Oxygen storage material and method for producing the same

Patent metadata

Field	Value
Publication number	US-10618029-B2
Application number	US-201816002147-A
Country	US
Kind code	B2
Filing date	Jun 7, 2018
Priority date	Jun 12, 2017
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

To provide an oxygen storage material that is capable of exhibiting an excellent oxygen storage capacity (OSC) even at a low temperature of about 300° C. and has a sufficiently high efficiency of use of cerium contained therein.
An oxygen storage material including a ceria-zirconia-copper oxide-based composite oxide that contains cerium, zirconium, and copper, in which
at least part of the copper is solid-dissolved in a composite oxide of the cerium and the zirconium, the ceria-zirconia-copper oxide-based composite oxide has a composition expressed by the following chemical formula (1):

Ce x Zr y Cu z O 2-z   (1)
where x, y, and z are numbers each satisfying conditions of x=0.3 to 0.7, y=0.15 to 0.7 (exclusive of y=0.7), z=0 to 0.15 (exclusive of z=0), and x+y+z=1, and a specific surface area of the ceria-zirconia-copper oxide-based composite oxide is 2 to 50 m 2 /g.

First claim

What is claimed is:

1. A method for producing an oxygen storage material, comprising:
mixing
at least one cerium compound selected from the group consisting of cerium chloride, cerium nitrate, cerium sulfate, cerium acetate, and cerium oxide,
at least one zirconium compound selected from the group consisting of zirconium chloride, zirconium nitrate, zirconium sulfate, zirconium acetate, and zirconium oxide,
at least one copper compound selected from the group consisting of copper chloride, copper nitrate, copper sulfate, copper acetate, and copper oxide, and
a hydrophilic organic compound in a solvent, to obtain a mixture, said hydrophilic organic compound being selected from the group consisting of glycine, glucose, urea, alanine and oxalyl hydrazine; and

obtaining the oxygen storage material comprising a ceria-zirconia-copper oxide-based composite oxide from the mixture through a solution combustion synthesis,
said ceria-zirconia-copper oxide-based composite oxide being that containing cerium, zirconium and copper,
wherein 90 at % or more of the copper is solid-dissolved in a composite oxide of the cerium and the zirconium,
the ceria-zirconia-copper oxide-based composite oxide has a composition expressed by the following chemical formula (1):
Ce x Zr y Cu z O 2-z   (1)

where x, y, and z are numbers each satisfying conditions of x=0.3 to 0.7, y=0.15 to 0.7 (exclusive of y=0.7), z=0 to 0.15 (exclusive of z=0), and x+y+z=1, and
a specific surface area of the ceria-zirconia-copper oxide-based composite oxide is 2 to 50 m 2 /g.

2. The method for producing an oxygen storage material according to claim 1 , wherein
the mixture is obtained by mixing cerium nitrate, zirconium nitrate, copper nitrate, and the hydrophilic organic compound in a solvent.

3. The method for producing an oxygen storage material according to claim 1 , wherein x, y, and z are numbers each satisfying conditions of x=0.3 to 0.7, y=0.15 to 0.67, z=0.03 to 0.15, and x+y+z=1.

4. The method for producing an oxygen storage material according to claim 1 , wherein
an average crystal size of the ceria-zirconia-copper oxide-based composite oxide is 20 to 100 nm.

5. The method for producing an oxygen storage material according to claim 1 , wherein
the ceria-zirconia-copper oxide-based composite oxide has a fluorite structure and contains no pyrochlore phase.

Assignees

• Toyota Motor Co Ltd

Inventors

• Goto Yoshihiro
• Morikawa Akira
• Miura Masahide
• Suzuki Hiromasa

Classifications

• B01J23/10 Primary

  of rare earths · CPC title

• B01J20/0237 Primary

  Compounds of Cu · CPC title

• C01B13/0203

  from inorganic compounds · CPC title

• B01D2255/908

  O2-storage component incorporated in the catalyst · CPC title

• B01D53/9445

  Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] · CPC title