Catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, comprising Mn supported on a CuO-Al2O3 mixed oxide

Abstract

The present invention relates to a catalyst for treating an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, the catalyst comprising: a first washcoat layer comprising Mn supported on a CuO-Al2O3 mixed oxide; and a substrate, the substrate having an inlet end and an outlet end, the catalyst further comprising one or more platinum group metals comprising Pt, Pd, or Pt and Pd, the one or more platinum group metals being at least partially contained in one or more of: (a) the first washcoat layer, (b) an optional second washcoat layer, or (c) the optional second and third washcoat layers. The present invention also relates to an exhaust gas treatment system including the catalyst, a method for treating an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons using the catalyst, and the use of the catalyst for the oxidation of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons.

Description

[Technical Field]

[0001] The present invention relates to a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxide (NO), and hydrocarbons, an exhaust gas treatment system including the catalyst, a method for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxide (NO), and hydrocarbons using the catalyst, and the use of the catalyst for the oxidation of one or more of formaldehyde, nitrogen oxide (NO), and hydrocarbons. [Background technology]

[0002] The present invention relates to the use of diesel oxidation catalysts (DOCs) with improved oxidation capabilities, particularly for the oxidation of one or more of formaldehyde (HCHO), nitrogen oxides (NO), and hydrocarbons (including diesel fuel). Formaldehyde is known to be a toxic material under increasingly stringent regulations in indoor air spaces due to its emissions from various building materials used in the construction industry. Stricter regulations are also being implemented for formaldehyde emissions from the engine exhaust of passenger vehicles and delivery vehicles. Manganese oxides (e.g., MnO) are generally known to be active in destroying formaldehyde under ambient conditions, but do not possess the thermal stability required to survive in a typical engine exhaust environment. In particular, phase transitions at high temperatures (e.g., above 400°C) cause the structure of MnO to collapse, resulting in surface area and pore volume that are so low that they are no longer catalytically effective. One way to improve the stability of Mn oxide (and other catalytically useful base metal oxides such as copper, ceria, and iron) at high temperatures may be to support them on refractory oxide materials that themselves have high stability when exposed to high temperatures in engine exhaust. Materials such as aluminum oxide (Al2O3) and zirconium oxide (ZrO2) may be useful in this regard.

[0003] A significant challenge to the inclusion of Mn-containing base metal oxide (BMO) catalysts in technologies for the reduction of exhaust emissions from diesel vehicles can be seen in the inherently low sulfur tolerance of manganese.

[0004] Pt and Pd supported on high-temperature resistant refractory metal oxide supports are known to provide efficient oxidation of CO and HC pollutants emitted from diesel engines. Vehicle manufacturers require such DOC compositions to meet increasingly stringent CO and HC exhaust emission requirements worldwide. An additional function of DOC compositions, when placed in the exhaust of a diesel vehicle, is to oxidize diesel fuel injected into the exhaust upstream of the DOC, creating a high-temperature exotherm that is used to thermally oxidize soot accumulated on a diesel particulate filter (DPF) or catalyzed soot filter (CSF) located downstream of the DOC composition. Alternatively, the hydrocarbon concentration in the exhaust stream may be increased for exotherm generation by adjusting the combustion process, such as through various post-injection methods. Temperatures above 600°C at the DPF or CSF inlet are preferred to provide efficient oxidation of retained soot. The concentration of diesel fuel injected into the exhaust stream required to provide the desired exotherm is fairly high, approximately 1% (10,000 ppm) or more on a C1 basis. The temperature at which the DOC composition can oxidize ("light-off") the injected fuel must be as low as possible, preferably below 300°C. In addition, the amount of hydrocarbon slip that bypasses the DOC catalyst during exotherm production must be as low as possible, preferably below 3,000 ppm, 2,000 ppm, or even 1,000 ppm.

[0005] WO 2022 / 047132(A1) relates to an oxidation catalyst composition for a catalyst article, an exhaust gas treatment system for reducing formaldehyde levels in engine exhaust emissions. In particular, claim 1 discloses an oxidation catalyst comprising a platinum group metal (PGM) component comprising Pd, Pt, or a combination thereof, a manganese component, and a first refractory metal oxide support material comprising zirconia.

[0006] US Patent No. 10,598,061 (B2) relates to a method and system for a diesel oxidation catalyst. In particular, claim 1 discloses a method comprising: producing NO2 in a catalyst comprising a washcoat containing zirconium, one or more base metal oxides, and palladium oxide, wherein the exhaust gas flow rate is between a lower threshold flow rate and an upper threshold flow rate; and promoting regeneration of a particulate filter located downstream of the catalyst via NO2 when the exhaust gas temperature is higher than the threshold temperature, wherein the palladium oxide is contained in an upstream portion of the catalyst relative to the direction of exhaust gas flow, and the one or more base metal oxides are contained in a downstream portion of the catalyst relative to the direction of exhaust gas flow.

[0007] U.S. Patent No. 10,392,980 (B2) relates to a method and system for a diesel oxidation catalyst. In particular, claim 1 discloses a method comprising passing a diesel combustion exhaust gas over a diesel oxidation catalyst having a washcoat containing zirconium oxide, palladium oxide, and at least one base metal oxide, wherein the washcoat is coated on a surface of a substrate, the at least one base metal oxide is coated on a downstream portion of the substrate in an amount greater than that coated on an upstream portion, and the palladium oxide is coated on an upstream portion of the substrate in an amount greater than that coated on a downstream portion, downstream referring to the axial direction of the exhaust gas flow, and the palladium oxide is 0.5 to 3 weight percent of the washcoat.

