SCR catalyst components

Abstract

The present invention relates to a composition comprising: a non-zeolitic oxide material containing alumina; and an 8-ring pore zeolitic material containing one or more of copper and iron, wherein the framework structure of the zeolitic material comprises a tetravalent element Y, a trivalent element X, and oxygen, wherein the molar ratio of Y:X, calculated as YO2:X2O3, is in the range of 2:1 to 40:1; wherein at least a portion of the outer surface of the zeolitic material is covered with a layer comprising the non-zeolitic oxide material; and wherein Y comprises one or more of Si, Sn, Ti, Zr, and Ge, and X comprises one or more of Al, B, In, and Ga.

Description

[Technical Field]

[0001] The present invention relates to a composition comprising an eight-membered ring-pore zeolite material containing one or more copper and iron, a method for preparing a composition comprising an eight-membered ring-pore zeolite material containing one or more copper and iron, and a method for using the above composition and a slurry containing the composition. Furthermore, the present invention relates to a selective catalytic reduction catalyst for treating exhaust gas of a combustion engine, comprising the above composition, a method for preparing the above catalyst, and a method for treating exhaust gas using the above catalyst. [Background technology]

[0002] The core-shell structure of zeolite materials is discussed in Patent Document 1 (US 2013 / 0101503 A1) and Patent Document 2 (US 2017 / 7050182 A1). However, neither of these documents discloses selective catalytic reduction techniques or methods for improving low-temperature and high-temperature NOx conversion rates. Patent Document 3 (CN 108993579 A) discloses the use of Fe-ZSM-5 zeolite material covered with cerium-impregnated mesoporous silica to improve selective catalytic reduction (SCR) activity at low temperatures, and Patent Document 4 (International Publication No. 2019 / 225909A) discloses alumina-coated zeolite material used to improve SCR activity at high temperatures. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] US 2013 / 0101503 A1 [Patent Document 2] US 2017 / 7050182 A1 [Patent Document 3] CN 108993579 A [Patent Document 4] International Publication No. 2019 / 225909A [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, none of these publications discuss SCR technology for filters that enable high NOx performance at both low and high temperatures while maintaining low back pressure. Therefore, there remains a need to provide compositions and / or selective catalytic reduction catalysts that enable improved NOx conversion rates at both low and high temperatures while minimizing filter back pressure. [Means for solving the problem]

[0005] Therefore, the present invention is (i) Non-zeolite oxide materials containing alumina (ii) An eight-membered ring-pore zeolite material containing one or more copper and iron, wherein the skeletal structure of the zeolite material contains a tetravalent element Y, a trivalent element X, and oxygen, and the molar ratio of Y:X is calculated as YO2:X2O3 and is in the range of 2:1 to 40:1. A composition comprising, The present invention relates to a composition in which at least a portion of the outer surface of a zeolite-based material according to (ii) is covered by a layer containing a non-zeolite-based oxide material according to (i), and Y comprises one or more of Si, Sn, Ti, Zr, and Ge, and X comprises one or more of Al, B, In, and Ga. [Modes for carrying out the invention]

[0006] (i) The non-zeolite oxidation material described above is preferably composed of alumina by 98-100% by mass, more preferably 99-100% by mass, even more preferably 99.5-100% by mass, and even more preferably 99.9-100% by mass.

[0007] (i) The alumina contained in the non-zeolite oxidation material described in (i) is preferably selected from the group consisting of γ-alumina, α-alumina, δ-alumina, θ-alumina, and η-alumina, more preferably selected from the group consisting of γ-alumina, α-alumina, and δ-alumina. It is more preferable that the alumina is γ-alumina. The layer containing the non-zeolite oxidation material described in (i) preferably has an average film thickness in the range of 2 nm to 100 nm, more preferably in the range of 5 nm to 70 nm, still more preferably in the range of 20 to 50 nm, still more preferably in the range of 25 nm to 47 nm, more preferably in the range of 25 to 35 nm, or still more preferably in the range of 40 to 47 nm, where the average thickness is determined as in Reference Example 4.

[0008] Preferably 40 to 100% by mass, more preferably 50 to 100% by mass, still more preferably 70 to 100% by mass of the non-zeolite oxidation material according to (i) is contained in the layer.

[0009] Preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, still more preferably 99.9 to 100% by mass of the layer is composed of the non-zeolite oxidation material according to (i).

[0010] The non-zeolite oxide material according to (i) is present in the composition preferably in an amount in the range of 5 to 50% by mass, more preferably in the range of 7 to 40% by mass, still more preferably in the range of 8 to 32% by mass, based on the mass of the 8-membered ring pore zeolite material according to (ii).

[0011] Also, regarding the 8-membered ring pore zeolite-based material according to (ii), it preferably has a framework type selected from the group consisting of CHA, AEI, RTH, LEV, DDR, KFI, ERI, AFX, LTA, mixtures of two or more of these, and mixed types of two or more of these. More preferably, it is selected from the group consisting of CHA, AEI, RTH, mixtures of two or more of these, and mixed types of two or more of these. Even more preferably, it is selected from the group consisting of CHA and AEI. It is even more preferable that the 8-membered ring pore zeolite-based material according to (ii) has a framework type of CHA.

[0012] The 8-membered ring pore zeolite-based material according to (ii) preferably contains copper, and the amount of copper in the zeolite-based material, calculated as CuO based on the mass of the 8-membered ring pore zeolite material, is more preferably in the range of 0.1 to 10% by mass, even more preferably in the range of 1.5 to 5.5% by mass, even more preferably in the range of 2.5 to 5.0% by mass, more preferably in the range of 3.0 to 4.75% by mass, and even more preferably in the range of 3.25 to 4.5% by mass.

[0013] The amount of iron contained in the 8-membered ring pore zeolite-based material, calculated as Fe2O3 based on the mass of the 8-membered ring pore zeolite material, is more preferably in the range of 0 to 0.01% by mass, even more preferably in the range of 0 to 0.001% by mass, and even more preferably in the range of 0 to 0.0001% by mass. In other words, it is more preferable that the 8-membered ring pore zeolite-based material is substantially free of iron, and even more preferable that it is free of iron.

[0014] Therefore, the present invention preferably (i) a non-zeolite-based oxidation material containing alumina (ii) an 8-membered ring pore zeolite-based material having a CHA framework structure and containing one or more of copper and iron, wherein the framework structure of the zeolite-based material contains a tetravalent element Y, a trivalent element X, and oxygen, and here, the molar ratio of Y:X, calculated as YO₂:X₂O₃, is in the range of 2:1 to 40:1, an 8-membered ring pore zeolite-based material comprising a composition (ii) At least a portion of the outer surface of the zeolite material according to (ii) is covered with a layer containing a non-zeolite oxide material according to (i), and Y comprises one or more of Si, Sn, Ti, Zr and Ge, and X comprises one or more of Al, B, In and Ga. The above-mentioned 8-membered ring-pore zeolite material more preferably comprises a composition containing copper.

[0015] In the present invention, of the skeletal structure of the 8-membered ring-pore zeolite material according to (ii), preferably 98 to 100% by mass, more preferably 99 to 100% by mass, even more preferably 99.5 to 100% by mass, and even more preferably 99.9 to 100% by mass is composed of X, Y, and O.

[0016] Y is preferably Si.

[0017] It is preferable that X is one or more of Al and B, and more preferably Al. It is preferable that Y is Si, and more preferably Al.

[0018] The molar ratio of Y:X, calculated as YO2:X2O3, is preferably in the range of 5:1 to 30:1, more preferably in the range of 10:1 to 24:1, even more preferably in the range of 12:1 to 22:1, even more preferably in the range of 15:1 to 20:1, and even more preferably in the range of 15:1 to 18:1. In the present invention, a composition according to the present invention, comprising an 8-membered ring-pore zeolite material having a molar ratio of Y:X within the above preferred range, calculated as YO2:X2O3, is believed to have improved catalytic activity compared to a composition comprising an 8-membered ring-pore zeolite material having a molar ratio of Y:X greater than 30:1, preferably greater than 24:1, more preferably greater than 22:1, more preferably greater than 20:1, and more preferably greater than 18:1, calculated as YO2:X2O3.

[0019] (ii) The outer surface of the zeolite material according to (ii) is preferably covered with a layer containing a non-zeolite oxidizing material according to (i) by a layer comprising 20-100%, more preferably 30-100%, even more preferably 50-95%, even more preferably 50-60%, or more preferably 80-90%. Therefore, the present invention preferably (i) Non-zeolite oxide materials containing alumina (ii) An eight-membered ring-pore zeolite material containing one or more copper and iron, wherein the skeletal structure of the zeolite material contains a tetravalent element Y, a trivalent element X, and oxygen, and the molar ratio of Y:X is calculated as YO2:X2O3 and is in the range of 2:1 to 40:1. A composition comprising, The present invention relates to a composition in which 20-100%, more preferably 30-100%, even more preferably 50-95%, even more preferably 50-60%, or more preferably 80-90% of the outer surface of a zeolite material according to (ii) is covered with a layer comprising a non-zeolite oxide material according to (i), and Y comprises one or more of Si, Sn, Ti, Zr, and Ge, and X comprises one or more of Al, B, In, and Ga. The present invention is more preferably: (i) Non-zeolite oxide materials containing alumina (ii) An 8-membered ring-pore zeolite material comprising one or more copper and iron and having a skeletal CHA, wherein the skeletal structure of the zeolite material comprises a tetravalent element Y, a trivalent element X, and oxygen, and the molar ratio of Y:X is calculated as YO2:X2O3 and is in the range of 2:1 to 40:1. A composition comprising, The present invention relates to a composition wherein 20-100%, more preferably 30-100%, even more preferably 50-95%, even more preferably 50-60%, and more preferably 80-90% of the outer surface of a zeolite material according to (ii) is covered with a layer comprising a non-zeolite oxide material according to (i), and Y comprises one or more of Si, Sn, Ti, Zr, and Ge, and X comprises one or more of Al, B, In, and Ga, and the 8-membered ring-pore zeolite material more preferably comprises copper.

