# US 8,273,486 B2 · Protecting a PEM fuel cell catalyst against carbon monoxide poisoning

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- Number: US 8,273,486 B2
- Document ID: US8273486B2
- Status: Granted
- Kind: B2
- Application number: 12/363,526
- Filed: 2009-01-30
- Published: 2010-08-05
- Granted: 2012-09-25
- Earliest claimed: 2009-01-30
- Assignees: Honeywell International Inc.
- Inventors: Mark Kaiser
- Web page: https://patentgrep.com/patent/US8273486B2

## CPC

- H01M 4/8605: {Porous electrodes}
- H01M 4/885: {followed by reduction of the catalyst salt precursor}
- H01M 4/8875: {Methods for shaping the electrode into free-standing bodies, like sheets, films or grids, e.g. moulding, hot-pressing, casting without support, extrusion without support}
- H01M 8/0668: Removal of carbon monoxide or carbon dioxide
- H01M 8/0687: {Reactant purification by the use of membranes or filters}
- H01M 8/1007: with both reactants being gaseous or vaporised (H01M8/12 takes precedence)
- Y02E 60/50: Fuel cells
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

An anode structure comprises an array of carbon nanotubes having a diffusion side and a membrane side, and catalyst particles interspersed on inner surfaces of the membrane side of the carbon nanotubes. The carbon nanotubes have an average diameter greater than the size of the hydrogen molecule but smaller than the size of the carbon monoxide molecule. Thus, hydrogen flowing toward the catalyst particles interspersed inside the carbon nanotubes are able to go through, while the flow of trace amounts of carbon monoxide contained in the hydrogen is blocked, preventing the poisoning of the catalyst particles by the carbon monoxide. A fuel cell utilizing the anode structure and a method for manufacturing the anode structure are also disclosed.

## Claims

### Claim 1

An anode structure comprising:
an array of carbon nanotubes having a diffusion side and a membrane side, said carbon nanotubes having an average nanotube inner diameter and an average nanotube length, wherein the average nanotube inner diameter is greater than the size of a hydrogen molecule but smaller than the size of a carbon monoxide molecule; and
catalyst particles interspersed on inner surfaces of said membrane side of said carbon nanotubes.

### Claim 2 (depends on 1)

The anode structure of claim 1, wherein said catalyst particles comprise platinum.

### Claim 3 (depends on 2)

The anode structure of claim 2, wherein said catalyst particles further comprise ruthenium and palladium.

### Claim 4 (depends on 1)

The anode structure of claim 1, wherein the average nanotube inner diameter is in a range of about 0.31 nm to about 0.36 nm.

### Claim 5 (depends on 4)

The anode structure of claim 4, wherein the average nanotube inner diameter is in a range of about 0.33 nm to about 0.34 nm.

### Claim 6 (depends on 1)

The anode structure of claim 1, wherein the average nanotube length ranges from about 100 nm to about 100,000 nm.

### Claim 7 (depends on 1)

The anode assembly of claim 1 wherein said array of carbon nanotubes comprises vertically aligned nanotubes.

### Claim 8 (depends on 1)

The anode assembly of claim 1 wherein said array of carbon nanotubes comprises single-walled nanotubes.

### Claim 9 (depends on 1)

The anode assembly of claim 1 wherein said array of carbon nanotubes comprises multi-walled nanotubes.