Disclosed herein is a continuous process for preparing zeolitic material with a CHA-type framework structure comprising SiO.sub.2 and X.sub.2O.sub.3 and the zeolitic material so-obtained. The processes comprises (i) preparing a mixture comprising one or more sources of SiO.sub.2, one or more sources of X.sub.2O.sub.3, seed crystals, one or more tetraalkylammonium cation R.sup.5R.sup.6R.sup.7R.sup.8N+-containing compounds as structure directing agent, and a liquid solvent system; (ii) continuously feeding the mixture prepared in (i) into a continuous flow reactor at a liquid hourly space velocity; and (iii) crystallizing the zeolitic material with a CHA-type framework structure from the mixture in the continuous flow reactor.

Provided are multi-zone catalyst articles, methods of manufacturing multi-zone catalyst articles, and methods for controlling emissions in diesel engine exhaust streams with multi-zone catalyst articles, where the emission treatment system of various embodiments effectively treats diesel engine exhaust with a single multi-zone catalyst article.

The invention relates to a leakage treatment member (50) and an exhaust aftertreatment unit (40) configured to be sealingly arranged in a fluid passage (30) of an exhaust aftertreatment system for treating exhaust from an internal combustion engine, said exhaust aftertreatment unit (40) comprising an exhaust aftertreatment element (42) confined by an outer wall (44) of said exhaust aftertreatment unit, said leakage treatment member being configured to be arranged between:—an inner perimeter (32) of the fluid passage of the exhaust aftertreatment system, and—the outer wall of the exhaust aftertreatment unit, the leakage treatment member comprising an exhaust aftertreatment component for aftertreatment of any leakage of exhaust gases past said aftertreatment unit in said fluid passage.

The present invention relates to a process for the preparation of a zeolitic material SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein X stands for a trivalent element, wherein said process comprises interzeolitic conversion of a first zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein the first zeolitic material has an FER-, TON-, MTT-, BEA-, MEL-, MWW-, MFS-, and/or MFI-type framework structure to a second zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein the second zeolitic material obtained in (2) has a different type of framework structure than the first zeolitic material. Furthermore, the present invention relates to a zeolitic material per se as obtainable and/or obtained according to the inventive process and to its use, in particular as a molecular sieve, as an adsorbent, for ion-exchange, or as a catalyst and/or as a catalyst support.

The invention relates to a method for improving the efficiency of an SCR system of an exhaust gas aftertreatment system (5) of an internal combustion engine (1), and to an internal combustion engine (1), wherein an operating medium is metered in upstream of the SCR catalytic converter (2) of the SCR system in a normal operating mode, wherein the operating medium comprises a reducing agent or can be converted into a reducing agent, wherein the reducing agent is stored at least temporarily in an SCR catalytic converter (2) of the SCR system, wherein the method comprises the following steps: operating of the internal combustion engine (1) in the normal operating mode, defining of a determined control value (6) by way of determining of the mass of an exhaust gas component which is measured overall at a point in the course of the exhaust gas aftertreatment system (5) during a first measurement window, determining of a calculated control value (7) by way of calculating of the mass of the exhaust gas component which occurs overall at the point in the course of the exhaust gas aftertreatment system (5) during the first measurement window, determining of the deviation (8) between the determined control value and the calculated control value, checking whether the determined deviation lies within a predefined deviation range, adapting of the metering quantity of the operating medium if the determined deviation lies outside the deviation range.

The invention provides an emission control system for treatment of an exhaust gas stream that includes an oxidation catalyst composition disposed on a substrate in fluid communication with the exhaust gas stream; at least one selective catalytic reduction (SCR) composition disposed on a substrate downstream from the oxidation catalyst composition, and a hydrogen injection article configured to introduce hydrogen into the exhaust gas stream upstream of the oxidation catalyst composition or downstream of the oxidation catalyst composition and upstream of the at least one SCR composition. The invention also provides a method of treating an exhaust gas stream, the method including receiving the exhaust gas stream into the emission control system of the invention and intermittently introducing hydrogen upstream of the oxidation catalyst article or downstream of the oxidation catalyst article and upstream stream of the SCR article.

A method for preparing an SCR catalyst may include: (1) placing a first aqueous solution containing a titanium oxide and a tungstate in an electric field environment, adjusting the pH value of the first aqueous solution, and adjusting the current direction of the electric field environment to obtain a first mixture; (2) providing a second mixture by, in the electric field environment, adding dropwise a second aqueous solution containing a soluble salt of one or more active components, a copper-organic polyamine complex and a dispersant to the first mixture, and adjusting the current direction; and (3) processing the second mixture to obtain the SCR catalyst. The one or more active components may be selected from Ce, Zr, Cu, Fe, Pr and Sc.

A CON zeolite satisfying the following (1) to (2):(1) The framework is CON as per the code specified by the International Zeolite Association (IZA); and (2) It contains silicon and aluminum, and the molar ratio of aluminum to silicon is 0.04 or more.

Provided is a method for producing an inexpensive, high-performance AEI type zeolite and an AEI type zeolite having a Si/Al ratio of 6.5 or less and an acidity of 1.2 mmol/g or more and 3.0 mmol/g or less, by using neither an expensive Y type zeolite as a raw material nor dangerous hydrofluoric acid. The method for producing an AEI type zeolite having a Si/Al ratio of 50 or less includes: preparing a mixture including a silicon atom material, an aluminum atom material, an alkali metal atom material, an organic structure-directing agent, and water; and performing hydrothermal synthesis of the obtained mixture, in which a compound having a Si content of 20% by weight or less and containing aluminum is used as the aluminum atom material; and the mixture includes a zeolite having a framework density of 14 T/1000 Å.sup.3 or more in an amount of 0.1% by weight or more with respect to SiO.sub.2 assuming that all Si atoms in the mixture are formed in SiO.sub.2.

Provided are a novel synthesis technique for producing pure phase aluminosilicate zeolite and a catalyst comprising the phase pure zeolite in combination with a metal, and methods of using the same.