[0020] In the present invention, it is preferable that 0 to 0.00001% by mass, more preferably 0 to 0.000001% by mass of the composition consists of any platinum group metal. In other words, it is preferable that the composition substantially contains no platinum group metals, and more preferably contains no platinum group metals.

[0021] Preferably, 98 to 100% by mass, more preferably 99 to 100% by mass, even more preferably 99.5 to 100% by mass, and even more preferably 99.9 to 100% by mass of the composition consists of a non-zeolite oxidizing material according to (i) and an 8-membered ring-pore zeolite material containing one or more copper and iron according to (ii).

[0022] It is preferable that one or more copper and iron contained in the composition is supported in an amount of 0.1% by mass or less, more preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0.0001% by mass or less, on a non-zeolite oxidizing material according to (i). In other words, it is preferable that not substantially, or more preferably not, one or more copper and iron are supported on a non-zeolite oxidizing material according to (i).

[0023] The composition of the present invention is preferably a calcined composition, more preferably a composition calcined under a gas atmosphere having a temperature in the range of 400 to 800°C, even more preferably in the range of 450 to 600°C, and even more preferably in the range of 450 to 550°C. The gas atmosphere is preferably air.

[0024] The present invention further relates to a method of using a composition according to the present invention as a catalytic component for the selective catalytic reduction of nitrogen oxides.

[0025] The present invention further relates to a slurry comprising a composition and a dispersant according to the present invention, wherein the dispersant is one or more of water, ethanol, acetic acid, nitric acid, lactic acid, and mixtures of two or more thereof. The dispersant is more preferably one or more of water and acetic acid, and more preferably water and acetic acid.

[0026] The present invention further relates to a method for preparing a composition, preferably a composition according to the present invention, (a) A step of providing an eight-membered ring-pore zeolite material containing one or more copper and iron, wherein the zeolite material preferably contains crystals having an average crystal size in the range of 0.05 to 5 micrometers, and this average crystal size is measured as in Reference Example 5, (b) A step of providing a source of a non-zeolite oxidizing material containing alumina, wherein the source of the non-zeolite oxidizing material is a colloidal dispersion containing particles of the non-zeolite oxidizing material, the particles of the non-zeolite oxidizing material have a Dv50 in the range of 30 to 200 nm, and the Dv50 is measured as in Reference Example 3, (c) A step of mixing the zeolite material obtained in (a) and the non-zeolite oxidizing material containing alumina obtained in (b) to form a mixture, (d)(c) is calcined in a gas atmosphere having a temperature in the range of 400 to 800°C, wherein the gas atmosphere is preferably air. Regarding methods including

[0027] In this invention, the order of steps for preparing the above-described composition is considered to be of great importance. In particular, it is important that the eight-membered ring-pore zeolite material already contains one or more copper and iron before being mixed with the colloidal dispersion according to b). In fact, it is believed that different products will be obtained if the zeolite material is mixed with the colloidal dispersion and one or more copper and iron rather than the zeolite material. In particular, the distribution of copper and / or iron in the composition will be different. When using the method of this invention, one or more copper and iron are mostly distributed within the zeolite material, but when mixing the zeolite material, colloidal dispersion and one or more copper and iron together, it is believed that the resulting composition will show more copper and / or iron supported on a non-zeolite oxidizing material (such as alumina).

[0028] (a) This is (a.1) Prepare an aqueous solution of one or more copper salts and iron salts, more preferably a copper salt, more preferably a copper acetate aqueous solution. (a.2) Mix the aqueous solution obtained in (a.1) with an 8-membered ring pore zeolite material; (a.3) The mixture obtained in (a.2) is to be calcined. Preferably, it includes, and more preferably consists of, these.

[0029] The mixing configuration in (a.2) preferably includes impregnating the 8-membered ring-pore zeolite material with the aqueous solution obtained in (a.1), and more preferably consists of this configuration.

[0030] The calcination in (a.3) is preferably carried out in a gas atmosphere having a temperature in the range of 400 to 800°C, more preferably in the range of 450 to 600°C, and even more preferably the gas atmosphere is air.

[0031] (a.3) The baking process is preferably carried out in a gas atmosphere for a period of 0.5 to 4 hours, more preferably in the range of 1.5 to 3 hours, and even more preferably the gas atmosphere is air.

[0032] The crystals of the 8-membered ring-pore zeolite material preferably have an average crystal size in the range of 0.06 to 2 micrometers, more preferably in the range of 0.07 to 1 micrometer, even more preferably in the range of 0.1 to 0.8 micrometers, and even more preferably in the range of 0.2 to 0.6 micrometers, where the average crystal size is determined as in Reference Example 5.

[0033] The 8-membered ring-pore zeolite material preferably contains particles having a Dv50 in the range of 0.5 to 4 micrometers, more preferably in the range of 1 to 3 micrometers, and even more preferably in the range of 1.5 to 2.5 micrometers, where Dv50 is determined as in Reference Example 3.

[0034] The 8-membered ring-pore zeolite material preferably contains particles having a Dv90 in the range of 2 to 15 micrometers, more preferably in the range of 3 to 10 micrometers, and even more preferably in the range of 4 to 8 micrometers, where Dv50 is determined as in Reference Example 3.

[0035] The colloidal dispersion containing particles of the non-zeolite oxidizing material provided in (b) is preferably an alumina sol. The particles of the non-zeolite oxidizing material, more preferably alumina particles, preferably have a Dv50 in the range of 50 to 150 nm, more preferably in the range of 70 to 120 nm, even more preferably in the range of 80 to 110 nm, and even more preferably in the range of 80 to 90 nm, where Dv50 is determined as in Reference Example 3. With respect to the present invention, it is considered that if Dv50 is higher than the above upper limit, a core-shell structure cannot be obtained around the 8-membered ring-pore zeolite material containing one or more copper and iron.

[0036] With regard to the present invention, it should be noted that the 8-membered ring-pore zeolite material is preferably defined as described above when describing the composition of the present invention.

[0037] With regard to the present invention, it should be noted that, when describing the composition of the present invention, the non-zeolite oxidation material is preferably the non-zeolite oxidation material as defined above.

[0038] With respect to the present invention, (c) is, (c.1) Prepare a mixture of water and a source of a non-zeolite oxidizing material containing alumina, more preferably alumina sol, obtained in (b). (c.2) Mix the zeolite material obtained in (a) and the mixture obtained in (c.1). It includes, and preferably consists of, these.

[0039] The calcination described in (d) is preferably carried out in a gas atmosphere having a temperature in the range of 450 to 600°C, more preferably in the range of 450 to 550°C, and even more preferably the gas atmosphere is air.

[0040] The calcination according to (d) is preferably carried out in a gas atmosphere for a period of 0.5 to 4 hours, more preferably in the range of 1 to 3 hours, and even more preferably in the range of 1.5 to 2.5 hours, and the gas atmosphere is even more preferably air.

[0041] The method of the present invention preferably comprises (a), (b), (c), and (d).

[0042] The present invention further relates to compositions, and more preferably to compositions obtained or that can be obtained by methods according to the present invention.

[0043] The present invention further relates to a selective catalytic reduction catalyst for treating exhaust gases of a combustion engine, (1) A substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by the inner wall of the substrate extending through the substrate, (2) A coating placed on the substrate (i) above, The present invention relates to a selective catalytic reduction catalyst comprising a composition according to the present invention, wherein the coating includes the above-mentioned composition.

[0044] The above coating (2) preferably further comprises an oxide binder, more preferably comprising one or more mixed oxides including zirconia, alumina, titania, silica, and two or more of Zr, Al, Ti, and Si, and more preferably comprising one or more of silica, alumina, and zirconia. The oxide binder is more preferably comprising one or more of alumina and zirconia, more preferably composed of these, and more preferably zirconia.

[0045] It is preferable that an oxide binder, more preferably zirconia, is included in the coating (2) in an amount calculated as an oxide, more preferably as ZrO2, based on the mass of the 8-membered ring-pore zeolite material, in the range of 0.1 to 10 mass%, more preferably 1 to 7 mass%, even more preferably 2 to 6.5 mass%, more preferably 3 to 6 mass%, and 4 to 5.5 mass%.

[0046] The coating (2) preferably contains the composition in an amount in the range of 80 to 100% by mass, based on the mass of the coating (2), more preferably in the range of 90 to 99% by mass, even more preferably in the range of 92 to 98% by mass, and even more preferably in the range of 94 to 97% by mass.

[0047] The filling amount of coating (2) is 1-3.5 g / in. 3 It is preferably in the range of 1.5 to 3 g / in. 3 A range of 1.75 to 2.5 g / in 3 It is within the range of [the specified range].

