The present invention relates to a wall flow filter for removing particles from the exhaust gas of internal combustion engines, which comprises a wall flow filter substrate having a length L and coatings Z and F that differ from one another, wherein the wall flow filter substrate comprises channels E and A, which extend in parallel between a first and a second end of the wall flow filter substrate, are separated by porous walls and form surfaces OE or OA, and wherein the channels E are closed at the second end and the channels A are closed at the first end, and wherein the coating Z is located in the porous walls and/or on the surfaces OA, but not on the surfaces OE, and comprises palladium and/or rhodium a cerium/zirconium mixed oxide, characterized in that the coating F is located in the porous walls and/or on the surfaces OE, but not on the surfaces O, and comprises a ceramic membrane and no precious metal.

The present invention relates to a wall flow filter for removing particles from the exhaust gas of internal combustion engines, which comprises a wall flow filter substrate having a length L and coatings Z and F that differ from one another, wherein the wall flow filter substrate comprises channels E and A, which extend in parallel between a first and a second end of the wall flow filter substrate, are separated by porous walls and form surfaces OE or OA, and wherein the channels E are closed at the second end and the channels A are closed at the first end, and wherein the coating Z is located in the porous walls and/or on the surfaces OA, but not on the surfaces OE, and comprises palladium and/or rhodium a cerium/zirconium mixed oxide, characterized in that the coating F is located in the porous walls and/or on the surfaces OE, but not on the surfaces O, and comprises a ceramic membrane and no precious metal.

The present invention relates to a wall-flow filter for removing particles from the exhaust gas of combustion engines, comprising a wall-flow filter substrate of length L and coatings Z and F that differ from one another, wherein the wall-flow filter substrate has channels E and A, which extend in parallel between a first and a second end of the wall-flow filter substrate, are separated by porous walls and form surfaces O.sub.E and O.sub.A respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end, and wherein the coating Z is located in the porous walls and/or on the surfaces O.sub.A, but not on the surfaces O.sub.E, and comprises palladium and/or rhodium a cerium/zirconium mixed oxide, characterized in that the coating F is located in the porous walls and/or on the surfaces O.sub.E, but not on the surfaces O.sub.A and comprises a particulate metal compound and no noble metal.

The present invention relates to a wall-flow filter for removing particles from the exhaust gas of combustion engines, comprising a wall-flow filter substrate of length L and coatings Z and F that differ from one another, wherein the wall-flow filter substrate has channels E and A, which extend in parallel between a first and a second end of the wall-flow filter substrate, are separated by porous walls and form surfaces O.sub.E and O.sub.A respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end, and wherein the coating Z is located in the porous walls and/or on the surfaces O.sub.A, but not on the surfaces O.sub.E, and comprises palladium and/or rhodium a cerium/zirconium mixed oxide, characterized in that the coating F is located in the porous walls and/or on the surfaces O.sub.E, but not on the surfaces O.sub.A and comprises a particulate metal compound and no noble metal.

The present invention relates to a SCR catalytic article, comprising a substrate and a copper-containing small pore zeolite, having a crystal structure characterized by a decrease of unit cell volume upon sulfurization and desulfurization of less than ?.sup.3 as determined by an X-ray powder diffraction, wherein the sulfurization and desulfurization are carried out in accordance with the processes as described in the specification, and to an exhaust treatment system comprising the same. The present invention also relates to a method for determining whether a metal-promoted small pore zeolite is resistant to irreversible sulfur poisoning and a method for evaluating whether a metal-promoted small pore zeolite is qualified for resistance to irreversible sulfur poisoning.

The present invention relates to a SCR catalytic article, comprising a substrate and a copper-containing small pore zeolite, having a crystal structure characterized by a decrease of unit cell volume upon sulfurization and desulfurization of less than ?.sup.3 as determined by an X-ray powder diffraction, wherein the sulfurization and desulfurization are carried out in accordance with the processes as described in the specification, and to an exhaust treatment system comprising the same. The present invention also relates to a method for determining whether a metal-promoted small pore zeolite is resistant to irreversible sulfur poisoning and a method for evaluating whether a metal-promoted small pore zeolite is qualified for resistance to irreversible sulfur poisoning.

