Exhaust Gas Treatment System for Ultra-Low NOx and Cold Start

Abstract

The present invention relates to an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, comprising: (i) a first catalyst having a coating and a first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium, (ii) a hydrocarbon injector for injecting a hydrocarbon-containing fluid into the exhaust gas stream exiting an outlet end of the first catalyst described in (i), and (iii) a second catalyst having a coating and a second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium.

Description

[Technical field]

[0001] The present invention relates to an exhaust gas treatment system for treating an exhaust gas stream from an internal combustion engine comprising a first vanadium-containing catalyst, a hydrocarbon injection device, and a second catalyst, a method for making the first vanadium-containing catalyst, and a method for treating exhaust gas from an internal combustion engine using the exhaust gas treatment system. [Background technology]

[0002] For example, systems with closed-coupled SCR (ccSCR) are known that are designed to meet ultra-low NOx and N2O emissions (e.g., CARB). US2018 / 0258811A1 discloses an exhaust treatment system that includes a first catalytic reduction device with a coating containing copper-activated zeolite (the first catalytic reduction device is the first active component in the exhaust treatment system) and a second catalytic reduction device with vanadium. US2017 / 0152780A1 also discloses an exhaust treatment system that includes a first catalytic reduction device, a particulate filter downstream of the first catalytic reduction device at least partially provided with a catalytic oxidation coating for trapping soot particles and oxidizing one or more nitrogen oxides, and a second catalytic reduction device downstream of the filter for reducing NOx.

[0003] The ccSCR (if based on Cu-zeolite SCR) may become sulfated over time due to SO3 generated by the engine and internal SO3 generated by the SCR, despite the absence of an upstream oxidation catalyst. Therefore, over time, the ccSCR will not be able to perform DeNOx sufficiently to meet ultra-low emission regulations. WO2018 / 224651A2 discloses an exhaust gas treatment system with a first catalyst (the first active component of the exhaust gas treatment system) comprising palladium supported on an oxide material and an SCR component, and a downstream second catalyst comprising a zeolite material containing a platinum group metal, one or more vanadium oxides, and one or more of copper and iron. However, to meet environmental demands, it is necessary to realize an exhaust gas treatment system that prevents sulfation and improves DeNOx while keeping costs down. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US2018 / 0258811A1 [Patent Document 2] US2017 / 0152780A1 [Patent Document 3] WO2018 / 224651A2 Summary of the Invention [Problem to be solved by the invention]

[0005] It is therefore an object of the present invention to provide an exhaust gas treatment system which prevents sulfation, improves general robustness against chemical fouling and poisoning, exhibits improved DeNOx to meet environmental requirements, has fast DeNOx response especially under transient conditions and is also cost-effective. Effect of the Invention

[0006] Surprisingly, it has been found that the exhaust gas treatment system according to the present invention prevents sulfation, improves general robustness against chemical fouling and poisoning, and exhibits improved DeNOx to meet environmental requirements by having fast DeNOx response, especially in transient conditions, while being cost-effective. [Brief description of the drawings]

[0007] [Figure 1] The figure shows the NOx conversion rate of the V-SCR catalyst of Reference Example 4 at two different temperatures, i.e., 200°C and 250°C. The NOx conversion rate was measured under the conditions of a space velocity of 50,000 / hr, NO of 500 ppm, and NH3 of 500 ppm. As is clear from this figure, the efficiency of the V-SCR catalyst improves with increasing temperature, and in particular, DeNOx is about 78% at 200°C, but increases to over 95% at 250°C. [Diagram 2] The graph shows the responsiveness of the catalyst (V-SCR catalyst) in Reference Example 4 and the catalyst (Cu-SCR catalyst) in Reference Example 6. DeNOx was measured at 210°C and a space velocity of 50,000 / hr. [Diagram 3]1 is a schematic diagram of an engine followed by an exhaust gas treatment system according to the present invention. In particular, the exhaust gas treatment system comprises an SCR catalyst, i.e. a V-SCR catalyst, and a Pd-DOC downstream of the V-SCR catalyst. In addition, a HC injector is installed between the outlet end of the V-SCR catalyst and the inlet end of the Pd-DOC, and a first urea injector is installed upstream of the inlet end of the V-SCR catalyst. In addition, the system comprises one of a first ammonia oxidation catalyst, an SCR catalyst, and a DOC / SCR mixed catalyst, which is located downstream of the Pd-DOC. The system further comprises a second ammonia oxidation (AMOX) catalyst and, optionally, a DOC at its outlet end. The system further comprises a catalyzed soot filter (CSF) downstream of the second AMOX catalyst and upstream of the SCR catalyst. In addition, a second urea injector is installed between the CSF and the SCR catalyst. Finally, the system further comprises an SCR catalyst or an AMOX catalyst. [Figure 4] The temperatures at the inlet and outlet ends of the V-SCR catalyst of the system of Comparative Example 1 and the temperature at the outlet end of the Pd-DOC of the system of Comparative Example 1 are shown versus time. [Diagram 5] 1 shows the inlet and outlet end temperatures of the Pd-DOC versus time during a hydrocarbon injection event in the system of Example 1. Also shown is the temperature of the upstream V-SCR. [Figure 6] The NOx conversion measured at the outlet of System 1 and System 2 under steady state conditions at 215° C. is shown. [Figure 7] The NOx conversion at the outlet end of the various catalysts forming systems A, B and C at 290° C. (steady state) is shown. [Figure 8] Nitrous oxide produced at the outlet end of various catalysts forming systems A, B and C at 290°C (steady state) is shown. [Figure 9] The NOx conversion at the outlet end of the various catalysts forming systems A, B and C during WHTC (transient state) is shown. [Figure 10]Nitrous oxide produced at the outlet end of the various catalysts forming systems A, B and C during WHTC (transient condition) is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Accordingly, the present invention provides an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium. Equipped with Here, the first catalyst described in (i) is a first catalyst of an exhaust gas treatment system provided downstream of an upstream end of an exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; In an exhaust gas treatment system, a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), and an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst. This relates to exhaust gas treatment systems.

[0009] It is preferred that the outlet end of the first catalyst described in (i) is in fluid communication with the inlet end of the second catalyst described in (iii), and that there is no catalyst disposed in the exhaust gas treatment system between the outlet end of the first catalyst described in (i) and the inlet end of the second catalyst described in (iii) for treating the exhaust gas flow exiting the first catalyst.

[0010] The first catalyst preferably comprises a nitrogen oxide (NOx) reducing component.

[0011] The vanadium oxide contained in the first catalyst is preferably one or more of vanadium oxide (V), vanadium oxide (IV), and vanadium oxide (III).

[0012] With regard to the coating of the first catalyst, it is suitable to contain vanadium oxide in an amount within the range of 1.0 to 10 wt %, more preferably 2.0 to 8.0 wt %, and even more preferably 2.5 to 6.0 wt %, based on the mass of the first oxide support.

[0013] It is preferable that the first oxide support containing titanium further contains one or more of tungsten, silicon, zirconium, and antimony, more preferably one or more of tungsten, silicon, and antimony. It is more preferable that the first oxide support further contains tungsten and silicon. Alternatively, it is more preferable that the first oxide support further contains antimony and silicon.

[0014] Thus, preferably, the present invention provides an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; wherein the coating comprises vanadium oxide in an amount in the range of 1.0 to 10 mass%, more preferably in the range of 2.0 to 8.0 mass%, based on the mass of the first oxide support, and the titanium-containing first oxide support further comprises one or more of tungsten, silicon, zirconium and antimony, more preferably one or more of tungsten, silicon and antimony; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium. Equipped with wherein the first catalyst according to (i) is a first catalyst of the exhaust gas treatment system downstream of an upstream end of the exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; The present invention relates to an exhaust gas treatment system in which a second catalyst described in (iii) is located downstream of the first catalyst described in (i) and downstream of the hydrocarbon injection device described in (ii), and the inlet end of the second catalyst is disposed upstream of the outlet end of the second catalyst.

[0015] From the viewpoint of the present invention, it is preferable that 80 to 98 mass%, more preferably 85 to 95 mass%, of the first oxide support is made of titania. It is preferable that 2 to 10 mass%, more preferably 5 to 15 mass% of the first oxide support is made of tungsten and silicon (calculated as WO3 and SiO2). Alternatively, it is preferable that 2 to 10 mass%, more preferably 5 to 15 mass% of the first oxide support is made of antimony and silicon (calculated as Sb2O3 and SiO2).

[0016] The first catalyst coating is 1-10 g / in 3 More preferably, the range is 2 to 7 g / in 3 More preferably, the range is 3 to 5.5 g / in 3 It is preferred to include the first oxide support at a loading (carrying amount) in the range of

[0017] It is preferred that the first catalyst coating further comprises an oxide binder selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, silica, and mixtures of two or more thereof, and even more preferably silica.

[0018] The coating of the first catalyst suitably comprises an oxide binder, more preferably an oxide binder as disclosed above, in an amount in the range of 0.5 to 10 mass %, more preferably in the range of 2 to 8 mass %, even more preferably in the range of 3 to 6 mass %, based on the mass of the first oxide support.

[0019] For the first catalyst, it is preferred that the coating comprises vanadium oxide supported on a first oxide support containing titanium, more preferably titania, and more preferably the first oxide support further comprises tungsten and silicon, and wherein said coating more preferably further comprises an oxide binder as defined above.

[0020] In the context of the present invention, it is preferred that 95-100% by weight, more preferably 98-100% by weight, more preferably 99-100% by weight, more preferably 99.5-100% by weight of the coating of the first catalyst consists of vanadium oxide supported on a first oxide support containing titanium, more preferably titania, and more preferably an oxide binder as defined above, and it is even more preferred that the first oxide support further contains tungsten and silicon.

[0021] It is suitable that up to 0.001% by mass of the first catalyst coating consists of palladium, preferably of palladium and rhodium, more preferably of palladium, platinum and rhodium, and even more preferably of platinum group metals, more preferably of 0-0.001% by mass, even more preferably of 0-0.0001% by mass, even more preferably of 0-0.00001% by mass.

[0022] Suitably, a maximum of 0.1% by mass of the first catalyst coating consists of zeolitic material, more preferably molecular sieve, more preferably 0-0.1% by mass, even more preferably 0-0.01% by mass, even more preferably 0-0.001% by mass.

[0023] It is preferred that the first substrate comprises one or more of cordierite, aluminum titanate and silicon carbide, more preferably one or more of cordierite and silicon carbide, more preferably cordierite, more preferably consisting of (those described above).

[0024] Suitably, the first substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, and more preferably a cordierite flow-through substrate.

[0025] Alternatively, it is preferred that the first substrate comprises a metal material, more preferably consists of a metal material, which more preferably comprises oxygen and one or more of iron, chromium and aluminum, more preferably consists of (those mentioned above).It is more preferred that the first substrate is a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, and even more preferably a metallic flow-through substrate.

[0026] The first catalyst is 1.5 to 12 g / in 3 and more preferably 2.5 to 8 g / in 3 and more preferably 3.5 to 6 g / in 3 It is preferred to include the coating at a loading in the range of

[0027] The first catalyst coating suitably spreads, ie extends, over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the first substrate.

[0028] The first catalyst described in (i) suitably comprises a coating and a first substrate.

[0029] For the second catalyst according to (iii), it is preferred that the second oxide support contained in the coating of the second catalyst comprises one or more of zirconium and aluminium, more preferably aluminium and optionally zirconium.

[0030] It is preferred that 90 to 100% by mass, more preferably 95 to 100% by mass, more preferably 98 to 100% by mass, more preferably 99 to 100% by mass of the second oxide support of the second catalyst coating is composed of aluminum, oxygen, and optionally zirconium.

[0031] More preferably, 60 to 95 mass %, more preferably 75 to 85 mass %, of the second oxide support is made of alumina, and 5 to 40 mass %, more preferably 15 to 25 mass % of the second oxide support is made of zirconia.

[0032] The second catalyst coating described in (iii) is preferably in the range of 0.25 to 5 g / in 3 More preferably, the range is 0.5 to 5 g / in 3 More preferably, the range is 0.75 to 4 g / in 3 More preferably, in the range of 1 to 2 g / in 3 It is preferred to include the second oxide support at a loading in the range of

[0033] (iii) The second catalyst coating has a coating density of 5 to 90 g / ft 3 range, preferably 10 to 70 g / ft 3 More preferably, it is in the range of 30 to 60 g / ft 3 It is preferred that the amount of palladium contained ranges from 0.1 to 1.0.

[0034] With respect to the second catalyst, it is preferred that palladium is the only platinum group metal present in the coating of the second catalyst described in (iii).

[0035] It is preferred that the second substrate comprises one or more of cordierite, aluminum titanate and silicon carbide, more preferably one or more of cordierite and silicon carbide, more preferably cordierite, more preferably consisting of (as described above).

[0036] Suitably, the second substrate is a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, more preferably a cordierite flow-through substrate.

[0037] Alternatively, it is preferred that the second substrate comprises, and more preferably consists of, a metal material, which more preferably comprises, and more preferably consists of, oxygen and one or more of iron, chromium and aluminum (as described above).It is more preferred that the second substrate is a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, and even more preferably a metallic flow-through substrate.

[0038] The second catalyst described in (iii) suitably comprises a coating and a second substrate.

[0039] It is suitable that a maximum of 0.1% by mass of the second catalyst coating consists of vanadium oxide, more preferably 0 to 0.1% by mass, even more preferably 0 to 0.01% by mass, and even more preferably 0 to 0.001% by mass.

[0040] For the second catalyst described in (iii), it is preferred that the second catalyst coating comprises palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminium and titanium, more preferably aluminium and zirconium.

[0041] It is suitable that 98 to 100% by mass, preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass of the second catalyst coating consists of palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum and titanium, more preferably aluminum and zirconium.