[0048] The coating (2) preferably extends over x% of the length in the axial direction of the substrate, more preferably from the inlet end to the outlet end of the substrate, where x is in the range of 80 to 100, more preferably 90 to 100, even more preferably 95 to 100, and more preferably 98 to 100.

[0049] Preferably 98 to 100% by mass, more preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, and more preferably 99.9 to 100% by mass of the coating (2) consists of the composition according to the present invention and more preferably the oxide binder defined above.

[0050] It is preferable that 0 to 0.00001% by mass, more preferably 0 to 0.000001% by mass of the coating (2) consists of platinum group metals. In other words, it is preferable, and more preferably, that the coating (2) substantially contains no platinum group metals.

[0051] The above-mentioned substrate is preferably a wall flow filter substrate or a flow-through substrate, more preferably a wall flow filter substrate, wherein the plurality of passages more preferably include an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end.

[0052] The above wall flow filter substrate is preferably a porous wall flow filter substrate, more preferably one or more of cordierite wall flow filter substrates, silicon carbide wall flow filter substrates, and aluminum titanate wall flow filter substrates, even more preferably one or more of silicon carbide wall flow filter substrates and aluminum titanate wall flow filter substrates, and more preferably silicon carbide wall flow filter substrates.

[0053] The coating is preferably located inside the inner wall of the wall flow filter substrate and / or on the surface of the inner wall of the wall flow filter substrate.

[0054] It is preferable that at least 95% by mass, more preferably 95-100% by mass, even more preferably 97-99.9% by mass, and even more preferably 98-99.5% by mass of the above coating is located within the inner wall of the wall flow filter substrate. The amount of coating within the inner wall of the substrate is quantified using an electron microscope, preferably a scanning electron microscope (SEM).

[0055] It is preferable that a maximum of 5% by mass, more preferably 0-5% by mass, even more preferably 0.1-3% by mass, and still more preferably 0.5-2% by mass of the above coating is present within the inner wall of the wall flow filter substrate. The amount of coating on the surface of the inner wall of the substrate is quantified using an electron microscope, preferably a scanning electron microscope (SEM).

[0056] The above coating is preferably applied inside the inner wall of the wall flow filter substrate and on the surface of the inner wall of the wall flow filter substrate.

[0057] The selective catalytic reduction catalyst of the present invention preferably comprises a substrate (1) and a coating (2).

[0058] The present invention further provides a method for preparing a selective catalytic reduction catalyst for treating exhaust gases of a combustion engine according to the present invention, (A) A step of preparing a mixture comprising water and a composition according to the present invention, preferably a composition prepared according to a manufacturing method according to the present invention. (B) A step of placing the mixture obtained according to (A) onto a substrate to obtain a substrate that has been treated with the mixture, wherein the substrate includes an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of channels defined by the inner wall of the substrate extending through the substrate, A step of obtaining a substrate having a coating placed thereon by firing (sintering) the mixture-treated substrate obtained according to (C)(B), Regarding methods including

[0059] Regarding (A), this is preferably, (A.1) Prepare a first mixture comprising water and a composition according to the present invention, more preferably a composition prepared by a method according to the present invention; (A.2) Add an oxide binder source, more preferably a zirconium salt, even more preferably zirconium acetate, to the first mixture obtained in (A.1) to obtain a second mixture; (A.3) More preferably, an organic acid is added to the second mixture obtained in (A.2) to obtain a third mixture. (A.4) More preferably, the second mixture obtained in (A.2) is ground, and even more preferably, the third mixture obtained in (A.3) is ground. More preferably, the step is to grind the particles of the above mixture until the Dv90 is in the range of 1 to 10 micrometers, more preferably in the range of 2 to 7 micrometers, and even more preferably in the range of 3 to 5 micrometers, where the Dv90 is measured as described in Reference Example 3. This includes, where (A) more preferably includes (A.1), (A.2) and (A.4), and even more preferably includes (A.1), (A.2), (A.3) and (A.4), and more preferably consists of these.

[0060] The organic acid added in accordance with (A.3) is preferably one or more of acetic acid, tartaric acid, citric acid, nitric acid, lactic acid, hydrochloric acid, and sulfuric acid, and the organic acid is more preferably acetic acid.

[0061] Placing the mixture obtained according to (A) onto the substrate described in (B) is preferably done by immersing the substrate in the mixture obtained according to (A). Thus, the mixture prepared according to (A) preferably penetrates / permeates the inner wall of the substrate and preferably remains on the surface of the inner wall of the substrate.

[0062] Preferably according to (B), the mixture prepared according to (A) is placed on the substrate over x% of the substrate's axial length, where x is in the range of 80 to 100, more preferably 90 to 100, even more preferably 95 to 100, and more preferably 98 to 100. Thus, the mixture prepared according to (A) is preferably infiltrated into the inner wall of the substrate and preferably on the surface of the inner wall of the substrate.

[0063] The mixture prepared according to (A) is preferably placed on the substrate from the inlet end to the outlet end.

[0064] Regarding (B), this is preferably, (B.1) A step of placing a first portion of the mixture obtained in (A) onto a substrate having an inlet end, an outlet end, a length in the substrate axial direction extending from the inlet end to the outlet end, and a plurality of passages defined by the inner wall of the substrate extending through the substrate, wherein the placement is more preferably carried out from the inlet end to the outlet end of the substrate; and a step of drying the substrate containing the first portion of the mixture placed thereon; (B.2) A step of placing the second portion of the mixture obtained in (A) onto a substrate containing the first portion of the mixture obtained in (B.1), more preferably the placement being from the inlet end toward the outlet end of the substrate; and more preferably the step of drying the substrate containing the first and second portions of the mixture placed thereon. Includes.

[0065] Therefore, the mixture prepared according to (A) preferably penetrates / infiltrates the inner wall of the substrate and preferably remains on the surface of the inner wall of the substrate.

[0066] more preferably, (B) is (B.1) A step of placing a first portion of the mixture obtained in (A) on a substrate having an inlet end, an outlet end, a length in the substrate axial direction extending from the inlet end to the outlet end, and a plurality of channels defined by the inner wall of the substrate extending through the substrate, wherein the placement is carried out from the inlet end of the substrate toward the outlet end of the substrate, more preferably over x% of the length in the substrate axial direction, where x is as defined above, and a step of drying the substrate containing the first portion of the mixture placed on the substrate; (B.2) A step of placing a second portion of the mixture obtained in (A) onto a substrate containing the first portion of the mixture obtained in (B.1), wherein this placement is carried out from the inlet end to the outlet end of the substrate, more preferably over x% of the length in the axial direction of the substrate, where x is as defined above; more preferably, a step of drying the substrate containing the first and second portions of the mixture placed on the substrate. Includes.

[0067] Alternatively, more preferably (B) is: (B'.1) A step of placing a first portion of the mixture obtained in (A) onto a substrate having a plurality of passages defined by an inlet end, an outlet end, a length in the substrate axial direction extending from the inlet end to the outlet end, and an inner wall of the substrate extending through the substrate, wherein the placement is carried out from the inlet end to the outlet end of the substrate, more preferably over Xa% of the length in the substrate axial direction, where Xa is in the range of 40 to 80, and even more preferably in the range of 50 to 70; a step of drying the substrate containing the first portion of the mixture placed on the substrate; (B'.2) A step of placing a second portion of the mixture obtained in (A) onto a substrate containing the first portion of the mixture obtained in (B'.1), wherein this placement is carried out from the outlet end to the inlet end of the substrate, more preferably over Xb% of the length in the axial direction of the substrate, where Xb is in the range of 40 to 80, more preferably in the range of 50 to 70; and more preferably a step of drying the substrate containing the first and second portions of the mixture placed on the substrate. Includes.

[0068] With respect to the present invention, the calcination according to (C) is preferably carried out in a gas atmosphere having a temperature in the range of 300 to 800°C, more preferably in the range of 350 to 700°C, and even more preferably the gas atmosphere is air.

[0069] The firing according to (C) is preferably carried out in a gas atmosphere for a period of 0.2 to 4 hours, more preferably in the range of 0.5 to 3 hours, and more preferably the gas atmosphere is air.

[0070] It is preferable that drying is carried out in a gas atmosphere having a temperature in the range of 90 to 150°C prior to calcination according to (C), more preferably in the range of 100 to 140°C, and even more preferably the gas atmosphere is air. Therefore, it is preferable that calcination according to (C) be carried out on a dried mixture-treated substrate.

[0071] (C) or prior to baking, drying is preferably carried out in a gas atmosphere for a period of 5 to 150 minutes, more preferably 10 to 120 minutes, and the gas atmosphere is even more preferably air.

[0072] The method of the present invention for preparing a selective catalytic reduction catalyst for treating exhaust gas of a combustion engine according to the present invention preferably comprises (A), (B), and (C).

[0073] The present invention further relates to a selective catalytic reduction catalyst for treating exhaust gases of a combustion engine, and more preferably to a selective catalytic reduction catalyst for treating exhaust gases of a combustion engine according to the present invention, which can be obtained by a method according to the present invention.

