Abstract: The invention provides a process for reducing the amounts of carbon monoxide, hydrocarbons and soot particles in the lean exhaust gas from an internal combustion engine using a particle filter, wherein the soot particles have a soot ignition temperature TZ and the particle filter is regenerated from time to time by raising the temperature of the particle filter to above the soot ignition temperature and burning the soot particles, wherein the temperature of the filter is increased to the temperature required to initiate soot ignition by burning additional fuel on the catalytic coating when the exhaust gas back pressure reaches a predetermined value. The process is characterised in that the particle filter is provided with a catalytic coating comprising a first group of components for reducing the ignition temperature of soot, said first group of components contains at least one oxygen storage component and at least one platinum group metal selected from the group consisting of platinum, palladium and rhodium.

Abstract: The present invention is directed to the removal of soot particles from the exhaust of a diesel engine. A device is provided that comprises a wall-flow filter having inflow channels and outflow channels, which are connected by pores. Preferably the inflow channels and outflow channels are alternately closed on opposite sides. The flow channels that are closed on the outflow side form the inflow channels and the flow channels that are closed on the inflow side form the outflow channels of the filter. In the inflow channels and/or the outflow channels of the filter, exhaust treatment structures are provided. The walls of the flow channels, as well as the exhaust treatment structures, are preferably coated with a catalyst layer. Since the exhaust does not need to flow through these exhaust treatment structures, the catalyst deposited thereon is not covered by soot. The filter function and the catalytic function of the catalyst layer on the exhaust treatment structures are thus largely separated from one another.

Abstract: The present invention is directed to a method and a device for the catalytic conversion of harmful substances contained in the exhaust gas of combustion engines, wherein the exhaust gas is forced to pass through a catalyst-carrying porous support. The support may be comprised of a catalytic material support itself, have a catalytic material coating its pores and/or have a catalytic layer on one or both of the surfaces through which the exhaust gas will travel.

Abstract: The invention provides a process for removing soot particles from exhaust gas from produced by a diesel engine. The process uses a particle filter that collects soot particles with the aid of nitrogen dioxide which is generated by catalytic oxidation of nitrogen monoxide contained in the exhaust gas. The process is characterized in that the particle filter is a deep-bed particle filter, having a filtration efficiency for the soot particles. The particle filter is coated with a catalytic coating for oxidizing nitrogen monoxide to nitrogen dioxide and the exhaust gas leaving the particle filter subsequently filtered through a particle filter serving as a soot barrier. The filter can have a filtration efficiency of over 95%.

Abstract: The present invention provides an exhaust gas treatment unit for an internal combustion engine. A first catalyst unit produces ammonia from corresponding constituents in a rich exhaust gas composition. A second catalyst unit that is located downstream of the first catalyst unit temporarily stores the ammonia produced by the first catalyst unit in the presence of a rich exhaust gas composition. In the presence of a lean exhaust gas composition, the nitrogen oxides present in the exhaust gas are subjected to a reduction reaction using the temporarily stored ammonia as reducing agent. The exhaust gas treatment unit also contains a third catalyst unit that is located between the other two catalyst units, and oxidizes the nitrogen oxides present in the exhaust gas at lean exhaust gas conditions to a such an extent that 25 to 75 vol. % of the nitrogen oxides entering the second catalyst unit consist of nitrogen dioxide.

Abstract: An exhaust gas treatment unit for the selective catalytic reduction of nitrogen oxides under lean exhaust gas conditions which contains at least one catalyst with catalytically active components for selective catalytic reduction (SCR components). The exhaust gas treatment unit is characterised in that the catalyst also contains, in addition to SCR components, at least one storage component for nitrogen oxides (NOx components).

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.