Synergistic SCR / DOC Configurations for Lowering Diesel Emissions

摘要

A motor-vehicle engine system comprises a first DOC configured to receive exhaust from an engine and an SCR device coupled downstream of the first DOC in a flow direction of the exhaust. The system further comprises a second DOC coupled downstream of the SCR device. The system takes advantage of hydrocarbon sorption in the SCR catalyst that is a function of temperature to enable reduced hydrocarbon emissions via oxidation at the second DOC.