Oxygen storage/release material

Patent metadata

Field	Value
Publication number	US-10329984-B2
Application number	US-201815911947-A
Country	US
Kind code	B2
Filing date	Mar 5, 2018
Priority date	Mar 2, 2017
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

An oxygen storage/release material includes: a ceria-zirconia composite oxide porous body that has at least one ordered phase of a pyrochlore phase and a κ phase, and that has a central pore diameter of 70 nm to 1 μm as measured by a mercury penetration method, and in which a cumulative pore volume of pores that each have a pore diameter in the range of 0.5 times to 2 times the central pore diameter is 40% or more of the cumulative pore volume of pores that each have a pore diameter in the range of 10 nm to 10 μm as measured by the mercury penetration method.

First claim

What is claimed is:

1. An oxygen storage/release material comprising:
a ceria-zirconia composite oxide porous body that has at least one ordered phase of a pyrochlore phase and a κ phase, and that has a central pore diameter of 70 nm to 1 μm as measured by a mercury penetration method, and in which a cumulative pore volume of pores that each have a pore diameter in the range of 0.5 times to 2 times the central pore diameter is 40% or more of the cumulative pore volume of pores that each have a pore diameter in the range of 10 nm to 10 μm as measured by the mercury penetration method.

2. The oxygen storage/release material according to claim 1 , wherein
in an X-ray diffraction pattern of the ceria-zirconia composite oxide porous body obtained by an X-ray diffraction measurement using CuKα, a ratio (I ord /I max ) between a intensity I ord of a peak derived from the ordered phase in a region of 2θ=14 to 15 deg and a intensity I max of a maximum peak in a region of 2θ=29 to 30 deg is 0.03 or more.

3. The oxygen storage/release material according to claim 1 , wherein
a content molar ratio of Ce and Zr in the ceria-zirconia composite oxide porous body is Ce:Zr=40:60 to 60:40.

4. The oxygen storage/release material according to claim 1 , wherein
the ceria-zirconia composite oxide porous body further comprises at least one additional element selected from the group consisting of Y and lanthanoides excluding Ce.

5. The oxygen storage/release material according to claim 4 , wherein
the additional element is at least one selected from the group consisting of La, Pr, Nd and Y.

6. The oxygen storage/release material according to claim 4 , wherein
a content molar ratios of Ce, Zr and the additional element in the ceria-zirconia composite oxide porous body are 0.667≤Ce/Zr≤1.5 and 0.667≤(Ce+M)/Zr≤1.5 (in the formula, M represents the additional element).

7. A catalyst for purification of exhaust gas comprising:
the oxygen storage/release material according to claim 1 .

8. The oxygen storage/release material according to claim 1 , wherein
the central pore diameter is 200 nm to 1 μm.

Assignees

• Toyota Chuo Kenkyusho Kk

Inventors

• Hatanaka Miho
• Suda Akihiko

Classifications

• F01N2570/16

  Oxygen · CPC title

• F01N2370/02

  used in catalytic reactors · CPC title

• F01N3/0864

  Oxygen · CPC title

• F01N3/0814

  combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts · CPC title

• B01J21/066

  Zirconium or hafnium; Oxides or hydroxides thereof · CPC title