Conformal thin film of precious metal on a support

Patent metadata

Field	Value
Publication number	US-9979028-B2
Application number	US-201414527121-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Dec 13, 2013
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A coated substrate for forming fuel cell catalyst layers includes a plurality of substrate particles, an adhesion layer disposed over the substrate particles, and a precious metal layer disposed over the adhesion layer. The substrate particles may be carbon powders, carbon nanorods, carbon nanotubes and combinations thereof; with a preferred aspect ratio from 10:1 to 25:1. The adhesion layer includes a tungsten metal layer and may be formed into a heterogeneous layer comprising a lattice-interrupting layer interposed between two tungsten metal layers. The lattice-interrupting layer reduces mechanical stress to the adhesion layer with extended thickness that may develop when it experiences changing environments, and can be any layer other than the metal layer, for example, Al 2 O 3 , Al, or WO x , where x is 1.5 to 3.0. Characteristically, the coated substrate is used in fuel cell applications such as providing the catalyst particles used in the cathode and/or anode catalyst layers.

First claim

What is claimed is:

1. A coated substrate comprises:
a plurality of substrate particles selected from the group consisting of carbon powders, carbon nanorods, carbon nanotubes, and combinations thereof;
an adhesion layer disposed over each substrate particle, the adhesion layer including a lattice interrupting layer interposed between two tungsten metal layers, the lattice interrupting layer being Al 2 O 3 , Al, or WO x where x is 1.5 to 3.0; and
a precious metal layer disposed over the adhesion layer; and
an intermediate layer interposed between the plurality of substrate particles and the adhesion layer wherein the intermediate layer includes a component selected from the group consisting of aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, tungsten oxide, titanium carbide, titanium nitrides, titanium oxynitride, and combinations thereof.

2. The coated substrate of claim 1 wherein the substrate particles have an average spatial dimension from about 20 nm to 1 micron.

3. The coated substrate of claim 1 wherein the substrate particles have a length-to-width aspect ratio from 10:1 to 25:1.

4. The coated substrate of claim 1 wherein the substrate particles have a length-to-width aspect ratio from 13:1 to 20:1.

5. The coated substrate of claim 1 wherein the substrate particles have a length-to-width aspect ratio of about 15:1.

6. The coated substrate of claim 1 wherein the precious metal layer includes a precious metal selected from the group consisting of platinum, gold, palladium, iridium, and alloys thereof, and combinations thereof.

7. The coated substrate of claim 1 wherein the adhesion layer has a thickness from about 0.5 to about 5 nanometers.

8. The coated substrate of claim 1 wherein the precious metal layer has a thickness from about 0.5 to about 5 nanometers.

9. The coated substrate of claim 1 wherein the intermediate layer has a thickness from about 0.5 to 10 nanometers.

10. The coated substrate of claim 1 wherein the lattice interrupting layer is Al 2 O 3 or Al.

11. The coated substrate of claim 1 wherein the lattice interrupting layer is Al 2 O 3 .

12. A coated substrate comprises:
a plurality of substrate particles having an average spatial dimension from about 20 nm to 1 micron and an average length-to-width aspect ratio greater than 10, the plurality of substrate particles being selected from the group consisting of carbon powders, carbon nanorods, carbon nanotubes, and combinations thereof;
an adhesion layer disposed over the substrate particle, the adhesion layer including a lattice interrupting layer interposed between two tungsten metal layers, the lattice interrupting layer being Al 2 O 3 , Al, or WO x , where x is 1.5 to 3.0; and
a precious metal layer disposed over the adhesion layer; and
an intermediate layer interposed between the plurality of substrate particles and the adhesion layer wherein the intermediate layer includes a component selected from the group consisting of aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, tungsten oxide, titanium carbide, titanium nitrides, titanium oxynitride, and combinations thereof.

13. The coated substrate of claim 12 wherein the average length-to-width aspect ratio is from greater than 10:1 to 25:1.

14. The coated substrate of claim 12 wherein the precious metal layer includes a precious metal selected from the group consisting of platinum, gold, palladium, iridium, and alloys thereof, and combinations thereof.

15. The coated substrate of claim 12 wherein the adhesion layer has a thickness from about 0.5 to about 5 nanometers, the precious metal layer has a thickness from about 0.5 to about 5 nanometers.

16. The coated substrate of claim 12 wherein the intermediate layer has a thickness from about 0.5 to 10 nanometers.

17. The coated substrate of claim 12 wherein the lattice interrupting layer is Al 2 O 3 or Al.

18. The coated substrate of claim 12 wherein the lattice interrupting layer is Al 2 O 3 .

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kongkanand Anusorn
• Kukreja Ratandeep S
• Clancey Joel W
• Cavanaugh Andrew
• George Steven M

Classifications

• H01M4/9041

  Metals or alloys (H01M4/92 takes precedence) · CPC title

• H01M4/926 Primary

  on carbon or graphite · CPC title

• H01M4/8657 Primary

  layered · CPC title

• H01M4/925

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

• H01M4/9083

  on carbon or graphite · CPC title