A method of producing hydrothermally stable chabazite (CHA) zeolites is disclosed. The disclosed method is based on the use of reaction mixtures that (1) are essentially void of alkali metal cations and (2) contain the N,N,N-trimethyl-1-adamantyl ammonium (TMAda+) organic as the sole OSDA. The disclosed method results in a higher crystalline CHA zeolite that exhibits hydrothermal stability. There is also disclosed a zeolite material having a CHA-type framework structure made by the disclosed method. A method of selective catalytic reduction of NOx in exhaust gas using the material described herein is also disclosed.

The present invention relates to a rare earth element containing zeolitic material having a framework structure selected from the group consisting of AEI, AFT, AFV, AFX, AVL, CHA, EMT, GME, KFI, LEV, LTN, and SFW, including mixtures of two or more thereof, the framework structure of the zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3, wherein X stands for a trivalent element, wherein the zeolitic material displays an SiO.sub.2:X.sub.2O.sub.3 molar ratio in the range of from 2 to 20, and wherein the zeolitic material contains one or more rare earth elements as counter-ions at the ion exchange sites of the framework structure. Furthermore, the present invention relates to a process for the production of the inventive rare earth element containing zeolitic material as well as to the use of the inventive rare earth element containing zeolitic material as such and as obtainable and/or obtained according to the inventive process.

The invention relates to a particle filter, which comprises a wall flow filter and SCR-active material, wherein the wall flow filter comprises ducts which extend in parallel between the first and the second end of the wall flow filter and which are alternately closed in a gas-tight manner either at the first or the second end and which are separated by porous walls, the pores of which have inner surfaces, and the SCR-active material is located in the form of a coating on the inner surfaces of the pores of the porous walls, characterized in that the coating has a gradient, such that the side of the coating facing the exhaust gas has a higher selectivity in the SCR reaction than the side of the coating that faces the inner surfaces of the pores. The SCR-active material is preferably a small-pore zeolite, which has a maximum ring size of eight tetrahedral atoms and is exchanged with copper and/or iron.

A catalytic article for treating an exhaust gas stream containing particulate matter, hydrocarbons, CO, and ammonia, the article may include: (a) a substrate having an inlet end and an outlet end defining an axial length; (b) a first catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve; and (c) a second catalyst coating including: 1) a platinum group metal distributed on a molecular sieve, and 2) a base metal distributed on a molecular sieve.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

The present disclosure features a high metal cation content zeolite-based binary catalyst (e.g., a high copper and/or iron content zeolite-based binary catalyst, where the zeolite can be a chabazite) for NO.sub.x reduction, having relatively low N.sub.2O make, and having low corresponding metal oxide content; where the metal in the metal oxide corresponds to the metal of the metal cation. The present disclosure also describes the synthesis of the zeolite-based binary catalyst having high metal cation content.

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.

The present invention relates to a method for producing automobile exhaust gas catalytic converters, to the catalytic converters as such and to the use thereof. In particular, the method comprises a step which results in a smaller particle size of the catalytically active material used.

A particle filter for treating exhaust gases includes an SCR catalyst that, when in the presence of a reductant such as ammonia, promotes selective catalytic reduction of NO.sub.x; an active oxidation catalyst that promotes oxidation of hydrocarbons and carbon monoxide; and an oxygen storage catalyst that alternately stores and releases oxygen, enhances soot oxidation, and stores NOx at temperatures below optimal SCR functioning. The particle filter may be included in a system having an oxidation catalytic device (OCD) upstream of the particle filter, and optionally includes one or more SCR converters upstream and/or downstream of the particle filter, and/or an ammonia slip catalyst downstream of the particle filter. The system may further be adapted for operation under a high frequency injection fuel control with an OCD having substantial NOx storage material content, or an NSC for improving the efficiency tradeoffs between soot oxidation during filter regeneration and NO.sub.x reduction.

A system for treatment of an exhaust gas stream from an engine is provided, containing an upstream selective catalytic reduction (SCR) catalyst, which receives the exhaust gas stream without any intervening catalyst, a diesel oxidation catalyst (DOC) positioned downstream thereof; a catalyzed soot filter (CSF) downstream of the diesel oxidation catalyst; a second SCR catalyst positioned downstream of the catalyzed soot filter; and an ammonia oxidation (AMOx) catalyst. The application also describes use of such systems to reduce nitrogen oxides (NOx) and hydrocarbons (HC) in an exhaust gas stream.