# US 11,305,269 B2 · Coated wall-flow filter

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- Number: US 11,305,269 B2
- Document ID: US11305269B2
- Status: Granted
- Kind: B2
- Application number: 17/045,860
- Filed: 2019-03-29
- Published: 2021-05-13
- Granted: 2022-04-19
- Earliest claimed: 2018-04-09
- Assignees: Umicore AG & Co. KG
- Applicants: Umicore AG & Co. KG
- Inventors: Naina Deibel; Martin Foerster; Antje Oltersdorf; Juergen Koch; Martin Roesch
- Web page: https://patentgrep.com/patent/US11305269B2

## CPC

- B01D 53/945: {characterised by a specific catalyst}
- B01D 46/2429: {of the honeycomb walls or cells}
- B01D 46/24492: {Pore diameter}
- B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas}
- B01J 21/04: Alumina
- B01J 23/464: {Rhodium}
- B01J 35/19: {Catalysts containing parts with different compositions}
- B01J 37/0215: {Coating}
- B01J 37/0221: {of particles}
- F01N 3/035: with catalytic reactors
- F01N 3/101: {Three-way catalysts}
- F01N 3/2066: {Selective catalytic reduction [SCR]}
- F01N 3/2803: {characterised by structure, by material or by manufacturing of catalyst support}
- B01D 2255/1023: Palladium
- B01D 2255/1025: Rhodium
- B01D 2255/2092: Aluminium
- B01D 2255/9155: Wall flow filters
- B01D 2279/30: for treatment of exhaust gases from IC Engines
- B01J 35/56: Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths
- F01N 2370/02: used in catalytic reactors
- Y02T 10/12: Improving ICE efficiencies
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

The present invention relates to a catalytically coated wall-flow filter, to a method for the production thereof and to the use thereof in order to reduce harmful exhaust gases of an internal combustion engine.

## Claims

### Claim 1

Catalytically active wall-flow filter for reducing the harmful substances in the exhaust gas of an internal combustion engine, wherein the wall-flow filter comprises walls with pores, and the wall-flow filter is coated with catalytically active material in the walls, with the wall-flow filter being selectively impinged on an inlet side with a dry powder/gas aerosol which has a high-melting compound in such a way that the powder is deposited in the pores of the filter walls and does not form a continuous layer on the walls of the filter.

### Claim 2 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that the aerosol is a mixture of air and a high-melting metal oxide, metal sulfate, metal phosphate, metal carbonate, or metal hydroxide powder.

### Claim 3 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that the catalytically active coating of the filter is selected from the group consisting of three-way catalyst, SCR catalyst, nitrogen oxide storage catalyst, oxidation catalyst, soot-ignition coating, hydrocarbon storage.

### Claim 4 (depends on 3)

Catalytically active wall-flow filter according to claim 3, characterized in that the catalytically active coating of the filter consists of at least one metal-ion-exchanged zeolite, cerium/zirconium mixed oxide, aluminum oxide and palladium, rhodium, or platinum, or combinations of these noble metals.

### Claim 5 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that said filter has a loading with the catalytic coating of 20 g/l to 200 g/l based on the volume of the filter.

### Claim 6 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that the ratio of average particle diameter (measured according to the most recent ISO 13320 on the date of application) d50 in the dry aerosol and the average pore diameter of the filter after coating with washcoat (measured according to DIN 66134, latest version on the date of application) is between 0.03 and 2.

### Claim 7 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that the loading of the filter with the powder is not more than 50 g/l based on the volume of the filter.

### Claim 8 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that the powder coating has an increasing gradient from the inlet end to the outlet end.

### Claim 9 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that the powder is also catalytically active with regard to reducing the harmful substances in the exhaust gas of an internal combustion engine.

### Claim 10 (depends on 1)

Catalytically active wall-flow filter according to claim 1, characterized in that said filter has an increase in filtration efficiency of at least 5% at a relative increase in the exhaust-gas back pressure of at most 10% compared to a fresh filter coated with catalytically active material but not treated with powder.

### Claim 11 (depends on 1)

Method for producing a catalytically active wall-flow filter according to claim 1, characterized in that a carrier gas is charged with a powder and sucked into a filter.

### Claim 12 (depends on 11)

Method for producing a catalytically active wall-flow filter according to claim 11, characterized in that the aerosol is sucked through the filter at a rate of 5 m/s to 50 m/s.

### Claim 13 (depends on 11)

Method for producing a catalytically active wall-flow filter according to claim 11, characterized in that the powder has a moisture content of less than 20% at the time of impingement on the wall-flow filter.

### Claim 14 (depends on 1)

A method of reducing harmful exhaust gases of an internal combustion engine, comprising passing the exhaust gas through a catalytically active wall-flow filter according to claim 1 in order to reduce harmful exhaust gases produced by the internal combustion engine.