Exhaust purification filter

• US 10,677,124 B2
• Filed: 09/24/2015
• Issued: 06/09/2020
• Est. Priority Date: 09/24/2015
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Otsuka, Shinichiro, Masumitsu, Noritaka, Yamada, Ryoko
• Primary Examiner(s): Lee, Brandon D
• Application Number:
  US15/762,682
• Publication Number:
  US 20180266289A1
• Time in Patent Office: 1,720 Days
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/1025 Rhodium
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/2066 Praseodymium
• CPC Class Codes: B01D 2255/2068 Neodymium
• CPC Class Codes: B01D 2255/20715 Zirconium
• CPC Class Codes: B01D 2255/407 Zr-Ce mixed oxides
• CPC Class Codes: B01D 2255/908 O2-storage component incorporated in the catalyst
• CPC Class Codes: B01D 2255/9155 Wall flow filters
• CPC Class Codes: B01D 2258/014 Stoichiometric gasoline engines
• CPC Class Codes: B01D 53/945 characterised by a specific catalyst
• CPC Class Codes: B01D 53/9454 characterised by a specific device
• CPC Class Codes: B01J 29/061 containing metallic elements added to the zeolite
• CPC Class Codes: B01J 29/068 Noble metals
• CPC Class Codes: F01N 2250/02 filtering and catalytic conversion
• CPC Class Codes: F01N 2330/06 Ceramic, e.g. monoliths
• CPC Class Codes: F01N 2330/30 Honeycomb supports characterised by their structural details
• CPC Class Codes: F01N 2370/02 used in catalytic reactors
• CPC Class Codes: F01N 2370/04 Zeolitic material
• CPC Class Codes: F01N 2510/06 for exhaust purification, e.g. catalytic reaction
• CPC Class Codes: F01N 3/0222 : the structure being monolithic, e.g. honeycombs
• CPC Class Codes: F01N 3/035 : with catalytic reactors , e.g. catalysed diesel particulate filters
• CPC Class Codes: F01N 3/101 : Three-way catalysts
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies

Abstract

Provided is a GPF capable of exhibiting better than conventional three-way purification function. A gasoline particulate filter (GPF) that is provided in an exhaust pipe of an engine and that performs purification by capturing particulate matter (PM) in exhaust gas is provided with a filter substrate in which a plurality of cells extending from an exhaust gas inflow-side end face to an outflow-side end face are defined by porous partition walls and in which openings at the inflow-side end face and openings at the outflow-side end face of the cells are alternately sealed; and a three-way catalyst (TWC) supported by the partition wall. The three-way catalyst is the GPF comprising a catalytic metal containing at least Rh, and a composite oxide having an oxygen storage capacity and containing Nd and Pr in a crystal structure.

Claims

1. An exhaust purification filter which is provided in an exhaust passage of a gasoline engine, and purifies by capturing particulate matter in exhaust gas of the gasoline engine, the exhaust purification filter comprising:

a filter substrate in which a plurality of cells extending from an inlet-side end face until an outlet-side end face of exhaust gas are formed to be divided by porous barrier walls, and an opening at the inlet-side end face and an opening at the outlet-side end face of the cells are alternately sealed; and

a three-way catalyst that is loaded on the barrier walls,

wherein the three-way catalyst is configured to include a catalytic metal containing at least Rh, and a CeZrNdPr complex oxide having an oxygen occlusion/release ability, and

wherein total content of Nd and Pr contained in the complex oxide is 12% by mass to 16% by mass.

2. The exhaust purification filter according to claim 1,

wherein the barrier wall has an average pore diameter of at least 15 μ

m, and

wherein the three-way catalyst has a particle size D90 when a cumulative distribution from a small particle size side of the particle distribution is 90% of no more than 5 μ

m.

3. The exhaust purification filter according to claim 1, wherein the three-way catalyst contains Rh and Pd as the catalytic metal, and is loaded onto surfaces within pores inside of the barrier wall in a state in which the Rh and Pd are mixed.

4. The exhaust purification filter according to claim 1, wherein the three-way catalyst is configured to be free of Ba.

5. The exhaust purification filter according to claim 1, wherein the complex oxide contains only Ce, Zr, Nd, and Pr.

6. The exhaust purification filter according to claim 2, wherein the three-way catalyst contains Rh and Pd as the catalytic metal, and is loaded onto surfaces within pores inside of the barrier wall in a state in which the Rh and Pd are mixed.

7. The exhaust purification filter according to claim 2, wherein the three-way catalyst is configured to be free of Ba.

8. The exhaust purification filter according to claim 3, wherein the three-way catalyst is configured to be free of Ba.

9. The exhaust purification filter according to claim 6, wherein the three-way catalyst is configured to be free of Ba.