Patent ID: 9597661
Date: 2017-03-21
CPC Classifications: B01D,B01J,F01N,Y02A,Y02T

Claim:
1. 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 (Pt) which may volatilise from a first washcoat coating comprising a catalyst composition upstream of the selective catalytic reduction (SCR) catalyst when the catalyst composition comprising platinum (Pt) is exposed to relatively extreme conditions including relatively high temperatures, the method comprising: trapping volatilised platinum (Pt) from the first washcoat coating in a second washcoat coating, wherein the second washcoat coating comprises at least one metal oxide, the catalyst composition comprises at least one platinum group metal (PGM) comprising platinum (Pt) supported on at least one support material disposed on a substrate monolith, wherein the second washcoat coating is disposed on the same substrate monolith as the catalyst composition, and wherein the substrate monolith is a flow-through monolith.