Analysis of the Driving Altitude and Ambient Temperature Impact on the Conversion Efficiency of Oxidation Catalysts

Worldwide emission standards are extending their requirements to cover engine operation under extreme ambient conditions and fill the gap between type-approval real driving conditions. The new boundaries affect performance raw emissions as well efficiency of exhaust aftertreatment systems. This study evaluates impact high altitude low temperature on light-off conversion an oxidation catalyst. results compared in a common range mass flow with baseline sea-level at 20 °C. A reduction CO HC efficiencies was found 2500 m −7 °C, relevant increase for both pollutants. analysis experimental data complemented use catalyst model identify causes leading deterioration light-off. allowed identifying, same temperature, contributions variation caused by change engine-out tailpipe pressure, which are, turn, manifested reactants partial pressure dwell time governing parameters.