# US 8,785,061 B2 · CO conversion catalyst for use in fuel cell in DSS operation, method for producing the same, and fuel cell system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,785,061 B2
- Document ID: US8785061B2
- Status: Granted
- Kind: B2
- Application number: 12/413,716
- Filed: 2009-03-30
- Published: 2009-12-24
- Granted: 2014-07-22
- Earliest claimed: 2008-06-24
- Assignees: Mitsubishi Heavy Industries, Ltd.
- Applicants: Masanao Yonemura; Toshinobu Yasutake; Tetsuya Shishido
- Inventors: Masanao Yonemura; Toshinobu Yasutake; Tetsuya Shishido
- Web page: https://patentgrep.com/patent/US8785061B2

## CPC

- H01M 8/0668: Removal of carbon monoxide or carbon dioxide
- B01J 23/72: Copper
- B01J 23/74: Iron group metals
- B01J 23/86: Chromium
- B01J 23/8892: {Manganese}
- C01B 3/16: using catalysts
- H01M 8/0618: {Reforming processes, e.g. autothermal, partial oxidation or steam reforming}
- B01J 37/03: Precipitation; Co-precipitation
- C01B 2203/0283: containing a CO-shift step, i.e. a water gas shift step
- C01B 2203/1076: Copper or zinc-based catalysts
- Y02E 60/50: Fuel cells
- Y02P 20/52: using catalysts, e.g. selective catalysts
- 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
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- 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

To provide a CO conversion catalyst for use in a fuel cell in a DSS operation, which includes a Cu—Al-Ox catalyst, in which the Cu—Al-Ox catalyst has a boehmite phase formed in at least a part of the Cu—Al-Ox catalyst. The CO conversion catalyst has an improved degree of dispersion of Cu metal by the boehmite phase formed therein, and hence can be prevented from sintering of copper caused due to steam, thereby achieving improved durability with respect to the function as the CO conversion catalyst.

## Claims

### Claim 1

A carbon monoxide conversion catalyst for use in a daily startup and shutdown operation of a fuel cell, comprising an amorphous Cu—Al-Ox catalyst which includes a boehmite phase formed in at least a part of the Cu—Al-Ox catalyst which is obtainable by
individually dropping solutions of respective nitrates of Cu and Al to ion-exchanged water, stirring to dissolve, and adding a precipitant to the resultant solution to precipitate Cu and Al;
maturing the solution in which Cu and Al are precipitated to form a precursor;
collecting the obtained catalyst by filtration, after drying, calcining at about 550° C. to give an amorphous Cu—Al-Ox conversion catalyst in which amorphous AlyOx and Cu0 particles are dispersed; and
exposing the calcined CO conversion catalyst to a temperature of 50 to 250° C. in a satured stream atmosphere at 70° C. or higher to form a boehmite phase in a part of the amorphous catalyst.

### Claim 2 (depends on 1)

The CO conversion catalyst according to claim 1, wherein the Cu—Al-Ox catalyst is formed by any one of a homogeneous precipitation method, a coprecipitation method, and a sol-gel method, and then treated with steam-containing gas.

### Claim 3 (depends on 1)

The CO conversion catalyst according to claim 1, wherein the Cu—Al-Ox catalyst has a Cu:Al molar ratio of 4:1 to 1:4.

### Claim 4 (depends on 1)

The CO conversion catalyst according to claim 1, further comprising, as an active component, at least one member selected from a group consisting of Mn, Fe, Co, Cr, and Ni.

### Claim 5 (depends on 1)

The CO conversion catalyst according to claim 1, wherein the Cu—Al-Ox catalyst is calcined at a temperature of 300 to 600° C.

### Claim 6 (depends on 1)

The CO conversion catalyst according to claim 1, wherein the Cu0 particles are from 1.20 to 1.93 times as large as the boehmite phase.

### Claim 7 (depends on 1)

A fuel cell system in a daily startup and shutdown operation using a hydrocarbon fuel, the system comprising:
reformer that reforms the hydrocarbon fuel to produce a reformed gas;
the CO conversion catalyst according to claim 1 for removing carbon monoxide from the reformed gas; and
a fuel cell that generates electricity.

### Claim 8

A method for producing a carbon monoxide conversion catalyst for use in a daily startup and shutdown operation of a fuel cell, the method comprising:
individually dropping solutions of respective nitrates of Cu and Al to ion-exchanged water, stirring to dissolve, and adding a precipitant to the resultant solution to precipitate Cu and Al;
maturing the solution in which Cu and Al are precipitated to form a precursor;
collecting the obtained catalyst by filtration, after drying, calcining at about 550° C. to give an amorphous Cu—Al-Ox conversion catalyst in which amorphous AlyOx and Cu0 particles are dispersed; and
exposing the calcined CO conversion catalyst to a temperature of 50 to 250° C. in a satured stream atmosphere at 70° C. or higher to form a boehmite phases in a part of the amorphous catalyst
wherein the Cu0 particles are from 1.20 to 1.93 times as large as the boehmite phases.

### Claim 9 (depends on 8)

The method according to claim 8, wherein the Cu—Al-Ox catalyst is formed by any one of a homogeneous precipitation method, a coprecipitation method, and a sol-gel method, and then treated with steam-containing gas.

### Claim 10 (depends on 8)

The method according to claim 8, wherein the Cu—Al-Ox catalyst has a Cu:Al molar ratio of 4:1 to 1:4.

### Claim 11 (depends on 8)

The method according to claim 8, further comprising, including, as an active component, at least one member selected from a group consisting of Mn, Fe, Co, Cr, and Ni.