Selective catalytic reduction
AssigneeJohnson Matthey Public Limited Company
InventorsPhilip Gerald Blakeman, Martyn Vincent Twigg, Andrew Peter Walker, Stanislaw Edmund Golunski, Guy Richard Chandler
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Abstract
A method of selectively catalysing the reduction of NOx in an exhaust gas flowing in an exhaust system of an internal combustion engine comprising a filter (40) for particulate matter comprising a catalyst capable of selectively catalysing the reduction of NOx with a reducing agent, which method comprising introducing a reducing agent, or a precursor thereof, into the exhaust gas and contacting the resulting gas with the filter (40).
Claims86
A method of selectively catalysing the reduction of NOx in an exhaust gas flowing in an exhaust system of a vehicle comprising a lean-burn internal combustion engine, which exhaust system comprising a first SCR catalyst for selectively catalysing the reduction of NOx with a nitrogenous reducing agent located at up to 1 metre downstream from an exhaust manifold or turbo of the engine, a filter for particulate matter located in an underfloor position, which filter comprising a second selective catalytic reduction (SCR) catalyst, which method comprising contacting the first SCR catalyst with the nitrogenous reducing agent in the presence of the exhaust gas.
A vehicle comprising a lean-burn internal combustion engine and an exhaust system therefor, which exhaust system comprising a first SCR catalyst for selectively catalysing the reduction of NOx with a nitrogenous reducing agent located at up to 1 metre from an exhaust manifold or turbo of the engine, a first means for introducing a nitrogenous reducing agent, or a precursor thereof, into an exhaust gas carried by the exhaust system upstream of the first selective catalytic reduction (SCR) catalyst and a filter for particulate matter located in an underfloor position of the vehicle, which filter comprising a second SCR catalyst.
Dependencies are inferred from the claim text.