[0042] Thus, preferably, the present invention provides an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; wherein the coating contains the vanadium oxide in an amount in the range of 1.0 to 10 mass%, more preferably in the range of 2.0 to 8.0 mass%, based on the mass of the first oxide support, and the titanium-containing first oxide support further contains one or more of tungsten, silicon, zirconium and antimony, more preferably one or more of tungsten, silicon and antimony; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) A second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate comprises a plurality of passages having an inlet end, an outlet end, and a length in a substrate axial direction extending from the inlet end to the outlet end of the second substrate and defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of aluminum and zirconium, wherein 98 to 100 mass % of the coating of the second catalyst consists of palladium supported on a second oxide support containing one or more of aluminum and zirconium. Equipped with wherein the first catalyst according to (i) is a first catalyst of the exhaust gas treatment system downstream of an upstream end of the exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; In an exhaust gas treatment system, a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), and an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst. This relates to exhaust gas treatment systems.

[0043] Suitably, a maximum of 0.1% by weight of the second catalyst coating consists of zeolitic material, more preferably molecular sieve, more preferably 0-0.1% by weight, even more preferably 0-0.01% by weight, even more preferably 0-0.001% by weight.

[0044] In view of the present invention, according to an alternative, it is preferred that the second catalytic coating according to (iii) further comprises a zeolitic material, the zeolitic material containing one or more of Cu and Fe.

[0045] It is preferred that the zeolitic material contained in the coating of the second catalyst has framework type AEI, GME, CHA, MFI, BEA, FAU, MOR or a mixture of two or more thereof, more preferably has framework type AEI, CHA, BEA or a mixture of two or more thereof, more preferably has framework type CHA or AEI, more preferably has framework type CHA.

[0046] It is preferable that 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 more preferably in the range of 0.5 to 10 mass%, more preferably in the range of 1 to 7 mass%, and even more preferably in the range of 2.5 to 6 mass%, based on the total mass of the zeolite material. It is more preferable that the amount of iron in the zeolite material, calculated as Fe2O3, is 0 to 0.01 mass%, more preferably in the range of 0 to 0.001 mass%, and even more preferably in the range of 0 to 0.0001 mass%, based on the total mass of the zeolite material.

[0047] It is preferable that 95 to 100 mass %, more preferably 98 to 100 mass %, further preferably 99 to 100 mass %, and more preferably 99.5 to 100 mass % of the framework structure of the zeolite material contained in the coating of the second catalyst is composed of Si, Al, O, and H. In this case, the molar ratio of Si to Al (calculated as molar SiO2:Al2O3) in the framework structure 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 35:1.

[0048] It is preferable that the zeolite material contained in the coating of the second catalyst contains iron, and in this case, the amount of iron contained 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 even more preferably in the range of 2.5 to 5.5 mass%, based on the total mass of the zeolite material. It is more preferable that 95 to 100 mass%, more preferably 98 to 100 mass%, even more preferably 99 to 100 mass%, and even more preferably 99.5 to 100 mass% of the framework structure of the zeolite material is composed of Si, Al, O, and H, and in this case, the molar ratio of Si to Al (calculated as molar SiO2:Al2O3) in the framework structure 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 even more preferably in the range of 15:1 to 35:1.

[0049] It is preferred that the zeolitic material contained in the coating of the second catalyst, more preferably having a framework CHA, has a mean crystallite size as measured by scanning electron microscopy of at least 0.1 micrometers, more preferably in the range 0.1 to 3.0 micrometers, more preferably in the range 0.3 to 1.5 micrometers, more preferably in the range 0.4 to 1.0 micrometers.

[0050] The second catalyst coating is 0.2 to 8 g / in 3 More preferably, the range is 0.5 to 6 g / in 3 More preferably, in the range of 1 to 4 g / in 3 and the second catalyst coating described in (iii) comprises a zeolite material at a loading in the range of 0.3 to 0.75 g / in. 3 , more preferably 0.4 to 0.6 g / in 3 It is preferred to include the second oxide support at a loading in the range of

[0051] For the second catalyst coating comprising a zeolitic material, it is preferred that the coating further comprises an oxide binder. It is more preferred that the oxide binder is selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, zirconia, and mixtures of two or more thereof, even more preferably zirconia. It is more preferred that the second catalyst coating comprises the oxide binder in an amount in the range of 0.5-10% by weight, preferably in the range of 2-8% by weight, more preferably in the range of 3-6% by weight, based on the total weight of the zeolitic material. It is preferable that 95 to 100% by mass, more preferably 98 to 100% by mass, even more preferably 99 to 100% by mass, and even more preferably 99.5 to 100% by mass of the coating of the second catalyst consists of a zeolite material containing one or more of palladium, Cu and Fe supported on a second oxide support containing one or more of zirconium, silicon, aluminum and titanium, and more preferably the oxide binder defined above.

[0052] From the viewpoint of the present invention, the second catalyst is preferably in an amount of 0.3 to 5 g / in 3 and more preferably 1 to 4 g / in 3 and more preferably 1.5 to 4.6 g / in 3 It is preferred to include the coating at a loading in the range of

[0053] The second catalyst coating preferably extends over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the second substrate.

[0054] The system of the present invention further comprises: (iv) a third catalyst having an inlet end and an outlet end and comprising a coating and a third substrate, wherein the third substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the third substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the third substrate, the coating comprising a zeolitic material containing one or more of vanadium oxides and one or more of Cu and Fe. It is preferable to have Here, in the exhaust gas treatment system, it is preferable that the third catalyst described in (iv) is located downstream of the second catalyst described in (iii), and the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst.

[0055] Thus, preferably, the present invention provides an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium; (iv) a third catalyst having an inlet end and an outlet end and comprising a coating and a third substrate, wherein the third substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the third substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the third substrate, the coating comprising a zeolitic material containing one or more of vanadium oxides and one or more of Cu and Fe. Equipped with wherein the first catalyst according to (i) is a first catalyst of the exhaust gas treatment system downstream of an upstream end of the exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; an exhaust gas treatment system, wherein a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), and an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst; The present invention relates to an exhaust gas treatment system in which a third catalyst described in (iv) is located downstream of the second catalyst described in (iii), and the inlet end of the third catalyst is disposed upstream of the outlet end of the third catalyst.

[0056] In accordance with the present invention, it is preferred that the outlet end of the second catalyst described in (iii) is in fluid communication with the inlet end of the third catalyst described in (iv), and that in this exhaust gas treatment system, no catalyst for treating the exhaust gas flow exiting the second catalyst is disposed between the outlet end of the second catalyst described in (iii) and the inlet end of the third catalyst described in (iv).

[0057] With regard to the third catalyst according to (iv), according to the first aspect, it is preferred that the coating of the third catalyst according to (iv) comprises a zeolitic material containing one or more of Cu and Fe.

[0058] It is preferred that the zeolitic material contained in the third catalyst coating has framework type AEI, GME, CHA, MFI, BEA, FAU, MOR or a mixture of two or more thereof, more preferably framework type AEI, CHA, BEA or a mixture of two or more thereof, more preferably framework type CHA or AEI. It is further preferred that the zeolitic material contained in the third catalyst coating has framework type CHA.

[0059] The zeolite material contained in the coating of the third catalyst contains copper, and in this case, the amount of copper contained in the zeolite material, calculated as CuO, is preferably in the range of 0.5 to 10 mass%, more preferably 1 to 8 mass%, even more preferably 2 to 7 mass%, and even more preferably 3 to 6 mass%, based on the total mass of the zeolite material. Also, 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 0 to 0.001 mass%, and even more preferably 0 to 0.0001 mass%, based on the total mass of the zeolite material.

[0060] It is preferable that 95 to 100 mass %, more preferably 98 to 100 mass %, further preferably 99 to 100 mass %, and more preferably 99.5 to 100 mass % of the framework structure of the zeolite material contained in the coating of the third catalyst is composed of Si, Al, O, and H. In this case, it is preferable that the molar ratio of Si to Al (calculated as molar SiO2:Al2O3) in the framework structure 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 35:1.

[0061] The zeolite material contained in the coating of the third catalyst contains iron, and in this case, 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%, and even more preferably in the range of 2.5 to 5.5 mass%, based on the total mass of the zeolite material. Also, 95 to 100 mass%, more preferably 98 to 100 mass%, even more preferably 99 to 100 mass%, and even more preferably 99.5 to 100 mass% of the framework structure of the zeolite material is composed of Si, Al, O, and H, and in this case, the molar ratio of Si:Al in the framework structure (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 even more preferably in the range of 15:1 to 35:1.

[0062] The zeolitic material contained in the coating of the third catalyst, more preferably having framework CHA, suitably has an average crystal grain size as measured by scanning electron microscopy of at least 0.1 micrometer, more preferably in the range of 0.1 to 3.0 micrometers, more preferably in the range of 0.3 to 1.5 micrometers, more preferably in the range of 0.4 to 1.0 micrometers.

[0063] The third catalyst coating is 0.5-8g / in 3 More preferably, the range is 0.75 to 5 g / in 3More preferably, the range is 1 to 3.5 g / in 3 It is more preferred to include the zeolite material at a loading in the range of 1000 to 2000 g / m2.

[0064] The third catalytic coating described in (iv) suitably further comprises an oxide binder.

[0065] The oxide binder is preferably selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, zirconia, and mixtures of two or more thereof, and even more preferably zirconia.

[0066] It is more preferred that the third catalyst coating comprises the oxide binder in an amount in the range of 0.5 to 10% by weight, preferably in the range of 2 to 8% by weight, more preferably in the range of 3 to 6% by weight, based on the total weight of the zeolitic material. With regard to the third catalyst as described in (iv) according to the first aspect, it is preferred that the coating comprises a zeolitic material containing one or more of Cu and Fe, wherein the zeolitic material has framework type AEI, GME, CHA, MFI, BEA, FAU, MOR or a mixture of two or more thereof, more preferably has framework type AEI, CHA, BEA or a mixture of two or more thereof, more preferably has framework type CHA or AEI, more preferably has framework type CHA, and further preferably the coating further comprises an oxide binder.

[0067] It is suitable that up to 0.001% by mass of the third catalyst coating consists of palladium, platinum and rhodium, preferably platinum group metals, more preferably 0 to 0.001% by mass, even more preferably 0 to 0.0001% by mass, still more preferably 0 to 0.00001% by mass.

[0068] Suitably, a maximum of 0.1% by mass of the third catalyst coating consists of vanadium oxide, more preferably 0 to 0.1% by mass, even more preferably 0 to 0.01% by mass, and even more preferably 0 to 0.001% by mass.

[0069] It is preferable that 95 to 100 mass %, more preferably 98 to 100 mass %, even more preferably 99 to 100 mass %, and even more preferably 99.5 to 100 mass % of the coating of the third catalyst is composed of a zeolite material containing one or more of Cu and Fe, and more preferably the oxide binder defined above.

[0070] In view of the present invention, it is preferred that the second catalytic coating as described in (iii) comprises, more preferably consists of, palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminium and titanium, preferably aluminium and optionally zirconium, and that the third catalytic coating as described in (iv) comprises, more preferably consists of, a zeolitic material containing one or more of Cu and Fe, and more preferably an oxide binder as defined above.

[0071] Thus, preferably, the present invention provides an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; wherein the coating comprises vanadium oxide in an amount in the range of 1.0 to 10 mass%, more preferably in the range of 2.0 to 8.0 mass%, based on the mass of the first oxide support, and the titanium-containing first oxide support further comprises one or more of tungsten, silicon, zirconium and antimony, more preferably one or more of tungsten, silicon and antimony; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate, the second catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium, preferably aluminum and optionally zirconium; (iv) a third catalyst having an inlet end and an outlet end and comprising a coating and a third substrate, wherein the third substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the third substrate, the third substrate comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the third substrate, the coating comprising a zeolitic material containing one or more of Cu and Fe, and more preferably an oxide binder as defined above. Equipped with wherein the first catalyst according to (i) is a first catalyst of the exhaust gas treatment system downstream of an upstream end of the exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; an exhaust gas treatment system, wherein a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), and an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst; The present invention relates to an exhaust gas treatment system in which a third catalyst described in (iv) is located downstream of the second catalyst described in (iii), and the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst according to the first aspect.

[0072] With respect to the third coating as described in (iv) of the second aspect, it is preferred that the third catalytic coating comprises vanadium oxide, in which case it is preferred that the vanadium oxide is one or more of vanadium(V) oxide, vanadium(IV) oxide and vanadium(III) oxide.

[0073] It is more preferable that the vanadium is supported on a third oxide support, and in this case, the coating of the third catalyst contains the vanadium oxide in an amount, more preferably in the range of 1.5 to 10 mass %, more preferably in the range of 2.5 to 8 mass %, and even more preferably in the range of 3 to 6 mass %, based on the mass of the third oxide support.

[0074] In the case where the third oxide support contains titanium, it is preferable that the third oxide support further contains one or more of tungsten, silicon, zirconium, and antimony, preferably one or more of tungsten, silicon, and antimony, and more preferably the third oxide support further contains tungsten and silicon, or the third oxide support further contains antimony and silicon.

[0075] It is more preferable that 80 to 98 mass % of the third oxide support is made of titania, more preferably 85 to 95 mass %. It is even more preferable that 2 to 10 mass % of the third oxide support is made of tungsten and silicon, more preferably 5 to 15 mass % (calculated as WO3 and SiO2). Alternatively, it is even more preferable that 2 to 10 mass % of the third oxide support is made of antimony and silicon, more preferably 5 to 15 mass % (calculated as Sb2O3 and SiO2).

[0076] The third catalyst coating is 1-10g / in 3 More preferably, the range is 2 to 7 g / in 3 More preferably, the range is 3 to 5.5 g / in 3 It is preferred to include the third oxide support at a loading in the range of

[0077] For the third catalytic coating comprising vanadium oxide, it is preferred that the third catalytic coating further comprises an oxide binder selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, silica, and mixtures of two or more thereof, even more preferably silica.

[0078] The coating suitably contains the oxide binder in an amount in the range of 0.5 to 10 mass %, preferably in the range of 2 to 8 mass %, more preferably in the range of 3 to 6 mass %, based on the mass of the third oxide support. With respect to the third coating as described in (iv) of the second aspect, it is preferred that the third catalytic coating further comprises a platinum group metal component, in which case it is preferred that the platinum group metal component is one or more of palladium, platinum and rhodium, more preferably one or more of palladium and platinum.

