Exhaust gas purification catalyst
AssigneeMitsui Mining & Smelting Co., Ltd.
InventorsShingo AKITA, Rikiya MYOCHI, Hiroki KURIHARA
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Abstract
An object of the present invention is to provide an exhaust gas purification catalyst capable of achieving both improvement of PM collection performance and suppression of pressure loss increase, and the present invention provides an exhaust gas purification catalyst (1) including: a wall-flow substrate; and at least one of a first catalyst layer (20) and a second catalyst layer (30), wherein the exhaust gas purification catalyst (1) satisfies the following formulae 1a and 2a: 1.3 × 10 - 3 ≤ Ra ( 1 a ) Xa × Ya ≤ 8. ( 2 a ) and/or satisfies the following formulae 1b and 2b: 1.3 × 10 - 3 ≤ Rb ( 1 b ) Xb × Yb ≤ 8. . ( 2 b )
Claims8
An exhaust gas purification catalyst comprising:
- a substrate extending in an exhaust gas flow direction;
- and at least one of a first catalyst layer and a second catalyst layer,
- wherein the substrate comprises:
- an inflow-side cell extending in the exhaust gas flow direction and having an open end on an exhaust gas inflow side thereof and a closed end on an exhaust gas outflow side thereof;
- an outflow-side cell extending in the exhaust gas flow direction and having a closed end on an exhaust gas inflow side thereof and an open end on an exhaust gas outflow side thereof;
- and
- a porous partition wall separating the inflow-side cell and the outflow-side cell from each other,
- wherein the first catalyst layer is formed on an inflow-side cell side of the partition wall from an end on an exhaust gas inflow side of the partition wall along the exhaust gas flow direction,
- wherein the second catalyst layer is formed on an outflow-side cell side of the partition wall from an end on an exhaust gas outflow side of the partition wall along a direction opposite to the exhaust gas flow direction, and
- wherein the exhaust gas purification catalyst satisfies the following formulae 1a and 2a:
- 1.3
- ×
- 10
- -
- 3
- ≤
- Ra
- (
- 1
-
- a
- )
- Xa
- ×
- Ya
- ≤
- 8.
- (
- 2
-
- a
- )
- wherein Ra represents a gas permeability (cm3/(cm2·s·Pa)) of the first catalyst layer and the partition wall as determined using a permporometer, Xa represents a 50% flow pore diameter (μm) of the first catalyst layer and the partition wall as determined by a bubble point method using a permporometer, and Ya represents a 10% flow pore diameter (μm) of the first catalyst layer and the partition wall as determined by a bubble point method using a permporometer,
- and/or satisfies the following formulae 1b and 2b:
- 1.3
- ×
- 10
- -
- 3
- ≤
- Rb
- (
- 1
-
- b
- )
- Xb
- ×
- Yb
- ≤
- 8.
- (
- 2
-
- b
- )
- wherein Rb represents a gas permeability (cm3/(cm2·s·Pa)) of the second catalyst layer and the partition wall as determined using a permporometer, Xb represents a 50% flow pore diameter (μm) of the second catalyst layer and the partition wall as determined by a bubble point method using a permporometer, and Yb represents a 10% flow pore diameter (μm) of the second catalyst layer and the partition wall as determined by a bubble point method using a permporometer.
Dependencies are inferred from the claim text.