Titania porous body and method for producing same

Patent metadata

Field	Value
Publication number	US-11772983-B2
Application number	US-202016942016-A
Country	US
Kind code	B2
Filing date	Jul 29, 2020
Priority date	Feb 14, 2018
Publication date	Oct 3, 2023
Grant date	Oct 3, 2023

Abstract

A titania porous body is entirely formed of titania. The titania porous body includes a titania framework, first pores, and second pores. The titania framework forms a three-dimensional network structure. The first pores are opening portions of the three-dimensional structure. The second pores are disposed in a surface of the titania framework. Such a titania porous body is also referred to as a titania monolith.

First claim

What is claimed is:

1. A titania porous body, the titania porous body being entirely formed of titania, the titania porous body comprising:
a titania framework formed of titania crystals and forming a three-dimensional network structure;
first pores comprising opening portions of the three-dimensional network structure;
second pores disposed in a surface of the titania framework formed of titania crystals; and
third pores disposed in the surface of the titania framework formed of titania crystals and having a smaller pore diameter than the second pores;
wherein the first pores, second pores, and third pores each have a pore diameter distribution that includes a peak, and the peak of each pore diameter distribution is at a different pore diameter.

2. The titania porous body according to claim 1 , wherein the first pores have a pore diameter of 0.05 to 50 μm, and the second pores have a pore diameter of 20 to 200 nm.

3. The titania porous body according to claim 1 , wherein the third pores have a pore diameter of 10 to 100 nm.

4. The titania porous body according to claim 1 , wherein the titania porous body is rutile.

5. A method for producing a titania porous body, the method comprising:
(a1) a step of forming a gel from a dispersion liquid while the dispersion liquid is allowed to stand, the dispersion liquid including soluble particles, a titanium (IV) alkoxide, a chelating agent, a porogen, and an inorganic salt, the soluble particles being dispersed in the dispersion liquid, the soluble particles being soluble in a predetermined liquid;
(a2) a step of removing the chelating agent from the gel obtained; and
(a3) a step of obtaining the titania porous body according to claim 1 by immersing the gel, from which the chelating agent was removed, in the predetermined liquid to dissolve the soluble particles into the predetermined liquid and thereafter firing the gel at a predetermined firing temperature; or obtaining the titania porous body according to claim 1 by firing the gel, from which the chelating agent was removed, at a predetermined firing temperature and thereafter immersing the gel in the predetermined liquid to dissolve the soluble particles into the predetermined liquid.

6. The method for producing a titania porous body according to claim 5 , wherein the predetermined liquid comprises an alkaline solution, and the soluble particles comprise silica particles or silicate salt particles.

7. A method for producing a titania porous body, the method comprising:
(b1) a step of forming a gel from a dispersion liquid while the dispersion liquid is allowed to stand, the dispersion liquid including flammable particles, a titanium (IV) alkoxide, a chelating agent, a porogen, and an inorganic salt, the flammable particles being dispersed in the dispersion liquid, the flammable particles being particles to be burned off at a predetermined temperature;
(b2) a step of removing the chelating agent from the gel obtained; and
(b3) a step of obtaining the titania porous body according to claim 1 by firing the gel, from which the chelating agent was removed, at a predetermined firing temperature.

8. The method for producing a titania porous body according to claim 7 , wherein the predetermined temperature is the predetermined firing temperature, and the flammable particles comprise organic particles.

9. The method for producing a titania porous body according to claim 5 , wherein the predetermined firing temperature is 400 to 1200° C.

10. The method for producing a titania porous body according to claim 7 , wherein the predetermined firing temperature is 400 to 1200° C.

11. The method for producing a titania porous body according to claim 5 , wherein, in the step (a3), the titania porous body is obtained by firing the gel, from which the chelating agent was removed, at a firing temperature of 900 to 1200° C., and thereafter immersing the gel in the predetermined liquid to dissolve the soluble particles into the predetermined liquid.

Assignees

• Ngk Insulators Ltd
• Emaus Kyoto Inc

Inventors

• Yamada Kazunari
• Shimizu Hideki
• Ishizuka Norio
• Oda Toshikazu
• Konishi Kyoko

Classifications

• C01G23/053 Primary

  Producing by wet processes, e.g. hydrolysing titanium salts · CPC title

• C01G23/08

  Drying; Calcining {; After treatment of titanium oxide} · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2006/17

  Pore diameter distribution · CPC title

• C04B35/624 Primary

  Sol-gel processing · CPC title