Iron oxide-zirconia composite oxide and method for producing same, and exhaust gas purification catalyst

Patent metadata

Field	Value
Publication number	US-9387464-B2
Application number	US-201314384283-A
Country	US
Kind code	B2
Filing date	Apr 26, 2013
Priority date	Apr 27, 2012
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A composite oxide with a high oxygen storage capacity is provided without using cerium. The composite oxide is an iron oxide-zirconia composite oxide containing iron, zirconium, and a rare-earth element. The total content of Fe 2 O 3 , ZrO 2 , and an oxide of the rare-earth element is not less than 90 mass %, the content of an iron oxide in terms of Fe 2 O 3 is 10 to 90 mass %, and the absolute value of the covariance COV(Fe, Zr+X) of the composite oxide, which has been baked in the atmosphere at a temperature of greater than or equal to 900° C. for 5 hours or more, is not greater than 20.

First claim

The invention claimed is:

1. An iron oxide-zirconia composite oxide comprising iron, zirconium, and a rare-earth element, wherein
a total content of Fe 2 O 3 , ZrO 2 , and an oxide of the rare-earth element (X) is not less than 90 mass %,
a content of an iron oxide in terms of Fe 2 O 3 is 10 to 90 mass %, and
an absolute value of covariance COV(Fe, Zr+X) of the composite oxide, which has been baked in the atmosphere at a temperature of greater than or equal to 900° C. for 5 hours or more, determined by the following Formulae (1) to (3), is not greater than 30:

⁢

[

Math
.

⁢
1

]

⁢

R
i

⁡

(
Fe
)

=

I
i

⁡

(
Fe
)

×
100

I
i

⁡

(
Fe
)

+

I
i

⁡

(
Zr
)

+

I
i

⁡

(
X
)

(
1
)

⁢

R
i

⁡

(

Zr
+
X

)

=

{

I
i

⁡

(
Zr
)

+

I
i

⁡

(
X
)

}

×
100

I
i

⁡

(
Fe
)

+

I
i

⁡

(
Zr
)

+

I
i

⁡

(
X
)

(
2
)

COV
⁡

(

Fe
,

Zr
+
X

)

=

1
n

⁢

∑

Assignees

• Miura Masahide
• Tanaka Atsushi
• Suzuki Takahiro
• Suzuki Tadashi
• Tanabe Toshitaka
• Takahashi Naoki
• Toyota Motor Co Ltd

Inventors

• Miura Masahide
• Tanaka Atsushi
• Suzuki Takahiro
• Suzuki Tadashi
• Tanabe Toshitaka
• Takahashi Naoki

Classifications

• C01P2004/03

  obtained by SEM · CPC title

• C01P2004/45

  Aggregated particles or particles with an intergrown morphology · CPC title

• C01P2004/61

  Micrometer sized, i.e. from 1-100 micrometer · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C01G25/00

  Compounds of zirconium · CPC title