[0074] The present invention further relates to a method for selective catalytic reduction of nitrogen oxides, (i) A process of providing an exhaust gas flow, preferably from an internal combustion engine, preferably from a diesel engine; (II) A step of passing the exhaust gas flow provided in (I) through a selective catalytic reduction catalyst according to the present invention, Regarding methods including

[0075] The present invention is further described by the following set of embodiments and combinations of embodiments arising from the relationship and (indicated) backreferences. In particular, it should be noted that in each example where the scope of an embodiment is referred to, such as "the composition according to any one of Embodiments 1 to 4," all embodiments within this scope are expressly disclosed to those skilled in the art, i.e., it should be understood by those skilled in the art that the wording of this term is synonymous with "the composition according to any one of Embodiments 1, 2, 3 and 4." Furthermore, it should be explicitly noted that the following set of embodiments does not constitute a set of claims that would determine the scope of protection, but rather represents a well-structured portion of the description directed toward the general and preferred aspects of the present invention.

[0076] "Embodiment 1" (i) Non-zeolite oxide materials containing alumina (ii) An eight-membered ring-pore zeolite material containing one or more copper and iron, wherein the skeletal structure of the zeolite material contains a tetravalent element Y, a trivalent element X, and oxygen, and the molar ratio of Y:X is calculated as YO2:X2O3 and is in the range of 2:1 to 40:1. A composition comprising, A composition in which at least a portion of the outer surface of a zeolite material according to (ii) is covered with a layer containing a non-zeolite oxide material according to (i), and Y comprises one or more of Si, Sn, Ti, Zr, and Ge, and X comprises one or more of Al, B, In, and Ga.

[0077] Embodiment 2 The composition according to Embodiment 1, wherein 98 to 100% by mass, preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, and even more preferably 99.9 to 100% by mass of the non-zeolite oxidizing material according to (i) is composed of alumina.

[0078] "Embodiment 3" The composition according to Embodiment 1 or 2, wherein the alumina contained in the non-zeolite oxide material according to (i) above is selected from the group consisting of γ-alumina, α-alumina, δ-alumina, θ-alumina, and η-alumina, preferably selected from the group consisting of γ-alumina, α-alumina, and δ-alumina, and more preferably the alumina is γ-alumina.

[0079] Embodiment 4 The composition according to any one of Embodiments 1 to 3, wherein the layer comprising a non-zeolite oxidizing material according to (i) above has an average thickness in the range of 2 nm to 100 nm, preferably in the range of 5 nm to 70 nm, more preferably in the range of 20 to 50 nm, more preferably in the range of 25 nm to 47 nm, even more preferably in the range of 25 to 35 nm, or even more preferably in the range of 40 to 47 nm, the average thickness being determined as described in Reference Example 4.

[0080] Embodiment 5 The composition according to any one of Embodiments 1 to 4, wherein the layer contains 40 to 100% by mass, preferably 50 to 100% by mass, and more preferably 70 to 100% by mass, of a non-zeolite-based oxidation material according to (i) above.

[0081] Embodiment 6 The composition according to any one of Embodiments 1 to 5, wherein 99 to 100% by mass, preferably 99.5 to 100% by mass, and more preferably 99.9 to 100% by mass of the above layer is composed of a non-zeolite oxidizing material according to (i).

[0082] Embodiment 7 The composition according to any one of Embodiments 1 to 6, wherein the non-zeolite oxidizing material according to (i) above is present in the composition in an amount in the range of 5 to 50% by mass, preferably in the range of 7 to 40% by mass, and more preferably in the range of 8 to 32% by mass, based on the mass of the 8-membered ring-pore zeolite material according to (ii).

[0083] Embodiment 8 The composition according to any one of Embodiments 1 to 7, wherein the 8-membered ring-pore zeolite material according to (ii) has a skeleton selected from the group consisting of CHA, AEI, RTH, LEV, DDR, KFI, ERI, AFX, LTA, two or more mixtures thereof, and two or more mixed forms thereof, preferably having a skeleton selected from the group consisting of CHA, AEI, RTH, two or more mixtures thereof, and two or more mixed forms thereof, more preferably having a skeleton selected from the group consisting of CHA and AEI, and even more preferably the 8-membered ring-pore zeolite material according to (ii) has a skeleton of CHA.

[0084] Embodiment 9 The composition according to any one of Embodiments 1 to 8, wherein the 8-membered ring-pore zeolite material according to (ii) above contains copper, and the amount of copper in the zeolite material is calculated as CuO based on the mass of the 8-membered ring-pore zeolite material and is preferably in the range of 0.1 to 10 mass%, more preferably in the range of 1.5 to 5.5 mass%, more preferably in the range of 2.5 to 5.0 mass%, even more preferably in the range of 3.0 to 4.75 mass%, and even more preferably in the range of 3.25 to 4.5 mass%.

[0085] Embodiment 10 The composition according to Embodiment 9, wherein the amount of iron contained in the above-mentioned 8-membered ring-pore zeolite material is calculated as Fe2O3 based on the mass of the 8-membered ring-pore zeolite material and is in the range of 0 to 0.01% by mass, preferably in the range of 0 to 0.001% by mass, and more preferably in the range of 0 to 0.0001% by mass.

[0086] Embodiment 11 The composition according to any one of Embodiments 1 to 10, wherein 98 to 100% by mass, preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, and more preferably 99.9 to 100% by mass of the skeletal structure of the 8-membered ring-pore zeolite material according to (ii) above, consists of X, Y, and O.

[0087] Embodiment 12 The composition according to any one of embodiments 1 to 11, wherein Y is Si.

[0088] Embodiment 13 The composition according to any one of Embodiments 1 to 12, wherein X is one or more of Al and B, preferably Al.

[0089] Embodiment 14 The composition according to any one of Embodiments 1 to 13, wherein the molar ratio of Y:X, calculated as YO2:X2O3, is in the range of 5:1 to 30:1, preferably in the range of 10:1 to 24:1, more preferably in the range of 12:1 to 22:1, even more preferably in the range of 15:1 to 20:1, and more preferably in the range of 15:1 to 18:1.

[0090] Embodiment 15 The composition according to any one of Embodiments 1 to 14, wherein 20 to 100%, preferably 30 to 100%, more preferably 50 to 95%, even more preferably 50 to 60%, and more preferably 80 to 90% of the outer surface of the zeolite material according to (ii) is covered with a layer comprising a non-zeolite oxidizing material according to (i).

[0091] Embodiment 16 The composition according to any one of Embodiments 1 to 15, wherein 0 to 0.00001% by mass, preferably 0 to 0.000001% by mass, of the composition consists of any platinum group metal.

[0092] Embodiment 17 The composition according to any one of Embodiments 1 to 16, wherein 98 to 100% by mass, preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, and even more preferably 99.9 to 100% by mass of the composition consists of a non-zeolite oxidizing material according to (i) and an 8-membered ring-pore zeolite material containing one or more copper and iron according to (ii).

[0093] Embodiment 18 A calcined composition, more preferably calcined under a gas atmosphere having a temperature in the range of 400 to 800°C, even more preferably in the range of 450 to 600°C, and even more preferably in the range of 450 to 550°C, wherein the gas atmosphere is preferably air, as described in any one of Embodiments 1 to 17.

[0094] Embodiment 19 A method for using a composition according to any one of Embodiments 1 to 18 as a catalyst component for the selective catalytic reduction of nitrogen oxides.

[0095] Embodiment 20 A slurry comprising a composition and a dispersant according to any one of Embodiments 1 to 18, wherein the dispersant is one or more of water, ethanol, acetic acid, nitric acid, lactic acid, and mixtures of two or more thereof, preferably the dispersant is one or more of water and acetic acid, and more preferably water and acetic acid.

[0096] Embodiment 21 A method for preparing a composition, preferably one of the compositions described in Embodiments 1 to 18, (a) A step of providing an eight-membered ring-pore zeolite material comprising one or more copper and iron, wherein the skeletal structure of the zeolite material comprises a tetravalent element Y, a trivalent element X, and oxygen, the molar ratio of Y:X is in the range of 2:1 to 40:1, calculated as YO2:X2O3, and the zeolite material preferably comprises crystals having an average crystal size in the range of 0.05 to 5 micrometers, the average crystal size being determined as described in Reference Example 5; (b) A step of providing a source of a non-zeolite oxidizing material containing alumina, wherein the source of the non-zeolite oxidizing material is a colloidal dispersion containing particles of the non-zeolite oxidizing material, wherein the particles of the non-zeolite oxidizing material have a Dv50 in the range of 30 to 200 nm, and the Dv50 is determined as described in Reference Example 3; (c) A step of mixing the zeolite material obtained in (a) with a source of a non-zeolite oxidizing material containing alumina obtained in (b) to form a mixture, (d) A step of calcining the mixture obtained in (c) in a gas atmosphere having a temperature in the range of 400 to 800°C, wherein the gas atmosphere is preferably air. A method that includes this.

[0097] Embodiment 22 Step (a) is, (a.1) A step of preparing an aqueous solution of one or more copper salts and iron salts, more preferably a copper salt, more preferably a copper acetate aqueous solution. (a.2) A step of mixing the aqueous solution obtained in (a.1) with an 8-membered ring pore zeolite material; (a.3) The process of calcining the mixture obtained in (a.2), The method according to Embodiment 21, which includes, and preferably comprises, these.

[0098] Embodiment 23 The method according to Embodiment 22, wherein the mixing in step (a.2) preferably comprises the step of impregnating an 8-membered ring-pore zeolite material with the aqueous solution obtained in step (a.1).

[0099] Embodiment 24 The method according to Embodiment 22 or 23, wherein the calcination in step (a.3) is carried out in a gas atmosphere having a temperature in the range of 400 to 800°C, preferably in the range of 450 to 600°C.

