Catalytic converter assembly in an exhaust gas posttreatment system

摘要

The invention relates to a catalyst arrangement in an exhaust gas after-treatment system of an internal combustion engine comprising an exhaust gas line in which an SCR catalyst is positioned in the direction of flow of the exhaust gas. A reducing agent production system has an NOx and CO/H2 production unit and a combined NOx storage/ammonia production unit in the standard gas-carrying path of the reducing agent production system which supplies ammonia as the reducing agent. The NOx and CO/H2 production unit is at least temporarily supplied via a fuel supply and an air supply with starting products for producing ammonia. The combined NOx storage/ammonia production unit has a plurality catalyst sections having different characteristic properties or functionalities, enabling a higher ammonia yield in the combined NOx storage/ammonia production unit. The catalyst formulations make it possible to adjust a temperature profile that additionally influences the ammonia production rate and contributes to higher ammonia yields.