Catalytic converter

Patent metadata

Field	Value
Publication number	US-10071365-B2
Application number	US-201314761847-A
Country	US
Kind code	B2
Filing date	Nov 26, 2013
Priority date	Jan 23, 2013
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

There is provided a catalytic converter that offers high exhaust gas cleaning performance by effectively utilizing a whole catalyst that constitutes the catalytic converter.
In a catalytic converter ( 10 ), catalytic layers ( 2 A, 2 B) made of a noble metal catalyst are formed on cell wall surfaces of a substrate ( 1 ) having a cell structure, and the catalytic layers ( 2 A, 2 B) extend in a longitudinal direction of the substrate ( 1 ) along which gas flows. The substrate ( 1 ) has a central region ( 1 A) having a relatively high cell density and a peripheral region ( 1 B) having a relatively low cell density. The length of each of the catalytic layers ( 2 B) in the longitudinal direction in the peripheral region ( 1 B) is longer than the length of each of the catalytic layers ( 2 A) in the longitudinal direction in the central region ( 1 A).

First claim

The invention claimed is:

1. A catalytic converter comprising:
a substrate that has a cell structure and is configured to allow gas to flow through the substrate; and
a catalytic layer that is made of a noble metal catalyst and is formed on a cell wall surface of the substrate, the catalytic layer extending in a longitudinal direction of the substrate, wherein:
the substrate has a central region and a peripheral region, the central region having a cell density higher than a cell density of the peripheral region, wherein a length of the substrate in the central region is equal to a length of the substrate in the peripheral region;
the catalytic layer includes a first catalytic layer provided in the central region and a second catalytic layer provided in the peripheral region;
a length of the second catalytic layer in the longitudinal direction is larger than a length of the first catalytic layer in the longitudinal direction; and
the first catalytic layer and the second catalytic layer are each composed of two or more layers and having a same number of layers, and wherein, in the longitudinal direction, a layer of the two or more layers constituting the second catalytic layer is longer than a corresponding layer of the two or more layers constituting the first catalytic layer.

2. The catalytic converter according to claim 1 , wherein a ratio of the length of the first catalytic layer in the longitudinal direction to a length of the substrate in the longitudinal direction is equal to or higher than 65%.

3. The catalytic converter according to claim 1 , wherein:
a ratio of the length of the first catalytic layer in the longitudinal direction to a length of the substrate in the longitudinal direction is 80%; and
a ratio of the length of the second catalytic layer in the longitudinal direction to the length of the substrate in the longitudinal direction is 85% to 100%.

4. The catalytic converter according to claim 1 , wherein the cell density of the central region is equal to or lower than two times the cell density of the peripheral region.

5. The catalytic converter according to claim 1 , wherein each of the first catalytic layer and the second catalytic layer has an end that is positioned at a downstream end of the substrate along a direction in which the exhaust gas flows through the substrate.

Assignees

• Aoki Yuki
• Suzuki Hiromasa
• Matsubara Hiroyuki
• Toyota Motor Co Ltd

Inventors

• Aoki Yuki
• Suzuki Hiromasa
• Matsubara Hiroyuki

Classifications

• B01J23/464

  Rhodium · CPC title

• B01D53/94

  by catalytic processes · CPC title

• F01N2510/0682

  having a discontinuous, uneven or partially overlapping coating of catalytic material, e.g. higher amount of material upstream than downstream or vice versa · CPC title

• F01N2510/0684

  having more than one coating layer, e.g. multi-layered coatings · CPC title

• B01D2255/1025

  Rhodium · CPC title