[0100] Embodiment 25 The method according to any one of embodiments 22 to 24, wherein the baking in step (a.3) is carried out for a period of time in the range of 0.5 to 4 hours, preferably in the range of 1.5 to 3 hours.

[0101] Embodiment 26 The crystals of the eight-membered ring-pore zeolite material have an average crystal size in the range of 0.06 to 2 micrometers, preferably in the range of 0.07 to 1 micrometer, more preferably in the range of 0.1 to 0.8 micrometers, and even more preferably in the range of 0.2 to 0.6 micrometers, the average crystal size being determined as described in Reference Example 5, according to any one of Embodiments 21 to 25.

[0102] Embodiment 27 The above 8-membered ring-pore zeolite material comprises particles having a Dv50 in the range of 0.5 to 4 micrometers, preferably in the range of 1 to 3 micrometers, more preferably in the range of 1.5 to 2.5 micrometers, wherein the Dv50 is determined as described in Reference Example 3, according to any one of Embodiments 21 to 26.

[0103] Embodiment 28 The above 8-membered ring-pore zeolite material comprises particles having a Dv90 in the range of 2 to 15 micrometers, more preferably in the range of 3 to 10 micrometers, and even more preferably in the range of 4 to 8 micrometers, where Dv50 is determined as described in Reference Example 3, according to any one of Embodiments 21 to 27.

[0104] Embodiment 29 The method according to any one of Embodiments 21 to 28, wherein the colloidal dispersion containing particles of a non-zeolite oxidizing material provided in (b) is an alumina sol.

[0105] "Embodiment 30" The method according to any one of Embodiments 21 to 29, wherein the particles of the non-zeolite oxidizing material, preferably the alumina particles, have a Dv50 in the range of 50 to 150 nm, preferably in the range of 70 to 120 nm, more preferably in the range of 80 to 110 nm, and more preferably in the range of 80 to 90 nm, where Dv50 is determined as described in Reference Example 3.

[0106] Embodiment 31 Process (c) is (c.1) A step of preparing a mixture of water and a source of a non-zeolite oxidizing material containing alumina, preferably alumina sol, obtained in (b), (c.2) A step of mixing the zeolite material obtained in (a) and the mixture obtained in (c.1), A method according to any one of embodiments 21 to 30, comprising, and preferably comprising, the following.

[0107] Embodiment 32 The method according to any one of Embodiments 21 to 31, wherein the baking is carried out in a gas atmosphere having a temperature in the range of 450 to 600°C, preferably in the range of 450 to 550°C, and the gas atmosphere is preferably air.

[0108] "Embodiment 33" The method according to any one of Embodiments 21 to 32, wherein the calcination is carried out in a gas atmosphere for a period of 0.5 to 4 hours, which is preferably in the range of 1 to 3 hours, more preferably in the range of 1.5 to 2.5 hours, and the gas atmosphere is more preferably air.

[0109] Embodiment 34 The method according to any one of Embodiments 21 to 33, comprising (a), (b), (c), and (d).

[0110] Embodiment 35 A composition obtained or obtainable by the method described in any one of Embodiments 21 to 34, preferably the composition described in any one of Embodiments 1 to 18.

[0111] Embodiment 36 A selective catalytic reduction catalyst for treating exhaust gases from a combustion engine, (1) A substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by the inner wall of the substrate extending through the substrate, (2) A coating placed on the substrate (i), A selective catalytic reduction catalyst comprising the above coating comprising the composition described in any one of embodiments 1 to 18 and 35.

[0112] Embodiment 37 The catalyst according to Embodiment 36, wherein the above coating (2) further comprises an oxide binder, the oxide binder preferably comprising one or more mixed oxides comprising zirconia, alumina, titania, silica, and two or more of Zr, Al, Ti, and Si, more preferably comprising one or more of silica, alumina, and zirconia, even more preferably comprising one or more of alumina and zirconia, and more preferably comprising zirconia.

[0113] Embodiment 38 The catalyst according to Embodiment 37, wherein an oxide binder, preferably zirconia, is included in the coating (2) in an amount calculated as an oxide, preferably as ZrO2, based on the mass of the 8-membered ring-pore zeolite material, in the range of 0.1 to 10 mass%, more preferably 1 to 7 mass%, even more preferably 2 to 6.5 mass%, more preferably 3 to 6 mass%, and more preferably 4 to 5.5 mass%.

[0114] Embodiment 39 The catalyst according to any one of embodiments 36 to 38, wherein the coating (2) contains the composition in an amount in the range of 80 to 100% by mass, based on the mass of the coating (2), and this amount is preferably in the range of 90 to 99% by mass, more preferably in the range of 92 to 98% by mass, and even more preferably in the range of 94 to 97% by mass.

[0115] Embodiment 40 The filling amount of coating (2) is 1-3.5 g / in. 3 The range is preferably 1.5 to 3 g / in. 3 A range of 1.75 to 2.5 g / in 3 A catalyst according to any one of embodiments 36 to 39, which falls within the range of [the specified range].

[0116] Embodiment 41 The catalyst according to any one of embodiments 36 to 40, wherein the coating (2) extends over x% of the length in the axial direction of the substrate, preferably from the inlet end to the outlet end of the substrate, and x is in the range of 80 to 100, preferably 90 to 100, more preferably 95 to 100, and more preferably 98 to 100.

[0117] Embodiment 42 A catalyst according to any one of embodiments 36 to 41, wherein 98 to 100% by mass of the coating (2), preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, and even more preferably 99.9 to 100% by mass, consists of the composition according to any one of embodiments 1 to 18 and 35 and preferably the oxide binder according to embodiment 37 or 38.

[0118] Embodiment 43 The above-mentioned substrate is a wall flow filter substrate or a flow-through substrate, preferably a wall flow filter substrate, wherein the plurality of passages preferably include an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end, according to any one of embodiments 36 to 42.

[0119] Embodiment 44 The catalyst according to Embodiment 43, wherein the above wall flow filter substrate is a porous wall flow filter substrate, where the wall flow filter substrate is preferably one or more of cordierite wall flow filter substrate, silicon carbide wall flow filter substrate, and aluminum titanate wall flow filter substrate, more preferably one or more of silicon carbide wall flow filter substrate and aluminum titanate wall flow filter substrate, and more preferably silicon carbide wall flow filter substrate.

[0120] Embodiment 45 The catalyst according to Embodiment 43 or 44, wherein the coating is present on the surface of the inner wall of the wall flow filter substrate and / or within the inner wall of the wall flow filter substrate, and preferably the coating is present on the surface of the inner wall of the wall flow filter substrate and within the inner wall of the wall flow filter substrate.

[0121] Embodiment 46 A catalyst according to any one of embodiments 36 to 45, comprising a substrate (1) and a coating (2).

[0122] Embodiment 47 A method for preparing a selective catalytic reduction catalyst for treating exhaust gas of a combustion engine described in any one of embodiments 36 to 46, (A) A step of preparing a mixture comprising water and a composition according to any one of embodiments 1 to 18 and 35, preferably a composition prepared according to a manufacturing method according to any one of embodiments 21 to 34. (B) A step of placing the mixture obtained according to (A) onto a substrate to obtain a substrate that has been treated with the mixture, wherein the substrate includes an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of channels defined by the inner wall of the substrate extending through the substrate. (C) A step of calcining a substrate that has been treated with a mixture according to (B) to obtain a substrate having a coating placed thereon, A method that includes this.

[0123] Embodiment 48 (A) (A.1) A step of preparing a first mixture comprising water and a composition according to any one of embodiments 1 to 18 and 35, preferably prepared by a method according to any one of embodiments 21 to 34; (A.2) A step of adding an oxide binder source, preferably a zirconium salt, more preferably zirconium acetate, to the first mixture obtained in (A.1) to obtain a second mixture; (A.3) Preferably, an organic acid is added to the second mixture obtained in (A.2) to obtain a third mixture; (A.4) Preferably grinding the second mixture obtained in (A.2), more preferably grinding the third mixture obtained in (A.3), and more preferably grinding the particles of the mixture until the Dv90 is in the range of 1 to 10 micrometers, more preferably in the range of 2 to 7 micrometers, and even more preferably in the range of 3 to 5 micrometers, wherein the Dv90 is determined as described in Reference Example 3. The method according to Embodiment 47, wherein (A) preferably comprises (A.1), (A.2), and (A.4), more preferably comprises (A.1), (A.2), (A.3), and (A.4).

[0124] Embodiment 49 The method according to Embodiment 48, wherein the organic acid added in accordance with (A.3) is one or more of acetic acid, tartaric acid, citric acid, nitric acid, lactic acid, hydrochloric acid, and sulfuric acid, and the organic acid is more preferably acetic acid.

[0125] Embodiment 50 The method according to any one of embodiments 47 to 49, wherein placing the mixture obtained according to (A) onto the substrate described in (B) is done by immersing the substrate in the mixture obtained according to (A).

[0126] Embodiment 51 The method according to any one of Embodiments 47 to 50, in which the mixture prepared according to (A) is placed on the inner wall of the substrate over x% of the length in the axial direction of the substrate, where x is in the range of 80 to 100, preferably in the range of 90 to 100, more preferably in the range of 95 to 100, and more preferably in the range of 98 to 100.

[0127] Embodiment 52 The method according to any one of embodiments 47 to 51, wherein the mixture prepared according to (A) is placed on the surface of the inner wall of the substrate from the inlet end to the outlet end of the substrate.

