A method includes: providing a SCR system comprising a SCR catalyst; heating the SCR system to a temperature greater than 500 degrees Celsius for a predetermined time so as to increase sulfur resistance of the SCR catalyst; and installing the SCR system in an aftertreatment system.

This mixing member is provided with a base portion disposed in the exhaust pipe, separated from an inner wall thereof, and a plurality of blade portions which extend from the base portion toward the inner wall, and which generate a swirling flow of the exhaust gas on a downstream side, in the exhaust direction, of the mixing member, wherein: the blade portions are disposed inclined with respect to the exhaust direction such that the position of a connecting portion with the base portion is at a most downstream position thereof, in the exhaust direction; and the base portion includes a reducing agent passage which penetrates through both end surfaces thereof in the exhaust direction, and which allows the reducing agent to pass through from an upstream side to a downstream side of the mixing member in the exhaust direction.

The present invention relates to a catalytically coated wall-flow filter, to a method for the production thereof and to the use thereof in order to reduce harmful exhaust gases of an internal combustion engine.

Provided is a β-zeolite that has an SiO.sub.2/Al.sub.2O.sub.3 ratio of less than 20 but yet is comparable or superior in heat resistance to conventional β-zeolites having SiO.sub.2/Al.sub.2O.sub.3 ratio of 20 or greater. This β-zeolite is characterized in that: in powder X-ray diffractometry using a CuKα-ray as a ray source, the full width at half maximum of a powder X-ray diffraction peak on the (302) plane is 0.15-0.50 inclusive; and the molar ratio of silica to alumina is less than 20.0. Preferably, the β-zeolite is obtained by a production method which comprises a crystallization step for crystallizing a composition comprising an alumina source, a silica source, an alkali source, a tetraethylammonium cation source and water, characterized in that the composition contains potassium and the molar ratio of potassium to silica exceeds 0.04.

Disdosed is a method of preparing a high-performance zeolite catalyst for reducing nitrogen oxide emissions, and more particularly a technique for preparing a zeolite catalyst, suitable for use in effectively removing nitrogen oxide (NOx), among exhaust gases emitted from vehicle internal combustion engines through selective catalytic reduction (SCR), thereby exhibiting high efficiency, high chemical stability and high thermal durability upon SCR using the prepared catalyst.

A process for the preparation of an extra-framework metal-containing aluminosilicate zeolite involves the steps of: (a) forming a reactant mixture A comprising (i) an aqueous slurry of an aluminosilicate zeolite in a H.sup.+-form, and (ii) a metal containing compound or free metal, wherein the mixture does not comprise ammonia, ammonium hydroxide or an ammonium salt, and (b) reacting the metal containing compound or free metal with the aluminosilicate zeolite in a H.sup.+-form in reactant mixture A and forming a product mixture B, a reaction mixture comprising the extra-framework metal-containing aluminosilicate zeolite. The metal comprises one or more of copper, iron, manganese, nickel and palladium. The step of reacting the metal with the aluminosilicate zeolite in a H.sup.+-form is performed in a single exchange. The extra-framework metal-containing aluminosilicate zeolite can then be used directly in forming a washcoat that can be applied to a support.

A metal-containing chabazite zeolite, which has an FTIR peak area ratio between the peak at 900-1300 cm.sup.−1 (Si—O—Si asymmetric stretch) and the peak at 765-845 cm.sup.−1 (˜805 cm.sup.−1 is Si—O—Si symmetric stretch) of at least 55. A method for preparing metal-containing CHA zeolites with high SCR activity at low reaction temperatures from alkali cation-free reaction mixtures that contain the three OSDA structures: metal-polyamine, N,N,N-trimethyl-1-adamantyl ammonium (TMAda+) and TMAOH. The metal-containing CHA zeolites produced by the disclosed method can be identified by XRD, FTIR spectroscopy, FT-VIS spectroscopy, and scanning electron microscopy. A method of selective catalytic reduction of NOx in exhaust gas using the material described herein is also disclosed.

An exhaust system includes an exhaust duct that defines an exhaust gas passage extending along an axis and which has a cross-section extending across the axis. At least one sensor opening in the exhaust duct is configured to receive an exhaust gas sensor. A baffle is positioned within the exhaust gas passage and includes a plurality of guide channels with open cross-sections. Each guide channel extends from a first end facing an inner surface of the exhaust duct to a second end opposite the first end. The guide channels guide exhaust gas from different regions of the cross-section toward the at least one sensor opening.

The present disclosures relate to a catalyst for removing a nitrogen oxide and a manufacturing method thereof, and the catalyst for removing the nitrogen oxide includes: a first catalyst that includes a zeolite support containing copper and having a first framework; and a second catalyst that is physically mixed with the first catalyst and includes a zeolite support containing copper and having a second framework different from the first framework.

A honeycomb structure comprising a pillar-shaped honeycomb structure body having a porous partition wall disposed so as to surround a plurality of cells, wherein let that A denotes an absolute value of open frontal area (%) in a plane of the honeycomb structure body orthogonal to the extending direction of the cells and P denotes an absolute value of porosity (%) of the partition wall, the honeycomb structure has a value represented by the following expression (1) that is 0.05 to 0.12, let that D denotes an average pore diameter (m) of the partition wall and G denotes a geometric surface area (mm.sup.2/mm.sup.3) of the partition wall, the honeycomb structure has a value represented by the following expression (2) that is 8 to 50 (μm×mm.sup.2/mm.sup.3), and the honeycomb structure has a hydraulic diameter of the cells that is 1.1 mm or more,
(1−A/100)×(1−P/100),  Expression (1)
D×G.  Expression (2)