Exhaust gas treatment system including a multi-functional catalyst

Abstract

The present invention relates to an exhaust gas treatment system for treating an exhaust gas stream emitted from a diesel engine, the exhaust gas treatment system including: a first catalyst having an inlet end and an outlet end and including a coating disposed on a substrate, the coating comprising palladium supported on an oxide material comprising zirconium, and further comprising one or more of vanadium oxide and a zeolite material comprising one or more of copper and iron; and a second catalyst having an inlet end and an outlet end and including a coating disposed on a substrate, the coating comprising one or more of vanadium oxide and a zeolite material comprising one or more of copper and iron, and up to 0.0001% by weight of the coating of the second catalyst consisting of a platinum group metal.

Description

[Technical Field]

[0001] The present invention relates to an exhaust gas treatment system for treating an exhaust gas stream discharged from a diesel engine and a method for treating an exhaust gas stream discharged from a diesel engine using said system. [Background Art]

[0002] A close coupled selective catalytic reduction (SCR) catalyst based on a copper-containing zeolitic material having a CHA-type framework structure is known to become sulfated over time by sulfur trioxide emitted from the engine and internally generated by the SCR catalyst, even in the absence of an upstream oxidation catalyst. As used herein, the term "close coupled" catalyst is used to define the first catalyst that receives the exhaust gas stream from the engine. Consequently, the close coupled SCR catalyst results in being unable to provide sufficient DeNOx to meet the requirements for ultra-low nitrogen oxides (NOx) and nitrous oxide (N2O) emissions such as those required by CARB after sulfation.

[0003] WO2018 / 224651A1 discloses different exhaust gas treatment systems for meeting requirements for ultra-low nitrogen oxides (NOx) and nitrous oxide (N2O) emissions such as those required by CARB after sulfation regeneration. However, there still remains a need for further reducing nitrous oxide emissions while maintaining or increasing DeNOx. [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] Therefore, the object of the present invention is to provide an exhaust gas treatment system for treating exhaust gas flow from a diesel engine that prevents sulfation in order to maintain sufficient DeNOx, meet environmental requirements, and significantly reduce nitrous oxide emissions.

[0005] Surprisingly, the exhaust gas treatment system according to the present invention and for treating exhaust gas flows emitted from diesel engines, as described below, has been found to enable regeneration after sulfation, not only to maintain or increase sufficient DeNOx to meet environmental requirements, but also to significantly reduce nitrous oxide emissions. [Means for solving the problem]

[0006] Accordingly, the present invention relates to an exhaust gas treatment system for treating an exhaust gas flow discharged from a diesel engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas flow into the exhaust gas treatment system, and the exhaust gas treatment system is (i) A first catalyst having an inlet end and an outlet end, comprising a coating disposed on a substrate, wherein the coating comprises palladium supported on an oxide material containing zirconium, and further comprises vanadium oxide and one or more zeolite materials containing one or more of copper and iron; (ii) A second catalyst having an inlet end and an outlet end, comprising a coating disposed on a substrate, wherein the coating comprises vanadium oxide and one or more zeolite materials comprising one or more copper and iron, and the coating of the second catalyst comprises a maximum of 0.0001% by mass of platinum group metals; Includes, (i) The first catalyst is a first catalyst of the exhaust gas treatment system located downstream of the upstream end of the exhaust gas treatment system, and the inlet end of the first catalyst is located upstream of the outlet end of the first catalyst; In the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and the inlet end of the second catalyst is located upstream of the outlet end of the second catalyst.

[0007] First catalyst It is preferable that the outlet end of the first catalyst according to (i) is in fluid communication with the inlet end of the second catalyst according to (ii), and that no catalyst for processing the exhaust gas flow from the first catalyst is located in the exhaust gas treatment system between the outlet end of the first catalyst according to (i) and the inlet end of the second catalyst according to (ii).

[0008] (i) The oxide material included in the coating of the first catalyst according to (i) preferably consists of zirconium and oxygen, preferably zirconia, of which 70 to 98% by mass, more preferably 75 to 95% by mass, and more preferably 80 to 90% by mass.

[0009] Preferably, the oxide material included in the coating of the first catalyst according to (i) comprises one or more of lanthanum, hafnium, aluminum, silicon, and titanium, more preferably one or more of lanthanum and hafnium, and more preferably lanthanum and hafnium.

[0010] Preferably 95 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the oxide material included in the coating of the first catalyst according to (i) consist of oxygen, zirconium, lanthanum, and hafnium. More preferably 1.5 to 15% by mass, and more preferably 5 to 15% by mass of the oxide material consists of lanthanum calculated as La2O3, and more preferably 0.5 to 15% by mass, and more preferably 1 to 5% by mass of the oxide material consists of hafnium calculated as HfO2.

[0011] Preferably 5 to 40% by mass, more preferably 7 to 20% by mass, and more preferably 8 to 15% by mass of the coating of the first catalyst according to (i) consists of an oxide material.

[0012] For the coating of the first catalyst, palladium, calculated as element Pd, is used at a rate of 1-80 g / ft. 3 Within the range of 5-50 g / ft, more preferably 5-50 g / ft 3 Within the range of 7.5 to 40 g / ft, more preferably 7.5 to 40 g / ft 3 Within the range, more preferably 10-20 g / ft 3 It is preferable to include it in a supported amount within the specified range.

[0013] The coating of the first catalyst according to (i) comprises a zeolite material containing one or more copper and iron, and it is preferable that 60 to 95% by mass, more preferably 80 to 93% by mass, and more preferably 82 to 92% by mass of the coating of the first catalyst according to (i) consists of the zeolite material containing one or more copper and iron.

[0014] With respect to the zeolite material included in the coating of the first catalyst, it is preferable that the zeolite material has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, preferably a framework structure of type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably a framework structure of type CHA or AEI, and more preferably a framework structure of type CHA.

[0015] Preferably, the zeolite material included in the coating of the first catalyst, more preferably the zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, more preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0016] The zeolite material included in the coating of the first catalyst contains copper, and the amount of copper in the zeolite material, calculated as CuO, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 2.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, and more preferably in the range of 2.5 to 3.5 mass%, based on the mass of the zeolite material. The amount of iron in the zeolite material, calculated as Fe2O3, is more preferably in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0017] The zeolite material preferably has a type CHA framework structure and more preferably contains copper in the amount disclosed above.

[0018] Preferably 95-100% by mass, more preferably 98-100% by mass, and more preferably 99-100% by mass of the framework structure of the zeolite material coating of the first catalyst consists of one or more of Si, Al, O, and optionally H and P, where, in the framework structure, the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, is more preferably in the range of 2:1-50:1, more preferably in the range of 4:1-45:1, more preferably in the range of 10:1-40:1, and more preferably in the range of 20:1-35:1.

[0019] The zeolite material included in the coating of the first catalyst may contain iron, and the amount of iron in the zeolite material, calculated as Fe2O3, may more preferably be in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, and more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material. More preferably 95 to 100 mass%, more preferably 98 to 100 mass%, and more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of Si, Al, O, and optionally one or more of H and P, and in the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is more preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 20:1 to 35:1.

[0020] In the context of the present invention, the coating of the first catalyst further comprises a metal oxide, the metal oxide more preferably comprising one or more of zirconia, alumina, titania, silica, and mixed oxides comprising two or more of Zr, Al, Ti, and Si, more preferably comprising one or more of alumina and zirconia, more preferably comprising zirconia, and more preferably being zirconia.

[0021] The coating of the first catalyst preferably contains the metal oxide, more preferably zirconia, in an amount ranging from 1 to 15% by mass, more preferably from 2 to 10% by mass, and more preferably from 3 to 8% by mass, based on the mass of the zeolite material containing one or more copper and iron.

[0022] Preferably, as an alternative, the coating of the first catalyst according to (i) contains vanadium oxide but does not contain a zeolite material containing one or more of copper and iron. The vanadium oxide is one or more of vanadium(V) oxide and vanadium(IV) oxide, and it is more preferable that the vanadium oxide optionally contains one or more of tungsten, iron and antimony. The vanadium oxide is preferably supported on an oxide material containing one or more of titanium, silicon and zirconium, more preferably an oxide material containing one or more of titanium and silicon, more preferably an oxide material containing one or more of titania and silica, and more preferably titania optionally contains one or more of tungsten and silicon.

[0023] In the context of the present invention, it is preferable that 95 to 100% by mass, more preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the coating of the first catalyst consist of palladium supported on an oxide material, a copper-containing zeolite material having a framework structure of type CHA, and more preferably the metal oxides defined above.

[0024] The substrate of the first catalyst preferably contains a ceramic or metallic substance.

[0025] Preferably, the substrate of the first catalyst comprises a ceramic material, more preferably consisting of a ceramic material, which preferably comprises one or more of alumina, silica, silicate, aluminosilicate, preferably cordierite or mullite, aluminotitanate, silicon carbide, zirconia, magnesia, preferably spinel, and titania, more preferably one or more of silicon carbide and cordierite, more preferably cordierite, and more preferably consisting of these. The substrate of the first catalyst is preferably cordierite. Alternatively, the substrate of the first catalyst preferably comprises a metallic material, more preferably consisting of a metallic material, where the metallic material preferably comprises oxygen and one or more of iron, chromium, and aluminum, and more preferably consisting of these.

[0026] The substrate of the first catalyst is preferably a monolith, more preferably a honeycomb monolith, and more preferably a flow-through type honeycomb monolith.

[0027] Preferably, the substrate of the first catalyst has a substrate length, and the coating of the first catalyst is placed on the substrate over 95-100%, more preferably 99-100%, of the substrate length.

[0028] The first catalyst is 1-6 g / in 3 Within the range of 1.5 to 5 g / in, more preferably 1.5 to 5 g / in 3 Within the range of 2-4 g / in, more preferably 2-4 g / in 3 It is preferable to include a coating in a supported amount within the specified range.

[0029] The coating on the first catalyst is preferably the only coating on the first catalyst.

[0030] Preferably, up to 0.001% by mass, more preferably 0 to 0.0001% by mass, and more preferably 0 to 0.00001% by mass of the coating of the first catalyst consist of platinum, iridium, osmium, and rhodium. In other words, the coating of the first catalyst is substantially free of platinum, iridium, osmium, and rhodium, and more preferably free of platinum, iridium, osmium, and rhodium.

[0031] Preferably, the coating of the first catalyst consists of ceria in a maximum of 0.1% by mass, more preferably 0 to 0.01% by mass, more preferably 0 to 0.001% by mass, and more preferably 0 to 0.0001% by mass. In other words, the coating of the first catalyst is preferably substantially ceria-free, and more preferably ceria-free.

[0032] Second catalyst The second catalyst according to (ii) is preferably a selective catalytic reduction catalyst. In fact, it is more preferably a selective catalytic reduction catalyst for the selective catalytic reduction of NOx.

[0033] With respect to the coating of the second catalyst according to (ii), it is preferable that it comprises a zeolite material containing one or more copper and iron, and that 80 to 100% by mass, more preferably 90 to 99% by mass, and more preferably 95 to 98% by mass of the coating of the second catalyst according to (ii) consists of the zeolite material containing one or more copper and iron.

[0034] Preferably, the zeolite material included in the coating of the second catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof; more preferably a framework structure of type AEI, CHA, BEA, or a mixture of two or more thereof; more preferably a framework structure of type CHA or AEI; and more preferably a framework structure of type CHA.

[0035] Preferably, the zeolite material included in the coating of the second catalyst, preferably a zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, more preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0036] The zeolite material included in the coating of the second catalyst contains copper, and the amount of copper in the zeolite material, calculated as CuO, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 2.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, and more preferably in the range of 2.5 to 3.5 mass%, based on the mass of the zeolite material.

[0037] The amount of iron contained in the zeolite material, when calculated as Fe2O3, is more preferably in the range of 0 to 0.01% by mass, more preferably in the range of 0 to 0.001% by mass, and more preferably in the range of 0 to 0.0001% by mass, based on the mass of the zeolite material.

