Electrodes having Pt nanoparticles on RuO2 nanoskins

Patent metadata

Field	Value
Publication number	US-10651478-B2
Application number	US-201213723878-A
Country	US
Kind code	B2
Filing date	Dec 21, 2012
Priority date	Oct 5, 2007
Publication date	May 12, 2020
Grant date	May 12, 2020

Abstract

An article having a titanium, titanium carbide, titanium nitride, tantalum, aluminum, silicon, or stainless steel substrate, a RuO2 coating on a portion of the substrate; and a plurality of platinum nanoparticles on the RuO2 coating. The RuO2 coating contains nanoparticles of RuO2. A method of: immersing the substrate in a solution of RuO4 and a nonpolar solvent at a temperature that is below the temperature at which RuO4 decomposes to RuO2 in the nonpolar solvent in the presence of the article; warming the article and solution to ambient temperature under ambient conditions to cause the formation of a RuO2 coating on a portion of the article; and electrodepositing platinum nanoparticles on the RuO2 coating.

First claim

What is claimed is:

1. An article comprising:
a substrate comprising titanium, a titanium carbide, a titanium nitride, tantalum, aluminum, silicon, or stainless steel;
a RuO 2 coating on a portion of the substrate;
wherein the coating comprises nanoparticles of RuO 2 ; and

a plurality of platinum nanoparticles on the RuO 2 coating;
wherein the RuO 2 coating is made by a method comprising:
immersing the substrate in a solution of RuO 4 and a nonpolar solvent at a temperature that is below the temperature at which RuO 4 decomposes to RuO 2 in the nonpolar solvent in the presence of the substrate; and
warming the substrate and solution to ambient temperature under ambient conditions to cause the formation of the coating.

2. The article of claim 1 , wherein the substrate comprises titanium.

3. The article of claim 1 , wherein the substrate is a planar substrate or a mesh.

4. The article of claim 1 , wherein the RuO 2 forms an electrically connected network across the substrate.

5. The article of claim 1 , wherein the RuO 2 coating has an average thickness of up to about 9 nanometers.

6. The article of claim 1 , wherein the method of making the coating further comprises:
heating the coating to a maximum temperature from 150° C. to 250° C.

7. The article of claim 1 , wherein the method of making the coating further comprises:
repeating the immersing and the warming of the substrate are repeated one or more times to form more than one RuO 2 layer in the coating.

8. The article of claim 1 , wherein the platinum nanoparticles have an average diameter less than about 5 nm.

9. The article of claim 1 , wherein platinum nanoparticles are formed at the RuO 2 coating by electrodeposition.

10. A fuel cell comprising:
an anode comprising the article of claim 1 ; and
a cathode.

11. A method comprising:
oxidizing methanol at the surface of the anode of the fuel cell of claim 10 .

12. A method comprising:
immersing a substrate comprising titanium, a titanium carbide, a titanium nitride, tantalum, aluminum, silicon, or stainless steel in a solution of RuO 4 and a nonpolar solvent at a temperature that is below the temperature at which RuO 4 decomposes to RuO 2 in the nonpolar solvent in the presence of the article;
warming the article and solution to ambient temperature under ambient conditions to cause the formation of a RuO 2 coating on a portion of the article; and
electrodepositing platinum nanoparticles on the RuO 2 coating.

13. The method of claim 12 , wherein the substrate comprises titanium.

14. The method of claim 12 , wherein the nonpolar solvent is a hydrocarbon.

15. The method of claim 12 , wherein the nonpolar solvent is petroleum ether.

16. The method of claim 12 , further comprising:
extracting the RuO 4 from an aqueous solution into the nonpolar solvent before immersing the article in the RuO 4 solution.

17. The method of claim 12 , wherein the immersing temperature is maintained by a dry ice bath or aqueous ice bath.

18. The method of claim 12 , further comprising:
equilibrating the article in an additional portion of the nonpolar solvent at the temperature before immersing the article in the RuO 4 solution.

19. The method of claim 12 , further comprising:
heating the article in air or oxygen to a temperature less than 250° C.

20. The article of claim 1 , wherein the plurality of platinum nanoparticles are made by electrodeposition.

Assignees

• Pietron Jeremy J
• Pomfret Michael B
• Chervin Christopher N
• Rolison Debra R
• Long Jeffrey W
• Us Gov Sec Navy

Inventors

• Pietron Jeremy J
• Pomfret Michael B
• Chervin Christopher N
• Rolison Debra R
• Long Jeffrey W

Classifications

• H01M4/925

  supported on carriers, e.g. powder carriers · CPC title

• H01M8/0236

  Glass; Ceramics; Cermets · CPC title

• H01M4/8853 Primary

  Electrodeposition · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M4/92

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title