Titanium-oxide catalyst and method of producing the same

• US 10,058,847 B2
• Filed: 03/17/2016
• Issued: 08/28/2018
• Est. Priority Date: 03/20/2015
• Status: Active Grant

• Current Assignee: Kochi University Of Technology, Nippon Pillar Packing Company Limited
• Original Assignee: Kochi University Of Technology, Nippon Pillar Packing Company Limited
• Inventors: Kobiro, Kazuya, Otani, Masataka, Moriwaki, Keiichiro, Hayashi, Yukimi
• Primary Examiner(s): Nguyen, Cam N
• Application Number:
  US15/072,673
• Publication Number:
  US 20160271588A1
• Time in Patent Office: 894 Days
• CPC Class Codes: B01D 2255/102 Platinum group metals
• CPC Class Codes: B01D 2255/1026 Ruthenium
• CPC Class Codes: B01D 2255/20707 Titanium
• CPC Class Codes: B01D 2255/9202 Linear dimensions
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/8671 Removing components of defined structure not provided for in B01D53/8603 - B01D53/8668
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 23/40 of the platinum group metals
• CPC Class Codes: B01J 23/462 Ruthenium
• CPC Class Codes: B01J 23/48 Silver or gold
• CPC Class Codes: B01J 23/70 of the iron group metals or copper
• CPC Class Codes: B01J 23/74 Iron group metals
• CPC Class Codes: B01J 35/23 in a colloidal state
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 35/391 Physical properties of the active metal ingredient
• CPC Class Codes: B01J 35/393 Metal or metal oxide crystallite size
• CPC Class Codes: B01J 35/397 Egg shell like
• CPC Class Codes: B01J 35/40 characterised by dimensions, e.g. grain size in a colloidal state B01J35/23; crystallite size B01J35/77
• CPC Class Codes: B01J 35/615 100-500 m2/g
• CPC Class Codes: B01J 37/009 Preparation by separation, e.g. by filtration, decantation, screening
• CPC Class Codes: B01J 37/031 : Precipitation
• CPC Class Codes: B01J 37/033 : Using Hydrolysis
• CPC Class Codes: B01J 37/18 : with gases containing free hydrogen
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 : Manufacture or treatment of nanostructures
• CPC Class Codes: Y10S 977/811 : Of specified metal oxide composition, e.g. conducting or semiconducting compositions such as ITO, ZnOx

Abstract

A titanium-oxide catalyst containing catalytic metal shows catalysis under high temperature conditions. A titanium-oxide catalyst contains a titanium-oxide nanoparticle assembly and ruthenium particles. The titanium-oxide nanoparticle assembly is an assembly of titanium-oxide nanoparticles, which are nanoparticles of titanium oxide. The ruthenium particles have a smaller particle diameter than the titanium-oxide nanoparticle assembly and the titanium-oxide nanoparticles. The ruthenium particles are dispersed and supported on a surface of the titanium-oxide nanoparticle assembly.

Claims

1. A titanium oxide catalyst, comprising:

a titanium oxide nanoparticle assembly that includes titanium oxide nanoparticles as primary particles; and

catalytic metal particles dispersed and supported on a surface of the titanium oxide nanoparticle assembly,

wherein each of the catalytic metal particles has a particle diameter smaller than a particle diameter of each of the primary particles; and

wherein an average distance between the catalytic metal particles is larger than an average distance between the primary particles.

2. The titanium oxide catalyst according to claim 1, wherein

the catalytic metal is supported in depressions formed by adjacent primary particles of the titanium oxide nanoparticle assembly.

3. The titanium-oxide catalyst according to claim 2, wherein

the content of the catalytic metal is 1 to 40 wt % inclusive of a total of 100 wt % of the titaniumoxide nanoparticle assembly and the catalytic metal.

4. The titanium oxide catalyst according to claim 2, wherein

the primary particles have a particle diameter of 2 to 50 nm inclusive.

5. The titanium oxide catalyst according to claim 2, wherein

the catalytic metal has a particle diameter of 1 to 10 nm inclusive, and

the primary particles have a particle diameter at least twice the particle diameter of the catalytic metal.