[0079] The platinum group metal component is preferably platinum and palladium, and in this case, the mass ratio of platinum to palladium, Pt:Pd, calculated as the platinum group metal elements, is more preferably in the range of 2:1 to 18:1, more preferably in the range of 5:1 to 15:1, and more preferably in the range of 8:1 to 12:1.

[0080] The third catalyst coating is 1-30g / in 3 More preferably, the range is 2 to 15 g / in 3 More preferably, the range is 5 to 12 g / in 3 It is preferred to include the platinum group metal component at a loading in the range of

[0081] The platinum group metal component is preferably supported on an oxide material, and in this case the oxide material is more preferably one or more of alumina, silica, zirconia and titania, more preferably one or more of alumina, silica and zirconia, more preferably one or more of alumina and silica, and in this case the oxide material is more preferably alumina doped with zirconia. The coating of the third catalyst is preferably 0.1 to 4 g / in 3 More preferably, the range is 0.2 to 2 g / in 3 and more preferably 0.5 to 1.5 g / in 3 More preferably, the platinum group metal component is supported by an oxide material having a loading in the range of 0.1 to 1000 nm.

[0082] With regard to the third catalyst according to (iv) of the second aspect, it is suitable that 95 to 100% by weight, more preferably 98 to 100% by weight, more preferably 99 to 100% by weight, more preferably 99.5 to 100% by weight of the coating of the third catalyst consists of a platinum group component, more preferably a platinum group component supported on an oxide material as defined above, and a vanadium oxide supported on a third oxide support, and more preferably an oxide binder as defined above.

[0083] With regard to the third catalyst as described in (iv) according to the second aspect, it is preferred that 95 to 100% by mass, more preferably 98 to 100% by mass, more preferably 99 to 100% by mass, more preferably 99.5 to 100% by mass of the coating of the third catalyst consists of a platinum group component, more preferably a platinum group component supported on an oxide material as defined above, and a zeolitic material containing one or more of Cu and Fe, and more preferably an oxide binder as defined above.

[0084] In view of the present invention, for the third catalyst described in (iv), it is preferred that the third substrate comprises one or more of cordierite, aluminum titanate and silicon carbide, more preferably one or more of cordierite and silicon carbide, more preferably cordierite, more preferably consisting of (as described above).

[0085] The third substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, and more preferably a cordierite flow-through substrate. The third substrate may be made of metal, like the first and second substrates.

[0086] The third catalyst is 0.75 to 10 g / in 3 More preferably, in the range of 1 to 7 g / in 3 and more preferably in the range of 1.5 to 5.5 g / in 3 It is preferred to include the coating at a loading in the range of

[0087] The third catalyst coating preferably extends over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the third substrate.

[0088] The third substrate of the third catalyst preferably has a substrate length in the range of 2.54 to 25.4 cm (1 to 10 inches), more preferably in the range of 3.81 to 17.78 cm (1.5 to 7 inches), and even more preferably in the range of 5.08 to 10.16 cm (2 to 4 inches).

[0089] The third substrate of the third catalyst suitably has a substrate width in the range of 10.16 to 43.18 cm (4 to 17 inches), more preferably in the range of 17.78 to 38.10 cm (7 to 15 inches), and even more preferably in the range of 22.86 to 30.48 cm (9 to 12 inches).

[0090] The third catalyst described in (iv) suitably comprises a coating and a third substrate.

[0091] The first substrate of the first catalyst preferably has a substrate length in the range of 2.54 to 25.4 cm (1 to 10 inches), more preferably in the range of 5.08 to 20.32 cm (2 to 8 inches), and even more preferably in the range of 7.62 to 15.24 cm (3 to 6 inches).

[0092] The first substrate of the first catalyst preferably has a substrate width in the range of 2.54 to 50.8 cm (1 to 20 inches), more preferably in the range of 12.7 to 43.18 cm (5 to 17 inches), and even more preferably in the range of 20.32 to 38.1 cm (8 to 15 inches).

[0093] The second substrate of the second catalyst preferably has a substrate length in the range of 2.54 to 25.4 cm (1 to 10 inches), more preferably in the range of 3.81 to 17.78 cm (1.5 to 7 inches), and even more preferably in the range of 5.08 to 10.16 cm (2 to 4 inches).

[0094] The second substrate of the second catalyst preferably has a substrate width in the range of 10.16 to 50.8 cm (4 to 20 inches), more preferably in the range of 17.78 to 43.18 cm (7 to 17 inches), and even more preferably in the range of 22.86 to 38.1 cm (9 to 15 inches).

[0095] In accordance with the present invention, it is preferred that the system further comprises a fourth catalyst, which is preferably one or more of an ammonia oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst.

[0096] The fourth catalyst is preferably an ammonia oxidation catalyst, in which case the fourth catalyst has an inlet end and an outlet end, and preferably comprises a coating and a fourth substrate. The fourth substrate has an inlet end, an outlet end, and a length in the substrate axial direction extending from the inlet end to the outlet end of the fourth substrate, and comprises a plurality of passages defined by an inner wall, where an interface between the passages and the inner wall is defined by a surface of the inner wall. A coating of the fourth catalyst is disposed on the surface of the inner wall of the fourth substrate, the coating comprising an ammonia oxidation component. In the exhaust gas treatment system, the fourth catalyst is located downstream of the third catalyst described in (iv), and the inlet end of the fourth catalyst is disposed upstream of the outlet end of the fourth catalyst. The outlet end of the third catalyst described in (iv) is in fluid communication with the inlet end of the fourth catalyst, and in the exhaust gas treatment system, no catalyst for treating exhaust gas leaving the third catalyst is disposed between the outlet end of the third catalyst and the inlet end of the fourth catalyst.

[0097] It is preferred that the ammonia oxidation component of the fourth catalytic coating comprises a platinum group metal component, one or more vanadium oxides, and a zeolitic material containing one or more of Cu and Fe, more preferably a platinum group metal component, and a zeolitic material containing one or more of Cu and Fe.

[0098] The ammonia oxidation component of the fourth catalyst coating preferably comprises, more preferably consists of, a platinum group metal component, more preferably one or more of palladium and platinum, supported on an oxide support, and a zeolitic material, more preferably a Cu-containing zeolitic material having a framework CHA (as described above).

[0099] Thus, preferably, the present invention provides an exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; Here, the coating more preferably contains the vanadium oxide in an amount in the range of 1.0 to 10 mass%, more preferably in the range of 2.0 to 8.0 mass%, based on the mass of the first oxide support, and the first oxide support containing titanium more preferably further contains one or more of tungsten, silicon, zirconium and antimony, more preferably one or more of tungsten, silicon and antimony; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium; (iv) a third catalyst having an inlet end and an outlet end and comprising a coating and a third substrate, wherein the third substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the third substrate, the third catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the third substrate, the coating comprising a zeolite material containing one or more of Cu and Fe. Equipped with wherein the first catalyst according to (i) is a first catalyst of the exhaust gas treatment system downstream of an upstream end of the exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; an exhaust gas treatment system, wherein a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), and an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst; wherein in the exhaust gas treatment system, a third catalyst as described in (iv) is located downstream of the second catalyst as described in (iii), and an inlet end of the third catalyst is disposed upstream of an outlet end of the third catalyst according to the first aspect; wherein the system further comprises a fourth catalyst, wherein the fourth catalyst is one or more of an ammonia oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst, more preferably an ammonia oxidation catalyst, wherein the fourth catalyst has an inlet end and an outlet end and comprises a coating and a fourth substrate; wherein a fourth substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the fourth substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein a coating of a fourth catalyst is disposed on the surface of the inner wall of the fourth substrate, the coating comprising an ammonia oxidation component; The present invention relates to an exhaust gas treatment system in which a fourth catalyst is located downstream of the third catalyst described in (iv), the inlet end of the fourth catalyst is disposed upstream of the outlet end of the fourth catalyst, and the outlet end of the third catalyst described in (iv) is in fluid communication with the inlet end of the fourth catalyst, and in which no catalyst for treating exhaust gas that has left the third catalyst in the exhaust gas treatment system is disposed between the outlet end of the third catalyst and the inlet end of the fourth catalyst.

[0100] From the viewpoint of the present invention, it is preferable that the system of the present invention further comprises a fifth catalyst, which is at least one of an ammonia oxidation catalyst, a diesel oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst, and is more preferably a catalyzed soot filter.

[0101] The fifth catalyst preferably has an inlet end and an outlet end and comprises a coating disposed on a fifth substrate, more preferably a wall-flow filter substrate, wherein in the exhaust gas treatment system, a fourth catalyst is located downstream of the third catalyst described in (iv), the inlet end of the fourth catalyst is disposed upstream of the outlet end of the fourth catalyst, and the outlet end of the fourth catalyst is in fluid communication with the inlet end of the fifth catalyst, and no catalyst is disposed between the outlet end of the fourth catalyst and the inlet end of the fifth catalyst for treating exhaust gas that has left the fourth catalyst in the exhaust gas treatment system.

[0102] The system of the present invention preferably further comprises a sixth catalyst, in which the sixth catalyst is preferably one or more of an ammonia oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst, more preferably a selective catalytic reduction catalyst. The selective catalytic reduction catalyst preferably comprises one or more vanadium oxides and a zeolite material containing one or more of Cu and Fe, more preferably a zeolite material containing one or more of Cu and Fe.

[0103] It is preferred that the sixth catalyst has an inlet end and an outlet end and comprises a coating on a sixth substrate, and in the exhaust gas treatment system, the sixth catalyst is positioned downstream of the fifth catalyst, the inlet end of the sixth catalyst is positioned upstream of the outlet end of the sixth catalyst, the outlet end of the fifth catalyst is in fluid communication with the inlet end of the sixth catalyst, and no catalyst is provided between the outlet end of the fifth catalyst and the inlet end of the sixth catalyst for treating exhaust gas leaving the fifth catalyst in the exhaust gas treatment system.

[0104] The system further comprises an injector for injecting a fluid into the exhaust gas stream emitted from the internal combustion engine, the injector being located upstream of the sixth catalyst and downstream of the fifth catalyst, the fluid being preferably an aqueous urea solution.

[0105] More preferably, the fifth catalyst is instead a diesel oxidation catalyst and the sixth catalyst is a catalyzed soot filter.

[0106] More preferably, the fifth catalyst has an inlet end and an outlet end and comprises a coating disposed on a fifth substrate, more preferably a wall-flow filter substrate, wherein in the exhaust gas treatment system, the fifth catalyst is located downstream of the fourth catalyst, the inlet end of the fifth catalyst is disposed upstream of the outlet end of the fifth catalyst, and the outlet end of the fourth catalyst is in fluid communication with the inlet end of the fifth catalyst, and no catalyst is disposed between the outlet end of the fourth catalyst and the inlet end of the fifth catalyst for treating exhaust gases exiting the fourth catalyst in the exhaust gas treatment system.

[0107] More preferably, the sixth catalyst has an inlet end and an outlet end and comprises a coating on a sixth substrate, and more preferably, in the exhaust gas treatment system, the sixth catalyst is disposed downstream of the fifth catalyst, the inlet end of the sixth catalyst is disposed upstream of the outlet end of the sixth catalyst, the outlet end of the fifth catalyst is in fluid communication with the inlet end of the sixth catalyst, and no catalyst is disposed between the outlet end of the fifth catalyst and the inlet end of the sixth catalyst for treating exhaust gas leaving the fifth catalyst in the exhaust gas treatment system.

[0108] The system of the present invention further comprises an injector for injecting a fluid into the exhaust gas stream emitted from the internal combustion engine, the injector being preferably located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system, and more preferably the fluid being an aqueous urea solution.

[0109] The system of the present invention further comprises an injector for injecting a fluid into the exhaust gas stream exiting the internal combustion engine, the injector(s) being preferably located upstream of the selective catalytic reduction catalyst, and more preferably the fluid being an aqueous urea solution.

[0110] It is preferred that no hydrocarbon injection device is located upstream of the first catalyst described in (i) and downstream of the upstream end of the exhaust gas treatment system.

[0111] The system of the present invention suitably comprises a first catalyst as described in (i), a hydrocarbon injection device as described in (ii), a second catalyst as described in (iii), and more preferably a third catalyst as defined above in (iv), and even more preferably one or more of the fourth to sixth catalysts as defined above.

[0112] The present invention further provides a method for producing a first catalyst of the exhaust gas treatment system of the present invention, comprising the steps of: (a) providing a mixture comprising water, a solution of vanadium oxide, and a first oxide material comprising titanium; (b) disposing the mixture from (a) on a surface of an inner wall of a first substrate to obtain a slurry-treated substrate, wherein the first substrate comprises a plurality of passages having an inlet end, an outlet end, and a length in a substrate axial direction extending from the inlet end to the outlet end of the first substrate and defined by the inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall; (c) optionally drying the slurry treated substrate from (b) to obtain a substrate having a coating disposed thereon; (d) calcining the slurry treated substrate obtained in (b), preferably the dried slurry treated substrate obtained in (c), to obtain a coated substrate. Including, Also, optionally, (b´) disposing the mixture obtained in (a) on the surface of the coating obtained in (d) disposed on the substrate; (c´) optionally drying the slurry treated substrate obtained in (b´); (d') calcining the slurry treated substrate obtained in (b') or the dried slurry treated substrate obtained in (c'). Including, Here, the present invention relates to a method for obtaining a first catalyst from (d) or (d').

[0113] Regarding (a), it is preferable that the following configuration is included. That is, (a.1) providing a mixture comprising water and a first oxide support containing titanium, wherein the first oxide support further comprises one or more of tungsten, silicon, zirconium and antimony, more preferably one or more of tungsten, silicon and antimony; (a.2) To the mixture obtained in (a.1) is added a solution of vanadium oxide, more preferably a solution of one or more of vanadium oxalate, ammonium vanadate and vanadium oxide, more preferably a solution of vanadium oxalate. (a.3) More preferably, a source of oxide binder is added. The source of oxide binder is one or more of colloidal silica, alumina, and zirconia, more preferably colloidal silica.

