OXIDATION CATALYST FOR INTERNAL COMBUSTION ENGINE EXHAUST GAS TREATMENT

• US 20140130760A1
• Filed: 01/20/2014
• Published: 05/15/2014
• Est. Priority Date: 10/06/2011
• Status: Active Grant

• Current Assignee: Johnson Matthey PLC
• Original Assignee: Johnson Matthey Japan G.K. (Johnson Matthey PLC), Johnson Matthey PLC
• Inventors: SUMIYA, SATOSHI, WANG, LIFENG, OYAMADA, HANAKO, BLAKEMAN, PHILIP GERALD, BROWN, MICHAEL GAVIN, CHATTERJEE, SOUGATO, CHIFFEY, ANDREW FRANCIS, GAST, JANE, PHILLIPS, PAUL RICHARD, RAJARAM, RAJ RAO, WALKER, ANDREW PETER
• Granted Patent: US 9,005,559 B2
• Time in Patent Office: Days
• US Class Current: 123/1.A
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2255/1021 Platinum
• CPC Class Codes: B01D 2255/1023 Palladium
• CPC Class Codes: B01D 2255/2065 Cerium
• CPC Class Codes: B01D 2255/207 Transition metals
• CPC Class Codes: B01D 2255/20707 Titanium
• CPC Class Codes: B01D 2255/50 Zeolites
• CPC Class Codes: B01D 2255/902 Multilayered catalyst
• CPC Class Codes: B01D 2255/9022 Two layers
• CPC Class Codes: B01D 2255/912 HC-storage component incorporated in the catalyst
• CPC Class Codes: B01D 2258/012 Diesel engines and lean burn gasoline engines
• CPC Class Codes: B01D 53/9431 Processes characterised by a specific device
• CPC Class Codes: B01D 53/944 Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts three-way-catalysts [TWC] B01D53/9445
• CPC Class Codes: B01D 53/9477 with catalysts positioned on separate bricks, e.g. exhaust systems
• CPC Class Codes: B01J 20/18 Synthetic zeolitic molecular sieves
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 21/12 Silica and alumina
• CPC Class Codes: B01J 2229/186 not in framework positions
• CPC Class Codes: B01J 23/42 Platinum
• CPC Class Codes: B01J 23/44 Palladium
• CPC Class Codes: B01J 29/06 : Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
• CPC Class Codes: B01J 29/068 : Noble metals
• CPC Class Codes: B01J 29/7007 : Zeolite Beta
• CPC Class Codes: B01J 29/7415 : Zeolite Beta
• CPC Class Codes: B01J 29/7615 : Zeolite Beta
• CPC Class Codes: B01J 29/763 : CHA-type, e.g. Chabazite, LZ-218
• CPC Class Codes: B01J 35/19 : Catalysts containing parts with different compositions
• CPC Class Codes: B01J 35/56 : Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
• CPC Class Codes: B01J 37/0244 : Coatings comprising several layers
• CPC Class Codes: B01J 37/0246 : Coatings comprising a zeolite
• CPC Class Codes: B01J 37/038 : to form slurries or suspensions, e.g. a washcoat
• CPC Class Codes: F01N 3/208 : Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F01N 3/2803 : characterised by structure, by material or by manufacturing of catalyst support
• CPC Class Codes: Y02A 50/20 : Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y10S 502/52712 : Plural layers on a support, each layer having a distinct function

Abstract

The invention provides an exhaust gas cleaning oxidation catalyst and in particular to an oxidation catalyst for cleaning the exhaust gas discharged from internal combustion engines of compression ignition type (particularly diesel engines). The invention further relates to a catalysed substrate monolith comprising an oxidising catalyst on a substrate monolith for use in treating exhaust gas emitted from a lean-burn internal combustion engine. In particular, the invention relates to a catalysed substrate monolith comprising a first washcoat coating and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating.

Claims

1-20. -20. (canceled)

21. A catalysed substrate monolith for treating exhaust gas emitted from a lean-burn internal combustion engine comprising an oxidising catalyst on a substrate monolith, wherein the catalysed substrate monolith comprises a first washcoat coating having a length L and a second washcoat coating, wherein the second washcoat coating is disposed in a layer above the first washcoat coating for at least some of length L, wherein the first washcoat coating comprises a catalyst composition comprising platinum (Pt) and at least one support material for the platinum, wherein the second washcoat coating comprises a catalyst composition comprising both platinum (Pt) and palladium (Pd) and at least one support material for the platinum and the palladium and wherein a weight ratio of platinum (Pt) to palladium (Pd) in the second washcoat coating is ≦

2.

40. A method of reducing or preventing a selective catalytic reduction (SCR) catalyst in an exhaust system of a lean-burn internal combustion engine from becoming poisoned with platinum which may volatilise from a first washcoat coating having a length L comprising a catalyst composition comprising platinum (Pt) and at least one support material for the platinum disposed on a substrate monolith upstream of the SCR catalyst when the catalyst composition comprising platinum is exposed to relatively extreme conditions including relatively high temperatures, which method comprising trapping volatilised platinum in a second washcoat coating disposed in a layer above the first washcoat coating for at least some of the length L, which second washcoat coating comprising a catalyst composition comprising both platinum (Pt) and palladium (Pd) and at least one support material for the platinum and the palladium and wherein a weight ratio of platinum to palladium in the second washcoat coating is ≦

2.