[0038] The zeolite material included in the coating of the second catalyst has a type CHA framework structure and more preferably contains copper in the amount disclosed above.

[0039] Preferably 95-100% by mass, more preferably 98-100% by mass, and more preferably 99-100% by mass of the framework structure of the zeolite material included in the coating of the second catalyst consist of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is more preferably in the range of 2:1-50:1, more preferably in the range of 4:1-40:1, more preferably in the range of 10:1-40:1, and more preferably in the range of 20:1-35:1.

[0040] The zeolite material included in the coating of the second catalyst contains iron, and the amount of iron in the zeolite material, calculated as Fe2O3, may more preferably be in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, and more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material. Preferably 95 to 100 mass%, more preferably 98 to 100 mass%, and more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of Si, Al, O, and optionally one or more of H and P, where, in the framework structure, the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, is more preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 40:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 20:1 to 35:1.

[0041] In the context of the present invention, the coating of the second catalyst further comprises a metal oxide, which more preferably comprises one or more of zirconia, alumina, titania, silica, and mixed oxides comprising two or more of Zr, Al, Ti, and Si, more preferably comprises one or more of alumina and zirconia, more preferably comprises zirconia, and more preferably is zirconia.

[0042] Preferably, the coating of the second catalyst contains a metal oxide, more preferably zirconia, in an amount ranging from 0.5 to 15% by mass, more preferably 1 to 8% by mass, and more preferably 1 to 5% by mass, based on the mass of a zeolite material containing one or more copper and iron.

[0043] Preferably 95-100% by mass, more preferably 98-100% by mass, more preferably 99-100% by mass, and more preferably 99.5-100% by mass of the coating of the second catalyst comprises a zeolite material containing one or more copper and iron, more preferably a zeolite material having a framework structure of type CHA, and preferably a zeolite material having the metal oxides defined above.

[0044] The coating of the second catalyst contains vanadium oxide, more preferably one or more of vanadium(V) oxide and vanadium(IV) oxide, and preferably optionally one or more of tungsten, iron and antimony. Preferably the vanadium oxide is supported on an oxide material containing one or more of titanium, silicon and zirconium, more preferably an oxide material containing one or more of titanium and silicon, more preferably an oxide material containing one or more of titania and silica, and more preferably titania, which optionally contains one or more of tungsten and silicon.

[0045] Preferably 95-100% by mass, more preferably 98-100% by mass, more preferably 99-100% by mass, and more preferably 99.5-100% by mass of the coating of the second catalyst consists of vanadium oxide supported on the oxide material defined above.

[0046] Preferably 0 to 0.0001% by mass, more preferably 0 to 0.00001% by mass, and more preferably 0 to 0.000001% by mass of the second catalyst consists of platinum group metals. In other words, the coating of the second catalyst is preferably substantially free of platinum group metals, and more preferably free of platinum group metals.

[0047] The base material of the second catalyst preferably contains a ceramic or metallic substance.

[0048] The substrate of the second catalyst comprises a ceramic material, more preferably consists of a ceramic material. More preferably, the ceramic material comprises one or more of alumina, silica, silicate and aluminosilicate, preferably cordierite or mullite, aluminotitanate, silicon carbide, zirconia, magnesia, preferably spinel, and titania, more preferably one or more of silicon carbide and cordierite, more preferably cordierite, and more preferably consists of the above materials. It is more preferred that the substrate of the second catalyst is cordierite. Alternatively, the substrate of the second catalyst preferably comprises a metallic material, more preferably consists of a metallic material, wherein the metallic material more preferably comprises oxygen and one or more of iron, chromium and aluminum, and more preferably consists of the above materials.

[0049] Preferably, the substrate of the second catalyst is a monolith, more preferably a honeycomb monolith, and still more preferably a flow-through honeycomb monolith.

[0050] Preferably, the substrate of the second catalyst has a substrate length, and the coating of the second catalyst is disposed on the substrate over 95 to 100%, more preferably 99 to 100%, of the substrate length.

[0051] Regarding the second catalyst, the second catalyst has a coating loading in the range of 1 to 6 g / in 3 , more preferably in the range of 1.25 to 4 g / in 3 , more preferably in the range of 1.5 to 3 g / in 3 , and it is preferred that the coating is comprised at the loading within the above range.

[0052] Regarding the coating of the second catalyst, it is preferred that said coating is the only coating of the second catalyst.

[0053] The coating of the first catalyst comprises, more preferably, palladium supported on a zirconium-containing oxide material, a copper-containing zeolite material having a type CHA framework structure, and the metal oxide defined above; and the coating of the second catalyst comprises, more preferably, a copper-containing zeolite material having a type CHA framework structure, and the metal oxide defined above, where it is preferable that up to 0.0001% by mass of the coating of the second catalyst consists of platinum group metals.

[0054] The substrate of the first catalyst preferably contains cordierite, and more preferably consists of cordierite, and the substrate of the second catalyst preferably contains cordierite, and more preferably consists of cordierite.

[0055] Preferably, the substrate on which the coating of the first catalyst is placed is the first substrate, and the substrate on which the coating of the second catalyst is placed is the second substrate, where the first and second substrates are different from each other. Alternatively, the substrate on which the coating of the first catalyst is placed and the substrate on which the coating of the second catalyst is placed together form a single substrate, the single substrate having an inlet end and an outlet end, the inlet end being located upstream of the outlet end, the coating of the first catalyst being arranged from the inlet end to the outlet end of the single substrate, the coating of the second catalyst being arranged from the outlet end to the inlet end of the single substrate, the coating of the first catalyst covering 25-75% of the substrate length, and the coating of the second catalyst covering 25-75% of the substrate length.

[0056] It is more preferable that the coating of the first catalyst covers 25-70%, more preferably 35-65%, and more preferably 45-55% of the substrate length, and the coating of the second catalyst covers 25-70%, more preferably 35-65%, and more preferably 45-55% of the substrate length. Alternatively, it is more preferable that the coating of the first catalyst covers 50-75%, more preferably 69-75% of the substrate length, and the coating of the second catalyst covers 25-50%, and more preferably 25-31% of the substrate length.

[0057] It is preferable that the coating of the first catalyst and the coating of the second catalyst overlap. Alternatively, it is preferable that there is a gap between the coating of the first catalyst and the coating of the second catalyst.

[0058] In the context of the present invention, the substrate of the first catalyst preferably has a substrate length in the range of 1 to 10 inches, more preferably in the range of 2 to 8 inches, more preferably in the range of 14 to 7.5 inches, and more preferably in the range of 5 to 7 inches.

[0059] Preferably, the substrate of the second catalyst has a substrate length in the range of 1 inch to 10 inches, more preferably in the range of 1.5 inches to 7 inches, more preferably in the range of 2 inches to 5 inches, and more preferably in the range of 2 inches to 4 inches.

[0060] Preferably, the length of the first substrate is longer than the length of the second substrate, and the ratio of the length of the first substrate to the length of the second substrate is more preferably in the range of 1.1:1 to 4:1, more preferably in the range of 1.5:1 to 3.5:1, and more preferably in the range of 1.9:1 to 2.1:1.

[0061] Preferably, the substrate of the first catalyst has a substrate width in the range of 4 to 17 inches, more preferably in the range of 7 to 15 inches, more preferably in the range of 8 to 14 inches, more preferably in the range of 9 to 13 inches, and more preferably in the range of 9 to 11 inches.

[0062] Preferably, the substrate of the second catalyst has a substrate width in the range of 4 to 20 inches, more preferably in the range of 7 to 18 inches, more preferably in the range of 9 to 16 inches, more preferably in the range of 10 to 15 inches, and more preferably in the range of 11 to 14 inches.

[0063] The exhaust gas treatment system of the present invention further comprises a first injector for injecting a fluid into the exhaust gas flow discharged from a diesel engine, wherein the first injector is preferably located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system. Preferably, the fluid is an aqueous urea solution.

[0064] The exhaust gas treatment system of the present invention further comprises a second injector for injecting a fluid into the exhaust gas flow discharged from a diesel engine, wherein the injector is located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system, and the fluid more preferably contains hydrocarbons.

[0065] Third catalyst The exhaust gas treatment system of the present invention (iii) A third catalyst comprising a first coating having an inlet end and an outlet end and disposed on a substrate, and a second coating disposed on the first coating, Here, the first coating comprises a platinum group metal supported on an oxide material, and optionally further comprises one or more zeolite materials containing vanadium oxide and one or more copper and iron. The second coating comprises vanadium oxide and one or more zeolite materials containing one or more of copper and iron. In this exhaust gas treatment system, it is preferable that the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and the inlet end of the third catalyst is located upstream of the outlet end of the third catalyst.

[0066] The outlet end of the second catalyst according to (ii) is in fluid communication with the inlet end of the third catalyst according to (iii), and it is preferable that no catalyst for treating the exhaust gas flow discharged from the second catalyst is placed in the exhaust gas treatment system between the outlet end of the second catalyst according to (ii) and the inlet end of the third catalyst according to (iii).

[0067] With respect to the third catalyst according to (iii), it is preferable that the catalyst is an ammonia oxidation catalyst.

[0068] Preferably, the platinum group metal included in the first coating of the third catalyst according to (iii) is one or more of platinum, palladium, rhodium, iridium, and osmium, more preferably one or more of platinum, palladium, and rhodium, more preferably one or more of platinum and palladium, and more preferably platinum.

[0069] With respect to the first coating of the third catalyst, the first coating is calculated to be a platinum group metal, more preferably platinum, as the elemental metal, more preferably as element Pt, at a density of 0.5 to 30 g / ft 3 Within the range of 1 to 15 g / ft, more preferably 1 to 15 g / ft 3 Within the range of 1.5 to 5 g / ft, more preferably 1.5 to 5 g / ft 3 It is preferable to include it in a supported amount within the specified range.

[0070] Preferably, the oxide material included in the first coating of the third catalyst according to (iii) comprises one or more of titania, zirconia, and alumina, more preferably one or more of titania and zirconia, and more preferably titania. When calculated as TiO2, it is more preferable that 85 to 98.5% by mass, more preferably 85 to 95% by mass of the oxide material consists of titania.

[0071] Preferably, the oxide material included in the coating of the third catalyst according to (iii) comprises one or more of silicon, aluminum, titanium, and zirconium, more preferably one or more of silicon and aluminum, and more preferably silicon.

[0072] Preferably, 95 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass, of the oxide material included in the coating of the third catalyst according to (iii) consists of oxygen, titanium, and silicon. More preferably, calculated as SiO2, 1.5 to 15% by mass, and more preferably 5 to 15% by mass, of the oxide material consists of silicon.

[0073] It is preferable that 70-100% by mass, more preferably 80-100% by mass, more preferably 90-100% by mass, more preferably 95-100% by mass, and more preferably 99-100% by mass of the first coating of the third catalyst according to (iii) consist of an oxide material.

[0074] As an alternative, it is preferable that 5 to 40% by mass, more preferably 7 to 20% by mass, and more preferably 8 to 15% by mass of the first coating of the third catalyst according to (iii) consist of an oxide material.

[0075] Preferably, the first coating of the third catalyst according to (iii) comprises a zeolite material containing one or more copper and iron, and 60 to 95% by mass, more preferably 80 to 93% by mass, and more preferably 82 to 92% by mass of the first coating of the third catalyst according to (iii) consists of the zeolite material containing one or more copper and iron.

[0076] With respect to the zeolite material included in the first coating of the third catalyst, it is preferable that the zeolite material has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, more preferably a framework structure of type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably a framework structure of type CHA or AEI, and more preferably a framework structure of type CHA.

[0077] Preferably, the zeolite material included in the first coating of the third catalyst, more preferably the zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, more preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0078] Preferably, the zeolite material included in the first coating of the third catalyst contains copper, and the amount of copper contained in the zeolite material, calculated as CuO, is more preferably in the range of 1 to 12 mass%, more preferably in the range of 1.5 to 10 mass%, more preferably in the range of 3 to 8 mass%, and more preferably in the range of 4.5 to 6.5 mass%, based on the mass of the zeolite material. Preferably, the amount of iron contained in the zeolite material, calculated as Fe2O3, is in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0079] The zeolite material included in the first coating of the third catalyst has a type CHA framework structure and contains copper, more preferably in the amount of copper disclosed above.