[0114] (b) suitably includes disposing the mixture over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the substrate.

[0115] The placement of the mixture described in (b) is preferably carried out by spraying the mixture onto the substrate or immersing the substrate in the mixture, more preferably by immersing the substrate in the mixture.

[0116] The drying described in (c) is suitably carried out in a gas atmosphere at a temperature in the range of 90 to 200°C, more preferably 120 to 160°C.

[0117] The drying described in (c) is preferably carried out in a gas atmosphere for a period of time in the range of 5 to 300 minutes, more preferably in the range of 20 to 60 minutes.

[0118] The dried slurry-treated base material obtained in (c) preferably has a moisture content in the range of 0 to 30%, more preferably in the range of 5 to 25%, and further preferably in the range of 15 to 20%.

[0119] The gas atmosphere preferably contains one or more of air, dilute air, and oxygen, and more preferably is one or more of these, and more preferably contains air, or is air.

[0120] The firing described in (d) is suitably carried out in a gas atmosphere at a temperature in the range of 300 to 600°C, more preferably in the range of 400 to 550°C.

[0121] The firing described in (d) is suitably carried out in a gas atmosphere for a duration in the range of 5 minutes to 120 minutes, more preferably in the range of 20 minutes to 40 minutes.

[0122] The gas atmosphere preferably contains one or more of air, dilute air, and oxygen, and more preferably is one or more of these, and more preferably contains air, or is air.

[0123] (b') suitably includes disposing the mixture over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the substrate.

[0124] The placement of the mixture described in (b') is preferably carried out by spraying the mixture onto the substrate or by immersing the substrate in the mixture, more preferably by immersing the substrate in the mixture.

[0125] The drying described in (c') is suitably carried out in a gas atmosphere having a temperature in the range of 90 to 200°C, more preferably in the range of 120 to 160°C.

[0126] The drying described in (c') is suitably carried out in a gas atmosphere for a duration in the range of 5 minutes to 300 minutes, more preferably in the range of 20 minutes to 60 minutes.

[0127] The dried slurry-treated base material obtained in (c') preferably has a moisture content in the range of 0 to 30%, more preferably in the range of 5 to 25%, and further preferably in the range of 15 to 20%.

[0128] The gas atmosphere preferably contains one or more of air, dilute air, and oxygen, and more preferably is one or more of these, and more preferably contains air, or is air.

[0129] The firing described in (d') is suitably carried out in a gas atmosphere at a temperature in the range of 300 to 600°C, more preferably in the range of 400 to 550°C.

[0130] The firing described in (d') is suitably carried out in a gas atmosphere for a duration in the range of 5 minutes to 120 minutes, more preferably in the range of 20 minutes to 40 minutes.

[0131] The gas atmosphere preferably contains one or more of air, dilute air, and oxygen, and more preferably is one or more of these, and more preferably contains air, or is air.

[0132] Suitably the method comprises (a), (b), (c), (d) and optionally (b'), (c') and (d').

[0133] The present invention further relates to a catalyst in an exhaust gas treatment system according to the invention, more preferably a first catalyst according to (i), which is obtained or obtainable by a method according to the invention.

[0134] The present invention further relates to the use of the catalyst of the present invention for the selective catalytic reduction of NOx.

[0135] The invention further relates to the use of an exhaust gas treatment system according to the invention for treating an exhaust gas stream leaving an internal combustion engine, preferably a diesel engine.

[0136] The present invention further provides a method for treating an exhaust gas stream exiting an internal combustion engine, comprising the steps of: (1) providing an exhaust gas stream from an internal combustion engine, preferably a diesel engine, wherein the exhaust gas stream comprises one or more of NOx, ammonia, nitric oxide, and hydrocarbons; (2) passing the exhaust gas stream prepared in (1) through the exhaust gas system of the present invention; The present invention relates to a method for providing the same.

[0137] The present invention will be described by the following series of embodiments and combinations of embodiments resulting from the indicated dependencies and backward references. In particular, it should be noted that in a section referring to a certain range of embodiments, for example in conjunction with a term such as "the system according to any one of the first to fourth embodiments", all embodiments within this range are expressly disclosed to those skilled in the art, that is, the wording of this term should be understood by those skilled in the art to be synonymous with "the system according to any one of the first, second, third and fourth embodiments". Furthermore, it should be explicitly pointed out that the following series of embodiments are not a set of claims in the claims that determine the scope of protection, but rather provide a properly organized description of the general and preferred aspects of the present invention.

[0138] 1. An exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium. Equipped with wherein the first catalyst described in (i) is a first catalyst of the exhaust gas treatment system downstream of an upstream end of the exhaust gas treatment device, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; In an exhaust gas treatment system, a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), and an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst. Exhaust gas treatment systems.

[0139] 2. The system of embodiment 1, wherein an outlet end of the first catalyst described in (i) is in fluid communication with an inlet end of the second catalyst described in (iii), and no catalyst for treating the exhaust gas stream exiting the first catalyst is disposed in the exhaust gas treatment system between the outlet end of the first catalyst described in (i) and the inlet end of the second catalyst described in (iii).

[0140] 3. The system of embodiment 1 or 2, wherein the first catalyst comprises a nitrogen oxide (NOx) reducing component.

[0141] 4. The system of any one of embodiments 1 to 3, wherein the vanadium oxide contained in the first catalyst is one or more of vanadium(V) oxide, vanadium(IV) oxide, and vanadium(III) oxide.

[0142] 5. The system according to any one of the preceding embodiments, wherein the coating of the first catalyst comprises the vanadium oxide in an amount ranging from 1.0 to 10% by weight, preferably in an amount ranging from 2.0 to 8.0% by weight, more preferably in an amount ranging from 2.5 to 6.0% by weight, based on the weight of the first oxide support.

[0143] 6. The first oxide support containing titanium further comprises one or more of tungsten, silicon, zirconium and antimony, preferably one or more of tungsten, silicon and antimony; 6. The system according to any one of the preceding embodiments, wherein the first oxide support preferably further comprises tungsten and silicon, or the first oxide support preferably further comprises antimony and silicon.

[0144] 7. The system according to any one of the preceding claims, wherein 80-98% by mass, more preferably 85-95% by mass, of the first oxide support is made of titania, and preferably 2-10% by mass, more preferably 5-15% by mass, of the first oxide support is made of tungsten and silicon, or antimony and silicon (calculated as WO3 and SiO2, or Sb2O3 and SiO2, respectively).

[0145] 8. The first catalyst coating is 1-10g / in 3 in the range of 2 to 7 g / in 3 More preferably, the range is 3 to 5.5 g / in 3 8. The system of any one of the preceding embodiments, comprising the first oxide support at a loading in the range of

[0146] 9. The first catalyst coating further comprises an oxide binder, the oxide binder being preferably selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, silica, and mixtures of two or more thereof, more preferably silica; 9. The system according to any one of the preceding embodiments, wherein the coating of the first catalyst comprises an oxide binder in an amount ranging from 0.5 to 10% by weight, more preferably ranging from 2 to 8% by weight, and even more preferably ranging from 3 to 6% by weight, based on the weight of the first oxide support.

[0147] 10. The system according to any one of the preceding embodiments, wherein 95-100% by weight, preferably 98-100% by weight, more preferably 99-100% by weight, more preferably 99.5-100% by weight of the coating of the first catalyst consists of vanadium oxide supported on a first oxide support containing titanium, preferably titania, more preferably the first oxide support further contains tungsten and silicon, and preferably an oxide binder as defined in embodiment 9.

[0148] 11. The system according to any one of the preceding embodiments, wherein up to 0.001% by weight of the coating of the first catalyst consists of palladium, preferably of palladium and rhodium, more preferably of palladium, platinum and rhodium, and more preferably of platinum group metals.

[0149] 12. The system according to any one of the preceding embodiments, wherein up to 0.1% by weight, preferably 0-0.1% by weight, more preferably 0-0.01% by weight, more preferably 0-0.001% by weight of the coating of the first catalyst consists of a zeolitic material, preferably a molecular sieve.

[0150] 13. The first substrate is made of one or more of cordierite, aluminum titanate, and silicon carbide, preferably one or more of cordierite and silicon carbide, more preferably cordierite; the first substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, more preferably a cordierite flow-through substrate; the first substrate comprises, preferably consists of, a metallic material, the metallic material preferably comprising, more preferably consisting of, oxygen and one or more of iron, chromium and aluminium (as previously described); 13. The system according to any one of embodiments 1 to 12, wherein the first substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, more preferably a metal flow-through substrate.

[0151] 14. The first catalyst is 1.5 to 12 g / in 3 in the range of 2.5 to 8 g / in 3 and more preferably 3.5 to 6 g / in 3 Coatings with loadings in the range of 14. The system of any one of the preceding embodiments, wherein the first catalyst coating extends over 95-100%, more preferably 98-100%, and even more preferably 99-100% of the axial length of the first substrate.

[0152] 15. The system of any one of embodiments 1 to 14, wherein the first catalyst described in (i) consists of a coating and a first substrate.

[0153] 16. The second oxide support contained in the coating of the second catalyst according to (iii) comprises one or more of zirconium and aluminium, preferably aluminium and, optionally, zirconium; More preferably, 90 to 100 mass%, more preferably 95 to 100 mass%, more preferably 98 to 100 mass%, more preferably 99 to 100 mass% of the second oxide support is composed of aluminum, oxygen, and optionally zirconium; The system according to any one of the first to fifth embodiments, wherein the second oxide support is preferably made of 60 to 95 mass%, more preferably 75 to 85 mass%, alumina, and the second oxide support is preferably made of 5 to 40 mass%, more preferably 15 to 25 mass%, zirconia.

[0154] 17. The second catalyst coating described in (iii) is 0.25 to 5 g / in 3 More preferably, the range is 0.5 to 5 g / in 3 More preferably, the range is 0.75 to 4 g / in 3 More preferably, in the range of 1 to 2 g / in 3 17. The system of any one of the preceding embodiments, comprising a second oxide support at a loading in the range of

[0155] 18. The second catalyst coating according to (iii) is 5 to 90 g / ft 3 range, preferably 10 to 70 g / ft 3 More preferably, it is in the range of 30 to 60 g / ft 3 18. The system of any one of the preceding embodiments, comprising palladium in an amount ranging from 0.1 to 0.5% by weight.

[0156] 19. The system of any one of the preceding embodiments, wherein palladium is the only platinum group metal present in the coating of the second catalyst described in (iii).

[0157] 20. The second substrate comprises (preferably consists of) one or more of cordierite, aluminum titanate, and silicon carbide, preferably one or more of cordierite and silicon carbide, more preferably cordierite; the second substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, more preferably a cordierite flow-through substrate; or the second substrate comprises, and preferably consists of, a metallic material, the metallic material preferably comprising (more preferably consisting of) oxygen and one or more of iron, chromium and aluminium; The system according to any one of the preceding embodiments, wherein the second substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, more preferably a metal flow-through substrate.

[0158] 21. The system of any one of the preceding embodiments, wherein the second catalyst described in (iii) comprises a coating and a second substrate.

[0159] 22. The system of any one of the preceding embodiments, wherein up to 0.1% by weight of the second catalyst coating consists of vanadium oxide, preferably 0-0.1% by weight, more preferably 0-0.01% by weight, more preferably 0-0.001% by weight.

[0160] 23. The system of any one of the preceding embodiments, wherein 98-100% by weight, preferably 99-100% by weight, more preferably 99.5-100% by weight, of the second catalyst coating consists of palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum, and titanium, preferably aluminum and zirconium.

[0161] 24. The system of any one of the preceding embodiments, wherein the second catalytic coating described in (iii) further comprises a zeolitic material, the zeolitic material containing one or more of Cu and Fe.

[0162] 25. The system according to embodiment 24, wherein the zeolitic material contained in the coating of the second catalyst has framework type AEI, GME, CHA, MFI, BEA, FAU, MOR or a mixture of two or more thereof, preferably has framework type AEI, CHA, BEA or a mixture of two or more thereof, more preferably has framework type CHA or AEI, more preferably has framework type CHA.

[0163] 26. 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 more preferably in the range of 0.5 to 10 mass %, more preferably in the range of 1 to 7 mass %, and even more preferably in the range of 2.5 to 6 mass %, based on the total mass of the zeolite material; 26. The system according to embodiment 24 or 25, wherein the amount of iron in the zeolitic material, calculated as Fe2O3, is more preferably in the range of 0 to 0.01% by weight, more preferably 0 to 0.001% by weight, even more preferably 0 to 0.0001% by weight, based on the total weight of the zeolitic material.

[0164] 27. The system according to any one of embodiments 24 to 26, wherein 95 to 100% by mass, preferably 98 to 100% by mass, further preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the framework structure of the zeolite material contained in the coating of the second catalyst is composed of Si, Al, O, and H, and the molar ratio of Si:Al in the framework structure (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 35:1.

[0165] 28. The system according to embodiment 24 or 25, wherein the zeolitic material contained in the coating of the second catalyst contains iron, the amount of iron contained in the zeolitic material, calculated as Fe2O3, is preferably in the range of 0.1 to 10.0% by weight, more preferably in the range of 1.0 to 7.0% by weight, even more preferably in the range of 2.5 to 5.5% by weight, based on the total weight of the zeolitic material; and preferably 95 to 100% by weight, more preferably 98 to 100% by weight, more preferably 99 to 100% by weight, even more preferably 99.5 to 100% by weight of the framework structure of the zeolitic material consists of Si, Al, O and H, and the molar ratio of Si to Al in the framework structure, 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, even more preferably in the range of 15:1 to 35:1.

[0166] 29. The system according to any one of embodiments 24 to 28, wherein the zeolitic material contained in the coating of the second catalyst, preferably a zeolitic material having a framework CHA, has a mean crystallite size measured by scanning electron microscopy of at least 0.1 micrometers, preferably in the range of 0.1 to 3.0 micrometers, more preferably in the range of 0.3 to 1.5 micrometers, more preferably in the range of 0.4 to 1.0 micrometers.

