CPC F01N 13/0097 (2014.06) [F01N 3/28 (2013.01); F01N 3/2807 (2013.01); F01N 3/2825 (2013.01); F01N 13/0093 (2014.06); F01N 2510/0682 (2013.01); F01N 2510/0684 (2013.01)] | 6 Claims |
1. An exhaust gas purification device comprising:
a substrate including an upstream end through which an exhaust gas is introduced into the device, and a downstream end through which the exhaust gas is discharged from the device, the substrate having a length (Ls) extending from the upstream end to the downstream end;
a first catalyst layer containing first catalyst particles, extending across a first region, and being in contact with the substrate, the first region extending from the upstream end to a first position, the first position being at a first distance (La) from the upstream end toward the downstream end;
a second catalyst layer containing second catalyst particles, extending across a second region, and being in contact with the substrate, the second region extending from the downstream end to a second position, the second position being at a second distance (Lb) from the downstream end toward the upstream end, wherein the second position is a same position as the first position; and
a third catalyst layer containing third catalyst particles, extending across a third region, and being in contact with at least the first catalyst layer, the third region extending from the upstream end to a third position, the third position being at a third distance (Lc) from the upstream end toward the downstream end, wherein the third distance (Lc) is 40% to 70% of the length (Ls) of the substrate;
wherein the third catalyst particles are particles that function as a catalyst for reducing NOx,
wherein the first catalyst layer has an inner surface defining macropores,
wherein a total mass of the third catalyst layer is 40 g/L based on a capacity of the substrate in the third region;
wherein the first catalyst particles comprise palladium;
wherein the second catalyst particles comprise rhodium; and
wherein the third catalyst particles comprise rhodium.
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