The invention relates to a catalyst device for purifying exhaust gases containing nitrogen oxide by means of selective catalytic reduction (SCR), comprising at least two catalytic regions, the first region containing vanadium oxide and cerium oxide, and the second region containing a molecular sieve containing iron. The invention also relates to uses, the catalyst device and methods for purifying exhaust gases.

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, independently of the actual drying process, in the catalytically active material used being dried. The invention is especially used in the coating of wall-flow filters.

An element frame for holding monoliths containing catalysts in the flow of exhaust gases from a combustion source, the element frame comprising two pairs of opposing walls, wherein the walls form a rectangular or square shape, an interior formed by the walls, an inlet end, an outlet end, at least one locking element, at least one mat and at least one monolith comprising an inlet, an outlet, four sides and at least one catalyst effective in reducing the concentration of one or more gases in the exhaust gas, wherein the at least one mat and the at least one monolith being positioned in the interior of the element frame so that there is at least one mat between the monolith and each adjacent wall, each locking element extending across the inlet end or outlet end of the element frame and being connected to two opposite sides of the element frame.

An exhaust gas purifying catalyst having first carrier particles, second carrier particles, and precious metal catalyst particles supported on the first and second carrier particles, wherein: the first carrier particles contain ceria, zirconia, and a rare-earth oxide other than ceria; the second carrier particles contain a rare-earth oxide other than ceria, and may contain ceria and zirconia; the contained proportion of ceria and zirconia in the first carrier particles is higher than the contained proportion of ceria and zirconia in the second carrier particles; the contained proportion of the rare-earth oxide in the second carrier particles is higher than the contained proportion of the rare-earth oxide in the first carrier particles; and the contained proportion of ceria in the first carrier particles is 45 wt % or less, while the precious metal catalyst particles include rhodium particles.

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.

One object is to provide a useful aldehyde decomposition catalyst, and an exhaust gas treatment apparatus and an exhaust gas treatment method using the aldehyde decomposition catalyst that achieve low cost and sufficient aldehyde decomposition performance with a small amount of the catalyst. An aldehyde decomposition catalyst of the present invention is made of a zeolite in a cation form NH.sub.4 having a structure of CHA or MOR and carrying Cu.

A method for the removal of nitrous oxide from off gas by direct decomposition or by selective catalytic reduction in presence of a reducing agent, comprising the steps of contacting the gas directly or together with the reducing agent or a precursor thereof with a catalyst comprising an Fe-AEI zeolite material essentially free of alkali metal ions (Alk) and having the following molar compositions:
SiO.sub.2: oAl.sub.2O.sub.3: pFe: qAlk wherein o is in the range from 0.001 to 0.2; wherein p is in the range from 0.001 to 0.2; wherein Alk is one or more of alkali ions and wherein q is less than 0.02.

A process for preparing a zeolitic material having framework type AEI and having a framework structure which comprises a tetravalent element Y, a trivalent element X, and oxygen, said process comprising (i) providing a zeolitic material having framework type CHA and having a framework structure comprising the tetravalent element Y, the trivalent element X, and oxygen; (ii) preparing a synthesis mixture comprising the zeolitic material provided in (i), water, a source of the tetravalent element Y other than the zeolitic material provided in (i), and an AEI framework structure directing agent; (ili) subjecting the synthesis mixture prepared in (ii) to hydrothermal synthesis conditions comprising heating the synthesis mixture to a temperature in the range of from 100 to 200° C. and keeping the synthesis mixture at a temperature in this range under autogenous pressure, obtaining the zeolitic material having framework type AEI; wherein Y is one or more of Si, Ge, Sn, Ti, Zr; wherein X is one or more of Al, B, Ga, In; wherein in the framework structure of the zeolitic material provided in (i), the molar ratio Y:X, calculated as YO2: X2O3, is at most 20:1 and, wherein; the process further comprises supporting a metal M selected from the transition metals of groups 7 to 12 of the periodic system of elements.

A catalyst article for treating a flow of a combustion exhaust gas comprises: a catalytically active substrate comprising one or more channels extending along an axial length thereof through which, in use, a combustion exhaust gas flows, the one or more channels having a first surface for contacting a flow of combustion exhaust gas; wherein the substrate is formed of an extruded vanadium-containing SCR catalyst material, wherein a first layer is disposed on at least a portion of the first surface, wherein the first layer comprises a washcoat of an ammonia slip catalyst composition comprising one or more platinum group metals supported on a particulate metal oxide support material, and wherein a layer comprising a washcoat of SCR catalyst composition is disposed on a surface in the one or more channels, wherein at least the portion of the first surface on which the first layer is disposed comprises a compound of copper, iron, cerium or zirconium or a mixture of any two or more thereof.

A reference material for performance evaluation of a catalyst of a selective catalytic reduction includes a ceramic carrier and a coating material that coats the ceramic carrier. The coating material includes copper (Cu), alumina (Al.sub.2O.sub.3), and silica (SiO.sub.2). A method of preparing the reference material includes mixing copper (Cu) and an acidic solution to prepare a copper-containing solution, mixing the copper-containing solution, alumina, and silica to prepare a mixture, and coating the mixture on the ceramic carrier, and drying and baking the mixture coated on the ceramic carrier.