Device and method for exhaust-gas treatment

A device and a method for treating the exhaust gas of an internal combustion engine are proposed, comprising an ozone reactor for supplying ozone to the exhaust gas at a delivery location, an oxidation reactor for the at least partial oxidation of nitrogen oxides and/or hydrocarbons being positioned upstream from the delivery location, the oxidation reactor being active independently of the operating state of the internal combustion engine, especially also at the exhaust-gas temperatures prevailing at the start or during the warm-up phase of the internal combustion engine.