Catalyst with lanthanide-doped zirconia and methods of making

Patent metadata

Field	Value
Publication number	US-9011784-B2
Application number	US-201213570055-A
Country	US
Kind code	B2
Filing date	Aug 8, 2012
Priority date	Aug 10, 2011
Publication date	Apr 21, 2015
Grant date	Apr 21, 2015

Abstract

The invention generally relates to three-way catalysts and catalyst formulations capable of simultaneously converting nitrogen oxides, carbon monoxide, and hydrocarbons into less toxic compounds. Such three-way catalyst formulations contain ZrO 2 -based mixed-metal oxide support oxides doped with an amount of lanthanide. Three-way catalyst formulations with the support oxides of the present invention demonstrate higher catalytic activity, efficiency and longevity than comparable catalysts formulated with traditional support oxides.

First claim

What is claimed is:

1. A catalyst system comprising an overcoat, wherein said overcoat comprises an oxygen storage material (OSM) and a support oxide in a 1.5:1 ratio (by weight), wherein:
said OSM is 30% CeO 2 , 60% ZrO 2 , 5% Nd 2 O 3 , and 5% Pr 6 O 11 (by weight); and
said support oxide is support oxide comprises La X % Zr (1-X) % O 2 and/or Pr X % Zr (1-X) % O 2 .

2. The support oxide of claim 1 , wherein said support oxide comprises La 5% Zr 95% O 2 , Pr 5% Zr 95% O 2 , La 10% Zr 90% O 2 , Pr 10% Zr 90% O 2 , La 15% Zr 85% O 2 , Pr 15% Zr 85% O 2 , or mixtures thereof.

3. A catalyst system according to claim 1 comprising an overcoat, wherein said overcoat comprises an oxygen storage material (OSM) and a support oxide in a 1.5:1 ratio (by weight), wherein:
said OSM is 30% CeO 2 , 60% ZrO 2 , 5% Nd 2 O 3 , and 5% Pr 6 O 11 (by weight); and
said support oxide is Pr 0.10 Zr 0.90 O 2 .

4. The catalyst system of claim 3 , wherein said catalyst system further comprises a washcoat, wherein said washcoat comprises an OSM and a support oxide in a 1.5:1 ratio (by weight), wherein:
said OSM is 30% CeO 2 , 60% ZrO 2 , 5% Nd 2 O 3 and 5% Pr 6 O 11 (by weight); and
said support oxide is La—Al 2 O 3 .

5. A catalytic convertor system comprising the catalyst system of claim 3 .

6. The catalytic convertor system of claim 5 , wherein said catalytic convertor comprises two or more catalytic converters.

7. The catalytic convertor system of claim 6 , wherein said catalytic convertor system comprises a close coupled catalytic converter.

Assignees

• Golden Stephen J
• Hatfield Randal
• Pless Jason D
• Clean Diesel Tech Inc

Inventors

• Golden Stephen J
• Hatfield Randal
• Pless Jason D

Classifications

• C01F17/32

  oxide or hydroxide being the only anion, e.g. NaCeO2 or MgxCayEuO · CPC title

• C04B35/50

  based on rare-earth compounds {(non-oxide rare earth compounds C04B35/5156)} · CPC title

• B01J37/0244

  Coatings comprising several layers · CPC title

• B01J37/0201

  Impregnation · CPC title

• B01J37/0036

  Grinding · CPC title