[0008] US Patent Application Publication No. 2018 / 333677(A1) relates to catalyst articles coated with a multi-layer catalyst composition, exhaust treatment systems including such catalyst articles, and methods of use and manufacture thereof. In particular, the catalyst article is defined in claim 1, wherein the catalyst article comprises a multi-layer catalyst composition adapted for the oxidation of gaseous HC and CO emissions and the conversion of NOx to N2, the catalyst article comprising a substrate adhered to the multi-layer catalyst composition, the multi-layer catalyst composition comprising a first layer, a second layer, and optionally an intermediate layer between the first and second layers, the first layer being located between the substrate and the second layer and comprising a first porous refractory oxide material impregnated with at least one base metal component, the second layer comprising a second porous refractory oxide material impregnated with at least one platinum group metal, the intermediate layer comprising a refractory oxide material, and the second layer being substantially free of alumina and / or the intermediate layer being present and substantially free of alumina.

[0009] US Patent Application Publication No. 2018 / 318805(A1) relates to diesel oxidation catalyst compositions, catalyst articles coated with such compositions, exhaust treatment systems including such catalyst articles, and methods of using the same. In particular, the diesel oxidation catalyst composition is defined in claim 1, wherein the composition comprises at least one platinum group metal impregnated on a porous refractory oxide material in particulate form and at least one base metal oxide impregnated on the porous refractory oxide material in particulate form, wherein the porous refractory oxide material impregnated with the at least one platinum group metal and the porous refractory oxide material impregnated with the at least one base metal oxide are in the form of a mixture, or the at least one platinum group metal and the at least one base metal oxide are impregnated on the same porous refractory oxide material.

[0010] M.C. Alvarez-Galvan et al., Applied Catalysis B. 2004, 51, 83-91, disclose alumina-supported manganese catalysts with manganese loadings ranging from 3.9 to 18.2 wt. %. Such catalysts were prepared and tested in the combustion of formaldehyde / methanol mixtures in a stream of air.

[0011] It was therefore an object of the present invention to provide a catalyst with improved performance with respect to the conversion of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, especially after exposure to sulfation and desulfation treatments. DETAILED DESCRIPTION OF THE INVENTION

[0012] It has been surprisingly found that an improved catalyst can be provided for the conversion of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons in exhaust gases. In particular, it has been surprisingly found that a catalyst can be provided that exhibits improved performance with respect to the conversion of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons after exposure to sulfation and desulfation treatments such as those encountered in typical applications. Furthermore, it has been surprisingly found that the catalyst according to the present invention exhibits improved oxidation function for hydrocarbons (HC) and nitrogen oxides (NO). In particular, it has been surprisingly found that the benefits of using a BMO-containing catalyst to reduce platinum group metals in diesel exhaust treatment systems are not limited to HCHO oxidation, but also extend to hydrocarbon and NO oxidation. This allows vehicle manufacturers to meet ever-more stringent vehicle emissions standards while also reducing the overall usage and cost of PGMs. It has also been surprisingly found that the use of a diesel oxidation catalyst (DOC) containing both a platinum group metal (PGM) catalyst and a base metal oxide (BMO) catalyst results in a catalyst with improved fuel combustion function. Furthermore, the catalysts of the present invention can be expected to be capable of oxidizing soot buildup on substrates, particularly wall-flow substrates, because they can produce NO, which oxidizes the soot, particularly with a Mn-containing washcoat layer. Additionally, the catalysts of the present invention can enable relatively low NO production, particularly due to the relatively low content of platinum group metals.

[0013] Accordingly, the present invention relates to a catalyst for the treatment of an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, the catalyst comprising: a first washcoat layer comprising Mn supported on a CuO-Al2O3 mixed oxide; a substrate; the substrate has an inlet end through which the exhaust gas flow can enter the catalyst and an outlet end through which the exhaust gas flow can exit the catalyst; The catalyst further comprises one or more platinum group metals including Pt, Pd, or Pt and Pd, wherein the one or more platinum group metals are: (a) a first washcoat layer; and (b) an optional second washcoat layer; or (c) at least partially contained in one or more of the optional second and third washcoat layers.

[0014] Preferably, the optional second washcoat layer is substantially free of Mn, and more preferably the optional second washcoat layer is free of Mn. Note that the Mn contained in the second washcoat layer may result from leakage of Mn into that layer from another layer containing Mn, particularly from the first washcoat layer.

[0015] Within the meaning of the present invention, a washcoat layer is substantially free of an element or compound when the washcoat layer contains the element or compound in an amount of 1 wt. % or less, preferably 0.5 wt. % or less, more preferably 0.1 wt. % or less, more preferably 0.05 wt. % or less, more preferably 0.01 wt. % or less, more preferably 0.005 wt. % or less, more preferably 0.001 wt. % or less, calculated as the element or compound, based on 100 wt. % of the washcoat layer.

[0016] It is preferred that the loading of Mn in the first washcoat layer, calculated as element, is in the range of 1 to 50 wt%, more preferably 2 to 30 wt%, more preferably 5 to 20 wt%, more preferably 8 to 12 wt%, based on 100 wt% of the first washcoat layer.

