# US 2019/0168200 A1 · PASSIVE NOx ADSORBER

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- Number: US 2019/0168200 A1
- Document ID: US20190168200A1
- Status: Published application
- Kind: A1
- Application number: 16/273,371
- Filed: 2019-02-12
- Published: 2019-06-06
- Earliest claimed: 2015-10-06
- Assignees: Johnson Matthey Public Limited Company
- Applicants: Johnson Matthey Public Limited Company
- Inventors: Andrew Francis CHIFFEY; Jack CORPS; Laura MITCHELL-DOWNIE; Francois MOREAU; Matthew O'BRIEN
- Web page: https://patentgrep.com/patent/US20190168200A1

## CPC

- B01J 29/7815: {Zeolite Beta}
- B01D 53/9422: {for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)}
- B01D 53/9481: {Catalyst preceded by an adsorption device without catalytic function for temporary storage of contaminants, e.g. during cold start}
- B01J 21/04: Alumina
- B01J 21/12: Silica and alumina
- B01J 23/44: Palladium
- B01J 23/63: with rare earths or actinides
- B01J 23/6562: {Manganese}
- B01J 29/00: Catalysts comprising molecular sieves {(molecular sieves per se C01B)}
- B01J 29/74: Noble metals
- B01J 29/743: {CHA-type, e.g. Chabazite, LZ-218}
- B01J 35/19: {Catalysts containing parts with different compositions}
- F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts}
- F01N 3/0842: {Nitrogen oxides}
- F01N 13/009: {having two or more separate purifying devices arranged in series}
- B01D 2255/1021: Platinum
- B01D 2255/1023: Palladium
- B01D 2255/2063: Lanthanum
- B01D 2255/2065: Cerium
- B01D 2255/2066: Praseodymium
- B01D 2255/20715: Zirconium
- B01D 2255/2073: Manganese
- B01D 2255/2092: Aluminium
- B01D 2255/2096: Bismuth
- B01D 2255/40: Mixed oxides
- B01D 2255/50: Zeolites
- B01D 2255/502: Beta zeolites
- B01D 2255/9022: Two layers
- B01D 2255/9035: Three zones
- B01D 2255/908: O2-storage component incorporated in the catalyst
- B01D 2255/91: NOx-storage component incorporated in the catalyst
- B01D 2255/915: Catalyst supported on particulate filters
- B01J 2235/00: Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties
- F01N 2370/04: Zeolitic material
- F01N 2510/063: zeolites
- F01N 2570/14: Nitrogen oxides
- F01N 2570/16: Oxygen
- Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- 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)
- 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)
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE

## Abstract

A NOx absorber catalyst for treating an exhaust gas from a lean burn engine. The NOx absorber catalyst comprises a molecular sieve catalyst comprising a noble metal and a molecular sieve, wherein the molecular sieve contains the noble metal; an oxygen storage material for protecting the molecular sieve catalyst; and a substrate having an inlet end and an outlet end.

## Claims

### Claim 1

A NOx absorber catalyst for treating an exhaust gas from a lean burn engine comprising:
a first layer comprising an oxygen storage material effective for protecting the molecular sieve catalyst by preventing the molecular sieve catalyst from becoming deactivated to NOx storage when exposed to rich exhaust gas conditions;
a second layer comprising a molecular sieve catalyst comprising a noble metal and a molecular sieve, wherein the molecular sieve contains the noble metal, and wherein the noble metal comprises palladium; and
a substrate having an inlet end and an outlet end;
wherein the first layer is disposed on the second layer.

### Claim 2 (depends on 1)

A NOx absorber catalyst according to claim 1, wherein the molecular sieve is selected from a small pore molecular sieve, a medium pore molecular sieve and a large pore molecular sieve.

### Claim 3 (depends on 1)

A NOx absorber catalyst according to claim 1, wherein the molecular sieve is a small pore molecular sieve having a Framework Type selected from the group consisting of ACO, AEI, AEN, AFN, AFT, AFX, ANA, APC, APD, ATT, CDO, CHA, DDR, DFT, EAB, EDI, EPI, ERI, GIS, GOO, IHW, ITE, ITW, LEV, KFI, MER, MON, NSI, OWE, PAU, PHI, RHO, RTH, SAT, SAV, SIV, THO, TSC, UEI, UFI, VNI, YUG, ZON and a mixture or intergrowth of any two or more thereof.

### Claim 4 (depends on 3)

A NOx absorber catalyst according to claim 3, wherein the small pore molecular sieve has a Framework Type that is AEI or CHA.

### Claim 5 (depends on 1)

A NOx absorber catalyst according to claim 1, wherein the molecular sieve has an aluminosilicate framework and a silica to alumina molar ratio of 10 to 200.

### Claim 6 (depends on 1)

A NOx absorber catalyst according to claim 1, wherein the oxygen storage material for protecting the molecular sieve catalyst comprises at least one of an oxide of cerium or a manganese compound, wherein the manganese compound comprises an oxide of manganese or manganese aluminate.

### Claim 7 (depends on 7)

A NOx absorber catalyst according to claim 7, wherein the oxygen storage material for protecting the molecular sieve catalyst comprises an oxide of cerium the oxygen, palladium, and optionally platinum, supported on the oxide of cerium.

### Claim 8 (depends on 1)

A NOx absorber catalyst according to claim 1 further comprising a lean NOx trap (LNT) region.

### Claim 9 (depends on 1)

A NOx absorber catalyst according to claim 1, wherein the substrate is a flow-through monolith or a filtering monolith.

### Claim 10 (depends on 1)

An exhaust system comprising a NOx absorber catalyst as defined in claim 1 and an emissions control device.

### Claim 11 (depends on 10)

An exhaust system according to claim 10, wherein the emissions control device is selected from the group consisting of a diesel particulate filter (DPF), a lean NOx trap (LNT), a lean NOx catalyst (LNC), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), a catalysed soot filter (CSF), a selective catalytic reduction filter catalyst, an ammonia slip catalyst (ASC) and combinations of two or more thereof.

### Claim 12 (depends on 10)

A vehicle comprising a lean burn engine and an exhaust system as defined in claim 10.

### Claim 13 (depends on 1)

A method of treating an exhaust gas from a lean burn engine comprising contacting the exhaust gas with a NOx absorber catalyst according to claim 1.