[0080] Preferably 95 to 100% by mass, more preferably 98 to 100% by mass, and more preferably 99 to 100% by mass of the framework structure of the zeolite material contained in the first coating of the third catalyst consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, when calculated as SiO2:Al2O3, is more preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 15:1 to 25:1.

[0081] The zeolite material included in the first coating of the third catalyst contains iron, and the amount of iron in the zeolite material, calculated as Fe2O3, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, and more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material. More preferably 95 to 100 mass%, more preferably 98 to 100 mass%, and more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 15:1 to 25:1.

[0082] With respect to the first coating of the third catalyst, the coating further comprises a metal oxide, more preferably comprising one or more of zirconia, alumina, titania, silica, and mixed oxides comprising two or more of Zr, Al, Ti, and Si, more preferably comprising one or more of alumina and zirconia, more preferably comprising zirconia, and more preferably being zirconia.

[0083] Preferably, the coating of the third catalyst contains a metal oxide, more preferably zirconia, in an amount ranging from 1 to 15% by mass, more preferably 2 to 10% by mass, and more preferably 3 to 8% by mass, based on the mass of the zeolite material containing one or more copper and iron.

[0084] Preferably 95-100% by mass, more preferably 98-100% by mass, more preferably 99-100% by mass, and more preferably 99.5-100% by mass of the coating of the third catalyst consist of a platinum group metal, more preferably platinum, and a copper-containing zeolite material having a framework structure of type CHA, supported on an oxide material, and preferably the metal oxide as defined above.

[0085] The first coating of the third catalyst according to (iii) contains vanadium oxide but does not contain a zeolite material containing one or more of copper and iron, the vanadium oxide is more preferably one or more of vanadium(V) oxide and vanadium(IV) oxide, and the vanadium oxide preferably optionally contains one or more of tungsten, iron and antimony.

[0086] Preferably, the vanadium oxide is supported on an oxide material containing one or more of titanium, silicon, and zirconium; more preferably, an oxide material containing one or more of titanium and silicon; more preferably, an oxide material containing one or more of titania and silica; and more preferably, titania, which optionally contains one or more of tungsten and silicon.

[0087] Preferably 95 to 100% by mass, more preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the first coating of the third catalyst consists of platinum group metals, more preferably platinum supported on an oxide material, and vanadium oxide supported on the oxide material as defined above.

[0088] With respect to the second coating of the third catalyst according to (iii), it is preferable that the coating comprises a zeolite material containing one or more copper and iron, and that 80 to 100% by mass, more preferably 90 to 99% by mass, and more preferably 95 to 98% by mass of the second coating of the third catalyst according to (iii) consists of the zeolite material containing one or more copper and iron.

[0089] The zeolite material included in the second coating of the third catalyst preferably has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, more preferably type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably type CHA or AEI, and more preferably type CHA framework structure.

[0090] Preferably, the zeolite material included in the second coating of the third catalyst, preferably a zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, more preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0091] The zeolite material included in the second coating of the third catalyst contains copper, and the amount of copper contained in the zeolite material, when calculated as CuO, is preferably in the range of 1 to 12 mass%, more preferably in the range of 1.5 to 10 mass%, more preferably in the range of 3 to 8 mass%, and more preferably in the range of 4.5 to 6.5 mass%, based on the mass of the zeolite material. More preferably, the amount of iron contained in the zeolite material, when calculated as Fe2O3, is in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0092] The zeolite material included in the second coating of the third catalyst has a type CHA framework structure and contains copper, more preferably in the amount of copper disclosed above.

[0093] Preferably 95 to 100% by mass, more preferably 98 to 100% by mass, and more preferably 99 to 100% by mass of the framework structure of the zeolite material contained in the second coating of the third catalyst consists of one or more of Si, Al, O, and optionally H and P, where, in the framework structure, the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, is more preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 15:1 to 25:1.

[0094] The zeolite material included in the second coating of the third catalyst contains iron, and the amount of iron in the zeolite material, calculated as Fe2O3, is more preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, and more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material. Furthermore, it is preferable that 95 to 100 mass%, more preferably 98 to 100 mass%, and more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of one or more of Si, Al, O, and optionally H and P. In the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is more preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 15:1 to 25:1.

[0095] With respect to the second coating of the third catalyst, the coating further comprises a metal oxide, more preferably comprising one or more of zirconia, alumina, titania, silica, and a mixed oxide comprising two or more of Zr, Al, Ti, and Si, more preferably comprising one or more of alumina and zirconia, more preferably comprising zirconia, and more preferably being zirconia.

[0096] Preferably, the second coating of the third catalyst contains a metal oxide, more preferably zirconia, in an amount ranging from 1 to 15% by mass, more preferably 2 to 10% by mass, and more preferably 3 to 8% by mass, based on the mass of a zeolite material containing one or more copper and iron.

[0097] Preferably 95 to 100% by mass, more preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the second coating of the third catalyst consists of a zeolite material containing one or more copper and iron, more preferably a zeolite material having a framework structure of type CHA, and more preferably a zeolite material that is a metal oxide as defined above.

[0098] The second coating of the third catalyst contains a vanadium oxide, more preferably one or more of vanadium(V) oxide and vanadium(IV) oxide, and preferably optionally contains one or more of tungsten, iron and antimony.

[0099] Preferably, the vanadium oxide is supported on an oxide material containing one or more of titanium, silicon, and zirconium; more preferably, an oxide material containing one or more of titanium and silicon; more preferably, an oxide material containing one or more of titania and silica; and more preferably, titania, wherein the titania optionally contains one or more of tungsten and silicon.

[0100] Preferably 95-100% by mass, more preferably 98-100% by mass, more preferably 99-100% by mass, and more preferably 99.5-100% by mass of the second coating of the third catalyst consists of vanadium oxide supported on the oxide material defined above.

[0101] Preferably 0 to 0.0001% by mass, more preferably 0 to 0.00001% by mass, and more preferably 0 to 0.000001% by mass of the second coating of the third catalyst consists of platinum group metals. In other words, the coating of the third catalyst is preferably substantially free of platinum group metals, and more preferably free of platinum group metals.

[0102] The substrate for the third catalyst preferably contains a ceramic or metallic substance.

[0103] Preferably, the substrate of the third catalyst includes, and more preferably consists of, one or more of alumina, silica, silicate, aluminosilicate, preferably cordierite or mullite, aluminotitanate, silicon carbide, zirconia, magnesia, preferably spinel, and titania, more preferably silicon carbide and one or more of cordierite, and more preferably cordierite. The substrate of the third catalyst contains cordierite, or more preferably consists of cordierite. Alternatively, the substrate of the third catalyst includes, and more preferably consists of, a metallic substance, where the metallic substance preferably includes, and more preferably consists of, oxygen and one or more of iron, chromium, and aluminum.

[0104] Preferably, the substrate of the third catalyst is a monolith, more preferably a honeycomb monolith, and more preferably a flow-through type honeycomb monolith.

[0105] Preferably, the substrate of the third catalyst has a substrate length, the first coating of the third catalyst is placed on the substrate over 95-100%, more preferably 99-100%, of the substrate length, and the second coating of the third catalyst is placed on the substrate over 95-100%, more preferably 99-100%, of the substrate length.

[0106] The third catalyst is 1-6 g / in 3 Within the range of 1.25 to 4 g / in, more preferably 1.25 to 4 g / in 3 Within the range of 1.5 to 2.5 g / in, more preferably 1.5 to 2.5 g / in 3 It is preferable that the first coating is included in a supported amount within the range of [specified range].

[0107] Preferably, the third catalyst is 0.25 to 4 g / in 3 Within the range of 0.5 to 2 g / in, more preferably 0.5 to 2 g / in 3 Within this range, more preferably 0.75 to 1.5 g / in 3 It is preferable to include a second coating in a supported amount within the specified range.

[0108] Preferably, the third catalyst is 1.25 to 10 g / in3 Within the range of 1.75 to 6 g / in, more preferably 1.75 to 6 g / in 3 Within the range, more preferably 2.25 to 4 g / in 3 It is preferable that the catalyst loading amount is within the range.

[0109] The third catalyst according to (iii) preferably consists of a first coating and a second coating.

[0110] Therefore, the present invention preferably relates to the exhaust gas treatment system defined above, Here, the coating of the first catalyst comprises, and more preferably consists of, palladium supported on a zirconium-containing oxide material and a copper-containing zeolite material having a type CHA framework structure, more preferably the metal oxide defined above. The coating of the second catalyst comprises a copper-containing zeolite material having a type CHA framework structure, more preferably a metal oxide as defined above, and more preferably consisting of the same, wherein up to 0.0001% by mass of the coating of the second catalyst consists of platinum group metals. The first coating of the third catalyst more preferably comprises, and more preferably consists of, platinum supported on an oxide material containing titania, a copper-containing zeolite material having a type CHA framework structure, and the metal oxide defined above. The second coating of the third catalyst more preferably comprises, and more preferably consists of, a copper-containing zeolite material having a type CHA framework structure, and more preferably consists of the metal oxide defined above.

[0111] In the context of the present invention, it is preferable that the substrate of the first catalyst contains cordierite, more preferably cordierite; the substrate of the second catalyst contains cordierite, more preferably cordierite; and the substrate of the third catalyst contains cordierite, more preferably cordierite.

[0112] Preferably, the substrate of the third catalyst has a substrate length in the range of 1 to 10 inches, more preferably in the range of 1.5 to 7 inches, more preferably in the range of 2 to 5 inches, and more preferably in the range of 2 to 4 inches.

[0113] The substrate of the first catalyst has a substrate length, and it is preferable that the length of the first substrate is longer than the length of the third substrate, and the ratio of the length of the first substrate to the length of the third substrate is more preferably in the range of 1.1:1 to 4:1, more preferably in the range of 1.5:1 to 3.5:1, and more preferably in the range of 1.9:1 to 2.1:1.

[0114] Preferably, the substrate of the third catalyst has a substrate width in the range of 4 inches to 20 inches, more preferably in the range of 7 inches to 18 inches, more preferably in the range of 9 inches to 16 inches, more preferably in the range of 10 inches to 15 inches, and more preferably in the range of 11 inches to 14 inches.

[0115] The exhaust gas treatment system of the present invention further includes one or more of a particulate filter, a diesel oxidation catalyst, and an ammonia oxidation catalyst, wherein one or more of the particulate filter, diesel oxidation catalyst, and ammonia oxidation catalyst are preferably located downstream of the second catalyst according to (ii). Alternatively, if the exhaust gas treatment system includes a third catalyst according to (iii), then one or more of the particulate filter, diesel oxidation catalyst, and ammonia oxidation catalyst are preferably located downstream of the third catalyst according to (iii).

[0116] The present invention further relates to a method for treating exhaust gas flow discharged from a diesel engine, wherein the method is: To provide exhaust gas flow from a diesel engine, The aforementioned gas is passed through the exhaust gas treatment system according to the present invention, Includes.

[0117] The present invention is described by the following series of embodiments and combinations of embodiments indicated by dependencies and backreferences. In particular, in each case where the scope of an embodiment is stated in the context of terms such as, for example, “one system of Embodiments 1 to 4,” it is intended that all embodiments within this scope are expressly disclosed to those skilled in the art, i.e., the usage of this term should be understood to those skilled in the art as synonymous with “one system of Embodiments 1, 2, 3, and 4.” Furthermore, it should be explicitly noted that the following series of embodiments represent a well-structured portion of the description directed to general and preferred embodiments of the present invention, rather than a series of claims that determine the scope of protection.

