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.

A method of reducing nitrogen oxides in exhaust gas of an internal combustion engine by selective catalytic reduction (SCR) comprises contacting the exhaust gas also containing ammonia and oxygen with a catalytic converter comprising a catalyst (2) comprising at least one crystalline small-pore molecular sieve catalytically active component (Z.sub.M,I) having a maximum ring opening of eight tetrahedral basic building blocks, which crystalline small-pore molecular sieve catalytically active component (Z.sub.M,I) comprising mesopores.

A catalyst for selective catalytic reduction of NO.sub.x having one or more transition metals selected from Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir, Pt, and mixtures thereof supported on a support, wherein the support has a molecular sieve having at least one intergrowth phase having at least two different small-pore, three-dimensional framework structures.

There is provided a zeolite having a CHA structure. When a total integrated intensity of a (211) plane, a (104) plane, and a (220) plane in an X-ray diffraction spectrum obtained by an X-ray powder diffraction method is defined as X.sub.0 and the total integrated intensity after heat endurance test for five hours at 900 C. under an air atmosphere is defined as X.sub.1, a ratio of X.sub.1 (X.sub.1/X.sub.0) to X.sub.0 is within a range from 0.2-0.7; and as measured by a .sup.27Al-NMR method after the heat endurance test for five hours at 900 C. under the air atmosphere, when a peak intensity of tetra-coordinated Al atoms is defined as P.sub.4 and a peak intensity of hexa-coordinated Al atoms is defined as P.sub.6, a ratio of P.sub.6 (P.sub.6/P.sub.4) to P.sub.4 is 0.1 or less.

Described are SCR catalyst systems comprising a first SCR catalyst composition and a second SCR catalyst composition arranged in the system, the first SCR catalyst composition promoting higher N.sub.2 formation and lower N.sub.2O formation than the second SCR catalyst composition, and the second SCR catalyst composition having a different composition than the first SCR catalyst composition, the second SCR catalyst composition promoting lower N.sub.2 formation and higher N.sub.2O formation than the first SCR catalyst composition. The SCR catalyst systems are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

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 stability 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 invention relates to a catalyst composition. More particularly, the present invention relates to a catalyst composition comprising a low SAR zeolite, copper in an amount of at least 2 wt %; and a rare earth element. The present invention also relates to a method for the manufacture of a catalyst composition. The present invention further relates to a catalyst article comprising a catalyst composition and a method for the treatment of an exhaust gas which comprises contacting an exhaust gas with a catalyst article comprising a catalyst composition.

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.

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 crystalline zeolites with an ERI/CHA intergrowth framework type and to a process for making said zeolites. The ERI content of the zeolites ranges from 10 to 85 wt.-%, based on the total weight of ERI and CHA. The zeolites may further comprise 0.1 to 10 wt.-% copper, calculated as CuO, and one or more alkali and alkaline earth metal cations in an amount of 0.1 to 5 wt.-%, calculated as pure metals. The process for making the zeolites with an ERI/CAH intergrowth framework type comprises a) the preparation of a first aqueous reaction mixture comprising a zeolite of the faujasite framework type, Cu-TEPA 01 and a base M(OH), b) the preparation of a second aqueous reaction mixture comprising a silica source, an alumina source, an alkali or alkaline earth metal chloride, bromide or hydroxide, a quaternary alkylammonium salt and hexamethonium bromide, c) combining the two reaction mixtures, and d) heating the combination of the two reaction mixtures to obtain a zeolite with an ERUCHA intergrowth framework type. The ERI/CHA intergrowth zeolite may subsequently be calcined.The zeolites according to the present invention are suitable SCR catalysts.