[0017] It is preferred that Mn is present in the form of one or more cations of Mn, and that Mn is more preferably contained in the first washcoat layer as one or more oxides, and that Mn is more preferably contained in the first washcoat layer as one or more oxides of Mn(II), Mn(III), Mn(II / III), and Mn(IV), more preferably as one or more oxides selected from the group consisting of MnO, Mn2O3, Mn3O4, MnO2, Mn(O)OH, and Mn-Zr mixed oxides, including mixtures of two or more of the following, and that the Mn-Zr mixed oxides are preferably contained in the first washcoat layer as a solid solution.

[0018] Preferably, CuO-Al2O3 mixed oxide is the particulate support material.

[0019] The first washcoat layer preferably contains Ce, and more preferably Ce is contained in the first washcoat layer as CeO2 and / or Ce2O3.

[0020] If the first washcoat layer contains Ce, it is preferred that the loading of Ce in the first washcoat layer, calculated as an element, is in the range of 1 to 50 wt%, more preferably 2 to 30 wt%, more preferably 5 to 20 wt%, more preferably 8 to 12 wt%, based on 100 wt% of the first washcoat layer.

[0021] Furthermore, when the first washcoat layer contains Ce, it is preferred that the Ce be supported on a CuO-Al2O3 mixed oxide.

[0022] Alternatively, it is preferred that the first washcoat layer is substantially free of Ce, and more preferably the first washcoat layer is free of Ce.

[0023] If the first washcoat layer is substantially free of Ce, then it is preferred that the catalyst is substantially free of Ce, and preferably the catalyst is Ce-free.

[0024] The first washcoat layer preferably comprises Cu supported on a particulate support material, more preferably the Cu is supported on a CuO-Al2O3 mixed oxide, and the first washcoat layer preferably comprises CuO, Cu2O, or CuO and Cu2O, more preferably CuO.

[0025] It should be noted that according to such a preferred embodiment, Cu is contained in the first washcoat layer in addition to the Cu in the CuO—Al 2 O 3 mixed oxide.

[0026] When the first washcoat layer comprises Cu supported on a particulate support material, it is preferred that the loading of Cu supported on the particulate support material in the first washcoat layer, calculated as the element, is in the range of 1 to 50 wt %, more preferably 2 to 30 wt %, more preferably 5 to 20 wt %, more preferably 8 to 12 wt %, based on 100 wt % of the first washcoat layer.

[0027] Alternatively, the first washcoat layer preferably does not substantially contain Cu that is not contained in the CuO—Al2O3 mixed oxide, and more preferably the first washcoat layer does not contain Cu that is not contained in the CuO—Al2O3 mixed oxide.

[0028] When the first washcoat layer is substantially free of Cu not contained in the CuO—Al2O3 mixed oxide, it is preferred that the catalyst is substantially free of Cu not contained in the CuO—Al2O3 mixed oxide, and more preferably the catalyst is free of Cu not contained in the CuO—Al2O3 mixed oxide.

[0029] It is preferred that the substrate is a wall-flow or flow-through substrate, more preferably a honeycomb wall-flow or honeycomb flow-through substrate, more preferably a honeycomb flow-through substrate, and the flow-through substrate is more preferably a flow-through substrate with highly porous walls.

[0030] The loading of the first washcoat layer is 0.5 to 5 g / in 3 The range is preferably 1 to 3 g / in 3 More preferably, it is in the range of 1.5 to 2.5 g / in 3 More preferably, the range is 1.7 to 2 g / in 3 It is more preferable that the range is:

[0031] Within the meaning of the present invention, the loading in a washcoat layer in a catalyst refers to the loading in the washcoat layer based on the volume of catalyst contained in the washcoat layer. Thus, within the meaning of the present invention, the loading in a washcoat layer contained only in a specific portion or zone of the catalyst is based on the volume of that portion or zone of the catalyst. Thus, as an example, if a washcoat layer is provided over 50% of the axial length of a honeycomb substrate, the loading is calculated based on 50% of the total volume of the honeycomb substrate.

[0032] The loading in the second washcoat layer is 0.25 to 6 g / in 3 , preferably 0.3 to 6 g / in 3 , more preferably 1 to 5 g / in 3 , more preferably 1.5 to 4 g / in 3 , more preferably 2 to 3.5 g / in 3 , more preferably 2.2 to 3.0 g / in 3 , more preferably 2.3 to 2.9 g / in 3 , more preferably 2.5 to 2.7 g / in 3 It is preferable that the range is:

[0033] It is preferred that the catalyst comprises one or more platinum group metals consisting of Pt, Pd, or Pt and Pd, more preferably that the catalyst comprises Pt, or Pt and Pd as the one or more platinum group metals, and even more preferably that the catalyst comprises Pt and Pd as the one or more platinum group metals.

[0034] Catalyst, calculated as element, 2 to 250 g / ft 3, more preferably 5 to 150 g / ft 3 , more preferably 10 to 125 g / ft 3 , more preferably 20 to 100 g / ft 3 , more preferably 25 to 85 g / ft 3 , more preferably 30 to 80 g / ft 3 , more preferably 40 to 60 g / ft 3 It is preferable that Pt is contained in a loading amount in the range of .