6. The titanium oxide catalyst according to claim 1, wherein

the content of the catalytic metal is 1 to 40 wt % inclusive of a total of 100 wt % of the titanium oxide nanoparticle assembly and the catalytic metal.

7. The titanium oxide catalyst according to claim 6, wherein

the primary particles have a particle diameter of 2 to 50 nm inclusive.

8. The titanium oxide catalyst according to claim 6, wherein

the catalytic metal has a particle diameter of 1 to 10 nm inclusive, and

the primary particles have a particle diameter at least twice the particle diameter of the catalytic metal.

9. The titanium oxide catalyst according to claim 1, wherein

the primary particles have a particle diameter of 2 to 50 nm inclusive.

10. The titanium oxide catalyst according to claim 9, wherein

the catalytic metal has a particle diameter of 1 to 10 nm inclusive, and

the primary particles have a particle diameter at least twice the particle diameter of the catalytic metal.

11. The titanium oxide catalyst according to claim 1, wherein

the catalytic metal has a particle diameter of 1 to 10 nm inclusive, and the primary particles have a particle diameter at least twice the particle diameter of the catalytic metal.

12. The titanium oxide catalyst according to claim 1, wherein

the titanium oxide nanoparticle assembly has a particle diameter of 100 to 2000 nm inclusive.

13. The titanium oxide catalyst according to claim 1, wherein

the catalytic metal is at least one metal selected from the group consisting of Ru, Pt, Pd, Au, Ag, Cu, Ni, Fe, Ir, Rh, and Re.

14. A titanium oxide catalyst according to claim 1,

wherein each of the catalytic metal particles is formed by a metal or a metal containing material that is different from titanium oxide.

15. The titanium oxide catalyst according to claim 1,

wherein the titanium oxide nanoparticle assembly is produced by reacting carboxylic acid with titanium compounds in supercritical fluid.

16. The titaniiimoxide catalyst according to claim 1,

wherein the titanium oxide catalyst is produced by adding a reducing agent to a solution containing the titanium oxide nanoparticle assembly and the catalytic metal sources so as to causing a reductive reaction, prior to a thermal treatment.

17. The titanium oxide catalyst according to claim 1,

wherein the titanium oxide nanoparticle assembly is produced by reacting carboxylic acid with titanium compounds in supercritical fluid;

and

wherein the titanium oxide catalyst is produced by adding a reducing agent to a solution containing the titanium oxide nanoparticle assembly and the catalytic metal sources so as to causing a reductive reaction, prior to a thermal treatment.

18. A method of producing a titanium oxide catalyst, the method comprising:

causing catalytic metal particles to be supported on a titanium oxide nanoparticle assembly, the titanium oxide nanoparticle assembly that includes titanium oxide nanoparticles as primary particles,

wherein an average distance between the catalytic metal particles is larger than an average distance between the primary particles.

19. The method of producing a titanium oxide catalyst according to claim 18, further comprising:

thermally treating the titanium oxide nanoparticle assembly on which the catalytic metal has been supported.

20. The method of producing a titanium oxide catalyst according to claim 19, wherein

the thermally treating includes thermally treating the titanium oxide nanoparticle assembly at a temperature of 300 to 400 °

C. inclusive for a time period of 5 to 15 minutes inclusive.

21. A method of producing a titanium oxide catalyst according to claim 18,

wherein each of the catalytic metal particles is formed by a metal or a metal containing material that is different from titanium oxide.

22. A method for performing hydrogen reduction of carbon dioxide, comprising

reducing the carbon dioxide using a titanium oxide catalyst,

wherein the catalyst comprises:

a titanium oxide nanoparticle assembly that includes titanium oxide nanoparticles as primary particles; and

catalytic metal particles dispersed and supported on a surface of the titanium oxide nanoparticle assembly, wherein each of the catalytic metal particles has a particle diameter smaller than a particle diameter of each of the titanium oxide nanoparticle assembly and the primary particles,

wherein an average distance between the catalytic metal particles is larger than an average distance between the primary particles.

23. A method for performing hydrogen reduction of carbon dioxide according to claim 22,

wherein each of the catalytic metal particles is formed by a metal or a metal containing material that is different from titanium oxide.