[0167] 30. The second catalyst coating is 0.2-8 g / in 3 More preferably, the range is 0.5 to 6 g / in 3 More preferably, in the range of 1 to 4 g / in 3 and (iii) a coating of the second catalyst in the range of 0.3 to 0.75 g / in 3 , more preferably 0.4 to 0.6 g / in 3 30. The system of any one of embodiments 24-29, comprising a second oxide support at a loading in the range of

[0168] 31. The second catalytic coating according to (iv) further comprises an oxide binder, wherein the oxide binder is preferably selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, zirconia, and mixtures of two or more thereof, more preferably zirconia; 31. The system according to any one of embodiments 24 to 30, wherein the coating of the second catalyst preferably comprises the oxide binder in an amount in the range of 0.5 to 10 wt.%, preferably in the range of 2 to 8 wt.%, more preferably in the range of 3 to 6 wt.%, based on the total weight of the zeolitic material.

[0169] 32. The system according to any one of embodiments 24 to 31, wherein 95 to 100% by weight, preferably 98 to 100% by weight, even more preferably 99 to 100% by weight, and even more preferably 99.5 to 100% by weight of the coating of the second catalyst consists of a zeolitic material containing one or more of palladium, Cu and Fe supported on a second oxide support containing one or more of zirconium, silicon, aluminum and titanium, and an oxide binder, preferably as defined in embodiment 31.

[0170] 33. The second catalyst is 0.3 to 5 g / in 3 in the range of 1 to 4 g / in 3 More preferably, the range is 1.5 to 4.6 g / in 3 Coatings with loadings in the range of 33. The system of any one of the preceding embodiments, wherein the second catalyst coating extends over 95-100%, more preferably 98-100%, and even more preferably 99-100% of the axial length of the second substrate.

[0171] 34.Furthermore, (iv) a third catalyst having an inlet end and an outlet end and comprising a coating and a third substrate, wherein the third substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the third substrate and comprises a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the third substrate, the coating comprising a zeolitic material containing one or more of vanadium oxides and one or more of Cu and Fe. Equipped with wherein in the exhaust gas treatment system, a third catalyst described in (iv) is located downstream of the second catalyst described in (iii), and an inlet end of the third catalyst is disposed upstream of an outlet end of the third catalyst.

[0172] 35. The system described in embodiment 34, wherein the outlet end of the second catalyst described in (iii) is in fluid communication with the inlet end of the third catalyst described in (iv), and no catalyst for treating the exhaust gas flow exiting the second catalyst is disposed in the exhaust gas treatment system between the outlet end of the second catalyst described in (iii) and the inlet end of the third catalyst described in (iv).

[0173] 36. The system of any one of embodiments 34 and 35, wherein the third catalytic coating described in (iv) comprises a zeolitic material containing one or more of Cu and Fe.

[0174] 37. The system according to embodiment 36, wherein the zeolitic material contained in the coating of the third catalyst has framework type AEI, GME, CHA, MFI, BEA, FAU, MOR or a mixture of two or more thereof, preferably has framework type AEI, CHA, BEA or a mixture of two or more thereof, more preferably has framework type CHA or AEI, more preferably has framework type CHA.

[0175] 38. The zeolitic material contained in the coating of the third catalyst contains copper, and in this case the amount of copper contained in the zeolitic material, calculated as CuO, is preferably in the range of 0.5 to 10 mass %, more preferably 1 to 8 mass %, even more preferably 2 to 7 mass %, and even more preferably 3 to 6 mass %, based on the total mass of the zeolitic material; 38. The system according to embodiment 36 or 37, wherein the amount of iron in the zeolitic material, calculated as Fe2O3, is more preferably in the range of 0 to 0.01% by weight, more preferably 0 to 0.001% by weight, and even more preferably 0 to 0.0001% by weight, based on the total weight of the zeolitic material.

[0176] 39. The system according to any one of embodiments 36 to 38, wherein 95 to 100% by mass, preferably 98 to 100% by mass, further preferably 99 to 100% by mass, and more preferably 99.5 to 100% by mass of the framework structure of the zeolite material contained in the coating of the third catalyst is composed of Si, Al, O, and H, and the molar ratio of Si:Al in the framework structure (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 35:1.

[0177] 40. The system according to embodiment 36 or 37, wherein the zeolite material in the coating of the third catalyst contains iron, the amount of iron in the zeolite material being preferably in the range of 0.1 to 10.0% by weight, more preferably in the range of 1.0 to 7.0% by weight, even more preferably in the range of 2.5 to 5.5% by weight, calculated as Fe2O3, based on the total weight of the zeolite material; and preferably 95 to 100% by weight, more preferably 98 to 100% by weight, more preferably 99 to 100% by weight, even more preferably 99.5 to 100% by weight of the framework structure of the zeolite material consists of Si, Al, O and H, and the molar ratio of Si to Al in the framework structure 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, even more preferably in the range of 15:1 to 35:1, calculated as molar SiO2:Al2O3.

[0178] 41. The system of any one of embodiments 36 to 40, wherein the zeolitic material contained in the coating of the third catalyst, preferably having framework type CHA, has an average crystal grain size of at least 0.1 micrometers, preferably in the range of 0.1 to 3.0 micrometers, more preferably in the range of 0.3 to 1.5 micrometers, more preferably in the range of 0.4 to 1.0 micrometers, as measured by scanning electron microscopy.

[0179] 42. The third catalyst coating is 0.5 to 8 g / in 3in the range of 0.75 to 5 g / in 3 More preferably, in the range of 1 to 3.5 g / in 3 42. The system of any one of embodiments 36-41, comprising a zeolite material at a loading in the range of

[0180] 43. The system of any one of embodiments 36-42, wherein the third catalytic coating described in (iv) further comprises an oxide binder, wherein the oxide binder is preferably selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, zirconia, and mixtures of two or more thereof, more preferably zirconia.

[0181] 44. The system of embodiment 42, wherein the third catalyst coating comprises the oxide binder in an amount in the range of 0.5 to 10% by weight, preferably in the range of 2 to 8% by weight, more preferably in the range of 3 to 6% by weight, based on the total weight of the zeolitic material.

[0182] 45. The system of any one of embodiments 36 to 44, wherein up to 0.001% by weight of the third catalytic coating, preferably 0-0.001% by weight, more preferably 0-0.0001% by weight, and even more preferably 0-0.00001% by weight, consists of palladium, platinum and rhodium, preferably platinum group metals.

[0183] 46. ​​The system of any one of embodiments 36-45, wherein up to 0.1 wt.%, preferably 0-0.1 wt.%, more preferably 0-0.01 wt.%, more preferably 0-0.001 wt.% of the third catalyst coating consists of vanadium oxide.

[0184] 47. The system according to any one of embodiments 36 to 46, wherein 95 to 100% by weight, preferably 98 to 100% by weight, more preferably 99 to 100% by weight, more preferably 99.5 to 100% by weight of the coating of the third catalyst consists of a zeolitic material containing one or more of Cu and Fe, and an oxide binder, preferably as described in embodiment 43 or 44.

[0185] 48. The system according to any one of embodiments 36 to 47, wherein the second catalytic coating according to (iii) comprises (preferably consists of) palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum and titanium, preferably aluminum and optionally zirconium, and wherein the third catalytic coating according to (iv) comprises (preferably consists of) a zeolitic material containing one or more of Cu and Fe, and an oxide binder preferably according to embodiment 43 or 44.

[0186] 49. The system of embodiment 34 or 35, wherein the third catalytic coating comprises vanadium oxide, the vanadium oxide being one or more of vanadium(V) oxide, vanadium(IV) oxide, and vanadium(III) oxide.

[0187] 50. The system of embodiment 49, wherein the vanadium is supported on a third oxide support, and the third catalyst coating comprises the vanadium oxide in an amount preferably in the range of 1.5 to 10 wt.%, more preferably in the range of 2.5 to 8 wt.%, and even more preferably in the range of 3 to 6 wt.%, based on the weight of the third oxide support.

[0188] 51. The system of embodiment 49 or 50, wherein the third oxide support comprises titanium, and the third oxide support further comprises one or more of tungsten, silicon, zirconium, and antimony, preferably one or more of tungsten, silicon, and antimony.

[0189] 52. The system of embodiment 51, wherein the third oxide support further comprises tungsten and silicon; or the third oxide support further comprises antimony and silicon.

[0190] 53. The system according to any one of embodiments 50 to 52, wherein 80 to 98% by weight, more preferably 85 to 95% by weight, of the third oxide support is made of titania, and preferably 2 to 10% by weight, more preferably 5 to 15% by weight, of the third oxide support is made of tungsten and silicon, or antimony and silicon (calculated as WO3 and SiO2, or Sb2O3 and SiO2, respectively).

[0191] 54. The third catalyst coating is 1-10g / in 3 in the range of 2 to 7 g / in 3 More preferably, the range is 3 to 5.5 g / in 3 54. The system of any one of embodiments 50-53, comprising a third oxide support at a loading in the range of

[0192] 55. The third catalytic coating further comprises an oxide binder, the oxide binder being preferably selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, silica, and mixtures of two or more thereof, more preferably silica; 55. The system according to any one of embodiments 50 to 54, wherein the coating comprises the oxide binder in an amount in the range of 0.5 to 10% by weight, preferably in the range of 2 to 8% by weight, more preferably in the range of 3 to 6% by weight, based on the weight of the third oxide support.

[0193] 56. The system of any one of embodiments 36-44 and 49-55, wherein the third catalytic coating further comprises a platinum group metal component, the platinum group metal component being one or more of palladium, platinum and rhodium, preferably one or more of palladium and platinum.

[0194] 57. The system of embodiment 56, wherein the platinum group metal components are platinum and palladium, and the mass ratio of platinum to palladium, Pt:Pd, calculated as elemental platinum group metal, is preferably in the range of 2:1 to 18:1, more preferably in the range of 5:1 to 15:1, more preferably in the range of 8:1 to 12:1.

[0195] 58. The third catalyst coating is 1-30g / in 3 More preferably, the range is 2 to 15 g / in 3 More preferably, in the range of 5 to 12 g / in 3 58. The system of embodiment 56 or 57, comprising the platinum group metal component at a loading in the range of

[0196] 59. The system of any one of embodiments 56-58, wherein the platinum group metal component is supported on an oxide material, the oxide material being preferably one or more of alumina, silica, zirconia, and titania, more preferably one or more of alumina, silica, and zirconia, more preferably one or more of alumina and silica, and the oxide material is more preferably alumina doped with zirconia.

[0197] 60. The third catalyst coating is 0.1 to 4 g / in 3 More preferably, the range is 0.2 to 2 g / in 3 and more preferably 0.5 to 1.5 g / in 3 60. The system of embodiment 59, comprising an oxide material supporting a platinum group metal component at a loading in the range of

[0198] 61. The system of any one of embodiments 56 to 60, wherein 95 to 100% by weight, preferably 98 to 100% by weight, more preferably 99 to 100% by weight, more preferably 99.5 to 100% by weight of the coating of the third catalyst consists of a platinum-group component, preferably supported on an oxide material as defined in embodiment 59 or 60, and vanadium oxide supported on a third oxide support, and an oxide binder, preferably as defined in embodiment 55.

[0199] 62. The system of any one of embodiments 56 to 60, wherein 95 to 100% by weight, preferably 98 to 100% by weight, more preferably 99 to 100% by weight, more preferably 99.5 to 100% by weight of the coating of the third catalyst consists of a platinum-group component, preferably supported on an oxide material as defined in embodiment 59 or 60, and a zeolitic material containing one or more of Cu and Fe, and an oxide binder, preferably as defined in embodiment 43 or 44.

[0200] 63. The third substrate comprises, preferably consists of, one or more of cordierite, aluminum titanate, and silicon carbide, preferably one or more of cordierite and silicon carbide, more preferably cordierite; 63. The system of any one of embodiments 34-62, wherein the third substrate is preferably a wall-flow filter substrate or a flow-through substrate, more preferably a flow-through substrate, more preferably a cordierite flow-through substrate.

[0201] 64. The third catalyst is 0.75 to 10 g / in 3 in the range of 1 to 7 g / in 3 More preferably, the range is 1.5 to 5.5 g / in 3 Coatings with loadings in the range of 64. The system of any one of embodiments 34 to 63, wherein the third catalyst coating extends over 95-100%, more preferably 98-100%, and even more preferably 99-100% of the axial length of the third substrate.

[0202] 65. The system of any one of embodiments 34 to 64, wherein the third substrate of the third catalyst has a substrate length in the range of 2.54 to 25.4 cm (1 to 10 inches), preferably in the range of 3.81 to 17.78 cm (1.5 to 7 inches), and more preferably in the range of 5.08 to 10.16 cm (2 to 4 inches).

[0203] 66. The system of any one of embodiments 34 to 65, wherein the third substrate of the third catalyst has a substrate width in the range of 10.16 to 43.18 cm (4 to 17 inches), preferably in the range of 17.78 to 38.10 cm (7 to 15 inches), and more preferably in the range of 22.86 to 30.48 cm (9 to 12 inches).

[0204] 67. The system of any one of embodiments 34-66, wherein the third catalyst described in (iv) consists of a coating and a third substrate.

[0205] 68. The system of any one of the preceding embodiments, wherein the first substrate of the first catalyst has a substrate length in the range of 2.54 to 25.4 cm (1 to 10 inches), preferably in the range of 5.08 to 20.32 cm (2 to 8 inches), and more preferably in the range of 7.62 to 15.24 cm (3 to 6 inches).

[0206] 69. The system of any one of the preceding embodiments, wherein the first substrate of the first catalyst has a substrate width in the range of 2.54 to 50.8 cm (1 to 20 inches), preferably in the range of 12.7 to 43.18 cm (5 to 17 inches), and more preferably in the range of 20.32 to 38.1 cm (8 to 15 inches).

[0207] 70. The system of any one of embodiments 34 to 64, wherein the second substrate of the second catalyst has a substrate length in the range of 2.54 to 25.4 cm (1 to 10 inches), preferably in the range of 3.81 to 17.78 cm (1.5 to 7 inches), and more preferably in the range of 5.08 to 10.16 cm (2 to 4 inches).