[0118] 1. An exhaust gas treatment system for treating the exhaust gas flow discharged from a diesel engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas flow into the exhaust gas treatment system, and the exhaust gas treatment system is (i) A first catalyst having an inlet end and an outlet end, comprising a coating disposed on a substrate, wherein the coating comprises palladium supported on an oxide material containing zirconium, and further comprises vanadium oxide and one or more zeolite materials containing one or more of copper and iron; (ii) A second catalyst having an inlet end and an outlet end, comprising a coating disposed on a substrate, wherein the coating comprises vanadium oxide and one or more zeolite materials comprising one or more copper and iron, and a maximum of 0.0001% by mass of the coating of the second catalyst comprises platinum group metals; Here, the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system, and the inlet end of the first catalyst is located upstream of the outlet end of the first catalyst; The exhaust gas treatment system wherein the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and the inlet end of the second catalyst is located upstream of the outlet end of the second catalyst.

[0119] 2. The exhaust gas treatment system according to Embodiment 1, wherein the outlet end of the first catalyst according to (i) is in fluid communication with the inlet end of the second catalyst according to (ii), and no catalyst for treating the exhaust gas flow discharged from the first catalyst is located in the exhaust gas treatment system between the outlet end of the first catalyst according to (i) and the inlet end of the second catalyst according to (ii).

[0120] 3. The exhaust gas treatment system according to Embodiment 1 or 2, wherein 70 to 98% by mass, preferably 75 to 95% by mass, and more preferably 80 to 90% by mass of the oxide material contained in the coating of the first catalyst according to (i) consists of zirconium and oxygen, preferably zirconia.

[0121] The exhaust gas treatment system according to any one of Embodiments 1 to 3, wherein the oxide material included in the coating of the first catalyst according to 4.(i) comprises one or more of lanthanum, hafnium, aluminum, silicon, and titanium, preferably one or more of lanthanum and hafnium, and more preferably lanthanum and hafnium.

[0122] 5.95 to 100% by mass, preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass, of the oxide material included in the coating of the first catalyst according to (i) consists of oxygen, zirconium, lanthanum, and hafnium; An exhaust gas treatment system according to any one of Embodiments 1 to 3, wherein preferably 1.5 to 15% by mass, more preferably 5 to 15% by mass, of the oxide material consists of lanthanum calculated as La2O3, and preferably 0.5 to 15% by mass, more preferably 1 to 5% by mass, of the oxide material consists of hafnium calculated as HfO2.

[0123] 6. An exhaust gas treatment system according to any one of Embodiments 1 to 5, wherein 5 to 40% by mass, preferably 7 to 20% by mass, and more preferably 8 to 15% by mass of the coating of the first catalyst according to (i) is made of an oxide material.

[0124] 7. The coating of the first catalyst contains palladium, calculated as element Pd, at a rate of 1 to 80 g / ft. 3 Within the range of 5 to 50 g / ft, preferably 5 to 50 g / ft 3 Within the range of 7.5 to 40 g / ft, more preferably 7.5 to 40 g / ft 3 Within the range, more preferably 10-20 g / ft 3 An exhaust gas treatment system according to any one of embodiments 1 to 6, including a load within the range of the following:

[0125] 8. The exhaust gas treatment system according to any one of Embodiments 1 to 7, wherein the coating of the first catalyst according to (i) comprises a zeolite material containing one or more copper and iron, and 60 to 95% by mass, preferably 80 to 93% by mass, more preferably 82 to 92% by mass of the coating of the first catalyst according to (i) consists of the zeolite material containing one or more copper and iron.

[0126] 9. An exhaust gas treatment system according to any one of Embodiments 1 to 8, wherein the zeolite material included in the coating of the first catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, preferably a framework structure of type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably a framework structure of type CHA or AEI, and more preferably a framework structure of type CHA.

[0127] 10. An exhaust gas treatment system according to any one of Embodiments 1 to 9, wherein the zeolite material included in the coating of the first catalyst, preferably a zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0128] 11. The zeolite material contained in the coating of the first catalyst contains copper, and the amount of copper contained in the zeolite material, when calculated as CuO, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 2.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, and more preferably in the range of 2.5 to 3.5 mass%, based on the mass of the zeolite material. The exhaust gas treatment system according to any one of Embodiments 1 to 10, wherein the amount of iron contained in the zeolite material, when calculated as Fe2O3, is more preferably in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0129] 12. An exhaust gas treatment system according to any one of Embodiments 1 to 11, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, of the framework structure of the zeolite material coating of the first catalyst consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 20:1 to 35:1.

[0130] 13. An exhaust gas treatment system according to any one of Embodiments 1 to 10, wherein the zeolite material included in the coating of the first catalyst contains iron, and the amount of iron in the zeolite material, calculated as Fe2O3, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material, and preferably 95 to 100 mass%, more preferably 98 to 100 mass%, more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, more preferably in the range of 20:1 to 35:1.

[0131] 14. The coating of the first catalyst further comprises a metal oxide, which preferably comprises one or more of zirconia, alumina, titania, silica, and mixed oxides comprising two or more of Zr, Al, Ti, and Si; more preferably comprises one or more of alumina and zirconia; more preferably comprises zirconia; more preferably is zirconia; The exhaust gas treatment system according to any one of embodiments 1 to 13, wherein the coating of the first catalyst contains the metal oxide in an amount ranging from 1 to 15% by mass, more preferably from 2 to 10% by mass, and more preferably from 3 to 8% by mass, based on the mass of the zeolite material containing one or more copper and iron.

[0132] The coating of the first catalyst according to 15.(i) contains vanadium oxide but does not contain zeolite material containing one or more of copper and iron. The exhaust gas treatment system according to any one of Embodiments 1 to 7, wherein the vanadium oxide is preferably one or more of vanadium(V) oxide and vanadium(IV) oxide, and the vanadium oxide optionally includes one or more of tungsten, iron and antimony.

[0133] 16. The exhaust gas treatment system according to Embodiment 15, wherein the vanadium oxide is supported on an oxide material comprising one or more of titanium, silicon, and zirconium, preferably an oxide material comprising one or more of titanium and silicon, more preferably an oxide material comprising one or more of titania and silica, and more preferably on titania, wherein the titania optionally comprises one or more of tungsten and silicon.

[0134] 17. An exhaust gas treatment system according to any one of Embodiments 1 to 14, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the coating of the first catalyst consists of palladium supported on an oxide material and a copper-containing zeolite material having a framework structure of type CHA, and preferably a metal oxide as defined in Embodiment 14.

[0135] 18. The exhaust gas treatment system according to any one of Embodiments 1 to 17, wherein the substrate of the first catalyst comprises a ceramic or metallic substance.

[0136] 19. The substrate of the first catalyst comprises a ceramic material, preferably consisting of a ceramic material, wherein the ceramic material preferably comprises one or more of alumina, silica, silicate, aluminosilicate, preferably cordierite or mullite, aluminotitanate, silicon carbide, zirconia, magnesia, preferably spinel, and titania, more preferably one or more of silicon carbide and cordierite, more preferably cordierite, or The exhaust gas treatment system according to any one of Embodiments 1 to 18, wherein the substrate of the first catalyst comprises a metallic substance, preferably consisting of a metallic substance, and the metallic substance preferably comprises oxygen and one or more of iron, chromium, and aluminum, more preferably consisting of these.

[0137] 20. An exhaust gas treatment system according to any one of Embodiments 1 to 19, wherein the substrate of the first catalyst is a monolith, preferably a honeycomb monolith, and more preferably a flow-through type honeycomb monolith.

[0138] 21. An exhaust gas treatment system according to any one of embodiments 1 to 20, wherein the substrate of the first catalyst has a substrate length, and the coating of the first catalyst is disposed on the substrate over 95 to 100%, more preferably 99 to 100%, of the substrate length.

[0139] 22. The above-mentioned catalyst is 1-6 g / in 3 Within the range of preferably 1.5 to 5 g / in 3 Within the range of 2-4 g / in, more preferably 2-4 g / in 3 An exhaust gas treatment system according to any one of embodiments 1 to 21, comprising a coating with a supported amount within the range.

[0140] 23. The exhaust gas treatment system according to any one of embodiments 1 to 22, wherein the coating of the first catalyst is the sole coating of the first catalyst.

[0141] 24. An exhaust gas treatment system according to any one of Embodiments 1 to 23, wherein up to 0.001% by mass, preferably 0 to 0.0001% by mass, more preferably 0 to 0.00001% by mass, of the coating of the first catalyst consists of platinum, iridium, osmium, and rhodium.

[0142] The exhaust gas treatment system according to any one of Embodiments 1 to 24, wherein the second catalyst according to 25.(ii) is a selective catalytic reduction catalyst.

[0143] The exhaust gas treatment system according to any one of Embodiments 1 to 25, wherein the coating of the second catalyst according to 26.(ii) comprises a zeolite material containing one or more copper and iron, and 80 to 100% by mass, preferably 90 to 99% by mass, and more preferably 95 to 98% by mass of the coating of the second catalyst according to (ii) consists of the zeolite material containing one or more copper and iron.

[0144] 27. An exhaust gas treatment system according to any one of Embodiments 1 to 26, wherein the zeolite material included in the coating of the second catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, preferably a framework structure of type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably a framework structure of type CHA or AEI, and more preferably a framework structure of type CHA.

[0145] 28. An exhaust gas treatment system according to any one of Embodiments 1 to 27, wherein the zeolite material included in the coating of the second catalyst, preferably a zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0146] 29. The zeolite material contained in the coating of the second catalyst contains copper, and the amount of copper contained in the zeolite material, calculated as CuO, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 2.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, and more preferably in the range of 2.5 to 3.5 mass%, based on the mass of the zeolite material; The exhaust gas treatment system according to any one of Embodiments 1 to 28, wherein the amount of iron contained in the zeolite material, when calculated as Fe2O3, is more preferably in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0147] 30. An exhaust gas treatment system according to any one of Embodiments 1 to 29, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, of the framework structure of the zeolite material contained in the coating of the second catalyst consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, when calculated as SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 40:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 20:1 to 35:1.

[0148] 31. An exhaust gas treatment system according to any one of Embodiments 1 to 28, wherein the zeolite material included in the coating of the second catalyst contains iron, and the amount of iron in the zeolite material, calculated as Fe2O3, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material, and preferably 95 to 100 mass%, more preferably 98 to 100 mass%, more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 40:1, more preferably in the range of 10:1 to 40:1, more preferably in the range of 20:1 to 35:1.

[0149] 32. The coating of the second catalyst further comprises a metal oxide, which preferably comprises one or more of zirconia, alumina, titania, silica, and mixed oxides comprising two or more of Zr, Al, Ti, and Si; more preferably comprises one or more of alumina and zirconia; more preferably comprises zirconia; more preferably comprises zirconia; The exhaust gas treatment system according to any one of Embodiments 1 to 31, wherein the coating of the second catalyst contains a metal oxide in an amount ranging from 0.5 to 15% by mass, more preferably 1 to 8% by mass, and more preferably 1.5 to 5% by mass, based on the mass of the zeolite material containing one or more copper and iron.

[0150] 33. An exhaust gas treatment system according to any one of Embodiments 1 to 32, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the coating of the second catalyst comprises a zeolite material containing one or more copper and iron, preferably a zeolite material having a framework structure of type CHA, and preferably a zeolite material that is a metal oxide as defined above in Embodiment 32.

[0151] 34. The exhaust gas treatment system according to any one of Embodiments 1 to 25, wherein the coating of the second catalyst comprises a vanadium oxide, the vanadium oxide preferably being one or more of vanadium(V) oxide and vanadium(IV) oxide, and the vanadium oxide optionally comprising one or more of tungsten, iron and antimony.

[0152] 35. The exhaust gas treatment system according to Embodiment 34, wherein the vanadium oxide is supported on an oxide material containing one or more of titanium, silicon, and zirconium, preferably an oxide material containing one or more of titanium and silicon, more preferably an oxide material containing one or more of titania and silica, and more preferably titania, wherein the titania optionally contains one or more of tungsten and silicon.