[0035] Within the meaning of the present invention, the loading of Pt, Pd, or Pt and Pd in ​​a catalyst refers to the loading of Pt, Pd, or Pt and Pd based on the volume of the catalyst in which Pt, Pd, or Pt and Pd are contained. If Pt, Pd, or Pt and Pd are contained in one or more zones of the catalyst, the loading of Pt, Pd, or Pt and Pd within the meaning of the present invention is preferably based on the volume of the catalyst in which one or more Pt, Pd, or Pt and Pd zones are contained. Thus, by way of example, if Pt, Pd, or Pt and Pd are provided in a zone extending over 50% of the axial length of a honeycomb substrate, the loading is calculated based on 50% of the total volume of the honeycomb substrate.

[0036] Catalyst, calculated as element, 1-80g / ft 3 , more preferably 5 to 60 g / ft 3 , more preferably 10 to 50 g / ft 3 , more preferably 15 to 40 g / ft 3 , more preferably 20 to 30 g / ft 3 It is preferable that Pd is contained in a loading amount in the range of .

[0037] Catalyst, calculated as an element, 2 to 250 g / ft 3 , more preferably 5 to 200 g / ft 3 , more preferably 10 to 150 g / ft 3 , more preferably 20 to 130 g / ft 3 , more preferably 30 to 125 g / ft 3 , more preferably 40 to 110 g / ft 3, more preferably 50 to 100 g / ft 3 , more preferably 60 to 90 g / ft 3 , more preferably 70 to 80 g / ft 3 It is preferred to include Pt and Pd with a total loading of Pt and Pd in ​​the range of

[0038] It is preferred that the catalyst comprises Pt and Pd in ​​a Pt:Pd weight ratio in the range of 30:70 to 90:10, more preferably 50:50 to 80:20, more preferably 60:40 to 75:25, more preferably 65:35 to 70:30.

[0039] One or more platinum group metals are supported on a particulate support material, more preferably selected from the group consisting of Al2O3, SiO2, TiO2, SiO2-doped Al2O3, Mn oxide-doped Al2O3, and mixtures of two or more thereof, and more preferably the one or more platinum group metals are supported on Al2O3, and / or SiO2-doped Al2O3, and / or Mn oxide-doped Al2O3, more preferably SiO2-doped Al2O3, or Al2O3, or Mn oxide-doped Al2O3, the Mn oxide-doped Al2O3 preferably containing 1 to 10 wt. %, more preferably 4 to 6 wt. %, Mn oxide, calculated as MnO2, based on 100 wt. % Mn oxide-doped Al2O3.

[0040] The first washcoat layer comprises a hydrocarbon trap material, the hydrocarbon trap material comprising a molecular sieve, preferably a zeolite, more preferably a zeolite having a maximum pore size of 12-membered rings, more preferably zeolite beta, the molecular sieve, preferably the zeolite, preferably comprising SiO2 and Al2O3, the molecular sieve, preferably the zeolite, more preferably having a pore size of 10:1 to 500:1, more preferably 10:1 to 100:1, more preferably 10:1 Preferably, the molecular sieve, preferably the zeolite, has a molar ratio of SiO2 to Al2O3 in the range of 1.0 to 7.0 wt. %, more preferably 3.0 to 5.0 wt. %, more preferably 4.0 to 4.5 wt. %, calculated as Fe2O3, based on the weight of the molecular sieve.

[0041] When the first washcoat layer includes a hydrocarbon trap material, the loading of the hydrocarbon trap material in the first washcoat layer is 0.01 to 2.0 g / in 3 in the range of 0.05 to 1.0 g / in 3 in the range of 0.05 to 0.3 g / in 3 It is preferable that the range is:

[0042] It is preferred that the catalyst comprises a second washcoat layer, and that the one or more platinum group metals are at least partially contained in the second washcoat layer, and more preferably that the one or more platinum group metals are completely contained in the second washcoat layer.

[0043] The second washcoat layer comprises a hydrocarbon trap material, the hydrocarbon trap material comprising a molecular sieve, more preferably a zeolite, more preferably a zeolite having a maximum pore size of 12-membered rings, more preferably zeolite beta, the molecular sieve, preferably the zeolite, preferably comprising SiO2 and Al2O3, the molecular sieve, preferably the zeolite, more preferably having a pore size of 10:1 to 500:1, more preferably 10:1 to 100:1, more preferably 10: It is preferred that the molecular sieve, preferably the zeolite, has a molar ratio of SiO2 to Al2O3 in the range of 1 to 40:1, more preferably 15:1 to 30:1, more preferably 20:1 to 25:1, and that the molecular sieve, preferably the zeolite, preferably contains Fe, and that the molecular sieve, preferably the zeolite, more preferably contains Fe in an amount in the range of 1.0 to 7.0 wt. %, more preferably 3.0 to 5.0 wt. %, more preferably 4.0 to 4.5 wt. %, calculated as Fe2O3, based on the weight of the molecular sieve.

[0044] When the second washcoat layer includes a hydrocarbon trap material, and the hydrocarbon trap material includes a molecular sieve, the loading of the hydrocarbon trap material in the second washcoat layer is 0.01 to 2.0 g / in 3 in the range of 0.05 to 1.0 g / in 3 in the range of 0.05 to 0.3 g / in 3 It is preferable that the range is:

[0045] According to a first alternative, the catalyst preferably comprises a second washcoat layer, the catalyst exhibiting a layered arrangement of the first washcoat layer and the second washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer.

