Method and system for core-shell catalyst processing

Patent metadata

Field	Value
Publication number	US-10541425-B2
Application number	US-201314904679-A
Country	US
Kind code	B2
Filing date	Jul 19, 2013
Priority date	Jul 19, 2013
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

According to an embodiment, a method of processing a material for a catalyst includes establishing an electrical potential on a porous electrode. Core particles are directed through the porous electrode. A layer of metal is deposited on the core particles as the particles pass through the porous electrode. According to an embodiment, an example assembly for processing a material for a catalyst includes a housing that establishes a path for particles to move through the housing. A porous electrode is situated within the housing for permitting core particles to move through the porous electrode. A layer of metal can be deposited on the core particles as the particles pass through the porous electrode.

First claim

We claim:

1. A method of processing a material for a catalyst, comprising:
establishing an electrical potential on a porous electrode;
directing core particles through the porous electrode;
depositing a layer of metal on the core particles as the particles pass through the porous electrode;
mixing the core particles having the deposited layer of metal with a solution including K 2 PtCl 4 , citric acid and citrate; and
replacing the deposited layer of metal with platinum to thereby establish a platinum monolayer on the core particles,
the concentration of citric acid and citrate together is greater than 10 times the concentration of the K 2 PtCl 4 in the solution;
the porous electrode has a length along a direction that the core particles travel as the core particles pass through the porous electrode; and
the length is selected to facilitate depositing a uniform monolayer of the metal on the core particles.

2. The method of claim 1 , wherein contact between the core particles and the porous electrode facilitates the depositing.

3. The method of claim 1 , wherein the core particles comprise palladium; and the layer of metal comprises copper.

4. The method of claim 3 , wherein the core particles comprise palladium nanoparticles supported on carbon particles.

5. The method of claim 1 , wherein the layer of metal comprises a monolayer of copper.

6. The method of claim 1 , wherein the porous electrode comprises carbon.

7. An assembly for processing a material for a catalyst, the assembly comprising:
a housing that establishes a path for core particles to move through the housing; a porous electrode situated within the housing for permitting core particles to move through the porous electrode whereby a layer of metal can be deposited on the core particles as the core particles pass through the porous electrode; and
a replacement chamber comprising a solution including K 2 PtCl 4 , citric acid and citrate, the replacement chamber providing a reservoir for mixing the core particles having a layer of metal deposited with the solution thereby replacing the deposited layer of metal with platinum to establish a platinum monolayer on the core particles,
the concentration of citric acid and citrate together is greater than 10 times the concentration of the K 2 PtCl 4 in the solution;
the porous electrode has a length along a direction that the core particles travel as the core particles pass through the porous electrode; and
the length is selected to facilitate depositing a uniform monolayer of the metal on the core particles.

8. The assembly of claim 7 , wherein the core particles comprise palladium; and the layer of metal comprises copper.

9. The assembly of claim 8 , wherein the core particles comprise palladium nanoparticles supported on carbon particles.

10. The assembly of claim 7 , wherein the porous electrode comprises carbon.

11. The assembly of claim 7 , wherein the metal layer comprises a monolayer of copper.

Assignees

• Audi Ag

Inventors

• Shao Minhua
• Weidner John W
• Odell Jonathan H

Classifications

• B22F1/18

  Non-metallic particles coated with metal · CPC title

• H01M4/9075

  Catalytic material supported on carriers, e.g. powder carriers (H01M4/8807, H01M4/881, H01M4/8814, H01M4/925 take precedence) · CPC title

• C25D17/12

  Shape or form (C25D17/14 takes precedence) · CPC title

• H01M4/92

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

• C25D7/006

  Nanoparticles · CPC title