Catalytic treatment device for internal combustion engine of motor vehicle, has reductor catalyst placed in upstream of silencer of exhaust line and associated to reduction units for reducing back pressure created in exhaust line

摘要

The device has an oxidation catalyst (1) e.g. nitrogen oxide trap, and selective catalyst reductor (SCR) catalyst (4) that is placed in upstream of a silencer (6) of an exhaust line. The SCR catalyst is associated to reduction units for reducing back pressure created in the exhaust line. A bypass line (7) and a bypass control valve (8) are provided external to the SCR catalyst. The control valve controls access to the by-pass line. An independent claim is also included for a method for catalytic treatment of gas in an exhaust line.