[0153] 36. The exhaust gas treatment system according to Embodiment 34 or 35, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the coating of the second catalyst is preferably vanadium oxide supported on an oxide material as defined in Embodiment 35.

[0154] 35. An exhaust gas treatment system according to any one of Embodiments 1 to 34, wherein 0 to 0.0001% by mass, preferably 0 to 0.00001% by mass, and more preferably 0 to 0.000001% by mass of the coating of the second catalyst is made of a platinum group metal.

[0155] 36. The exhaust gas treatment system according to any one of Embodiments 1 to 35, wherein the substrate of the second catalyst comprises a ceramic or metallic substance.

[0156] 37. The substrate of the second catalyst comprises a ceramic material, preferably consisting of a ceramic material, the ceramic material preferably comprising one or more of alumina, silica, silicate, aluminosilicate, preferably cordierite or mullite, aluminotitanate, silicon carbide, zirconia, magnesia, preferably spinel, and titania, more preferably silicon carbide and one or more of cordierite, more preferably cordierite, and more preferably consisting of these; or The exhaust gas treatment system according to any one of Embodiments 1 to 36, wherein the substrate of the second catalyst contains a metallic substance, preferably consisting of a metallic substance, and the metallic substance preferably contains oxygen and one or more of iron, chromium, and aluminum, more preferably consisting of these.

[0157] 38. An exhaust gas treatment system according to any one of Embodiments 1 to 37, wherein the substrate of the second catalyst is a monolith, preferably a honeycomb monolith, and more preferably a flow-through type honeycomb monolith.

[0158] 39. An exhaust gas treatment system according to any one of embodiments 1 to 38, wherein the substrate of the second catalyst has a substrate length, and the coating of the second catalyst is disposed on the substrate over 95 to 100%, preferably 99 to 100%, of the substrate length.

[0159] 40. The second catalyst is 1-6 g / in 3 Within the range of preferably 1.25 to 4 g / in 3 Within the range of 1.5 to 3 g / in, more preferably 1.5 to 3 g / in 3 An exhaust gas treatment system according to any one of embodiments 1 to 39, comprising a coating with a load amount within the range.

[0160] 41. The exhaust gas treatment system according to any one of Embodiments 1 to 40, wherein the coating of the second catalyst is the sole coating of the second catalyst.

[0161] 42. An exhaust gas treatment system according to any one of Embodiments 1 to 41, wherein the coating of the first catalyst comprises, preferably, a zirconium-containing oxide material, palladium supported on a copper-containing zeolite material having a type CHA framework structure, and a metal oxide as defined in Embodiment 14, and more preferably, a coating of the second catalyst comprises, preferably, a copper-containing zeolite material having a type CHA framework structure, and a metal oxide as defined in Embodiment 32, and more preferably, a coating of the second catalyst comprises a platinum group metal up to 0.0001% by mass.

[0162] 43. An exhaust gas treatment system according to any one of Embodiments 1 to 42, wherein the substrate of the first catalyst contains cordierite, preferably made of cordierite, and the substrate of the second catalyst contains cordierite, preferably made of cordierite.

[0163] 44. An exhaust gas treatment system according to any one of embodiments 1 to 43, wherein the substrate on which the coating of the first catalyst is disposed is the first substrate, and the substrate on which the coating of the second catalyst is disposed is the second substrate, and the first substrate and the second substrate are different from each other.

[0164] 45. An exhaust gas treatment system according to any one of embodiments 1 to 43, wherein a substrate of the first catalyst on which the coating of the first catalyst is disposed and a substrate of the second catalyst on which the coating of the second catalyst is disposed together to form a single substrate, the single substrate having an inlet end and an outlet end, the inlet end being located upstream of the outlet end, the coating of the first catalyst being disposed from the inlet end to the outlet end of the single substrate, the coating of the second catalyst being disposed from the outlet end to the inlet end of the single substrate, the coating of the first catalyst covering 25 to 75% of the substrate length, and the coating of the second catalyst covering 25 to 75% of the substrate length.

[0165] 46. ​​The exhaust gas treatment system according to Embodiment 45, wherein the coating of the first catalyst covers 25 to 70%, preferably 35 to 65%, more preferably 45 to 55%, of the substrate length, and the coating of the second catalyst covers 25 to 70%, preferably 35 to 65%, more preferably 45 to 55%, of the substrate length.

[0166] 47. The exhaust gas treatment system according to Embodiment 45, wherein the coating of the first catalyst covers 50-75%, preferably 69-75%, of the substrate length, and the coating of the second catalyst covers 25-50%, preferably 25-31%, of the substrate length.

[0167] 48. An exhaust gas treatment system according to any one of embodiments 45 to 47, wherein the coating of the first catalyst and the coating of the second catalyst overlap.

[0168] 49. An exhaust gas treatment system according to any one of embodiments 45 to 47, wherein there is a gap between the coating of the first catalyst and the coating of the second catalyst.

[0169] 50. An exhaust gas treatment system according to any one of Embodiments 1 to 49, wherein the substrate of the first catalyst has a substrate length in the range of 1 to 10 inches, preferably in the range of 2 to 8 inches, more preferably in the range of 14 to 7.5 inches, and more preferably in the range of 5 to 7 inches.

[0170] 51. An exhaust gas treatment system according to any one of Embodiments 1 to 50, wherein the substrate of the second catalyst has a substrate length in the range of 1 inch to 10 inches, preferably in the range of 1.5 inches to 7 inches, more preferably in the range of 2 inches to 5 inches, and more preferably in the range of 2 inches to 4 inches.

[0171] 52. The exhaust gas treatment system according to Embodiment 50 or 51, wherein the length of the first substrate is longer than the length of the second substrate, and the ratio of the length of the first substrate to the length of the second substrate is preferably in the range of 1.1:1 to 4:1, preferably in the range of 1.5:1 to 3.5:1, and more preferably in the range of 1.9:1 to 2.1:1.

[0172] 53. An exhaust gas treatment system according to any one of Embodiments 1 to 52, wherein the substrate of the first catalyst has a substrate width in the range of 4 to 17 inches, preferably in the range of 7 to 15 inches, more preferably in the range of 8 to 14 inches, more preferably in the range of 9 to 13 inches, and more preferably in the range of 9 to 11 inches.

[0173] 54. The exhaust gas treatment system according to any one of embodiments 1 to 53, wherein the substrate of the second catalyst has a substrate width in the range of 4 to 20 inches, preferably in the range of 7 to 18 inches, more preferably in the range of 9 to 16 inches, more preferably in the range of 10 to 15 inches, and more preferably in the range of 11 to 14 inches.

[0174] 55. An exhaust gas treatment system according to any one of embodiments 1 to 54, further comprising a first injector for injecting a fluid into the exhaust gas flow discharged from the diesel engine, wherein the first injector is located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system.

[0175] 56. The exhaust gas treatment system according to embodiment 55, wherein the fluid is an aqueous urea solution.

[0176] 57. An exhaust gas treatment system according to any one of embodiments 1 to 56, further comprising a second injector for injecting a fluid into the exhaust gas flow discharged from the diesel engine, wherein the injector is located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system, and the fluid preferably comprises a hydrocarbon.

[0177] 58. The exhaust gas treatment system (iii) A third catalyst comprising a first coating having an inlet end and an outlet end and disposed on a substrate, and a second coating disposed on the first coating, Here, the first coating comprises a platinum group metal supported on an oxide material, and optionally further comprises one or more zeolite materials comprising vanadium oxide and one or more copper and iron. The second coating comprises vanadium oxide and one or more zeolite materials containing one or more of copper and iron; Herein, in the exhaust gas treatment system, the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and the inlet end of the third catalyst is located upstream of the outlet end of the third catalyst, according to any one of embodiments 1 to 57.

[0178] The exhaust gas treatment system according to Embodiment 58, wherein the outlet end of the second catalyst according to (ii) is in fluid communication with the inlet end of the third catalyst according to (iii), and no catalyst for treating the exhaust gas flow discharged from the second catalyst is located in the exhaust gas treatment system between the outlet end of the second catalyst according to (ii) and the inlet end of the third catalyst according to (iii).

[0179] The exhaust gas treatment system according to Embodiment 58 or 59, wherein the third catalyst according to 60.(iii) is an ammonia oxidation catalyst.

[0180] The exhaust gas treatment system according to any one of embodiments 58 to 60, wherein the platinum group metal included in the first coating of the third catalyst according to 61.(iii) is one or more of platinum, palladium, rhodium, iridium, and osmium, preferably one or more of platinum, palladium, and rhodium, more preferably one or more of platinum and palladium, and more preferably platinum.

[0181] 62. The first coating of the third catalyst is made of the platinum group metal, preferably platinum, which is calculated as the elemental metal, preferably element Pt, at a concentration of 0.5 to 30 g / ft. 3 Within the range of 1 to 15 g / ft, preferably 1 to 15 g / ft 3 Within the range of 1.5 to 5 g / ft, more preferably 1.5 to 5 g / ft 3 An exhaust gas treatment system according to any one of embodiments 58 to 61, including a load within the range.

[0182] The oxide material included in the first coating of the third catalyst according to 63.(iii) comprises one or more of titania, zirconia, and alumina, preferably one or more of titania and zirconia, more preferably titania; An exhaust gas treatment system according to any one of embodiments 58 to 62, wherein, when calculated as TiO2, more preferably 85 to 98.5% by mass, more preferably 85 to 95% by mass of the oxide material is titania.

[0183] The exhaust gas treatment system according to any one of embodiments 58 to 63, wherein the oxide material included in the coating of the third catalyst according to 64.(iii) comprises one or more of silicon, aluminum, titanium, and zirconium, preferably one or more of silicon and aluminum, and more preferably silicon.

[0184] 95 to 100% by mass, preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass, of the oxide material included in the coating of the third catalyst according to 65.(iii) consists of oxygen, titanium, and silicon; An exhaust gas treatment system according to any one of embodiments 58 to 64, wherein, when calculated as SiO2, preferably 1.5 to 15% by mass, more preferably 5 to 15% by mass of the oxide material is silicon.

[0185] An exhaust gas treatment system according to any one of embodiments 58 to 65, wherein 5 to 40% by mass, preferably 7 to 20% by mass, more preferably 8 to 15% by mass of the first coating of the third catalyst according to 66.(iii) consists of the oxide material, or preferably 70 to 100% by mass, more preferably 80 to 100% by mass, more preferably 90 to 100% by mass, more preferably 95 to 100% by mass, more preferably 99 to 100% by mass of the first coating of the third catalyst according to (iii) consists of the oxide material.

[0186] The exhaust gas treatment system according to any one of embodiments 58 to 66, wherein the first coating of the third catalyst according to 67.(iii) comprises a zeolite material containing one or more copper and iron, and 60 to 95% by mass, preferably 80 to 93% by mass, more preferably 82 to 92% by mass of the first coating of the third catalyst according to (iii) consists of the zeolite material containing one or more copper and iron.

[0187] 68. An exhaust gas treatment system according to any one of embodiments 58 to 67, wherein the zeolite material included in the first coating of the third catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, preferably a framework structure of type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably a framework structure of type CHA or AEI, and more preferably a framework structure of type CHA.

[0188] 69. An exhaust gas treatment system according to any one of embodiments 58 to 68, wherein the zeolite material included in the first coating of the third catalyst, preferably a zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0189] 70. The zeolite material contained in the first coating of the third catalyst contains copper, and the amount of copper contained in the zeolite material, calculated as CuO, is preferably in the range of 1 to 12 mass%, more preferably in the range of 1.5 to 10 mass%, more preferably in the range of 3 to 8 mass%, and more preferably in the range of 4.5 to 6.5 mass%, based on the mass of the zeolite material. The exhaust gas treatment system according to any one of embodiments 58 to 69, wherein the amount of iron contained in the zeolite material, when calculated as Fe2O3, is more preferably in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0190] 71. An exhaust gas treatment system according to any one of embodiments 58 to 70, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, of the framework structure of the zeolite material contained in the first coating of the third catalyst consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, when calculated as SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 15:1 to 25:1.