[0046] When the catalyst comprises a second washcoat layer, the catalyst exhibits a layered arrangement of a first washcoat layer and a second washcoat layer, and one or more platinum group metals are at least partially contained in the second washcoat layer, it is preferred, according to a first alternative, that the first washcoat layer is provided on the substrate and the second washcoat layer is provided on the first washcoat layer.

[0047] Furthermore, when the catalyst comprises a second washcoat layer, the catalyst exhibits a layered arrangement of a first washcoat layer and a second washcoat layer, and one or more platinum group metals are at least partially contained in the second washcoat layer, it is preferred, according to a first alternative, that the second washcoat layer is provided on the substrate and the first washcoat layer is provided on the second washcoat layer.

[0048] Furthermore, when the catalyst comprises a second washcoat layer, the catalyst exhibits a layered arrangement of the first washcoat layer and the second washcoat layer, and the one or more platinum group metals are at least partially contained in the second washcoat layer, according to a first alternative, the catalyst comprises a third washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer, the second washcoat layer, and the third washcoat layer, and the third washcoat layer is provided on the substrate along its axial length starting from the inlet end of the substrate. Preferably, a first washcoat layer is disposed on the substrate along its axial length beginning at the outlet end of the substrate, a second washcoat layer is disposed completely over the first washcoat layer, the length of the first washcoat layer is less than the axial length of the substrate to create an upstream zone including the third washcoat layer and a downstream zone including the first and second washcoat layers, and one or more platinum group metals are at least partially contained in the third washcoat layer. Alternatively, it is preferred that the catalyst includes a third washcoat layer, the catalyst exhibiting a zoned arrangement of a first washcoat layer, a second washcoat layer, and a third washcoat layer, the third washcoat layer being disposed on the substrate along its axial length starting from the inlet end of the substrate, the second washcoat layer being disposed on the substrate along its axial length starting from the outlet end of the substrate, the first washcoat layer being disposed completely over the second washcoat layer, the length of the second washcoat layer being shorter than the axial length of the substrate to create an upstream zone comprising the third washcoat layer and a downstream zone comprising the first and second washcoat layers, and the one or more platinum group metals being at least partially contained in the third washcoat layer.Alternatively, it is preferred that the catalyst includes a third washcoat layer, the catalyst exhibiting a zoned arrangement of the first, second, and third washcoat layers, the third washcoat layer being disposed on the substrate along its axial length beginning at the outlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length beginning at the inlet end of the substrate, and the second washcoat layer being disposed completely over the first washcoat layer, the length of the first washcoat layer being shorter than the axial length of the substrate to create a downstream zone comprising the third washcoat layer and an upstream zone comprising the first and second washcoat layers, and the one or more platinum group metals being at least partially contained in the third washcoat layer. Alternatively, it is preferred that the catalyst includes a third washcoat layer, the catalyst exhibiting a zoned arrangement of the first, second, and third washcoat layers, the third washcoat layer being disposed on the substrate along its axial length beginning at the outlet end of the substrate, the second washcoat layer being disposed on the substrate along its axial length beginning at the inlet end of the substrate, the first washcoat layer being disposed completely over the second washcoat layer, the length of the second washcoat layer being shorter than the axial length of the substrate to create a downstream zone comprising the third washcoat layer and an upstream zone comprising the first and second washcoat layers, and the one or more platinum group metals being at least partially contained in the third washcoat layer.

[0049] According to a second alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the second washcoat layer being provided on the substrate along its axial length starting from the inlet end of the substrate, the first washcoat layer being provided on the substrate along its axial length starting from the outlet end of the substrate, the length of the first washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0050] According to a third alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the first washcoat layer being provided on the substrate along its axial length starting from the inlet end of the substrate, and the second washcoat layer being provided on the substrate along its axial length starting from the outlet end of the substrate, the length of the first washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0051] According to a fourth alternative, the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first and second washcoat layers, the second washcoat layer being provided on the substrate along its axial length starting from the inlet end of the substrate, the first washcoat layer being provided on the substrate along its axial length starting from the outlet end of the substrate, the length of the second washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0052] According to a sixth alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the first washcoat layer being provided on the substrate along its axial length starting from the inlet end of the substrate, the second washcoat layer being provided on the substrate along its axial length starting from the outlet end of the substrate, the length of the second washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0053] When the catalyst includes a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second or fourth alternative, it is preferred that the catalyst includes a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibits a zoned arrangement of the second and third washcoat layers, the second washcoat layer being disposed on the substrate along the axial length of the substrate starting from the inlet end of the substrate, and the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the outlet end of the substrate, the length of the third washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first and third washcoat layers.

[0054] When the catalyst includes a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the third or fifth alternative, it is preferred that the catalyst includes a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibits a zoned arrangement of the second and third washcoat layers, the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the inlet end of the substrate, and the second washcoat layer being disposed on the substrate along the axial length of the substrate starting from the outlet end of the substrate, and the length of the third washcoat layer being shorter than the axial length of the substrate to create an upstream zone comprising the first and third washcoat layers, and a downstream zone comprising the second washcoat layer.

[0055] When the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second, third, fourth, or fifth alternative, it is preferred that the first and second washcoat layers are adjacent to each other.