[0128] Embodiment 53 (B) (B.1) A step of placing a first portion of the mixture obtained in (A) onto a substrate having an inlet end, an outlet end, a length in the substrate axial direction extending from the inlet end to the outlet end, and a plurality of passages defined by the inner wall of the substrate extending through the substrate, and drying the substrate containing the first portion of the mixture placed thereon, wherein the placement is preferably carried out from the inlet end to the outlet end of the substrate; (B.2) A step of placing the second portion of the mixture obtained in (A) onto a substrate containing the first portion of the mixture obtained in (B.1), and preferably drying the substrate containing the first and second portions of the mixture placed thereon, wherein the placement is carried out from the inlet end toward the outlet end of the substrate. A method according to any one of embodiments 47 to 52, including the method described above.

[0129] Embodiment 54 The method according to any one of Embodiments 47 to 53, wherein the calcination is carried out in a gas atmosphere having a temperature in the range of 300 to 800°C, preferably in the range of 350 to 700°C, and the gas atmosphere is preferably air.

[0130] Embodiment 55 The method according to any one of Embodiments 47 to 54, wherein the calcination is carried out in a gas atmosphere for a period of 0.2 to 4 hours, preferably in the range of 0.5 to 3 hours, and the gas atmosphere is preferably air.

[0131] Embodiment 56 A selective catalytic reduction catalyst for treating exhaust gases of a combustion engine, preferably obtainable by following the method of any one of Examples 47 to 55, or obtained, as described in any one of Embodiments 36 to 46.

[0132] Embodiment 57 A method for selective catalytic reduction of nitrogen oxides, (i) A process of providing an exhaust gas flow, preferably from an internal combustion engine, preferably from a diesel engine; (II) A step of passing the exhaust gas flow provided in (I) through a selective catalytic reduction catalyst according to any one of embodiments 36 to 46 and 56, Methods that include...

[0133] In this invention, the term "based on the mass of the zeolite material" refers to the mass of the zeolite material alone, meaning that it does not include copper and / or iron.

[0134] Furthermore, in the present invention, the term “inner wall surface” should be understood as the “bare,” “exposed,” or “empty” surface of the wall, that is, as the untreated wall surface made of the wall material, apart from any unavoidable impurities that may contaminate the surface.

[0135] In the present invention, the expression "coating disposed on a substrate (i)" includes the fact that the coating may be disposed within the inner wall of the substrate (i) and / or on the surface of the inner wall of the substrate (i).

[0136] Furthermore, in this invention, the term "combustion engine" preferably refers to a diesel engine.

[0137] Furthermore, in the present invention, the term "alumina sol" can be used interchangeably with "colloidal alumina."

[0138] In the present invention, the particles of the given zeolite material are formed by aggregates or masses of crystals of the zeolite material. In other words, the aggregates or masses of crystals of the given zeolite material form the particles of the zeolite material.

[0139] In the present invention, the term "outer surface" of a given zeolite-based material refers to the outer surface of the crystal (or particles) of the zeolite-based material.

[0140] Furthermore, in the context of the present invention, a configuration in which "X is one or more of A, B, and C" where X is a given feature and each of A, B, and C represents a specific embodiment of the above feature should be understood as disclosing that X is either A or B or C, A and B, or A and C, or B and C, or A and B and C. Those skilled in the art should note that the above abstract terms can be translated into concrete examples, for example, if X is a chemical element and A, B, and C are specific elements such as Li, Na, and K, or if X is a temperature and A, B, and C are specific temperatures such as 10°C, 20°C, and 30°C. In this regard, it should be noted that the above terms can be extended to embodiments that specify the above features less, for example, "X is one or more of A and B," to embodiments that disclose that X is A, or B, or A and B, or embodiments that specify the above features more, for example, "X is one or more of A, B, C, and D," to embodiments that disclose that X is A, or B, or C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C, or B and D, or B and C and D, or A and B and C and D.

[0141] Furthermore, in this invention, with respect to the mass percentage of one or more components, the term "consists of (composed of)" indicates the amount of the component in mass percentage based on 100% by mass of the actual substance. For example, the statement "0 to 0.00001% by mass of the above composition consists of X" indicates that, with the components constituting the above composition being 100% by mass, 0 to 0.00001% by mass of the composition is X.

[0142] The present invention will be further described in detail by the following reference examples, comparative examples, and examples. [Examples]

[0143] Reference Example 1: Measurement of BET specific surface area The BET specific surface area was determined using liquid nitrogen according to DIN 66131 or DIN-ISO 9277.

[0144] Reference Example 2: Measurement of average porosity and average pore diameter of porous wall-flow substrates The average porosity of the porous wall-flow substrate was determined by mercury intrusion using the mercury intrusion method described in DIN 66133 and ISO 15901-1.

[0145] Reference Example 3: Determination of Volume-Based Particle Size Distribution The particle size distribution was determined by static light scattering using a Sympatec HELOS(3200)&QUIXEL instrument, where the optical density of the sample was in the range of 6-10%.

[0146] Reference Example 4: Determination of the average thickness of a layer containing a non-zeolite oxidizing material in a composition. To determine the thickness of the layer applied to the outer surface of the zeolite-based material in the composition, the composition was first coated onto a substrate such as that used in Example 1 or 2, dried at 130°C for 30 minutes, and then baked at 450°C for 2 hours. At least 10 TEM (transmission electron microscope) images of the coated substrate were also prepared. The thickness of the given layer was measured on at least 10 TEM images by applying a scale to several parts of the image and averaging across all measurement points for all crystals / particles (an example is shown in Figure 8). Figure 8.1 or 8.2 shows how the layer thickness was determined in one TEM image.

[0147] Reference Example 5: Determination of the average crystal diameter of zeolite-based materials The average crystal diameter of zeolite-based materials was determined by analyzing TEM images of the zeolite-based material powder. The size of individual crystals was determined by averaging the crystal sizes of 20 to 30 individual crystals from at least two TEM images taken at magnifications ranging from 5000 to 12000.

[0148] Comparative Example 1: A method for producing a selective catalytic reduction catalyst containing a copper-containing zeolite material, not according to the present invention. Slurry 1: CuO powder with a Dv50 of 33 micrometers was added to water. The amount of CuO was calculated so that it was 4.15% by mass relative to the mass of chabazite in the coating after calcination, with the total amount of copper being calculated as CuO. The resulting mixture was ground using a continuous grinding apparatus so that the particle Dv50 value was approximately 2 micrometers and the particle Dv90 value was approximately 5 micrometers. The resulting slurry had a solid content of 8% by mass relative to the mass of the slurry. Acetic acid and an aqueous solution of zirconium acetate were added to the CuO-containing mixture to form a slurry. The amount of acetic acid was calculated so that it was 1.7% by mass relative to the chabazite, and the amount of zirconium acetate was calculated so that the amount of zirconia in the coating was 5% by mass based on the mass of chabazite, with the amount of zirconium acetate calculated as ZrO2. Separately, chabazite (2.2 micrometers Dv50, 5.2 micrometers Dv90, SiO2:Al2O3 with an average crystal size of 0.4 micrometers) was added to water to form a mixture with a solid content of 36% by mass based on the mass of the mixture. This Cu-chabazite mixture was mixed into a copper-containing slurry. The amount of Cu-chabazite was calculated so that the amount of chabazite packed after calcination was 84% ​​of the amount of coating packed in the catalyst after calcination. The resulting slurry was pulverized using a continuous grinding apparatus so that the particle Dv90 value was approximately 5 micrometers.

[0149] Slurry 2: Separately, the solid content is 12% by mass relative to the mass of the above slurry, and it is a mixture of water and alumina (Al2O3) 95% by mass and SiO2 5% by mass, approximately 180m 2 An aqueous slurry was prepared containing alumina + silica (with a BET specific surface area of ​​approximately 5 micrometers and a Dv90 of approximately 5 micrometers per g). The amount of alumina + silica was calculated so that the amount of alumina + silica after calcination was 10% by mass relative to the mass of chabazite after calcination.

[0150] Subsequently, slurries 1 and 2 were combined, and the solid content of the resulting final slurry was about 31% by mass based on the total mass of the final slurry. A non-porous and uncoated wall flow filter substrate, silicon carbide (average porosity 60.5%, average pore diameter 20 micrometers, 350 CPSI, and 0.28 mm (11 mils) wall thickness, diameter: 1.5 inches (38.1 mm) × length: 6 inches (152.4 mm)) was coated twice with the final slurry over 100% of the axial length of the substrate from the inlet end to the outlet end. To do this, the substrate was immersed in the final slurry from the inlet end until the slurry reached the top of the substrate. Further, a pressure pulse was applied to the inlet end to evenly distribute the slurry within the substrate. Additionally, the coated substrate was dried at 130 °C for 30 minutes and calcined at 450 °C for 2 hours. This was repeated once. The final coating loading after calcination was about 2 g / in 3 but this was about 1.68 g / in 3 of the CHA zeolite-based material, 0.17 g / in 3 of alumina + silica, about 0.084 g / in 3 of zirconia, and contained 4.15% by mass of Cu (calculated as CuO).

[0151] Characterization Analysis of the TEM micrograph (Figure 1) of the resulting coated substrate demonstrates that no alumina was found around the zeolite-based material crystals. Instead, Si-doped alumina was intermittently dispersed between or within the chabazite crystals or particles (= agglomerates of chabazite crystals), or was independently dispersed in separate sections of the sample (not shown in Figure 1). Without wishing to be bound by any theory, this is thought to be due to the significantly higher particle size of the Si-doped alumina compared to the particle size of the chabazite crystals.