[0191] 72. The exhaust gas treatment system according to any one of embodiments 58 to 69, wherein the zeolite material included in the first coating of the third catalyst contains iron, and the amount of iron in the zeolite material, calculated as Fe2O3, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material, and preferably 95 to 100 mass%, more preferably 98 to 100 mass%, more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, more preferably in the range of 15:1 to 25:1.

[0192] 73. The first coating of the third catalyst further comprises a metal oxide, which preferably comprises one or more of zirconia, alumina, titania, silica, and mixed oxides comprising two or more of Zr, Al, Ti, and Si; more preferably comprises one or more of alumina and zirconia; more preferably comprises zirconia; more preferably comprises zirconia; The exhaust gas treatment system according to any one of embodiments 58 to 72, wherein the first coating of the third catalyst contains a metal oxide in an amount ranging from 1 to 15% by mass, more preferably 2 to 10% by mass, and more preferably 3 to 8% by mass, based on the mass of the zeolite material containing one or more copper and iron.

[0193] 74. An exhaust gas treatment system according to any one of embodiments 58 to 73, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the first coating of the third catalyst consists of a platinum group metal, preferably platinum, and preferably a metal oxide as defined in embodiment 73, supported on a copper-containing zeolite material having an oxide material and a framework structure of type CHA.

[0194] The first coating of the third catalyst according to 75.(iii) contains vanadium oxide but does not contain a zeolite material containing one or more of copper and iron. The exhaust gas treatment system according to any one of embodiments 58 to 66, wherein the vanadium oxide is preferably one or more of vanadium(V) oxide and vanadium(IV) oxide, and the vanadium oxide optionally includes one or more of tungsten, iron and antimony.

[0195] 76. The exhaust gas treatment system of Embodiment 75, wherein the vanadium oxide is supported on an oxide material containing one or more of titanium, silicon, and zirconium, preferably an oxide material containing one or more of titanium and silicon, more preferably an oxide material containing one or more of titania and silica, and more preferably titania, wherein the titania optionally contains one or more of tungsten and silicon.

[0196] 77. An exhaust gas treatment system according to Embodiment 75 or 76, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the first coating of the third catalyst consists of a platinum group metal, preferably platinum, supported on an oxide material, and a vanadium oxide supported on an oxide material as defined in Embodiment 76.

[0197] The second coating of the third catalyst according to 78.(iii) comprises a zeolite material containing one or more copper and iron; The exhaust gas treatment system according to any one of embodiments 58 to 77, wherein 80 to 100% by mass, preferably 90 to 99% by mass, and more preferably 95 to 98% by mass of the second coating of the third catalyst according to (iii) is made of a zeolite material containing one or more copper and iron.

[0198] 79. An exhaust gas treatment system according to any one of embodiments 58 to 78, wherein the zeolite material included in the second coating of the third catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof, preferably type AEI, CHA, BEA, or a mixture of two or more thereof, more preferably a framework structure of type CHA or AEI, and more preferably a framework structure of type CHA.

[0199] 80. An exhaust gas treatment system according to any one of embodiments 58 to 79, wherein the zeolite material included in the second coating of the third catalyst, preferably a zeolite material having a framework structure type CHA, has an average crystallite size of at least 0.5 micrometers, preferably in the range of 0.5 to 1.5 micrometers, more preferably in the range of 0.6 to 1.0 micrometers, and more preferably in the range of 0.6 to 0.8 micrometers, as determined by scanning electron microscopy.

[0200] 81. The zeolite material contained in the second coating of the third catalyst contains copper, and the amount of copper contained in the zeolite material, when calculated as CuO, is preferably in the range of 1 to 12 mass%, more preferably in the range of 1.5 to 10 mass%, more preferably in the range of 3 to 8 mass%, and more preferably in the range of 4.5 to 6.5 mass%, based on the mass of the zeolite material. The exhaust gas treatment system according to any one of embodiments 58 to 80, wherein the amount of iron contained in the zeolite material, when calculated as Fe2O3, is more preferably in the range of 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and more preferably in the range of 0 to 0.0001 mass%, based on the mass of the zeolite material.

[0201] 82. An exhaust gas treatment system according to any one of embodiments 58 to 81, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, of the framework structure of the zeolite material contained in the second coating of the third catalyst consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, when calculated as molar SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, and more preferably in the range of 15:1 to 25:1.

[0202] 83. An exhaust gas treatment system according to any one of embodiments 58 to 82, wherein the zeolite material contained in the second coating of the third catalyst contains iron, and the amount of iron contained in the zeolite material, calculated as Fe2O3, is preferably in the range of 0.1 to 10.0 mass%, more preferably in the range of 1.0 to 7.0 mass%, more preferably in the range of 2.5 to 5.5 mass%, based on the mass of the zeolite material, and preferably 95 to 100 mass%, more preferably 98 to 100 mass%, more preferably 99 to 100 mass%, of the framework structure of the zeolite material consists of one or more of Si, Al, O, and optionally H and P, and in the framework structure, the molar ratio of Si to Al, calculated as SiO2:Al2O3, is preferably in the range of 2:1 to 50:1, more preferably in the range of 4:1 to 45:1, more preferably in the range of 10:1 to 40:1, more preferably in the range of 15:1 to 25:1.

[0203] 84. The second coating of the third catalyst further comprises a metal oxide, which preferably comprises one or more of a mixed oxide comprising zirconia, alumina, titania, silica, and two or more of Zr, Al, Ti, and Si; more preferably comprises one or more of alumina and zirconia; more preferably comprises zirconia; more preferably comprises zirconia; The exhaust gas treatment system according to any one of embodiments 58 to 83, wherein the second coating of the third catalyst contains the metal oxide in an amount ranging from 1 to 15% by mass, more preferably 2 to 10% by mass, and more preferably 3 to 8% by mass, based on the mass of the zeolite material containing one or more copper and iron.

[0204] 85. An exhaust gas treatment system according to any one of embodiments 58 to 84, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the second coating of the third catalyst consists of a zeolite material containing one or more copper and iron, preferably a copper-containing zeolite material having a framework structure of type CHA, and preferably a metal oxide as defined in embodiment 84.

[0205] 86. An exhaust gas treatment system according to any one of embodiments 58 to 77, wherein the second coating of the third catalyst comprises a vanadium oxide, the vanadium oxide preferably one or more of vanadium(V) oxide and vanadium(IV) oxide, and the vanadium oxide optionally comprises one or more of tungsten, iron and antimony.

[0206] 87. The exhaust gas treatment system of Embodiment 86, wherein the vanadium oxide is supported on an oxide material containing one or more of titanium, silicon, and zirconium, preferably an oxide material containing one or more of titanium and silicon, more preferably an oxide material containing one or more of titania and silica, and more preferably titania, wherein the titania optionally contains one or more of tungsten and silicon.

[0207] 88. The exhaust gas treatment system according to Embodiment 86 or 87, wherein 95 to 100% by mass, preferably 98 to 100% by mass, more preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the second coating of the third catalyst consists of vanadium oxide, preferably vanadium oxide supported on an oxide material as defined in Embodiment 87.

[0208] 89. An exhaust gas treatment system according to any one of embodiments 58 to 88, wherein 0 to 0.0001% by mass, preferably 0 to 0.00001% by mass, and more preferably 0 to 0.000001% by mass of the second coating of the third catalyst is made of a platinum group metal.

[0209] 90. The exhaust gas treatment system according to any one of embodiments 58 to 89, wherein the substrate of the third catalyst comprises a ceramic or metallic substance.

[0210] 91. The substrate of the third catalyst comprises a ceramic material, preferably consisting of a ceramic material, the ceramic material preferably comprising one or more of alumina, silica, silicate, aluminosilicate, preferably cordierite or mullite, aluminotitanate, silicon carbide, zirconia, magnesia, preferably spinel, and titania, more preferably silicon carbide and one or more of cordierite, more preferably cordierite, and more preferably consisting of these; or The exhaust gas treatment system according to any one of embodiments 58 to 90, wherein the substrate of the third catalyst contains a metallic substance, preferably consisting of a metallic substance, and the metallic substance preferably contains oxygen and one or more of iron, chromium, and aluminum, more preferably consisting of these.

[0211] 92. An exhaust gas treatment system according to any one of embodiments 58 to 91, wherein the substrate of the third catalyst is a monolith, preferably a honeycomb monolith, and more preferably a flow-through type honeycomb monolith.

[0212] 93. An exhaust gas treatment system according to any one of embodiments 58 to 92, wherein the substrate of the third catalyst has a substrate length, the first coating of the third catalyst is disposed on the substrate over 95 to 100%, more preferably 99 to 100%, of the substrate length, and the second coating of the third catalyst is disposed on the substrate over 95 to 100%, more preferably 99 to 100%, of the substrate length.

[0213] 94. The third catalyst is 1-6 g / in 3 Within the range of preferably 1.25 to 4 g / in 3 Within the range of 1.5 to 2.5 g / in, more preferably 1.5 to 2.5 g / in 3 An exhaust gas treatment system according to any one of embodiments 58 to 93, comprising the first coating in a supported amount within the range.

[0214] 95. The third catalyst is 0.25~4 g / in 3 Within the range, preferably 0.5 to 2 g / in 3 Within this range, more preferably 0.75 to 1.5 g / in 3 An exhaust gas treatment system according to any one of embodiments 58 to 94, comprising the second coating in a supported amount within the range.

[0215] 96. The third catalyst is 1.25-10 g / in 3 Within the range of preferably 1.75 to 6 g / in 3 Within the range, more preferably 2.25 to 4 g / in 3 An exhaust gas treatment system according to any one of embodiments 58 to 95, including a catalyst loading amount within the range.

[0216] The exhaust gas treatment system according to any one of embodiments 58 to 96, wherein the third catalyst according to 97.(iii) comprises the first coating and the second coating.

[0217] 98. The coating of the first catalyst comprises, preferably, palladium supported on a zirconium-containing oxide material, a copper-containing zeolite material having a type CHA framework structure, and a metal oxide as defined in Embodiment 14, preferably consisting of these. The coating of the second catalyst comprises, preferably, a copper-containing zeolite material having a framework structure of type CHA, and a metal oxide as defined in Embodiment 32, and preferably consists of these, wherein up to 0.0001% by mass of the coating of the second catalyst consists of platinum group metals. The exhaust gas treatment system according to any one of embodiments 58 to 97, wherein the first coating of the third catalyst preferably comprises platinum supported on an oxide material containing titania, a copper-containing zeolite material having a type CHA framework structure, and preferably a metal oxide as defined in Embodiment 73, and more preferably a metal oxide as defined in Embodiment 73, and the second coating of the third catalyst preferably comprises a copper-containing zeolite material having a type CHA framework structure, and preferably a metal oxide as defined in Embodiment 84, and more preferably a metal oxide as defined in Embodiment 84.

[0218] 99. An exhaust gas treatment system according to any one of embodiments 58 to 98, wherein the substrate of the first catalyst contains cordierite, preferably made of cordierite; the substrate of the second catalyst contains cordierite, preferably made of cordierite; and the substrate of the third catalyst contains cordierite, preferably made of cordierite.

[0219] 100. An exhaust gas treatment system according to any one of embodiments 58 to 99, wherein the substrate of the third catalyst has a substrate length in the range of 1 to 10 inches, preferably in the range of 1.5 to 7 inches, more preferably in the range of 2 to 5 inches, and more preferably in the range of 2 to 4 inches.

[0220] 101 An exhaust gas treatment system according to Embodiment 100, wherein the length of the first substrate is longer than the length of the third substrate, and the ratio of the length of the first substrate to the length of the third substrate is preferably in the range of 1.1:1 to 4:1, more preferably in the range of 1.5:1 to 3.5:1, and more preferably in the range of 1.9:1 to 2.1:1.

[0221] 102. An exhaust gas treatment system according to any one of embodiments 58 to 101, wherein the substrate of the third catalyst has a substrate width in the range of 4 inches to 20 inches, preferably in the range of 7 inches to 18 inches, more preferably in the range of 9 inches to 16 inches, more preferably in the range of 10 inches to 15 inches, and more preferably in the range of 11 inches to 14 inches.

