An automotive exhaust aftertreatment system includes a reducing agent mixer. The reducing agent mixer includes a mixer body and doser that injects a reducing agent into the mixer body. The reducing agent mixer mixes an exhaust stream and the reducing agent prior to the exhaust stream being discharged from the reducing agent mixer.

A composite material comprises a macroporous silicate-based material at least partially substituted with at least one microporous zeolite, wherein the microporous zeolite is functionalised with either copper, iron or both copper and iron, and wherein the composite material is in the form of particles. The composite material can be obtained using a method comprising the steps of: (i) providing a mixture comprising a silicate-containing scaffold having a macroporous structure, an aluminium source and an organic template; (ii) hydrothermally treating the mixture to form a microporous zeolite-containing structure substantially retaining the macroporous structure of the silicate-containing scaffold; (iii) incorporating copper, iron or both copper and iron into the zeolite. The silicate-containing scaffold can be a diatomaceous earth.

The present invention relates to a catalyst for the treatment of an exhaust gas of a diesel combustion engine, said catalyst particularly comprising a specific substrate and a coating disposed on the surface of the internal walls of said substrate, the coating particularly comprising a specific first non-zeolitic oxidic material, and a specific zeolitic material comprising Fe and Cu, wherein the catalyst exhibits a weight ratio of Fe, calculated as Fe.sub.2O.sub.3, relative to Cu, calculated as CuO, Fe.sub.2O.sub.3:CuO, of less than 0.1:1. Further, the present invention relates to a specific process for preparing said catalyst. Yet further, the present invention relates to a system comprising said catalyst and to a use thereof.

A system of controlling ammonia levels in a catalytic exhaust system comprising: means to provide a target value for ammonia slip/ammonia output from said system or a catalytic unit of said system; first comparison means to compare said target value with a feedback value to provide a command value based on said comparison, and means to control the dosing of a reducing agent such as urea into said exhaust system based on said command value; means to input said command value to a transfer function or model to provide an estimated value of ammonia slip/ammonia output from said catalytic unit/system; means to measure actual ammonia slip/ammonia output from said unit/system; second comparison means to compare said actual value with said estimated value; means to provide said feedback value based on the output from said comparison means.

An oxidation catalyst composite, methods, and systems for the treatment of exhaust gas emissions from a diesel engine are described. More particularly, an oxidation catalyst composite including a first washcoat comprising a zeolite, Pt, and first refractory metal oxide support containing manganese, a second washcoat comprising a second refractory metal oxide support, a Pt component and a Pd component, and a third washcoat comprising palladium and a rare earth oxide component is described.

The present invention addresses the problem and purpose of providing a honeycomb structure that has a sufficiently high strength and is excellent in endurance, and a catalyst for cleaning an exhaust gas using the same that is excellent in resistance to sulfur oxide (SOX). The honeycomb structure of the present invention is one consists of a flat inorganic fiber sheet comprising an inorganic fiber sheet having supported thereon an inorganic binder and zeolite, and a corrugated inorganic fiber sheet comprising an inorganic fiber sheet having supported thereon the same inorganic binder and zeolite, which are alternately combined with each other, wherein it is characterized in that the zeolite has a particle diameter (i.e., a median particle diameter, D50) of from 0.5 to 10.0 m.

The present disclosure is directed to microporous crystalline aluminosilicate structures with GME topologies having pores containing organic structure directing agents (OSDAs) comprising at least one piperidinium cation, the compositions useful for making these structures, and methods of using these structures. In some embodiments, the crystalline zeolite structures have a molar ratio of Si:Al that is greater than 3.5.

A method for operating an exhaust system of an internal combustion engine of a motor vehicle, in which exhaust gas from the internal combustion engine flows through a first SCR catalytic converter, which is followed by an ammonia barrier catalytic converter, and flows through a second SCR catalytic converter which is disposed downstream of the ammonia barrier catalyst, includes introducing a reducing agent introduced into the exhaust gas by a first metering device upstream of the first SCR catalytic converter and by a second metering device upstream of the second SCR catalytic converter. When a predetermined threshold value of a temperature of a region of the exhaust system is exceeded, a quantity of reducing agent introduced into the exhaust gas by the first metering device is increased.

A method for preparing a molecular sieve SCR (selective catalytic reduction) catalyst and a prepared catalyst therethrough. In the method, several molecular sieves are mixed and modified by transition metal or rare-earth metal via ion exchange, then loaded Fe by equivalent-volume impregnation, and loaded Cu by one or more liquid ion exchange. This present invention, combined with several techniques, such as modification of stable molecular sieve by transition and rare-earth metal, Fe loading by equivalent-volume impregnation and Cu loading by one or more liquid ion exchange, and after through stable and effective modification and loading control, the obtained catalyst material is coated on a carrier substrate via size mixing and coating process to be prepared into an integral catalyst.

The present invention relates to a particle filter which comprises a wall-flow filter and SCR-catalytically active material, wherein the wall-flow filter comprises ducts which extend in parallel between a first and a second end of the wall-flow filter and which are alternately closed off in gas-type fashion either at the first or at the second end and which are separated by porous walls, and wherein the SCR-active material comprises a zeolite which is exchanged with copper and/or iron and which is situated in the form of a coating in the porous walls of the wall-flow filter, characterized in that the SCR-catalytically active coating comprises palladium.