[0056] Furthermore, when the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second, third, fourth, or fifth alternative, it is preferred that the second and third washcoat layers are adjacent to each other.

[0057] Furthermore, when the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second, third, fourth, or fifth alternative, it is preferred that a portion of the second washcoat layer overlaps at least a portion of the first washcoat layer, and more preferably the second washcoat layer overlaps the first washcoat layer over a portion in the range of 10 to 100%, more preferably 15 to 80%, more preferably 20 to 50% of the axial length of the first washcoat layer.

[0058] Furthermore, when the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second, third, fourth, or fifth alternative, it is preferred that a portion of the first washcoat layer overlaps at least a portion of the second washcoat layer, and more preferably the first washcoat layer overlaps the second washcoat layer over a portion in the range of 10 to 100%, more preferably 15 to 80%, more preferably 20 to 50% of the axial length of the second washcoat layer.

[0059] Furthermore, when the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second, third, fourth, or fifth alternative, it is preferred that a portion of the third washcoat layer overlaps at least a portion of the first washcoat layer, and preferably the third washcoat layer overlaps the first washcoat layer over a portion in the range of 10 to 100%, more preferably 15 to 80%, more preferably 20 to 50% of the axial length of the first washcoat layer.

[0060] According to a sixth alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the second washcoat layer being provided on the substrate along its entire length, the first washcoat layer being provided on the second washcoat layer along its axial length starting from the outlet end of the substrate, the length of the first washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0061] According to a seventh alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the second washcoat layer being provided on the substrate along its entire length, the first washcoat layer being provided on the second washcoat layer along its axial length starting from the inlet end of the substrate, the length of the first washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0062] When the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the sixth or seventh alternative, it is preferred that the length of the first washcoat layer is in the range of 10 to 90%, more preferably 30 to 80%, more preferably 50 to 70% of the axial length of the substrate.

[0063] According to an eighth alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the first washcoat layer being provided on the substrate along its entire length, the second washcoat layer being provided on the first washcoat layer along its axial length starting from the inlet end of the substrate, the length of the second washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0064] When the catalyst includes a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the eighth alternative, it is preferred that the catalyst includes a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibits a zoned arrangement of the second and third washcoat layers, the second washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the inlet end of the substrate, and the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the outlet end of the substrate, and the length of the third washcoat layer being shorter than the axial length of the substrate to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the third washcoat layer.

[0065] According to a ninth alternative, the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the first washcoat layer being provided on the substrate along its entire length, the second washcoat layer being provided on the first washcoat layer along its axial length starting from the outlet end of the substrate, the length of the second washcoat layer being shorter than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and it is preferred that the one or more platinum group metals are at least partially contained in the second washcoat layer.

[0066] When the catalyst includes a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the ninth alternative, it is preferred that the catalyst includes a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibits a zoned arrangement of the second and third washcoat layers, the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the inlet end of the substrate, and the second washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the outlet end of the substrate, and the length of the third washcoat layer being shorter than the axial length of the substrate to create an upstream zone comprising the third washcoat layer and a downstream zone comprising the second washcoat layer.

[0067] When the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the eighth or ninth alternative, and the catalyst comprises a third washcoat layer, it is preferred that the second and third washcoat layers are adjacent to each other.

[0068] The length of the first washcoat layer is preferably in the range of 5 to 100% of the axial length of the substrate, more preferably 10 to 90% of the axial length of the substrate, preferably 15 to 75%, more preferably 20 to 60%, more preferably 25 to 50%, more preferably 35 to 45%.

[0069] When the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers, preferably according to the eighth or ninth alternative, it is preferred that the length of the second washcoat layer is in the range of 5 to 100% of the axial length of the substrate, more preferably 10 to 90%, more preferably 15 to 75%, more preferably 20 to 60%, more preferably 25 to 50%, more preferably 35 to 45% of the axial length of the substrate.

[0070] When the catalyst includes a second washcoat layer and a third washcoat layer, the length of the third washcoat layer is preferably in the range of 5 to 100% of the axial length of the substrate, preferably 10 to 90%, more preferably 15 to 75%, more preferably 20 to 60%, more preferably 25 to 50%, and more preferably 35 to 45% of the axial length of the substrate.

[0071] Furthermore, when the catalyst comprises a second washcoat layer and a third washcoat layer, it is preferred that the third washcoat layer is substantially free of sulfur trapping material, and preferably the third washcoat layer is free of sulfur trapping material.

[0072] Furthermore, when the catalyst comprises a second washcoat layer and a third washcoat layer, the third layer comprises a hydrocarbon trap material, and the hydrocarbon trap material comprises a molecular sieve, preferably a zeolite, more preferably a zeolite having a maximum pore size of 12-membered rings, more preferably zeolite beta, and the molecular sieve, preferably the zeolite, preferably comprises SiO2 and Al2O3, and the molecular sieve, preferably the zeolite, preferably has a pore size of 10:1 to 500:1, more preferably 10:1 to 1000:1. Preferably, the molecular sieve, preferably the zeolite, has a molar ratio of SiO2 to Al2O3 in the range of 0.00:1, more preferably 10:1 to 40:1, more preferably 15:1 to 30:1, more preferably 20:1 to 25:1, and the molecular sieve, preferably the zeolite, preferably contains Fe, and the molecular sieve, preferably the zeolite, more preferably contains Fe in an amount in the range of 1.0 to 7.0 wt. %, more preferably 3.0 to 5.0 wt. %, more preferably 4.0 to 4.5 wt. %, calculated as Fe2O3, based on the weight of the molecular sieve.