It is an object of the present invention to provide an exhaust gas purifying catalyst filter which has enhanced soot collection performance without increasing pressure loss caused by the formation of a catalyst layer in a partition wall of a wall flow type substrate.

A gasoline engine exhaust gas purifying catalyst filter for purifying exhaust gas of a gasoline engine includes: a wall flow type substrate in which an introduction-side cell having an open exhaust gas introduction-side end, and a discharge-side cell adjacent to the introduction-side cell and having an open exhaust gas discharge-side end are defined by a porous partition wall; and a catalyst layer formed in a pore of the partition wall. An absolute value of a maldistribution degree of the catalyst layer formed in the pore of the partition wall is 4.50 or less. A wash coat amount, excluding a mass of a platinum group, of the catalyst layer formed in the pore of the partition wall, is 40 g/L or more and 50 g/L or less. The catalyst layer formed in the pore of the partition wall is a single layer. The catalyst layer is free of Ba.

It is an object of the present invention to provide an exhaust gas purifying catalyst filter which has enhanced soot collection performance without increasing pressure loss caused by the formation of a catalyst layer in a partition wall of a wall flow type substrate.

A gasoline engine exhaust gas purifying catalyst filter for purifying exhaust gas of a gasoline engine includes: a wall flow type substrate in which an introduction-side cell having an open exhaust gas introduction-side end, and a discharge-side cell adjacent to the introduction-side cell and having an open exhaust gas discharge-side end are defined by a porous partition wall; and a catalyst layer formed in a pore of the partition wall. An absolute value of a maldistribution degree of the catalyst layer formed in the pore of the partition wall is 4.50 or less. A wash coat amount, excluding a mass of a platinum group, of the catalyst layer formed in the pore of the partition wall, is 40 g/L or more and 50 g/L or less. The catalyst layer formed in the pore of the partition wall is a single layer. The catalyst layer is free of Ba.

The present invention relates to the technical field of catalyst preparation, disclosing a preparation method and application of a coated vanadium-tungsten-titanium oxide monolithic SCR catalyst. The method includes the steps of mixing a vanadium oxide precursor, a tungsten oxide precursor, titanium dioxide, an inorganic adhesive, an organic adhesive and a macromolecular surfactant with deionized water and stirring them to obtain a thick liquid; adding a pH adjuster to the thick liquid to make its pH 1.5-4.5; impregnating a cordierite honeycomb carrier in the thick liquid to obtain a preliminarily-impregnated catalyst and dried and calcined the preliminarily-impregnated catalyst to obtain a finished catalyst. The method has advantages such as simple operation, easy repetition and short time-consuming, so it can be applied to exhaust gas post-treatment of a marine diesel engine, and provide a good choice for catalysts used to denitrify medium and high temperature exhausted gas from marine engines.

The present invention relates to the technical field of catalyst preparation, disclosing a preparation method and application of a coated vanadium-tungsten-titanium oxide monolithic SCR catalyst. The method includes the steps of mixing a vanadium oxide precursor, a tungsten oxide precursor, titanium dioxide, an inorganic adhesive, an organic adhesive and a macromolecular surfactant with deionized water and stirring them to obtain a thick liquid; adding a pH adjuster to the thick liquid to make its pH 1.5-4.5; impregnating a cordierite honeycomb carrier in the thick liquid to obtain a preliminarily-impregnated catalyst and dried and calcined the preliminarily-impregnated catalyst to obtain a finished catalyst. The method has advantages such as simple operation, easy repetition and short time-consuming, so it can be applied to exhaust gas post-treatment of a marine diesel engine, and provide a good choice for catalysts used to denitrify medium and high temperature exhausted gas from marine engines.