Abstract: The invention relates to an SCR catalytic convertor system and a method for operating a reductant metering process of an SCR catalytic converter system (14) of an internal combustion engine (10), wherein the SCR catalytic converter system (14) has a first SCR exhaust emission control device (16), an SCR catalytic converter (18) arranged downstream of the SCR exhaust emission control device, and a reductant metering device (20) for metering a reductant into the exhaust gas flow upstream of the first SCR exhaust emission control device (16), wherein the reductant metering process is controlled at least depending on a temperature of the first SCR exhaust emission control device (16) and of the SCR catalytic converter (18) arranged downstream, wherein (I) if the temperature of the first SCR exhaust emission control device (16) is greater than or equal to a predetermined minimum temperature (T_SPF min) and the SCR catalytic converter (18) arranged downstream is less than a predetermined minimum temperature (T_SCR

Abstract: An exhaust-gas aftertreatment device for an aftertreatment of the exhaust-gas of an internal combustion engine includes an SCR catalytic converter and an SCR particulate filter downstream of the SCR catalytic converter. The SCR catalytic converter has an SCR catalytic coating for a selective reduction of nitrogen oxides in the presence of a reducing agent added to the exhaust-gas in a metered manner. The SCR catalytic converter has a flow-through substrate. The SCR catalytic coating of the SCR catalytic converter is disposed on the flow-through substrate. The SCR particulate filter has an SCR catalytic coating for a selective reduction of nitrogen oxides in the presence of the reducing agent added to the exhaust-gas in a metered manner. The SCR particulate filter has a particulate filter substrate. The SCR catalytic coating of the SCR particulate filter is disposed on the particulate filter substrate.

Abstract: The invention relates to an SCR catalytic convertor system and a method for operating a reductant metering process of an SCR catalytic converter system (14) of an internal combustion engine (10), wherein the SCR catalytic converter system (14) has a first SCR exhaust emission control device (16), an SCR catalytic converter (18) arranged downstream of the SCR exhaust emission control device, and a reductant metering device (20) for metering a reductant into the exhaust gas flow upstream of the first SCR exhaust emission control device (16), wherein the reductant metering process is controlled at least depending on a temperature of the first SCR exhaust emission control device (16) and of the SCR catalytic converter (18) arranged downstream, wherein (I) if the temperature of the first SCR exhaust emission control device (16) is greater than or equal to a predetermined minimum temperature (T_SPF min) and the SCR catalytic converter (18) arranged downstream is less than a predetermined minimum temperature (T_SCR

Abstract: A catalytic converter configuration for an internal combustion engine that is capable of running lean has an exhaust gas duct and a NOx storage catalytic converter arranged in the exhaust gas duct. A novel method allows desulfurizing the NOx storage catalytic converter. An H2S storage catalytic converter is provided. This catalytic converter is capable of storing hydrogen sulfide under a rich or stoichiometric exhaust gas atmosphere with lambda?1 and oxidizing hydrogen sulfide under a lean exhaust gas atmosphere with lambda>1.

Abstract: Thermal catalysts, particularly catalysts coated with precious metals, are used to reduce the concentration of CO, HC and NOx in exhaust gases from internal-combustion engines. While catalysts coated with precious metals exhibit catalytic activity from about 140.degree. C., to ensure very low emission levels thermal catalysts need to be heated during cold starting so that the pollutants produced during the cold start react. The specification discloses a catalyst with a photocatalytic semiconductor illuminated with UV light for this purpose. Suitable for use as the photocatalytic material is e.g. titanium dioxide. This enables pollutant levels to be reduced immediately after the engine has been started and even at relatively low ambient temperatures. The invention is suitable for use with diesel engines and lean-mixture spark-ignition engines.