[0208] 71. The system of any one of embodiments 34 to 65, wherein the second substrate of the second catalyst has a substrate width in the range of 10.16 to 50.8 cm (4 to 20 inches), preferably in the range of 17.78 to 43.18 cm (7 to 17 inches), and more preferably in the range of 22.86 to 38.1 cm (9 to 15 inches).

[0209] 72. The system of any one of embodiments 34-71, further comprising a fourth catalyst, the fourth catalyst being one or more of an ammonia oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst.

[0210] 73. A fourth catalyst is an ammonia oxidation catalyst, the fourth catalyst having an inlet end and an outlet end and comprising a coating and a fourth substrate, the fourth substrate having an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the fourth substrate, the fourth substrate comprising a plurality of passages defined by an inner wall, an interface between the passages and the inner wall being defined by a surface of the inner wall, the coating being disposed on the surface of the inner wall of the fourth substrate, the coating comprising an ammonia oxidation component; In the exhaust gas treatment system, a fourth catalyst is located downstream of the third catalyst described in (iv), and an inlet end of the fourth catalyst is disposed upstream of an outlet end of the fourth catalyst; The system of embodiment 72, wherein the outlet end of the third catalyst described in (iv) is in fluid communication with the inlet end of the fourth catalyst, and the exhaust gas treatment system does not have a catalyst disposed between the outlet end of the third catalyst and the inlet end of the fourth catalyst for treating exhaust gas exiting the third catalyst.

[0211] 74. The system of embodiment 73, wherein the ammonia oxidation component of the fourth catalytic coating comprises a zeolitic material containing a platinum group metal component, one or more of vanadium oxides, and one or more of Cu and Fe, preferably a zeolitic material containing a platinum group metal component, and one or more of Cu and Fe.

[0212] 75. The system of embodiment 74, wherein the ammonia oxidation component of the fourth catalytic coating comprises, preferably consists of, a zeolitic material having framework type CHA, preferably containing one or more of a platinum group metal component, preferably palladium and platinum, and Cu, supported on an oxide support.

[0213] 76. The system of any one of embodiments 72-75, further comprising a fifth catalyst, the fifth catalyst being one or more of an ammonia oxidation catalyst, a diesel oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst, preferably a catalyzed soot filter.

[0214] 77. An exhaust gas treatment system comprising a fifth catalyst having an inlet end and an outlet end and comprising a coating on a fifth substrate, preferably a wall-flow filter substrate, the fifth catalyst being disposed downstream of the fourth catalyst, and the inlet end of the fifth catalyst being disposed upstream of the outlet end of the fifth catalyst; The system of embodiment 76, wherein the outlet end of the fourth catalyst is in fluid communication with the inlet end of the fifth catalyst, and in the exhaust gas treatment system, no catalyst for treating exhaust gas leaving the fourth catalyst is disposed between the outlet end of the fourth catalyst and the inlet end of the fifth catalyst.

[0215] 78. The method further comprises the step of: providing a sixth catalyst, the sixth catalyst being one or more of an ammonia oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst, preferably a selective catalytic reduction catalyst; 78. The system of embodiment 76 or 77, wherein the selective catalytic reduction catalyst preferably comprises a zeolitic material containing one or more of vanadium oxides and one or more of Cu and Fe, more preferably a zeolitic material containing one or more of Cu and Fe.

[0216] 79. An exhaust gas treatment system comprising a sixth catalyst having an inlet end and an outlet end and comprising a coating on a sixth substrate, the sixth catalyst being disposed downstream of the fifth catalyst, and the inlet end of the sixth catalyst being disposed upstream of the outlet end of the sixth catalyst; The system of embodiment 78, wherein the outlet end of the fifth catalyst is in fluid communication with the inlet end of the sixth catalyst, and in the exhaust gas treatment system, no catalyst for treating the exhaust gas leaving the fifth catalyst is disposed between the outlet end of the fifth catalyst and the inlet end of the sixth catalyst.

[0217] 80. Further comprising an injector for injecting a fluid into an exhaust gas stream exiting the internal combustion engine, the injector being located upstream of the sixth catalyst and downstream of the fifth catalyst; 80. A system as claimed in claim 78 or 79, wherein the fluid is preferably an aqueous urea solution.

[0218] 81. Further comprising an injector for injecting a fluid into an exhaust gas stream exiting the internal combustion engine, the injector being located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system; The fluid is preferably an aqueous urea solution; 81. The system of any one of embodiments 1-80, wherein no hydrocarbon injection device is disposed upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system.

[0219] 82. A system according to any one of the preceding embodiments, comprising a first catalyst as defined in (i), a hydrocarbon injection device as defined in (ii), a second catalyst as defined in (iii), preferably a third catalyst as defined in (iv) as defined in any one of the preceding embodiments 34 to 67, more preferably one or more of the fourth to sixth catalysts as defined in any one of the preceding embodiments 72 to 79, and even more preferably an injection device(s) as defined in embodiment 80 or 81.

[0220] 83. A method for producing a first catalyst of an exhaust gas treatment system according to any one of embodiments 1 to 82, comprising: (a) providing a mixture including water, a solution of vanadium oxide, and a first oxide material containing titanium; (b) disposing the mixture from (a) on a surface of an inner wall of a first substrate to obtain a slurry-treated substrate, wherein the first substrate comprises a plurality of passages having an inlet end, an outlet end, and a length in a substrate axial direction extending from the inlet end to the outlet end of the first substrate and defined by the inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall; (c) optionally drying the slurry treated substrate from (b) to obtain a substrate having a coating disposed thereon; (d) calcining the slurry treated substrate obtained in (b), preferably the dried slurry treated substrate obtained in (c), to obtain a coated substrate. Including, Also, optionally, (b´) disposing the mixture obtained in (a) on the surface of the coating obtained in (d) disposed on the substrate; (c´) optionally drying the slurry treated substrate obtained in (b´); (d') calcining the slurry treated substrate obtained in (b') or the dried slurry treated substrate obtained in (c'). Including, Obtaining a first catalyst from (d) or (d'); method.

[0221] 84. Paragraph (a) above: (a.1) providing a mixture comprising water and a first oxide support comprising titanium, wherein the first oxide support further comprises one or more of tungsten, silicon, zirconium and antimony, more preferably one or more of tungsten, silicon and antimony; (a.2) adding to the mixture obtained in (a.1) a solution of vanadium oxide, preferably a solution of one or more of vanadium oxalate, ammonium vanadate and vanadium oxide, more preferably a solution of vanadium oxalate, (a.3) preferably adding a source of oxide binder, where the source of oxide binder is one or more of colloidal silica, alumina, and zirconia, more preferably colloidal silica; 84. The method of embodiment 83, comprising:

[0222] 85. The method of embodiment 83 or 84, wherein (b) comprises disposing the mixture over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the substrate.

[0223] 86. The method according to any one of embodiments 83 to 85, wherein the placement of the mixture described in (b) is carried out by spraying the mixture onto the substrate or by immersing the substrate in the mixture, preferably by immersing the substrate in the mixture.

[0224] 87. The method according to any one of embodiments 83 to 86, wherein the drying according to (c) is carried out in a gas atmosphere having a temperature in the range of 90 to 200 °C, preferably in the range of 120 to 160 °C.

[0225] 88. The method according to any one of embodiments 83 to 87, wherein the drying according to (c) is carried out in a gas atmosphere for a duration ranging from 5 minutes to 300 minutes, preferably from 20 minutes to 60 minutes.

[0226] 89. The method according to any one of embodiments 83 to 88, wherein the dried slurry-treated substrate obtained in (c) has a moisture content in the range of 0 to 30%, preferably in the range of 5 to 25%, and more preferably in the range of 15 to 20%.

[0227] 90. The method of any one of embodiments 87-89, wherein the gas atmosphere comprises, preferably is, one or more of air, lean air, and oxygen, more preferably air.

[0228] 91. The method according to any one of embodiments 83 to 90, wherein the calcination according to (d) is carried out in a gas atmosphere having a temperature in the range of 300 to 600 °C, preferably in the range of 400 to 550 °C.

[0229] 92. The method according to any one of embodiments 83 to 91, wherein the calcination according to (d) is carried out in a gas atmosphere for a duration ranging from 5 minutes to 120 minutes, preferably from 20 minutes to 40 minutes.

[0230] 93. The method of embodiment 91 or 92, wherein the gas atmosphere comprises (preferably is) one or more of air, lean air, and oxygen, more preferably air.

[0231] 94. The method of any one of embodiments 83 to 93, wherein (b') comprises disposing the mixture over 95 to 100%, more preferably 98 to 100%, and even more preferably 99 to 100% of the axial length of the substrate.

[0232] 95. The method according to any one of embodiments 83 to 94, wherein the placement of the mixture described in (b') is carried out by spraying the mixture onto the substrate or by immersing the substrate in the mixture, preferably by immersing the substrate in the mixture.

[0233] 96. The method according to any one of embodiments 83 to 95, wherein the drying according to (c') is carried out in a gas atmosphere having a temperature in the range of 90 to 200 °C, preferably in the range of 120 to 160 °C.

[0234] 97. The method according to any one of embodiments 83 to 96, wherein the drying according to (c') is carried out in a gas atmosphere for a duration ranging from 5 minutes to 300 minutes, preferably from 20 minutes to 60 minutes.

[0235] 98. The method according to any one of embodiments 83 to 97, wherein the dried slurry-treated substrate obtained in (c') has a moisture content in the range of 0 to 30%, preferably in the range of 5 to 25%, and more preferably in the range of 15 to 20%.

[0236] 99. The method of embodiment 96 or 97, wherein the gas atmosphere comprises (preferably is) one or more of air, lean air, and oxygen, more preferably air.

[0237] 100. The method according to any one of embodiments 83 to 99, wherein the calcination according to (d') is carried out in a gas atmosphere having a temperature in the range of 300 to 600 °C, preferably in the range of 400 to 550 °C.

[0238] 101. The method according to any one of embodiments 83 to 100, wherein the calcination according to (d') is carried out in a gas atmosphere for a duration ranging from 5 minutes to 120 minutes, preferably from 20 minutes to 40 minutes.

[0239] 102. The method of embodiment 100 or 101, wherein the gas atmosphere comprises (preferably is) one or more of air, lean air, and oxygen, more preferably air.

[0240] 103. The method of any one of embodiments 83-102, consisting of (a), (b), (c), (d) and, optionally, (b'), (c') and (d').

[0241] 104. A catalyst in an exhaust gas treatment system according to any one of embodiments 1 to 82, preferably the first catalyst according to (i), obtained or obtainable by the method according to any one of embodiments 83 to 103.

[0242] 105. Use of the catalyst according to embodiment 104 for the selective catalytic reduction of NOx.

[0243] 106. Use of an exhaust gas treatment according to any one of embodiments 1 to 82 for the treatment of an exhaust gas stream emitted from an internal combustion engine, preferably a diesel engine.

[0244] 107. A method for treating an exhaust gas stream emitted from an internal combustion engine, comprising: (1) providing an exhaust gas stream from an internal combustion engine, preferably a diesel engine, wherein the exhaust gas stream comprises one or more of NOx, ammonia, nitric oxide, and hydrocarbons; (2) Passing the exhaust gas stream prepared in (1) through the exhaust gas system of any one of embodiments 1 to 82. The method includes:

[0245] In the context of the present invention, the term "inner wall surface" is to be understood as the "bare" or "uncovered" or "blank" surface of the wall, i.e. the surface of the wall in its untreated state consisting of the material of the wall in question - except for unavoidable impurities which may contaminate the surface.

[0246] Furthermore, in the context of the present invention, the term "X is one or more of A, B, C" is understood to disclose that X is either A or B or C, A and B, A and C, B and C, or A, B and C, where X is a given feature and each of A, B, and C represents a specific realization of said feature. In this regard, it should be noted that a person skilled in the art can convert the above abstract terms into concrete examples. For example, X is a chemical element and A, B, and C are concrete elements such as Li, Na, and K, or X is a temperature and A, B, and C are concrete temperatures such as 10°C, 20°C, and 30°C, etc. In this regard, it should be noted that a person skilled in the art can extend the above terms to less specific realizations of said features. For example, "X is one or more of A and B" discloses that X is A or B, or A and B. Also, it should be noted that the above terms may alternatively be expanded to more specific realizations of the feature, for example, "X is one or more of A, B, C, and D" discloses that X is any of 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, or A and B and D, or B and C and D.

[0247] In the context of the present invention, the term "no catalyst is disposed downstream of the outlet end of the Xth catalyst" should be understood as meaning that no catalyst or catalytic component is disposed downstream of the outlet end of the Xth catalyst, but this does not exclude the presence of one or more injection devices exemplified by the embodiments of the present invention.

[0248] In the context of the present invention, the term "width of the substrate" should be understood to refer to the diameter of the substrate if the substrate is cylindrical.

[0249] In the context of the present invention, the term "consists of" in relation to the weight percent of one or more components indicates the weight percent amount of that component based on 100 weight percent of the entity in question. For example, the expression "0-0.001 weight percent of the first catalytic coating consists of palladium" indicates that of the 100 weight percent components that make up the coating, 0-0.001 weight percent is palladium.

[0250] In the context of this invention, the term "close coupled" catalyst is used to define a catalyst that is the first catalyst to receive the exhaust gas stream leaving the engine (the catalyst is located close - immediately adjacent - to the engine, with no other catalytic components in between).

[0251] In the context of the present invention, the term "internal combustion engine" refers to a diesel engine or a gasoline engine, preferably a diesel engine.

[0252] The present invention will be further described with reference to the following Reference Examples, Comparative Examples and Examples. EXAMPLES

[0253] Reference Example 1: Measurement of particle size distribution (Dv90) Particle size distribution was measured by static light scattering using a Sympatec HELOS instrument. The optical density of the samples was in the range of 5–10%.

[0254] Reference Example 2: Preparation of CuCHA zeolite The zeolitic material with Cu-containing framework type CHA used in the examples herein was prepared according to the teachings of US8293199B2, see Example 2, column 15, lines 26-52 of US8293199B2 for details.