[0152] Example 1: Method for Producing a Selective Catalytic Reduction Catalyst Containing a Zeolite-Based Material Containing Copper In the first step, a zeolite material having a skeletal CHA structure (Dv50 of 2.2 micrometers, Dv90 of 5.2 micrometers, SiO2:Al2O3 of 18, average crystal size approximately 0.4 micrometers) was added to an aqueous solution of copper acetate (3.51 mass% Cu, calculated as CuO). The amount of copper acetate aqueous solution provided was sufficient to fill the pores of the CHA zeolite material through initial wetting and impregnation, and the resulting Cu content, calculated as CuO, was approximately 4.15 mass%. After impregnation, the Cu-containing zeolite material was calcined in air at 500°C for 2 hours.

[0153] In the second step, alumina sol (boehmite-colloidal dispersion: solid content 22-25% by mass and Dv50 of alumina particles in the dispersion at approximately 90 nm) was dispersed in water and impregnated into the calcined Cu-zeolite material so that the mass percentage of alumina relative to the mass of the calcined zeolite material was 10% by mass. After impregnation, the Cu-zeolite material + alumina was calcined in air at 500°C for 2 hours. Next, the calcined Cu-zeolite + alumina was dispersed in water and an aqueous zirconium acetate solution to form a slurry. The amount of zirconium acetate was calculated as ZrO2, and the amount of zirconia in the coating was calculated to be 5% by mass based on the mass of the zeolite material. Finally, acetic acid (1.7% by mass based on the mass of the zeolite material) was added to the slurry. The obtained slurry was pulverized using a continuous grinding apparatus so that the particle Dv90 value was approximately 4 micrometers, and the solid content of the obtained slurry was adjusted to 31% by mass relative to the mass of the slurry.

[0154] The obtained slurry was coated twice onto a porous, uncoated wall-flow filter substrate, silicon carbide (average porosity 60.5%, average pore size 20 micrometers and 350 CPSI, wall thickness 0.3 mm (13 mil), diameter: 1.5 inches (38 mm) × length: 6 inches (152 mm)), following the coating method described in Comparative Example 1 above. The final coating load after calcination was approximately 2.1 g / in. 3 This is approximately 1.764 g / in of CHA zeolite-based material.3 , alumina 0.176 g / in 3 zirconia has a density of approximately 0.088 g / in 3 It also contained 4.15 mass% of Cu (calculated as CuO, based on the mass of the CHA zeolite material).

[0155] Characterization: TEM analysis of the obtained coated substrates (Figure 2.1) showed that approximately 50-60% of the crystals exhibited some degree of alumina coating. Some zeolite material crystals lacked a visible alumina layer, while others were partially encased in alumina, forming an alumina shell around the zeolite material core. Only a small number of chabazite crystals were completely encased in alumina. The average thickness of the alumina layer was determined to be approximately 31 nm, similar to Reference Example 4.

[0156] Example 2: Method for producing a selective catalytic reduction catalyst containing a copper-containing zeolite material The catalyst in Example 2 was prepared in the same manner as the catalyst in Example 1, except that the amount of alumina sol was increased so that the mass percentage of alumina was 30% based on the mass of the zeolite material after calcination. The final coating filling amount after calcination was approximately 2.1 g / in. 3 So, this is a CHA zeolite-based material at approximately 1.51 g / in. 3 , alumina 0.45g / in 3 zirconia has a density of approximately 0.076 g / in 3 It also contained 4.15% by mass of Cu (calculated as CuO based on the mass of the CHA zeolite material).

[0157] Characterization: TEM analysis of the obtained coated substrate (Figure 2.2) clearly shows that a substantial portion of the chabazite crystal is covered by an alumina coating. Some zeolite material crystals have little to no alumina coating (10-20% of the crystals). Many zeolite material crystals are completely encased in alumina, as evidenced by the alumina morphology observed on the surface and sides of the primary chabazite crystal. The average thickness of the alumina layer was determined to be approximately 43 nm, as in Reference Example 4. Therefore, it is clear that in the catalyst of Example 2, alumina forms a shell around the CHA zeolite material core. A summary table is shown below.

[0158] [Table 1] a ISIE, In-situ ion exchange of zeolite materials that have not been pre-exchanged. *: Based on the mass of zeolite-based material SAR: Molar ratio of silica to alumina

[0159] Example 3: Testing of catalysts from Comparative Example 1, Examples 1 and 2 - NOx conversion rate and back pressure 3.1 NOx conversion rate The catalyst was hydrothermally aged in an oven at 800°C for 16 hours prior to testing (in 20% O2, 10% H2O, and % N2). The NOx conversion rate of the catalyst was measured on a laboratory reactor using a 20 ppm ammonia slip. The reactor was equipped with a 3-Fourier transform infrared spectroscopy (FTIR) system for measuring reactant and product concentrations, and the temperature was controlled using preheaters and heaters positioned around the sample holder. The gas flow was controlled by several mass flow controllers that allowed for the mixing of different reaction gases. Measurements were performed at 200°C (500 ppm NO, NH3 / NOx=1.5, 10% O2, 5% CO2, 5% H2O, 80 ppm C3H6 (C1 reference)) at a space velocity of 40 k / h, and at 600°C (500 ppm NO, NH3 / NOx=2.0, 10% O2, 5% CO2, 5% H2O, 80 ppm C3H6 (C1 reference)) at space velocities of 40 k / h and 80 k / h. The results are shown in Figures 3 and 4.

[0160] 3.2 Back pressure 27m 3 The volumetric flow rate in / h and the low-temperature flow back pressure data recorded at 293K are shown in Figure 5 (fresh catalyst).

[0161] Figures 1 to 3 show that the low-temperature (200°C) performance of Example 1 decreased by approximately 2% (close to experimental error) and by 6% in Example 2 compared to Comparative Example 1, while the high-temperature (600°C) performance increased by 8% in Example 1 and 20% in Example 2 compared to Comparative Example 1. Therefore, Example 3 shows no significant loss of low-temperature NOx activity and a significant improvement in high-temperature performance. The catalyst of the present invention also provides a reduction in back pressure of approximately 2.5% (Example 1) and almost 15% (Example 2). In fact, the catalyst of Example 2 shows strong advantages in back pressure and high-temperature performance and does not significantly lose low-temperature NOx activity.

[0162] Therefore, although we do not wish to be bound by any particular theory, it is thought that using nanodispersed alumina instead of silica-alumina in selective catalytic reduction catalysts containing zeolite materials may improve the catalytic performance and stability of catalysts based on zeolite materials, and that increasing the amount of nanodispersed alumina may reduce back pressure and increase NOx performance at high temperatures after aging. Furthermore, although we do not wish to be bound by any particular theory, it is thought that forming an alumina coating enclosing CHA zeolite materials may reduce back pressure and (as this increases heat resistance) increase NOx performance at high temperatures after hydrothermal aging. It is thought that the alumina around the zeolite material may react with CuO and AlOx formed in the engine or during oven aging.

[0163] Comparative Example 2: A method for producing a selective catalytic reduction catalyst containing a copper-containing zeolite material, which does not conform to the present invention. The catalyst of Comparative Example 2 was manufactured in the same manner as the catalyst of Comparative Example 1, except that a different wall flow filter was used, namely an uncoated wall flow filter substrate with pores, silicon carbide (average porosity 60.5%, average pore size 20 micrometers and 350 CPSI and wall thickness 0.3 mm (13 mil), diameter: 2.28 inches (58 mm) × length: 5.9 inches (150.5 mm)), and the final wash coat filling amount was approximately 1.8 g / in. 3 This is because it is a CHA zeolite-based material at 1.512 g / in 3 Alumina + Silica 0.15g / in 3 Zirconia 0.0756 g / in 3 It also contained 4.15 mass% of Cu (calculated as CuO, based on the mass of the CHA zeolite material).

[0164] Comparative Example 3: A method for producing a selective catalytic reduction catalyst containing a copper-containing zeolite material, which does not conform to the present invention. The catalyst for Comparative Example 3 was prepared in the same manner as the catalyst for Comparative Example 2, except that the amount of silica-alumina was increased to 20% by mass, based on the mass of chabazite after calcination. The final wash coat filling amount was approximately 1.8 g / in. 3 This is 1.394 g / in 3 CHA zeolite-based material, 0.279 g / in 3 Alumina + Silica, 0.07 g / in 3 Based on the mass of the zirconia and CHA zeolite-based materials, it was calculated as containing 4.15% by mass of CuO.

[0165] Example 4: Method for producing a selective catalytic reduction catalyst containing a copper-containing zeolite material The catalyst of Example 4 was prepared in the same manner as the catalyst of Example 1, except that the amount of alumina sol was increased so that the mass% of alumina relative to the mass of the zeolite material after calcination was 20% by mass, the amount of CHA zeolite material was reduced to 77.4% by mass relative to the final coating filling amount, and a different wall flow filter was used. The different wall flow filter used was a porous, uncoated wall flow filter substrate, silicon carbide (average porosity 60.5%, average pore size 20 micrometers and 350 CPSI and wall thickness 0.3 mm (13 mil), diameter: 2.28 inches (58 mm) × length: 5.9 inches (150.5 mm)). The final coating filling amount after calcination was approximately 1.8 g / in. 3 So, this is approximately 1.394 g / in of CHA Zeolit ​​ingredients. 3 , alumina 0.279 g / in 3 zirconia has a density of approximately 0.07 g / in 3 Based on the mass of the CHA zeolite material, and calculated as CuO, it contained 4.15 mass% of Cu.