[0073] If the third layer includes a hydrocarbon trap material, the loading of the hydrocarbon trap material in the third washcoat layer is 0.01 to 2.0 g / in 3 in the range of 0.05 to 1.0 g / in 3 in the range of 0.05 to 0.3 g / in 3 It is preferable that the range is:

[0074] Furthermore, when the catalyst comprises a second washcoat layer and a third washcoat layer, it is preferred that the one or more platinum group metals are at least partially contained in the third washcoat layer.

[0075] When one or more platinum group metals are at least partially contained in the third washcoat layer, the one or more platinum group metals are supported on a particulate support material, preferably selected from the group consisting of Al2O3, SiO2, TiO2, SiO2-doped Al2O3, Mn oxide-doped Al2O3, and mixtures of two or more thereof, and preferably the one or more platinum group metals are supported on Al2O3, and / or SiO2-doped Al2O3, and / or Mn oxide-doped Al2O3, more preferably SiO2-doped Al2O3, or Al2O3, or Mn oxide-doped Al2O3, and the Mn oxide-doped Al2O3 preferably contains 1 to 10 wt. %, more preferably 4 to 6 wt. %, Mn oxide, calculated as MnO2, based on 100 wt. % Mn oxide-doped Al2O3.

[0076] Furthermore, when the catalyst comprises a second washcoat layer and a third washcoat layer, it is preferred that the catalyst comprises the second washcoat layer and the third washcoat layer, the one or more platinum group metals are completely contained in the second washcoat layer and the third washcoat layer, the weight ratio of the one or more platinum group metals contained in the second washcoat layer to the one or more platinum group metals contained in the third washcoat layer is in the range of 0.5:1 to 5.0:1, more preferably 1.0:1 to 2.0:1, more preferably 1.4:1 to 1.6:1, the one or more platinum group metals contained in the second washcoat layer preferably include, and more preferably consist of, Pt and Pd, and the one or more platinum group metals contained in the third washcoat layer preferably include, and more preferably consist of Pt and Pd.

[0077] When the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth alternative, it is preferred that the one or more platinum group metals are entirely contained in the second washcoat layer or the second and third washcoat layers.

[0078] Furthermore, when the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth alternative, it is preferred that the one or more platinum group metals are at least partially contained in the first washcoat layer.

[0079] It is preferred that the substrate is a metallic substrate or a ceramic substrate, more preferably the substrate is a ceramic substrate, more preferably the substrate comprises cordierite and / or SiC, preferably cordierite, more preferably the substrate consists of cordierite and / or SiC, preferably cordierite.

[0080] When the catalyst comprises a second washcoat layer and the catalyst exhibits a zoned arrangement of the first and second washcoat layers according to the second, third, fourth, fifth, sixth, seventh, eighth or ninth alternative, the substrate consists of two separate monoliths, the first monolith being provided upstream of the second monolith, the washcoat layer or layers of the upstream zone being contained on the first monolith and the washcoat layer or layers of the downstream zone being contained on the second monolith, more preferably the washcoat layer or layers of the upstream zone being contained on the second monolith. The first monolith containing the washcoat layer and the second monolith containing the downstream zone washcoat layer or layers are obtained or can be obtained by compartmentalizing a catalyst according to any one of the embodiments disclosed herein according to the second, third, fourth, fifth, sixth, seventh, eighth or ninth alternative into two separate monoliths, preferably wherein the upstream zone washcoat layer or layers are contained on the first monolith and the downstream zone washcoat layer or layers are contained on the second monolith.

[0081] The present invention further relates to an exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit for exhaust gases from the internal combustion engine, wherein the exhaust gas conduit contains one or more catalysts according to any one of the embodiments disclosed herein, preferably one, two, three, or four catalysts according to any of the embodiments disclosed herein.

[0082] Preferably, the internal combustion engine is a compression ignition engine, more preferably a diesel engine.

[0083] Preferably the internal combustion engine is a lean gasoline engine.

[0084] Alternatively, the internal combustion engine is powered by an oxygenated fuel, which preferably comprises one or more of methanol and biofuel.

[0085] Preferably, the system includes one or more of an electric heater, a fuel burner, a fuel injector, a selective catalytic reduction (SCR) catalyst, an ammonia oxidation (AMOX) catalyst, a catalyzed soot filter (CSF), a diesel particulate filter (DPF), a selective catalytic reduction catalyst on filter (SCRoF), and a diesel exotherm catalyst (DEC).

[0086] According to a first alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a diesel exothermic catalyst (DEC), a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst.

[0087] According to a second alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a diesel exothermic catalyst (DEC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst.

[0088] According to a third alternative, the system preferably comprises, in sequential order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a diesel exothermic catalyst (DEC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0089] According to a fourth alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of the embodiments disclosed herein, a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst.

[0090] According to a fifth alternative, the system comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, and wherein the substrates are preferably a wall-flow substrate, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0091] According to a sixth alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst.

