Exhaust system for a lean-burn IC engine comprising a PGM component and a SCR catalyst

摘要

Methods are disclosed for reducing or preventing a selective catalytic reduction (SCR) catalyst disposed on a first substrate monolith in an exhaust system of a lean-burn internal combustion engine from becoming poisoned with platinum group metal (PGM) which may volatilize from a catalyst composition comprising PGM disposed on at least one second substrate monolith upstream of the SCR catalyst. The methods comprise adsorbing volatilized PGM in at least one PGM trapping material, which is disposed on a third substrate monolith disposed between the first substrate monolith and the second substrate monolith.