[0222] 103. An exhaust gas treatment system according to any one of Embodiments 1 to 102, further comprising one or more of a particulate filter, a diesel oxidation catalyst, and an ammonia oxidation catalyst, wherein one or more of the particulate filter, the diesel oxidation catalyst, and the ammonia oxidation catalyst are located downstream of the second catalyst according to (ii), or, if the third catalyst is included in the system, downstream of the third catalyst according to (iii) as defined in any one of Embodiments 58 to 102.

[0223] 104. A method for treating exhaust gas flow discharged from a diesel engine, wherein the method is: To provide exhaust gas flow from a diesel engine, The aforementioned gas is passed through the exhaust gas treatment system described in any one of Embodiments 1 to 103, Methods that include...

[0224] In the context of this invention, "amount of a given component / coating" (unit: g / in) 3 or g / ft 3 The term refers to the mass of the component / coating per unit volume of the substrate, where the volume of the substrate is defined as the product of the cross-section of the substrate and the axial length of the substrate in which the component / coating exists. For example, extending over x% of the axial length of the substrate, X g / in 3 When referring to the amount of a first coating having a load of , the load is the total volume of the substrate (in units in in) 3 This refers to X grams of the first coating per x% of ).

[0225] In the context of the present invention, when the amount of copper and / or iron contained in the zeolite material is defined as a mass percentage based on the mass of the zeolite material, it should be noted that this means it is based on the mass of the zeolite material, i.e., the mass of the zeolite material containing each of the copper and / or iron.

[0226] Furthermore, in the context of the present invention, the phrase "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 realization of the aforementioned feature) should be understood to mean that X is either A, or B, or C, or A and B, or A and C, or B and C, or A, B, and C. In this regard, it should be noted that those skilled in the art can translate the above abstract terms into concrete examples, for example, specific examples where X is a chemical element and A, B, and C are specific elements such as Li, Na, and K, or specific examples where X is a temperature and A, B, and C are specific temperatures such as 10°C, 20°C, and 30°C. In this regard, a person skilled in the art can extend the above terms to less specific realizations of the features, for example, "X is one or more of A and B" can be extended to indicate "X is either A or B or A and B", for example, "X is one or more of A, B, C and D" can be extended to indicate "X is either 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 A and B and D or B and C and D or A and B and C and D".

[0227] Furthermore, in the context of the present invention, the term “inner wall surface” is understood to mean the “bare,” “exposed,” or “blank” surface of the wall, i.e., the untreated surface of the wall made of the wall material, excluding unavoidable impurities that may contaminate the surface. For example, in the context of the present invention, the first coating of the third catalyst is preferably placed on the inner wall surface of the substrate, more preferably on the inner wall surface of the flow-through substrate.

[0228] In the context of the present invention, the term "consists of" with respect to the mass percentage of one or more components indicates the mass percentage amount of the component based on 100 mass percent of the entity. For example, the phrase "0 to 0.0001 mass percent of the first coating consists of platinum group metals" indicates that of the 100 mass percent of components constituting the coating, 0 to 0.0001 mass percent are platinum group metals.

[0229] The present invention is further illustrated by the following reference examples, comparative examples, and embodiments.

[0230] Examples Example 1: Determining the values ​​of Dv10, Dv50, and Dv90 The particle size distribution was measured using static light scattering with a Sympatec HELOS instrument, and the optical density of the sample was in the range of 5-10%.

[0231] Reference Example 2: Measurement of BET specific surface area The BET specific surface area was measured using liquid nitrogen in accordance with DIN 66131 or DIN ISO 9277.

[0232] Reference Example 3: General Coating Methods To coat one or more flow-through substrates with a coating, the flow-through substrate was vertically immersed in a predetermined mixture for a specific length of the substrate, filling the substrate with the required amount of mixture. In this way, the mixture came into contact with the walls of the substrate. The substrate was left in the mixture for a specified time, usually 1 to 10 seconds. A vacuum was applied to draw the mixture into the substrate. The substrate was then removed from the mixture. The substrate was rotated around its axis so that the immersed side faced upward, and the mixture, charged with high-pressure air, was pressed into the substrate.

[0233] Reference Example 4: Preparation of a multifunctional catalyst (mixing - single coating) Zirconium-based oxide support (67m with 88% ZrO2 containing 10% La2O3 and 2% HfO2) 2Initial wetting and impregnation of Pd into a BET specific surface area of ​​16 micrometers (Dv50) per g. First, the available pore volume of the oxide support was determined, and based on this value, a diluted palladium salt solution with a volume equal to the available pore volume was prepared. Next, this diluted solution was dropped onto a Zr-based oxide support over 30 minutes under constant stirring to obtain a wet material. Then, the obtained material was calcined in an oven at 590°C and allowed to cool. After calcination, the obtained powder was mixed with distilled water to form an aqueous mixture with a solid content of 40%, and the pH was adjusted to 3.75 using an organic acid. At this point, the slurry was pulverized until the particles of the mixture had a Dv90 of 10 micrometers.

[0234] Separately, Cu-CHA zeolite material (calculated as Cu:CuO, based on the mass of Cu-CHA, 3.25 mass%, 25 micrometers, Dv90, 31 SiO2:Al2O3, approximately 625 m 2 A CHA (Cu-CHA) with a BET specific surface area of ​​1 / g was added to deionized water to form a mixture. Furthermore, a soluble zirconium solution (30% by mass ZrO2) was added as a binder to the mixture containing water and Cu-CHA. The pH was adjusted to 7. The solid content of the final mixture was 43% by mass.

[0235] At this point, the Pd-impregnated ZrO2 mixture was mixed with the Cu-CHA mixture, and the pH was adjusted again to 7. The final mixture was mounted on a honeycomb flow-through monolithic cordierite substrate (diameter: 26.67 cm (10.5 inches) x length: 15.24 cm (6 inches), 400 / (2.54) 2 The mixture was in a state where it could be placed on a cylindrical substrate with a cell / square centimeter density and a wall thickness of 0.10 mm (4 mil). The substrate was coated with the final mixture according to the coating method defined in Reference Example 3 of this specification. Target 3.0 g / in 3To achieve the wash coat support, the substrate was coated twice along its entire length, once from the inlet end to the outlet end, and once from the outlet end to the inlet end. After each coating step, a drying and firing step was performed. To dry the coated substrate, it was placed in a 90°C oven for approximately 30 minutes. After drying, the coated substrate was fired at 590°C for 30 minutes. The final load of coating on the catalyst after firing was 3.0 g / in. 3 This includes 2.56 g / in 3 Cu-CHA, 0.3g / in 3 Zirconia / HfO3 / La2O3, 0.13g / in 3 Zirconia (binder) and 15g / ft 3 This includes Pd-carrying.

[0236] Reference Example 5: Preparation of Selective Catalytic Reduction (SCR) Catalysts An aqueous solution of zirconium acetate was diluted with water. The amount of zirconia supported in the catalyst after calcination (calculated as ZrO2) was 0.06 g / in. 3 The amount of zirconium acetate was calculated accordingly. To this, Cu-CHA zeolite prepared according to Invention Example 2, column 15, lines 26-52 of US8293199B2 was added, except that the zeolite was spray-dried. The amount of Cu-CHA was such that the Cu-CHA loading in the catalyst after calcination was 2.04 g / in. 3 The calculation was performed to achieve the following result. The resulting slurry was then ground until the Dv90, determined as described in Reference Example 1 of this specification, resulted in a value of 10 micrometers.

[0237] Next, the final slurry was placed on an uncoated honeycomb flow-through cordierite monolith substrate (diameter: 31.75 cm (12.5 inches) x length: 7.62 cm (3 inches), 400 / (2.54) 2The wash coat was applied along the entire length of a cylindrical substrate with cells per square centimeter and a wall thickness of 0.1 mm (4 mil). The coated substrate was then dried at 120°C for 10 minutes, then at 160°C for 30 minutes, and finally baked at 450°C for 30 minutes. The wash coat load after baking was 2.1 g / in. 3 That was the case.

[0238] Reference Example 6: Preparation of an ammonia oxidation (AMOX) catalyst First coating (bottom coating): Si-doped titania powder (10% by mass of SiO2, 200m 2 Platinum ammine solution was added to a BET specific surface area (Dv90) of 20 micrometers per g. After calcination at 590°C, the final Pt / Si-titania had a Pt content of 0.46 mass% based on the mass of Si-titania. This material was added to water, and the slurry was pulverized until the resulting Dv90 was 10 micrometers, as described in Reference Example 1. Zirconium acetate solution was added to an aqueous slurry of Cu-CHA zeolite material (5.1 mass% CuO, 18 SiO2:Al2O3 molar ratio) so that the ZrO2 content after calcination would be 5 mass% based on the mass of the zeolite material. The Pt-containing slurry was added to this Cu-CHA slurry and stirred to prepare the final slurry. Next, this final slurry is poured from the inlet side to the outlet side of the substrate onto an uncoated honeycomb flow-through type cordierite monolith substrate (diameter: 31.75 cm (12.5 inches) x length: 7.62 cm (3 inches), 400 / (2.54) 2 A first (bottom) coating was formed by placing the material along the entire length of a cylindrical substrate (cells / cm², wall thickness 0.1 mm (4 mils)) using the coating method described in Reference Example 3. The coated substrate was then dried and fired. The load of the first coating after firing was approximately 2 g / in. 3 So, 1.67g / in 3 Cu-CHA loading amount: 0.08 g / in 3 ZrO2 load: 0.25 g / in 3 Si-titania loading amount: 2g / ft 3This includes the amount of PGM loaded.

[0239] Second coating (top coating): A zirconyl acetate solution was added to an aqueous slurry of Cu-CHA zeolite material (5.1% by mass of CuO, 18% of SiO2:Al2O3 molar ratio) so that the amount of ZrO2 after calcination would be 5% by mass, based on the mass of the zeolite material. Next, this slurry was placed over the entire length of a honeycomb cordierite monolith substrate coated with the first coating, from the inlet side to the outlet side, and the first coating was covered using the coating method described in Reference Example 3. The coated substrate was then dried and calcined. The amount of the second coating after calcination was 1.0 g / in. 3 That was the case.

[0240] The final catalyst load (bottom coating + top coating) in the catalyst after calcination is approximately 3 g / in. 3 That was the case.

[0241] Reference Example 7: Preparation of a multifunctional catalyst (layered) Second coating (bottom coating): An aqueous solution of zirconium acetate was diluted with water. The amount of zirconia supported in the catalyst after calcination (calculated as ZrO2) was 0.08 g / in. 3 The amount of zirconium acetate was calculated accordingly. To this, Cu-CHA zeolite prepared according to Invention Example 2, column 15, lines 26-52 of US8293199B2 was added, except that the zeolite was spray-dried. The amount of Cu-CHA was such that the Cu-CHA loading in the catalyst after calcination was 2.6 g / in 3 The calculation was performed to achieve the following result. The resulting slurry was then ground until the Dv90, determined as described in Reference Example 1 of this specification, resulted in a value of 10 micrometers.

[0242] Next, the final slurry was placed on an uncoated honeycomb cordierite monolith substrate (diameter: 26.67 cm (10.5 inches) x length: 15.24 cm (6 inches), 400 / (2.54)2 The wash coat was applied along the entire length of a cylindrical substrate with cells per square centimeter and a wall thickness of 0.1 mm (4 mil). The coated substrate was then dried at 120°C for 10 minutes, then at 160°C for 30 minutes, and finally baked at 450°C for 30 minutes. The wash coat load after baking was 2.7 g / in. 3 That was the case.

