oxygen or hydrogen production.

First claim

The invention claimed is:

1. A process of producing oxygen from water, comprising:
forming an anode comprising a metal oxide catalyst, said metal oxide comprising a metal ionic species and an oxygen anionic species, said metal ionic species comprising Co, Fe, Zn, or Cu, said metal ionic species is not Ir, said forming comprising heating a metal ionic species to 400 degrees Celsius or less for an oxidation time in the presence of an oxidation gas comprising oxygen; and
contacting said anode with water in the presence of light of intensity and wavelength to produce oxygen from said water.

2. The process of claim 1 wherein said metal ionic species is Co 2+ or Co 3+ .

3. The process of claim 1 wherein said heating is from 250 degrees Celsius to 400 degrees Celsius.

4. The process of claim 1 wherein said oxidation time is for 2 hours or more.

5. The process of claim 1 wherein said oxidation time is from 3 to 6 hours.

6. The process of claim 1 wherein said oxidation time is for 4 hours at 350 degrees Celsius.

7. The process of claim 1 wherein said oxidation gas is air.

8. The process of claim 1 wherein said oxidation gas is provided as a purified source.

9. The process of claim 1 wherein said metal ionic species is Co and said oxygen is from air.

10. The process of claim 1 wherein the metal ionic species comprises at least a first and a second type of metal ionic species.

11. The process of claim 1 wherein said anode comprises a substrate, and said metal oxide coating at least a portion of said substrate.

12. The process of claim 11 wherein said substrate is a silicon bead or a CuO nanowire.

13. The process of claim 1 wherein said metal oxide is Co 3 O 4 .

14. The process of claim 1 wherein said metal ionic species is contacted to a substrate prior to said heating.

15. The process of claim 14 wherein said metal ionic species is Co 2+ or Co 3+ .

16. A process of producing oxygen from water, comprising:
forming an anode comprising a metal oxide catalyst, said metal oxide comprising a metal ionic species and an oxygen anionic species, said metal ionic species comprising Co, Fe, Zn, or Cu, said metal ionic species is not Ir, said forming comprising heating a solid metal ionic species to 400 degrees Celsius or less for an oxidation time in the presence of an oxidation gas comprising oxygen; and
contacting said anode with water in the presence of light to produce oxygen from said water.

Assignees

• Jia Hongfei
• Banerjee Debasish
• Toyota Eng & Mfg North America

Inventors

• Jia Hongfei
• Banerjee Debasish

Classifications

• C02F2001/46138

  Electrodes comprising a substrate and a coating · CPC title

• C02F1/4672

  by electrooxydation · CPC title

• Y02E60/368

  Cross-Sectional Technologies · mapped topic

• C25B1/003 Primary

  Chemistry & Metallurgy · mapped topic

• C02F1/46109 Primary

  Electrodes · CPC title