# US 2013/0156687 A1 · Ammonia oxidation/decomposition catalyst

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- Number: US 2013/0156687 A1
- Document ID: US20130156687A1
- Status: Published application
- Kind: A1
- Application number: 13/819,070
- Filed: 2010-08-31
- Published: 2013-06-20
- Earliest claimed: 2010-08-31
- Assignees: Hitachi Zosen Corporation
- Inventors: Sadao Araki; Susumu Hikazudani; Takuma Mori; Akira Taniguchi
- Web page: https://patentgrep.com/patent/US20130156687A1

## CPC

- C01B 3/047: Decomposition of ammonia
- B01J 23/002: {Mixed oxides other than spinels, e.g. perovskite}
- B01J 23/10: of rare earths
- B01J 23/14: of germanium, tin or lead
- B01J 23/22: Vanadium
- B01J 23/26: Chromium
- B01J 23/34: Manganese
- B01J 23/63: with rare earths or actinides
- B01J 23/66: Silver or gold
- B01J 23/83: with rare earths or actinides
- B01J 37/0201: {Impregnation}
- B01J 37/031: {Precipitation}
- B01J 2523/00: Constitutive chemical elements of heterogeneous catalysts
- Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The present invention provides an ammonia oxidation/decomposition catalyst including a support composed of an oxidizable and reducible metal oxide and a catalytically active metal supported thereon. By bringing the ammonia oxidation/decomposition catalyst including a support composed of an oxidizable and reducible metal oxide and a catalytically active metal supported thereon into contact with ammonia and air at ordinary temperature, the support in a reduced state reacts with oxygen to generate oxidation heat, and the temperature of the catalyst layer is increased in a moment. Once the temperature of the catalyst layer is increased to a temperature at which ammonia and oxygen react with each other, the ammonia oxidation reaction proceeds autonomously after that. The heat generated in this exothermic reaction is used in the course of decomposing ammonia in the presence of the catalytically active metal, thereby producing hydrogen.

## Claims

### Claim 1

A process for producing hydrogen by carrying out oxidation/decomposition of ammonia in the presence of an ammonia oxidation/decomposition catalyst comprising a support composed of an oxidizable and reducible metal oxide and a catalytically active metal supported thereon, the process comprising:
reducing the support by heating in a hydrogen stream, and
bringing ammonia and air into contact with the catalyst at ordinary temperature, such that the reduced support reacts with oxygen to generate oxidation heat, the temperature of the catalyst layer is increased in a moment to a temperature at which ammonia react with oxygen, and the heat generated by the ammonia oxidation according to the following equation:
NH3+3/402→1/2N2+3/2H2O (exothermic reaction)
is used in decomposing ammonia in the presence of the catalyst according to the following equation:
2NH3→3H2+N2 (endothermic reaction),
thereby producing hydrogen.

### Claim 2 (depends on 1)

The process for producing hydrogen according to claim 1, wherein the metal oxide is a composite oxide.

### Claim 3 (depends on 1)

The process for producing hydrogen according to claim 1, wherein the metal oxide is a rare earth metal oxide.

### Claim 4 (depends on 3)

The process for producing hydrogen according to claim 3, wherein the rare earth metal oxide is cerium oxide, lanthanum oxide, or samarium oxide.

### Claim 5 (depends on 2)

The process for producing hydrogen according to claim 2, wherein the metal oxide is a composite oxide of a rare earth metal and at least one metal selected from the group consisting of magnesium, titanium, zirconium, yttrium, aluminum, silicon, cobalt, iron, and gallium.

### Claim 6 (depends on 2)

The process for producing hydrogen according to claim 2, wherein the metal oxide is a composition oxide of a rare earth metal and at least two metals selected from the group consisting of magnesium, titanium, zirconium, yttrium, aluminum, silicon, cobalt, iron, and gallium.

### Claim 7 (depends on 1)

The process for producing hydrogen according to claim 1, wherein the catalytically active metal is at least one metal selected from the group consisting of a metal belonging to the Group VIII, tin, copper, silver, manganese, chromium, and vanadium.

### Claim 8 (depends on 1)

The process for producing hydrogen according to claim 1, wherein the catalyst is subjected to a reduction treatment at 200° C. or higher.

### Claim 9 (depends on 2)

The process for producing hydrogen according to claim 2, wherein the metal oxide is a rare earth metal oxide.