[0255] Reference Example 3: Measurement of BET specific surface area The BET specific surface area of ​​alumina was measured according to DIN 66131 or DIN ISO 9277 using liquid nitrogen.

[0256] Reference Example 4: Preparation of vanadium-containing SCR catalyst (hereinafter referred to as "V-SCR catalyst") Doped titania powder (87% by weight TiO, 8% by weight WO, 5% by weight SiO, BET specific surface area 85 m 2 Vanadium oxalate and colloidal silica were added to an aqueous mixture of titania, tungsten oxide, and silica (Tv90 = 2.5 micrometers) to obtain 5% V2O5 by weight based on the weight of titania + tungsten oxide + silica in the calcined catalyst, and 2% silica by weight (from the colloidal silica) in the calcined catalyst. A portion of the final slurry was placed over the entire length of an uncoated honeycomb flow-through cordierite monolith substrate (a 10.5 inch diameter by 6 inch length cylindrical substrate with a 400 / (2.54) per square centimeter coating density according to methods well known in the art. 2 After the coated substrate was dried and calcined, the remaining portion of the final slurry was placed over the entire length of the coated substrate, followed by drying and calcination to obtain a catalyst concentration of about 4.5 g / in 3 A final coating loading of 1000 g was obtained.

[0257] The catalytic activity (NOx conversion rate) of the obtained catalyst was measured and is shown in FIG.

[0258] Reference Example 5: Preparation of palladium-containing diesel oxidation catalyst (hereinafter referred to as "Pd-DOC") Zr-doped alumina powder (ZrO2 20 mass%, BET200m 2Palladium nitrate solution was added to the Pd / Zr-alumina (Zr-alumina 0.425 ml / g, Dv90 125 microns, total pore volume 0.5 ml / g). After calcination at 590° C., the Pd content of the final Pd / Zr-alumina was 1.5% by weight based on the weight of the Zr-alumina. This material was added to water and the resulting slurry was milled as described in Example 1 until the resulting Dv90 was 10 microns. The final slurry was placed over the entire length of an uncoated honeycomb flow-through cordierite monolith substrate (a 10.5 inch diameter by 3 inch length cylindrical substrate with a cell count of 400 / (2.54) cells) according to methods well known in the art. 2 / cm2, wall thickness 0.1 millimeter (4 mils). The substrate was then dried and calcined. The loading of the calcined coating in the catalyst was about 91 g / l (1.5 g / in 3 ) and Pd is 40g / ft 3 It was.

[0259] Reference Example 6: Preparation of copper-containing SCR catalyst (hereinafter referred to as "Cu-SCR").

[0260] A zirconyl acetate solution was added to an aqueous slurry of Cu-CHA (5.1 wt% Cu calculated as CuO, SiO2:Al2O3 molar ratio of 18) to achieve 5 wt% ZrO2 based on the weight of Cu-CHA in the calcined catalyst. This final slurry was placed over the entire length of an uncoated honeycomb flow-through cordierite monolith substrate (a 10.5 in. diameter by 6 in. length cylindrical substrate with 400 / (2.54) cells per square centimeter) according to methods well known in the art. 2 The substrate was then dried and fired. The firing loading was 128.15 g / l (2.1 g / in 3 ) was.

[0261] Reference Example 8.1: Comparative test of V-SCR catalyst of Reference Example 4 and Cu-SCR catalyst of Reference Example 6 The DeNOx of the catalysts of Reference Examples 4 and 6 was measured at 210°C and a space velocity of 50,000 / h to examine the responsiveness of the catalyst of Reference Example 4 (V-SCR catalyst) and the catalyst of Reference Example 6 (Cu-SCR catalyst). Both the V-SCR catalyst and the Cu-SCR catalyst were tested at steady state with the engine in a test cell with an engine-out level of about 550 ppm NOx. As can be seen from Figure 2, the V-SCR catalyst showed maximum NOx conversion after about 600 seconds. From this figure, it can be seen that the V-SCR catalyst of Reference Example 4 is more responsive than the Cu-SCR catalyst of Reference Example 6. Without being bound to a particular theory, it is assumed that the V-SCR catalyst has a faster response at low ammonia storage and a smaller ammonia storage capacity than the Cu-SCR catalyst.

[0262] Therefore, Reference Example 8.1 shows that when high-speed response is required, the V-SCR catalyst (Reference Example 4) is a better candidate for close-coupled operation than the Cu-SCR catalyst (Reference Example 6).

[0263] Comparative Example 1: Preparation of an exhaust gas treatment system not according to the present invention An exhaust gas treatment device not according to the present invention was prepared by combining the catalyst of Reference Example 4 ("V-SCR catalyst") and the catalyst of Reference Example 5 ("Pd-DOC"), positioning the catalyst of Reference Example 5 downstream of the catalyst of Reference Example 4, and installing a hydrocarbon (HC) injection device upstream of the catalyst of Reference Example 4.

[0264] Example 1: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment device according to the present invention was produced by combining the catalyst of Reference Example 4 ("V-SCR catalyst") and the catalyst of Reference Example 5 ("Pd-DOC"), positioning the catalyst of Reference Example 5 downstream of Reference Example 4, and installing a hydrocarbon (HC) injection device downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 5.

[0265] Example 2: Use of the exhaust gas treatment systems of Example 1 and Comparative Example 1 - Control of exotherms within the system The inlet and outlet temperatures of the V-SCR catalyst of the two systems, and the inlet and outlet temperatures of the Pd-DOC of the two systems were measured. The exhaust gas treatment system was installed in a close-coupled position immediately downstream of the engine. HC was injected through the HC injector. The injection time is shown in Figure 4 and Figure 5.

[0266] FIG. 4 shows the inlet and outlet temperatures of the V-SCR catalyst and the outlet temperature of the Pd-DOC as a function of time for the exhaust gas treatment system of Comparative Example 1 when the HC injector is placed in front of the V-SCR catalyst. At low temperatures, i.e., below 300° C., the V-SCR generates only a small amount of heat, with most of the heat appearing to be concentrated in the Pd-DOC. After about 58 minutes, the injection of HC is stopped and the temperature of the inlet end of the V-SCR is increased. Without being bound by any particular theory, it is believed that at low temperatures some of the HC adsorbs on the V-SCR and as the temperature increases the adsorbed HC oxidizes on the V-SCR catalyst, generating an uncontrollable heat generation of temperatures above 600° C. Thus, the V-SCR is exposed to temperatures outside its operation window. As a result, the catalyst's support may sinter and reduce its surface area, which may result in loss of activity. Also, exposure to 600° C. as described above may cause sublimation of the vanadia.

[0267] FIG. 5 shows the V-SCR and Pd-DOC inlet temperatures and Pd-DOC outlet temperature as a function of time for a system according to the present invention with the HC injector located downstream of the V-SCR catalyst and upstream of the Pd-DOC. No excessive heat was observed when the HC injection was stopped and the inlet temperature was increased, suggesting that the HC are adsorbed on the Pd-DOC without being oxidized. By placing the HC injector after the V-SCR, it is ensured that the V-SCR does not adsorb HC during an active regeneration event, since high concentrations of HC do not pass through the V-SCR. Thus, Example 2 shows that in addition to providing an exhaust gas treatment system with a close-coupled (cc) V-SCR, it is important to place the HC injector downstream of said cc-V-SCR, thereby maintaining the efficiency and durability of the exhaust gas treatment system.

[0268] Reference Example 7: Preparation of AMOX catalyst Zr-doped alumina powder (ZrO2 20 mass%, BET200m 2 A platinum ammine solution was added to a Pt / Zr-alumina (Pt content 1.85 wt.% based on the weight of Zr-alumina after calcination at 590°C) in the final Pt / Zr-alumina. This material was added to water and the resulting slurry was milled as described in Reference Example 1 until the resulting Dv90 was 10 microns. A zirconyl acetate solution was added to an aqueous slurry of Cu-CHA (5.1 wt.% Cu calculated as CuO, SiO2:Al2O3 molar ratio of 18) to achieve 5 wt.% ZrO2 based on the weight of Cu-CHA after calcination. The milled Pt / Zr-alumina slurry was added to the Zr / Cu-CHA slurry and mixed. This final slurry was then applied to an uncoated flow-through honeycomb cordierite monolith substrate (diameter: 26.67 cm (10.5 inches) x length: 7.62 cm (3 inches), 400 / (2.54) per square centimeter) 2The catalyst was then placed over the entire length of a cylindrical substrate (1.5 x 10 cells, 0.1 mm (4 mil) wall thickness). The substrate was then dried and calcined. The loading of the calcined coating in the catalyst was approximately 3.0 g / in 3 It was 15.26g / l (0.25g / in 3 0.28g / l (8g / ft ) on Zr-alumina 3 ) Pt loading and 158.66 g / l (2.6 g / in 3 ) Cu-CHA+7.93g / l(0.13g / in 3 ) ZrO2.

[0269] Reference Example 8.2: Testing of exhaust gas treatment systems using cc-V-SCR catalyst or cc-Cu-SCR catalyst - Sulfation resistance A first exhaust gas treatment system (System 1) was prepared by combining the catalyst of Reference Example 4 (V-SCR catalyst) with the catalyst of Reference Example 7, with the catalyst of Reference Example 7 positioned downstream of the V-SCR catalyst. A second exhaust gas treatment system (System 2) was prepared by combining the catalyst of Reference Example 6 (Cu-SCR catalyst) with the catalyst of Reference Example 7, with the catalyst of Reference Example 7 positioned downstream of the Cu-SCR catalyst. The NOx conversion was measured at 215° C. under steady-state conditions (engine-out NOx=250 ppm, SV=40 k / h, ammonia-to-NOx ratio (ANR) 0.85) for 200 hours during simulated low-load driving. The results are shown in FIG. 6.

[0270] FIG. 6 shows that the second system using the cc-Cu-SCR catalyst has an initial NOx conversion of almost 60% and drops to about 40% after 200 hours of low temperature operation. The first system with the cc-V-SCR catalyst has an initial NOx conversion of about 73% and a stable NOx conversion of 66-68% for over 200 hours. Thus, in this example, the hybrid system with the cc-V-SCR with AMOX containing Cu-CHA is more stable than the system with the cc-Cu-CHA with AMOX containing Cu-CHA downstream catalyst. Without wishing to be bound by theory, it is believed that the cc-V-SCR catalyst reduces the effects of sulfation and hydrocarbon fouling in exhaust gas treatment systems.

[0271] Example 3: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment system according to the present invention was fabricated by combining in series the catalyst of Reference Example 4 ("V-SCR catalyst"), a hydrocarbon (HC) injector, the catalyst of Reference Example 5 ("Pd-DOC"), and the catalyst of Reference Example 6 ("Cu-SCR catalyst"), in which the catalyst of Reference Example 5 was positioned downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 6 was positioned downstream of the catalyst of Reference Example 5, and the HC injector was installed downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 5.

[0272] Reference Example 9: Preparation of palladium-containing SCR catalyst ("Pd / ZrO2-Cu-SCR catalyst") Palladium nitrate solution was added to zirconium oxide (pore volume 0.420 ml / g). After calcination at 590° C., the final Pd / zirconia had a Pd content of 3.5% by weight based on the weight of Zr-alumina. This material was added to water and the resulting slurry was milled as described in Reference Example 1 until the resulting Dv90 was 10 microns. Zirconyl-acetate solution was added to an aqueous slurry of Cu-CHA (about 3% by weight Cu calculated as CuO, molar ratio SiO2:Al2O3 ratio of about 32) prepared according to Reference Example 2, such that the calcined ZrO2 was 5% by weight. This mixture was spray dried and milled as described in Reference Example 1 until the resulting Dv90 was 5 microns. The milled Pd / ZrO2 slurry was added to the Zr / Cu-CHA slurry and mixed. The final slurry was applied to an uncoated honeycomb flow-through cordierite monolith substrate (diameter: 26.67 cm (10.5 in) x length: 7.62 cm (3 in), 400 / (2.54) per square centimeter). 2 The catalyst was then placed over the entire length of a cylindrical substrate (1.5 x 10 cells, 0.1 mm (4 mil) wall thickness). The substrate was then dried and calcined. The loading of the calcined coating in the catalyst was approximately 3.0 g / in 3 It was 30.51g / l (0.5g / in 3 1.06g / l (30g / ft 3 ) of Pd was supported, and 144.02 g / l (2.36 g / in 3 ) of Cu-CHA plus 7.32g / l (0.12g / in 3 ) ZrO2.

[0273] Reference Example 10: Preparation of AMOX catalyst with mass ratio Pt:Pd of 10:1 Zr-doped alumina powder (ZrO2 20% by mass, BET 200m 2To a Cu-CHA (Zr-alumina) ... This mixture was spray dried and milled as described in Reference Example 1 to a resulting Dv90 of 5 microns. The milled Pd / Zr-alumina slurry was added to the Zr / Cu-CHA slurry and mixed. This final slurry was then applied to an uncoated flow-through honeycomb cordierite monolith substrate (diameter: 26.67 cm (10.5 inches) x length: 7.62 cm (3 inches), 400 / (2.54) per square centimeter). 2 The catalyst was placed over the length of a cylindrical substrate (100 x 100 x 10 cells, 0.1 mm (4 mil) wall thickness). The substrate was then dried and calcined. The calcined coating loading for this catalyst was approximately 3 g / in 3 , Cu-CHA is 2.75g / in 3 , ZrO2 is 0.13g / in 3 , Zr-alumina is 0.25g / in 3 , Pt+Pd is 8g / ft 3 was included.

[0274] Example 4: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment system according to the present invention was fabricated by serially combining the catalyst of Reference Example 4 ("V-SCR catalyst"), a hydrocarbon (HC) injector, the catalyst of Reference Example 9 ("Pd / ZrO2-Cu-SCR catalyst"), and the catalyst of Reference Example 10 ("AMOX catalyst"), in which the catalyst of Reference Example 9 was located downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 10 was located downstream of the catalyst of Reference Example 9, and the HC injector was located downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 9.