[0166] Example 5: Testing of catalysts from Comparative Examples 2, 3 and 4 - NOx conversion rate and back pressure 5.1 NOx conversion rate The catalyst was hydrothermally aged in an 800°C oven (20% O2, 10% H2O in %N2) for 16 hours prior to testing. The NOx conversion rate of the catalyst was measured at two different temperatures, 220°C and 660°C, in a 2L, 140kW, Euro 6 engine. At 220°C: conversion rate at 20 ppm slip, volumetric flow rate 33 m³ 3 / h, 110 ppm NOx, and 1.5 NSR (NH3 / NOx). At 660°C: Conversion at maximum ammonia slip, volumetric flow rate 63 m³ 3 NOx at 335 ppm / h and NSR (NH3 / NOX) of 2. The results are shown in Figure 6.

[0167] 5.2 Back pressure Volumetric flow rate 65 m 3 Low-temperature flow back pressure data recorded at / h and 293 K is shown in Figure 7 (fresh catalyst).

[0168] As can be seen from Figures 6 and 7, the back pressure and NOx conversion rate are similar to those of the catalysts in Comparative Examples 2 and 3, and the increase in silica-alumina content from 10% to 20% does not result in a significant change in performance. However, the catalyst of Example 4 shows a strong reduction in back pressure and improved high-temperature NOx performance. These results demonstrate that the catalyst preparation method and the type of alumina used in Example 4 provide advantages in both back pressure and catalytic performance. While we do not wish to be bound by any theory, it is thought that the use of a composition according to the present invention (i.e., using a zeolite material covered with a layer of alumina) to prepare a selective catalytic reduction catalyst as one of Example 4 makes it possible to reduce back pressure. Secondly, encapsulation of zeolite material crystals in an alumina layer (shell) appears to improve durability against thermal exposure, resulting in an improved high-temperature NOx conversion rate after aging compared to designs in which the zeolite particles are not encapsulated in an alumina layer (Comparative Examples 2 and 3). [Brief explanation of the drawing]

[0169] [Figure 1]Figure 1 shows a TEM micrograph of Cu-chabazite + alumina-silica used in Comparative Example 1. [Figure 2] Figure 2.1 shows a TEM micrograph of the Cu-chabazite + alumina used in Example 1, where the white arrows indicate the alumina layer on the outer surface of the zeolite material. [Figure 3] Figure 2.2 shows a TEM micrograph of Cu-chabazite + alumina in Example 2, where the white arrows indicate the alumina layer on the outer surface of the zeolite material. [Figure 4] Figure 3 shows the NOx conversion rate (SV: 40k / h) measured at 200°C for the catalysts of Comparative Example 1 and Examples 1 and 2. [Figure 5] Figure 4 shows the NOx conversion rates (SV: 40 and 80 k / h) measured at 600°C for the catalysts of Comparative Example 1 and Examples 1 and 2. [Figure 6] Figure 5 shows the cold flow back pressure recorded for the catalysts of Comparative Example 1 and Examples 1 and 2 at a volumetric flow rate of 27 m³ / h. [Figure 7] Figure 6 shows the NOx conversion rates for the catalysts of Comparative Examples 2 and 3 and Example 4, measured at 20 ppm NH3 and 220°C, and at maximum NH3 slip and 660°C. [Figure 8] Figure 7 shows the cold flow back pressure recorded for the catalysts of Comparative Examples 2 and 3 and Example 4 at a volumetric flow rate of 65 m³ / h. [Figure 9] Figure 8.1 shows the measurement of the average thickness of the layer containing the non-zeolite oxide material (10% by mass of alumina, based on the mass of the zeolite material). [Figure 10] Figure 8.2 shows the measurement of the average thickness of the layer containing the non-zeolite oxide material (30% by mass of alumina, based on the mass of the zeolite material).

[0170] References - US 2013 / 0101503 A1 - US 2017 / 7050182 A1 - CN 108993579 A - WO 2019 / 225909 A

Claims

1. (i) Non-zeolite oxide materials containing alumina (ii) An eight-membered ring-pore zeolite material containing one or more copper and iron, wherein the skeletal structure of the zeolite material contains a tetravalent element Y, a trivalent element X, and oxygen, where the molar ratio of Y:X is Y ２ :X ２ O ３ Calculated as follows, 8-membered ring-pore zeolite materials in the range of 2:1 to 40:1, A composition comprising, At least a portion of the surface of the crystal of the zeolite material according to (ii) is covered with a layer containing a non-zeolite oxide material according to (i), and Y comprises Si and optionally one or more of Sn, Ti, Zr and Ge, and X comprises Al and optionally one or more of B, In and Ga. The crystals of the 8-membered ring-pore zeolite material have an average crystal size in the range of 0.2 to 5 micrometers and A composition characterized in that the layer containing a non-zeolite-based oxidizing material according to (i) above has an average thickness in the range of 20 to 50 nm.

2. The composition according to claim 1, characterized in that 98 to 100% by mass of the non-zeolite oxidizing material according to (i) is composed of alumina.

3. The composition according to claim 1 or 2, characterized in that the layer containing a non-zeolite oxidizing material according to (i) has an average thickness in the range of 25 nm to 47 nm.

4. The composition according to any one of claims 1 to 3, characterized in that 99 to 100% by mass of the aforementioned layer is composed of a non-zeolite-based oxidizing material according to (i).

5. The composition according to any one of claims 1 to 4, characterized in that the eight-membered ring-pore zeolite material according to (ii) has a skeleton selected from the group consisting of CHA, AEI, RTH, LEV, DDR, KFI, ERI, AFX, LTA, two or more mixtures thereof, and two or more mixed types thereof.

6. The composition according to any one of claims 1 to 5, characterized in that 20 to 100% of the outer surface of the crystal of the zeolite material according to (ii) is covered with a layer containing a non-zeolite oxidizing material according to (i).

7. A slurry comprising the composition and dispersant described in any one of claims 1 to 6, wherein the dispersant is water, ethanol, acetic acid, nitric acid, lactic acid, and a mixture of two or more thereof.

8. A method for preparing the composition according to any one of claims 1 to 6, (a) A step of providing an eight-membered ring-pore zeolite material containing one or more copper and iron, wherein the skeletal structure of the zeolite material contains a tetravalent element Y, a trivalent element X and oxygen, and the molar ratio of Y:X is Y ２ :X ２ O ３ The calculation is performed so that the ratio is in the range of 2:1 to 40:1, and the zeolite material includes crystals having an average crystal size in the range of 0.2 to 5 micrometers, and the process (b) A step of providing a source of a non-zeolite oxidizing material containing alumina, wherein the source of the non-zeolite oxidizing material is a colloidal dispersion containing particles of the non-zeolite oxidizing material, and the particles of the non-zeolite oxidizing material have a Dv50 in the range of 30 to 110 nm, and (c) A step of mixing the zeolite material obtained in (a) with a source of a non-zeolite oxidizing material containing alumina obtained in (b) to form a mixture, (d) A step of calcining the mixture obtained in (c) in a gas atmosphere having a temperature in the range of 400 to 800°C. A method characterized by including the following.

9. The method according to claim 8, characterized in that the crystals of the eight-membered ring-pore zeolite material have an average crystal size in the range of 0.2 to 2 micrometers.

10. The method according to claim 8 or 9, characterized in that the eight-membered ring-pore zeolite material contains particles having a Dv50 in the range of 0.5 to 4 micrometers.

11. The method for producing a product according to any one of claims 8 to 10, characterized in that the colloidal dispersion containing particles of a non-zeolite oxidizing material provided in (b) is an alumina sol.

12. The method according to any one of claims 8 to 11, characterized in that the particles of the non-zeolite oxidizing material have a Dv50 in the range of 50 to 110 nm.

13. A selective catalytic reduction catalyst for treating exhaust gases from a combustion engine, (1) A substrate including a plurality of passages defined by an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and the inner wall of the substrate extending through the substrate, (2) A coating placed on the substrate (i), The coating comprises the composition described in any one of claims 1 to 6, and A selective catalytic reduction catalyst, wherein the substrate is a wall flow filter substrate, and the plurality of passages include an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end.

14. The catalyst according to claim 13, wherein the coating (2) further comprises an oxide binder, the oxide binder comprising zirconia, alumina, titania, silica, and one or more mixed oxides containing two or more of Zr, Al, Ti, and Si.

15. The catalyst according to claim 13 or 14, characterized in that the coating (2) contains the composition in an amount ranging from 80 to 100% by mass, based on the mass of the coating (2).

16. A method for preparing a selective catalytic reduction catalyst for treating exhaust gas of a combustion engine according to any one of claims 13 to 15, (A) A step of preparing a mixture comprising water and the composition according to any one of claims 1 to 6. (B) A step of placing the mixture obtained according to (A) onto a substrate to obtain a substrate that has been treated with the mixture, wherein the substrate includes an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by the inner wall of the substrate extending through the substrate. (C) A step of calcining a substrate that has been treated with a mixture according to (B) to obtain a substrate having a coating placed thereon, A method that includes this.

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