Roll-to-Roll Fabrication of High Performance Fuel Cell Electrode with Core-Shell Catalyst Using Seeded Electrodes

Patent metadata

Field	Value
Publication number	US-2016365583-A1
Application number	US-201514735696-A
Country	US
Kind code	A1
Filing date	Jun 10, 2015
Priority date	Jun 10, 2015
Publication date	Dec 15, 2016
Grant date	—

Abstract

A method for forming a fuel cell catalyst includes a step of forming an ionomer-containing layer including carbon particles and an ionomer. Tungsten-nickel alloy particles are formed on the carbon particles. At least a portion of the nickel in the tungsten-nickel alloy particles is replaced with palladium to form palladium-coated particles. The palladium-coated particles include a palladium shell covering the tungsten-nickel alloy particles. The palladium-coated particles are coated with platinum to form an electrode layer including core shell catalysts distributed therein.

First claim

What is claimed is:

1 . A method for forming a fuel cell catalyst, the method comprising:
a) forming an ionomer-containing layer including carbon particles and an ionomer; b) forming tungsten-nickel alloy particles on the carbon particles; c) replacing at least a portion of the nickel in the tungsten-nickel alloy particles with palladium to form palladium-coated particles, the palladium-coated particles having a palladium shell covering the tungsten-nickel alloy particles; and d) coating the palladium-coated particles with platinum to form an electrode layer including core shell catalysts distributed therein.

2 . The method of claim 1 wherein the ionomer-containing layer is formed on a gas diffusion layer.

3 . The method of claim 1 wherein the ionomer-containing layer further includes tungsten metal supported on the carbon particles.

4 . The method of claim 3 wherein the tungsten metal supported on the carbon particles allows uniform tungsten-nickel alloy formation in step b).

5 . The method of claim 1 wherein the tungsten-nickel alloy electrochemically formed is step b) from a solution including a nickel-containing salt and a tungsten-containing salt.

6 . The method of claim 5 wherein the nickel-containing salt is NiSO 4 or (Ni) 3 (PO 4 ) 2 .

7 . The method of claim 5 wherein the tungsten-containing salt is a metal tungstate.

8 . The method of claim 1 wherein the tungsten-nickel alloy is electrochemically formed using a constant current or multiple current pulses.

9 . The method of claim 1 wherein steps a), b), c), and d) are sequentially performed in a continuous manner.

10 . The method of claim 1 wherein the nickel in the tungsten-nickel alloy is at least partially replaced with palladium in step c) by a galvanic displacement reaction in which the tungsten-nickel alloy particles are contacted with a palladium-containing solution.

11 . The method of claim 10 wherein the palladium-containing solution includes PdCl 2 .

12 . The method of claim 1 wherein the palladium-coated particles are coated with platinum by depositing copper on the palladium-coated particles and then replacing at least a portion of the copper with platinum.

13 . The method of claim 12 wherein the copper is electrochemically formed.

14 . The method of claim 13 wherein the palladium-coated particles are coated with platinum from a solution including a platinum-containing salt and a copper containing salt.

15 . The method of claim 14 wherein a potential is applied to the palladium-coated particles for a first period of time to form the copper on the palladium-coated particles with platinum then replacing at least a portion of the copper.

16 . The method of claim 15 wherein an open circuit is applied for a second period of time to allow platinum to replace copper.

17 . The method of claim 15 wherein the palladium-coated particles are subjected to an anodic potential hold or potential cycling to dissolve excess transition metals.

18 . The method of claim 1 further comprising incorporating the electrode layer into a fuel cell.

19 . A method for forming a fuel cell catalyst, the method comprising:
a) forming an ionomer-containing layer including carbon particles and an ionomer; b) electrochemically forming tungsten-nickel alloy particles on the carbon particles from a solution including a nickel-containing salt and a tungsten-containing salt; c) replacing at least a portion of the nickel in the tungsten-nickel alloy particles with palladium by a galvanic displacement reaction in which the tungsten-nickel alloy particles are contacted with a palladium-containing solution to form palladium-coated particles; and d) coating the palladium-coated particles with platinum to form an electrode layer including core shell catalysts distributed therein wherein the palladium-coated particles are coated with platinum by depositing copper on the palladium-coated particles and then replacing at least a portion of the copper with platinum.

20 . The method of claim 19 wherein the nickel-containing salt is NiSO 4 or (NO 3 (PO 4 ) 2 , the tungsten-containing salt is a metal tungstate, and the palladium-containing solution includes PdCl 2 .

Assignees

• Gm Global Tech Operations Llc

Inventors

• Kongkanand Anusorn
• Cai Yun

Classifications

• H01M4/8853 Primary

  Electrodeposition · CPC title

• H01M4/9041

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

• B05D5/00

  Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures · CPC title

• H01M4/8657 Primary

  layered · CPC title

• H01M4/96

  Carbon-based electrodes · CPC title