Exhaust gas purification catalyst and production method thereof

Patent metadata

Field	Value
Publication number	US-10245579-B2
Application number	US-201415118213-A
Country	US
Kind code	B2
Filing date	Feb 18, 2014
Priority date	Feb 18, 2014
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

An exhaust gas purification catalyst contains an oxide 1 and an oxide 2. The catalyst has pores P 1-260 with a pore size of from 1 nm to 260 nm, that can be measured by the nitrogen absorption method, and the total sum ΣPV 1-260 of the pore volume PV 1-260 of the pores is equal to or greater than 0.79 cm 3 /g. The oxide 1 is an oxide with an oxygen release capability. The oxide 2 is represented by La x M 1-x M′O 3-δ (2), where M is at least one element selected from the group consisting of Ba, Sr and Ca, M′ is at least one element selected from the group consisting of Fe, Co, Ni and Mn, δ is the amount of oxygen deficiency, x satisfies 0≤x≤1, and δ satisfies 0≤δ≤1.

First claim

The invention claimed is:

1. An exhaust gas purification catalyst containing an oxide 1 that is an oxide of an oxygen storage material with an oxygen release/storage function and an oxide 2 that is represented by the following formula (2):
La x M 1-x M′O 3-δtm ( 2)

where M is at least one element selected from the group consisting of Ba, Sr and Ca, M′ is at least one element selected from the group consisting of Fe, Co, Ni and Mn, δ is the amount of oxygen deficiency, x satisfies 0≤x≤1, and δ satisfies 0≤δ≤1,
wherein the exhaust gas purification catalyst has pores P 1-260 with a pore size of from 1 nm to 260 nm, that can be measured by a nitrogen absorption method, and
a total sum ΣPV 1-260 of a pore volume PV 1-260 of the pores is equal to or greater than 0.79 cm 3 /g.

2. The exhaust gas purification catalyst according to claim 1 ,
wherein the exhaust gas purification catalyst is obtained by making the oxide 1 support the oxide 2, and
an increase ratio ΔδPV 100-260 of a total sum of a pore volume of pores with a pore size of from 100 nm to 260 nm by the supporting process satisfies ΔΣPV 100-260 1, where the increase ratio ΔΣPV 100-260 of the total sum the pore volume is represented by the following equation (1),
ΔΣPV 100-260 =(Total Sum δPV 100-260 of Pore Volume of the Exhaust Gas Purification Catalyst after the Supporting Process) /0.11  (1).

3. The exhaust gas purification catalyst according to claim 1 , wherein the oxide 1 contains cerium (Ce) and/or zirconium (Zr).

4. The exhaust gas purification catalyst according to claim 2 , wherein the oxide 1 contains cerium (Ce) and/or zirconium (Zr).

5. The exhaust gas purification catalyst according to claim 1 , wherein the oxide 1 is a complex oxide that contains cerium (Ce) and/or zirconium (Zr).

6. The exhaust gas purification catalyst according to claim 2 , wherein the oxide 1 is a complex oxide that contains cerium (Ce) and/or zirconium (Zr).

7. A method of producing the exhaust gas purification catalyst of claim 1 , comprising the steps of:
mixing a precursor of the oxide 2 with the oxide 1 before calcining the oxide 1, drying and then calcining a resultant mixture.

8. The method of producing the exhaust gas purification catalyst according to claim 7 , wherein the precursor of the oxide 2 is a carboxylate of lanthanum (La) and at least one element selected from the group consisting of barium (Ba), strontium (Sr), calcium (Ca), iron (Fe), cobalt (Co), nickel (Ni) and manganese (Mn).

Assignees

• Nissan Motor

Inventors

• Fujimoto Misaki
• Hanaki Yasunari

Classifications

• B01J35/1042

  Operations & Transport · mapped topic

• B01D2255/92

  Dimensions · CPC title

• B01J35/1061

  Operations & Transport · mapped topic

• B01J35/1047

  Operations & Transport · mapped topic

• B01D2255/2068

  Neodymium · CPC title