[0275] Example 5: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment system according to the present invention was prepared by serially combining the catalyst of Reference Example 4 ("V-SCR catalyst"), a hydrocarbon (HC) injector, the catalyst of Reference Example 5 ("Pd-DOC"), the catalyst of Reference Example 6 ("Cu-SCR catalyst"), and the catalyst of Reference Example 7 ("AMOX catalyst"), in which the catalyst of Reference Example 5 was located downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 6 was located downstream of the catalyst of Reference Example 5, the catalyst of Reference Example 7 was located downstream of the catalyst of Reference Example 6, and the HC injector was located downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 5.

[0276] Example 6: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment system according to the present invention was fabricated by serially combining the catalyst of Reference Example 4 ("V-SCR catalyst"), a hydrocarbon (HC) injector, the catalyst of Reference Example 5 ("Pd-DOC"), the catalyst of Reference Example 9 ("Pd / ZrO2-Cu-SCR catalyst") and the catalyst of Reference Example 10 ("AMOX catalyst"), in which the catalyst of Reference Example 5 was located downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 9 was located downstream of the catalyst of Reference Example 5, the catalyst of Reference Example 10 was located downstream of the catalyst of Reference Example 9, and the HC injector was located downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 5.

[0277] Reference Example 11: Preparation of palladium-containing diesel oxidation catalyst (hereinafter referred to as "Pd-DOC2") Pd-DOC of Example 11 was prepared similarly to Pd-DOC of Example 5, except that the amount of palladium used was reduced. The loading of the calcined coating in the catalyst was about 91 g / l (1.5 g / in 3 ) with Pd of 30g / ft 3 It was.

[0278] Example 7: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment system according to the present invention was prepared by serially combining the catalyst of Reference Example 4 ("V-SCR catalyst" - Cat. 1), a hydrocarbon (HC) injection device, the catalyst of Reference Example 11 ("Pd-DOC2" - Cat. 2) and the catalyst of Reference Example 6 ("Cu-SCR catalyst" - Cat. 3). In this case, the catalyst of Reference Example 11 was located downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 6 was located downstream of the catalyst of Reference Example 11, and the HC injection device was located downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 11.

[0279] Example 8: Preparation of an exhaust gas treatment system according to the present invention An exhaust gas treatment system according to the present invention was prepared by serially combining the catalyst of Reference Example 4 ("V-SCR catalyst" - Cat. 1), a hydrocarbon (HC) injection device, the catalyst of Reference Example 9 ("Pd / ZrO2-Cu-SCR catalyst" - Cat. 2) and the catalyst of Reference Example 6 ("Cu-SCR catalyst" - Cat. 3). In this case, the catalyst of Reference Example 9 was located downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 6 was located downstream of the catalyst of Reference Example 9, and the HC injection device was located downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 9.

[0280] Reference Example 12: Preparation of platinum-containing diesel oxidation catalyst (hereinafter referred to as "Pt-DOC") Titania powder (TiO2 100% by mass, BET specific surface area 200m 2 / g, Dv90 of 20 micrometers) was wet-impregnated with platinum ammine solution. The amount of titania was 0.75 g / in after calcination, resulting in a titania loading of 0.75 g / in 3After calcination at 590 °C, the Pt content of the final Pt / TiO2 was about 1.7 wt % based on the mass of titania. This material was added to acetic acid and water to form a Pt / titania slurry. In parallel, alumina (100 wt %, BET specific surface area about 200 m 2 A binder slurry was prepared by mixing 0.2 g / in2 of alumina with a dilute solution of nitric acid (HNO3). The amount of alumina was adjusted so that the alumina loading in the calcined catalyst was 0.2 g / in2. 3 The alumina slurry was added with a zirconium acetate solution (a mixture of acetic acid and zirconium hydroxide). The amount of alumina was calculated so that the alumina loading in the catalyst after calcination was 0.25 g / in. 3 The resulting mixture was ground until it had a Dv90 of 10 microns, as measured by the method described in Reference Example 1. Finally, the Al / Zr mixture and the Pt / TiO2 slurry were combined with octanol to form a final slurry with a pH of about 4.5.

[0281] This final slurry was then placed over the entire length of an uncoated honeycomb flow-through cordierite monolith substrate (a 10.5 inch diameter by 3 inch length cylindrical substrate with 400 / (2.54) cells per square centimeter) according to methods well known in the art. 2 , with a wall thickness of 0.1 millimeter (4 mils). The substrate was then dried and calcined. The calcined coating loading in this catalyst was about 62 g / l (about 1 g / in 3 ), Pt is about 22g / ft 3 It was.

[0282] Comparative Example 2: Preparation of an Exhaust Gas Treatment System Not Containing the Present Invention An exhaust gas treatment system not according to the present invention was prepared by serially combining the catalyst of Reference Example 4 ("V-SCR catalyst" - Cat. 1), a hydrocarbon (HC) injection device, the catalyst of Reference Example 12 ("Pt-DOC" - Cat. 2), and the catalyst of Reference Example 6 ("Cu-SCR catalyst" - Cat. 3). At this time, the catalyst of Reference Example 12 was located downstream of the catalyst of Reference Example 4, the catalyst of Reference Example 6 was located downstream of the catalyst of Reference Example 12, and the HC injection device was located downstream of the catalyst of Reference Example 4 and upstream of the catalyst of Reference Example 12.

[0283] Example 9: Use of the exhaust gas treatment systems of Examples 7, 8 and Comparative Example 2 - Production of DeNOx and N2O The exhaust gas treatment system of Example 7 (System A), the exhaust gas treatment system of Example 8 (System B), and the exhaust gas treatment system of Comparative Example 2 (System C) were tested under steady-state conditions (load point: 290°C, space velocity: 1100 kg / h E.O.NOx=670 ppm) and transient conditions (WHTC test cycle with EO (engine-out) NOx of around 300 g (cum), average temperature during cycle of 235°C-Tmax=330°C; Tmin=170°C-ANR (ammonia / NOx ratio)=1.05). The results are shown in Figures 7 to 10.

[0284] Figures 7 and 8 show that the use of Pt / TiO2 (Pt-DOC) as the second catalyst (Cat. 2) of the exhaust gas treatment system does not significantly reduce the NOx conversion measured at the outlet end of Cat. 2. It also shows that it leads to a lower NOx conversion of at least 10% at the outlet end of the exhaust gas treatment system C (not according to the invention). Furthermore, it shows that the use of Pt / TiO2 (Pt-DOC) as the second catalyst (Cat. 2) leads to a surprising increase in the production of nitrous oxide at the outlet end of the second catalyst (Cat. 2) and the third catalyst (Cat. 3). The comparison results can be seen in Figures 9 and 10. Without wishing to be bound by any particular theory, it is believed that the second catalyst made of Pt / TiO2 oxidizes the reductant (ammonia) that slips through the first catalyst to nitrous oxide, which results in a decrease in the NOx conversion at the outlet end of the system. Thus, Example 9 shows that the use of Pd-DOC or Pd / ZrO2-Cu-SCR as the second catalyst in an exhaust gas treatment system can improve the reduction rate of NOx while significantly reducing the production of nitrous oxide compared to a platinum on titania second catalyst. References -US2017 / 152780A1 -US2018 / 258811A1 -WO2018 / 224651A2

Claims

1. 1. An exhaust gas treatment system for treating an exhaust gas stream emitted from an internal combustion engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising: (i) a first catalyst having an inlet end and an outlet end and comprising a coating and a first substrate, wherein the first substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the first substrate, the first catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the first substrate, the coating comprising vanadium oxide supported on a first oxide support containing titanium; (ii) a hydrocarbon injection device for injecting a hydrocarbon containing fluid into the exhaust gas stream exiting the outlet end of the first catalyst described in (i); (iii) a second catalyst having an inlet end and an outlet end and comprising a coating and a second substrate, wherein the second substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the second substrate, the second substrate comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the second substrate, the coating comprising palladium supported on a second oxide support containing one or more of zirconium, silicon, and aluminum. Equipped with Here, the first catalyst described in (i) is a first catalyst of an exhaust gas treatment system provided downstream of an upstream end of the exhaust gas treatment system, and an inlet end of the first catalyst is disposed upstream of an outlet end of the first catalyst; wherein in the exhaust gas treatment system, a second catalyst as described in (iii) is located downstream of the first catalyst as described in (i) and downstream of the hydrocarbon injection device as described in (ii), an inlet end of the second catalyst is disposed upstream of an outlet end of the second catalyst; and 1. An exhaust gas treatment system, wherein the first oxide support containing titanium further comprises tungsten and silicon.

2. 10. The system of claim 1, wherein the first catalytic coating comprises the vanadium oxide in an amount ranging from 1.0 to 10 weight percent based on the weight of the first oxide support.

3. 2. The system of claim 1, wherein the first oxide support comprises 80 to 98 mass % titania.

4. 2 to 10 mass % of the first oxide support is composed of tungsten and silicon, or antimony and silicon (respectively WO ３ and SiO ２ , or Sb ２ O ３ and SiO ２ The system of claim 3 .

5. The system of any one of claims 1 to 4, wherein the second oxide support included in the second catalytic coating of (iii) comprises one or more of zirconium and aluminum.

6. The system according to claim 5, wherein 90 to 100 mass % of the second oxide support is made of aluminum and oxygen.

7. 6. The system of claim 5, wherein 60 to 95 wt. % of the second oxide support is made of alumina, and 5 to 40 wt. % of the second oxide support is made of zirconia.

8. (iii) The second catalyst coating has a coating weight of 5 to 90 g / ft ３ The system of any one of claims 1 to 7, comprising palladium in an amount ranging from 0.1 to 0.

5.

9. 9. The system of claim 8, wherein palladium is the only platinum group metal present in the second catalytic coating of (iii).

10. 10. The system of claim 1, wherein 98 to 100% by weight of the second catalytic coating consists of palladium supported on a second oxide support comprising one or more of zirconium, silicon, aluminum and titanium.

11. 10. The system of any one of claims 1 to 9, wherein the second catalytic coating of (iii) further comprises a zeolitic material, the zeolitic material containing one or more of Cu and Fe.

12. 12. The system of claim 11, wherein the zeolitic material contained in the coating of the second catalyst has framework types AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof.

13. The system of claim 11 , wherein the second catalytic coating of (iii) further comprises an oxide binder.

14. 14. The system of claim 13, wherein the oxide binder is selected from the group consisting of alumina, silica, zirconia, and mixtures of two or more thereof.

15. The system of claim 13, wherein the second catalyst coating comprises the oxide binder in an amount ranging from 0.5 to 10 wt. %, based on the total weight of the zeolitic material.

16. moreover, (iv) a third catalyst having an inlet end and an outlet end and comprising a coating and a third substrate, wherein the third substrate has an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the third substrate, the third catalyst comprising a plurality of passages defined by an inner wall, wherein an interface between the passages and the inner wall is defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the third substrate, the coating comprising a zeolitic material containing one or more of vanadium oxides and one or more of Cu and Fe. Equipped with 16. The exhaust gas treatment system of claim 1, wherein the third catalyst described in (iv) is located downstream of the second catalyst described in (iii), and the inlet end of the third catalyst is disposed upstream of the outlet end of the third catalyst.

17. 17. The system of claim 16, wherein an outlet end of the second catalyst described in (iii) is in fluid communication with an inlet end of the third catalyst described in (iv), and in the exhaust gas treatment system, no catalyst for treating the exhaust gas flow exiting the second catalyst is disposed between the outlet end of the second catalyst described in (iii) and the inlet end of the third catalyst described in (iv).

18. 18. The system of claim 16 or 17, wherein the third catalytic coating of (iv) comprises a zeolitic material containing one or more of Cu and Fe.

19. 20. The system of claim 18, wherein the zeolitic material included in the third catalyst coating has framework types AEI, GME, CHA, MFI, BEA, FAU, MOR, or a mixture of two or more thereof.

20. 10. The system of claim 8 or 9, wherein the second catalytic coating of (iii) comprises palladium supported on a second oxide support containing one or more of zirconium, silicon, aluminum and titanium, and wherein the third catalytic coating of (iv) comprises a zeolitic material containing one or more of Cu and Fe.

21. the system further comprising a fourth catalyst, the fourth catalyst being one or more of an ammonia oxidation catalyst, a catalyzed soot filter, and a selective catalytic reduction catalyst; wherein a fourth catalyst has an inlet end and an outlet end and comprises a coating and a fourth substrate, the fourth substrate having an inlet end, an outlet end, and a substrate axial length extending from the inlet end to the outlet end of the fourth substrate, the fourth substrate comprising a plurality of passages defined by an inner wall, an interface between the passages and the inner wall being defined by a surface of the inner wall, wherein the coating is disposed on the surface of the inner wall of the fourth substrate, the coating comprising an ammonia oxidizing component; 21. The exhaust gas treatment system of claim 16, wherein the fourth catalyst is located downstream of the third catalyst described in (iv), and the inlet end of the fourth catalyst is disposed upstream of the outlet end of the fourth catalyst.

22. 22. The system of claim 21, wherein the fourth catalyst is an ammonia oxidation catalyst.

23. 22. The system of claim 21, wherein the outlet end of the third catalyst described in (iv) is in fluid communication with the inlet end of the fourth catalyst, and in the exhaust gas treatment system, no catalyst for treating exhaust gas exiting the third catalyst is disposed between the outlet end of the third catalyst and the inlet end of the fourth catalyst.

24. the exhaust gas treatment system further comprising an injector for injecting a fluid into an exhaust gas stream exiting the internal combustion engine, the injector being located upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system; A system according to any one of the preceding claims, wherein no hydrocarbon injection device is arranged upstream of the first catalyst and downstream of the upstream end of the exhaust gas treatment system.

25. 25. The system of claim 24, wherein the fluid is an aqueous urea solution.

26. 1. A method for treating an exhaust gas stream emitted from an internal combustion engine, comprising: (1) providing an exhaust gas stream from an internal combustion engine, wherein the exhaust gas stream comprises one or more of NOx, ammonia, nitric oxide, and hydrocarbons; (2) passing the exhaust gas stream prepared in (1) through an exhaust gas treatment system according to any one of claims 1 to 25. The method according to claim 1, further comprising:

Images