[0243] First coating (top coat): Zirconium-based oxide support (67m with 88% ZrO2 containing 10% La2O3 and 2% HfO2) 2 Initial wetting impregnation of Pd into a BET specific surface area of ​​1 / g (Dv50 of 3 micrometers, Dv90 of 16 micrometers). First, the available pore volume of a given oxide support was determined, and based on this value, a diluted palladium salt solution having a volume equal to the available pore volume was prepared. The palladium nitrate salt solution (calculated as element Pd, with a palladium content of 17.56 mass%) was mixed with distilled water and stirred until the solid content decreased to 6.1%. This diluted solution was then added dropwise to a Zr-based oxide support over 30 minutes under constant stirring to obtain a solid material containing approximately 25 mass% water. Next, the obtained material was calcined in an oven at 590°C and allowed to cool. After calcination, the obtained powder was mixed with distilled water to form an aqueous mixture with a final solid content of 41% based on the mass of the mixture, and the pH of the aqueous phase of the mixture was set to 3.75 using an organic acid. At this point, the slurry was pulverized until the particles of the mixture had a Dv90 of 10 micrometers.

[0244] After grinding, a zirconium hydroxide solution (calculated as ZrO2, with a zirconia content of 50% by mass) and a zirconium acetate solution (calculated as ZrO2, with a zirconia content of 30% by mass) were added to the mixture. The amount of ZrOH was calculated to correspond to 1 / 35 of the amount of Al-based oxide support. The amount of ZrOAc was calculated to correspond to 1 / 10 of the amount of Al-based oxide support. The solid content of the resulting final mixture had decreased to 38% by mass based on the mass of the final mixture. At this point, the mixture was ready to be placed on a substrate already coated with a bottom coating. The substrate coated with the bottom coating was coated once with the final mixture over its entire length according to the coating method defined in Reference Example 3 of this specification. The drying conditions were the same as for the bottom coating, and the coated substrate was calcined in a band calcination oven at various temperature stages, including 450°C for about 30 minutes. The final load of the top coating on the catalyst after calcination was 0.3 g / in 3 So, 0.26g / in 3 Zr-based oxide support, 0.03 g / in 3 Zirconia (from ZrOH and ZrOAc) and 15g / ft 3 This includes the amount of Pd loaded.

[0245] The final catalyst load (bottom coating + top coating) in the catalyst after calcination is approximately 3 g / in. 3 That was the case.

[0246] Comparative Example 1: Preparation of an exhaust gas treatment system not according to the present invention The system of Comparative Example 1 was prepared by combining three catalysts: a multifunctional layered catalyst (catalyst A) according to Reference Example 7, a selective catalytic reduction catalyst (catalyst B) according to Reference Example 5, and an ammonia oxidation catalyst (catalyst C) according to Reference Example 6. Catalyst A is the first catalyst in the system and is located upstream of catalyst B, catalyst B is located downstream of catalyst A and upstream of catalyst C, and catalyst C is located downstream of catalyst B.

[0247] Example 1 Preparation of the exhaust gas treatment system according to the present invention The system of Example 1 was prepared by combining three catalysts, namely the multifunctional mixed catalyst (Catalyst A) according to Reference Example 4, the selective catalytic reduction catalyst (Catalyst B) according to Reference Example 5, and the ammonia oxidation catalyst (Catalyst C) according to Reference Example 6. Catalyst A is the first catalyst of the system and is located upstream of Catalyst B, Catalyst B is located downstream of Catalyst A and upstream of Catalyst C, and Catalyst C is located downstream of Catalyst B.

[0248] Comparative Example 2 Preparation of an exhaust gas treatment system not according to the present invention The system of Comparative Example 2 was prepared by combining three catalysts, namely the multifunctional mixed catalyst (Catalyst A) according to Reference Example 4, the ammonia oxidation catalyst (Catalyst B) according to Reference Example 6, and the ammonia oxidation catalyst (Catalyst C) according to Reference Example 6. Catalyst A is the first catalyst of the system and is located upstream of Catalyst B, Catalyst B is located downstream of Catalyst A and upstream of Catalyst C, and Catalyst C is located downstream of Catalyst B.

[0249] Comparative Example 3 Preparation of an exhaust gas treatment system not according to the present invention The system of Comparative Example 3 was prepared by combining three catalysts, namely the multifunctional layered catalyst (Catalyst A) according to Reference Example 7, the multifunctional layered catalyst (Catalyst B) according to Reference Example 7, and the ammonia oxidation catalyst (Catalyst C) according to Reference Example 6. Catalyst A is the first catalyst of the system and is located upstream of Catalyst B, Catalyst B is located downstream of Catalyst A and upstream of Catalyst C, and Catalyst C is located downstream of Catalyst B.

[0250] [Table 1]

[0251] Example 2 Testing of the systems of Comparative Examples 1 to 3 and Example 1 - NOx conversion and N2O emission NOx conversion rate and N2O emission amount were measured at a high temperature of 390°C at the inlet of the system. The test was carried out on an EU VI 13L engine under steady-state conditions.

[0252] [Table 2]

[0253] As can be seen from Figure 2, in the exhaust gas treatment system of Example 1, NOx conversion was achieved at 85% at the outlet end of catalyst A, 100% at the outlet end of catalyst B, and 100% at the outlet end of catalyst C, out of the two systems. In contrast, the exhaust gas treatment systems of Comparative Examples 1 to 3 show that the NOx conversion rate at the outlet end of catalyst A is low or similar, i.e., about 82% or 85%, and the NOx conversion rate at the outlet end of catalyst B is low, i.e., less than about 99% and less than 95%. Furthermore, as can be seen from Figure 3, the lowest nitrous oxide emissions were obtained in the system of Example 1 according to the present invention, which includes a multifunctional mixed catalyst as the first catalyst (A) and a downstream SCR catalyst (B) that does not contain platinum group metals. Therefore, this example shows that the system according to the present invention can improve NOx conversion while reducing nitrous oxide emissions compared to other systems (which use a layered multifunctional catalyst and / or a second catalyst containing platinum group metals as the first catalyst of the system). Comparative examples include prior art such as WO2018 / 224651A1.

[0254] Example 4: Testing of the systems of Comparative Examples 1-3 and Example 1 - NOx conversion and N2O emission NOx conversion and N2O emissions were measured during transient HDD US FTP statutory cycles where the system inlet temperature was in the range of 155–277°C over the cycle. The test was performed with 150g of EU VI 13L over FTP, and urea administration was performed using NOx according to the administration method of ANR1.1. Cold soaks were taken between cycles, and three FTPs were performed consecutively. To ensure stable readings and eliminate the influence of ammonia storage in Cu-zeolite, the results of the third FTP were reported.

[0255] As can be seen from Figures 4 and 5, the exhaust gas treatment system of Example 1 exhibits the highest NOx conversion rates at the outlet ends of catalysts A, B, and C, i.e., approximately 56%, 86%, and 88%, respectively, and the lowest N2O emissions at the outlet ends of the catalysts in the system, compared to the systems of Comparative Examples 1 to 3. Therefore, this example demonstrates that the system according to the present invention can improve NOx conversion while reducing nitrous oxide emissions, compared to other systems that use a layered multifunctional catalyst as the first catalyst in the system, under steady-state and transient conditions. [Brief explanation of the drawing]

[0256] [Figure 1] This diagram schematically shows a system containing three catalysts: Catalyst A, Catalyst B, and Catalyst C. The attached diagram is not necessarily drawn to scale. [Figure 2] This figure shows the NOx conversion rates measured downstream of catalysts A, B, and C under steady-state conditions for the systems of Example 1 and Comparative Examples 1-3. [Figure 3] This figure shows the N2O emissions measured downstream of catalysts A, B, and C under steady-state conditions for the systems of Example 1 and Comparative Examples 1-3. [Figure 4] This figure shows the NOx conversion rates measured downstream of catalysts A, B, and C under transient test conditions for the systems of Example 1 and Comparative Examples 1-3. [Figure 5] This figure shows the N2O emissions measured downstream of catalysts A, B, and C under transient test conditions for the systems of Example 1 and Comparative Examples 1-3.

[0257] Cited literature -WO2018 / 224651A1

Claims

1. An exhaust gas treatment system for treating the exhaust gas flow discharged from a diesel engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas flow into the exhaust gas treatment system, and the exhaust gas treatment system is (i) A first catalyst having an inlet end and an outlet end, comprising a coating disposed on a substrate, wherein the coating is the sole coating of the first catalyst, and the coating comprises palladium supported on a zirconium oxide material and a zeolite material comprising one or more of copper and iron; (ii) A second catalyst having an inlet end and an outlet end, comprising a coating disposed on a substrate, wherein the coating comprises one or more of vanadium oxide and a zeolite material comprising one or more of copper and iron, and the coating of the second catalyst comprises a maximum of 0.0001% by mass of platinum group metals; (iii) A third catalyst comprising a first coating disposed on a substrate and having an inlet end and an outlet end, and a second coating disposed on the first coating, wherein the first coating comprises a platinum group metal supported on an oxide material and optionally comprises one or more zeolite materials comprising vanadium oxide, copper and iron, and the second coating comprises one or more zeolite materials comprising vanadium oxide, copper and iron, and the third catalyst comprising Here, the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system, and the inlet end of the first catalyst is located upstream of the outlet end of the first catalyst; In the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and the inlet end of the second catalyst is located upstream of the outlet end of the second catalyst. The exhaust gas treatment system wherein the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and the inlet end of the third catalyst is located upstream of the outlet end of the third catalyst.

2. The exhaust gas treatment system according to claim 1, wherein 70 to 98% by mass of the oxide material contained in the coating of the first catalyst according to (i) consists of zirconium and oxygen.

3. The exhaust gas treatment system according to claim 1 or 2, wherein the oxide material included in the coating of the first catalyst according to (i) further comprises one or more of lanthanum, hafnium, aluminum, silicon, and titanium.

4. The exhaust gas treatment system according to any one of claims 1 to 3, wherein 5 to 40% by mass of the coating of the first catalyst according to (i) is made of the oxide material.

5. The exhaust gas treatment system according to any one of claims 1 to 4, wherein the coating of the first catalyst according to (i) comprises a zeolite material containing one or more copper and iron, and 60 to 95% by mass of the coating of the first catalyst according to (i) consists of the zeolite material containing one or more copper and iron.

6. The exhaust gas treatment system according to any one of claims 1 to 5, wherein the zeolite material included in the coating of the first catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof.

7. The exhaust gas treatment system according to any one of claims 1 to 6, wherein the coating of the second catalyst according to (ii) comprises a zeolite material containing one or more copper and iron, and 80 to 100% by mass of the coating of the second catalyst according to (ii) consists of the zeolite material containing one or more copper and iron.

8. The exhaust gas treatment system according to any one of claims 1 to 7, wherein the zeolite material included in the coating of the second catalyst has a framework structure of type AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof.

9. The coating of the first catalyst comprises palladium supported on a zirconium-containing oxide material and a copper-containing zeolite material having a type CHA framework structure, and The exhaust gas treatment system according to any one of claims 1 to 8, wherein the coating of the second catalyst comprises a copper-containing zeolite material having a type CHA framework structure, and up to 0.0001% by mass of the coating of the second catalyst consists of platinum group metals.

10. The exhaust gas treatment system according to any one of claims 1 to 9, further comprising a first injector for injecting a fluid into the exhaust gas flow discharged from the diesel engine, wherein the first injector is located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system.

11. The exhaust gas treatment system according to any one of claims 1 to 10, wherein the platinum group metal included in the first coating of the third catalyst by (iii) is one or more of platinum, palladium, rhodium, iridium, and osmium.

12. The exhaust gas treatment system according to any one of claims 1 to 11, wherein the oxide material included in the first coating of the third catalyst according to (iii) includes one or more of titania, zirconia, and alumina.

13. The exhaust gas treatment system according to any one of claims 1 to 12, wherein 5 to 40% by mass of the first coating of the third catalyst according to (iii) is made of an oxide material, or 70 to 100% by mass of the first coating of the third catalyst according to (iii) is made of an oxide material.

14. A method for treating exhaust gas flow discharged from a diesel engine, wherein the method is: To provide exhaust gas flow from a diesel engine, The gas is passed through the exhaust gas treatment system according to any one of claims 1 to 13, Methods that include...

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