Corrosion-resistant catalyst

Patent metadata

Field	Value
Publication number	US-2017117556-A1
Application number	US-201615284032-A
Country	US
Kind code	A1
Filing date	Oct 3, 2016
Priority date	Oct 23, 2015
Publication date	Apr 27, 2017
Grant date	—

Abstract

A method for forming a corrosion-resistant catalyst for fuel cell catalyst layers is provided. The method includes a step of depositing a conformal Pt or platinum alloy thin layer on NbO 2 substrate particles to form Pt-coated NbO 2 . The Pt-coated NbO 2 particles are then incorporated into a fuel cell catalyst layer.

First claim

What is claimed is:

1 . A method for forming a corrosion-resistant catalyst comprising:
depositing a conformal Pt thin layer or platinum alloy thin layer on NbO 2 substrate particles to form Pt-coated NbO 2 particles; and incorporating the Pt-coated NbO 2 particles into a fuel cell catalyst layer.

2 . The method of claim 1 wherein the conformal Pt thin layer is formed by an atomic layer deposition process.

3 . The method of claim 2 wherein the atomic layer deposition process is a reductive H 2 -plasma process during which surface NbO 2 is reduced to NbO or Nb.

4 . The method of claim 2 wherein the atomic layer deposition process is a H 2 thermal process in which NbO 2 is contacted with molecular hydrogen.

5 . The method of claim 1 wherein a platinum alloy thin layer is deposited, the platinum alloy thin layer including a component selected from the group consisting of platinum-iridium alloys, platinum-palladium alloys, and platinum-gold alloys.

6 . The method of claim 1 wherein the Pt thin layer or platinum alloy thin layer has a thickness from about 0.3 to 20 nm.

7 . The method of claim 1 wherein a conformal Pt thin layer is deposited on NbO 2 substrate particles by a deposition cycle in which the NbO 2 substrate particles are contacted with vapor of a platinum-containing compound such that at least a portion of the vapor of the platinum-containing compound such compound adsorbs or reacts with a substrate surface to form a modified surface.

8 . The method of claim 7 wherein the platinum-containing compound is trimethyl(methylcyclopentadienyl)platinum.

9 . The method of claim 7 wherein the deposition includes contacting the modified surface with a vapor of a reducing agent to react and form at least a portion of the conformal Pt thin layer or platinum alloy thin layer.

10 . The method of claim 9 wherein the reducing agent is molecular hydrogen.

11 . The method of claim 9 wherein the reducing agent is formed by a reductive H 2 -plasma.

12 . The method of claim 9 wherein the deposition cycle is at a temperature from about 50 to 400° C.

13 . The method of claim 9 wherein a pressure for the deposition cycle is from about 10 −6 Torr to about 760 Torr.

14 . The method of claim 9 wherein a pressure for the deposition cycle is from about 0.1 millitorr to about 10 Torr.

15 . The method of claim 9 wherein the NbO 2 substrate particles are subjected to 1 to 5000 deposition cycles.

16 . The method of claim 9 wherein the NbO 2 substrate particles are subjected to 10 to 300 deposition cycles.

17 . An ink composition comprising:
Pt-coated NbO 2 particles formed by depositing a conformal Pt thin layer or platinum alloy thin layer on NbO 2 substrate particles to form the Pt-coated NbO 2 particles; ionomer; and solvent.

18 . The ink composition of claim 17 wherein:
the Pt-coated NbO 2 particles are present in an amount of about 1 weight percent to 10 weight percent of the total weight of the ink composition;
the ionomers are present in an amount from about 5 weight percent to about 40 weight percent of the ink composition; and
the balance is the solvent.

19 . The ink composition of claim 17 wherein the conformal Pt thin layer or platinum alloy thin layer is formed by contacting the NbO 2 substrate particles with vapor of a platinum-containing compound such that at least a portion of the vapor of the platinum-containing compound such compound adsorbs or reacts with a substrate surface to form a modified surface.

20 . The ink composition of claim 19 wherein the modified surface is contacted with a vapor of a reducing agent to react and form at least a portion of the conformal Pt thin layer or platinum alloy thin layer.

Assignees

• Gm Global Tech Operations Llc
• Univ Colorado Regents

Inventors

• Kongkanand Anusorn
• Clancey Joel W
• George Steven M

Classifications

• C23C16/45553

  characterized by the use of precursors specially adapted for ALD · CPC title

• H01M4/928 Primary

  Unsupported catalytic particles; loose particulate catalytic materials, e.g. in fluidised state · CPC title

• H01M4/8867

  Vapour deposition · CPC title

• C23C16/18

  from metallo-organic compounds · CPC title

• H01M4/921

  Alloys or mixtures with metallic elements · CPC title