[0092] According to a seventh alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0093] According to an eighth alternative, the system comprises, in sequential order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, optional fuel injector, a catalyst according to any of the embodiments disclosed herein, and preferably the substrates are a wall-flow substrate, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0094] According to a ninth alternative, the system preferably comprises, in sequential order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction over filter (SCRoF), and an ammonia oxidation (AMOX) catalyst.

[0095] According to a tenth alternative, the system preferably comprises, in sequential order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or fuel injector, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction over filter (SCRoF), and an ammonia oxidation (AMOX) catalyst.

[0096] According to an eleventh alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or fuel injector, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0097] According to a twelfth alternative, the system comprises, in sequential order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or fuel injector, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of the embodiments disclosed herein, a catalyst according to any of the embodiments disclosed herein, and preferably the substrates are a wall-flow substrate, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0098] According to a thirteenth alternative, it is preferred that the system comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0099] According to a fourteenth alternative, the system preferably comprises, in sequential order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction catalyst on filter (SCRoF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0100] According to a fifteenth alternative, the system preferably comprises, in consecutive order in the direction of the exhaust gases, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of the embodiments disclosed herein, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction catalyst on a filter (SCRoF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst.

[0101] Still further, the present invention relates to a method for the treatment of an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, the method comprising: (A) providing an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons; (B) directing the exhaust gas stream provided in (A) through a catalyst according to any one of the embodiments disclosed herein.

[0102] Preferably, the exhaust gas stream provided in (A) comprises one or more sulfur-containing compounds, more preferably SO2 and / or SO3.

[0103] The exhaust gas flow provided at (A) is NO X It is preferred that the compound contains:

[0104] Preferably, the exhaust gas stream provided in (A) comprises CO.

[0105] Preferably, the exhaust gas stream provided in (A) comprises formaldehyde.

[0106] Preferably, the exhaust gas stream provided in (A) comprises nitrogen oxides (NO).

[0107] It is preferred that the exhaust gas stream provided in (A) comprises hydrocarbons, preferably C1 to C20 hydrocarbons, more preferably C2 to C10 hydrocarbons.

[0108] Still further, the present invention relates to the use of a catalyst according to any one of the embodiments disclosed herein for the oxidation of one or more of formaldehyde, nitrogen oxides (NO) and hydrocarbons, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO) and hydrocarbons in an exhaust gas stream, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO) and hydrocarbons in the exhaust gas stream of an internal combustion engine, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO) and hydrocarbons in the exhaust gas stream of a compression ignition engine, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO) and hydrocarbons in the exhaust gas stream of a diesel engine.

[0109] The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and reverse references as indicated. In particular, in each case where a range of embodiments is mentioned, for example, in the context of a term such as "the catalyst of any one of embodiments 1 to 4," it is noted that all embodiments within this range are expressly disclosed to those skilled in the art, that is, this expression is understood by those skilled in the art to be synonymous with "the catalyst of any one of embodiments 1, 2, 3, and 4." Furthermore, it is clearly noted that the following set of embodiments represents a properly structured part of the general description directed to preferred aspects of the present invention, and therefore properly supports, but does not represent, the scope of the claims of the present invention. 1. A catalyst for the treatment of an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, the catalyst comprising: a first washcoat layer comprising Mn supported on a CuO-Al2O3 mixed oxide; a substrate; the substrate has an inlet end through which the exhaust gas flow can enter the catalyst and an outlet end through which the exhaust gas flow can exit the catalyst; The catalyst further comprises one or more platinum group metals including Pt, Pd, or Pt and Pd, wherein the one or more platinum group metals are: (a) a first washcoat layer; and (b) an optional second washcoat layer; or (c) a catalyst at least partially contained in one or more of the optional second and third washcoat layers. 2. The catalyst of embodiment 1, wherein the optional second washcoat layer is substantially free of Mn, preferably the optional second washcoat layer is free of Mn. 3. The catalyst of embodiment 1 or 2, wherein the loading of Mn in the first washcoat layer, calculated as element, is in the range of 1 to 50 wt.%, preferably 2 to 30 wt.%, more preferably 5 to 20 wt.%, more preferably 8 to 12 wt.%, based on 100 wt.% of the first washcoat layer. 4. The catalyst of any one of embodiments 1 to 3, wherein Mn is present in the form of one or more cations of Mn, and wherein Mn is preferably contained in the first washcoat layer as one or more oxides, and more preferably as one or more oxides selected from the group consisting of MnO, Mn2O3, Mn3O4, MnO2, Mn(O)OH, and Mn-Zr mixed oxides, including mixtures of two or more of the following: MnO, Mn2O3, Mn3O4, MnO2, Mn(O)OH, and Mn-Zr mixed oxides, and wherein the Mn-Zr mixed oxides are preferably contained in the first washcoat layer as a solid solution. 5. The catalyst of any of embodiments 1-4, wherein the CuO-Al2O3 mixed oxide is the particulate support material. 6. The catalyst of any of embodiments 1-5, wherein the first washcoat layer comprises Ce, and the Ce is preferably contained in the first washcoat layer as CeO2 and / or Ce2O3. 7. The catalyst of embodiment 6, wherein the loading of Ce in the first washcoat layer, calculated as element, is in the range of 1 to 50 wt.%, preferably 2 to 30 wt.%, more preferably 5 to 20 wt.%, more preferably 8 to 12 wt.%, based on 100 wt.% of the first washcoat layer. 8. The catalyst of embodiment 6 or 7, wherein Ce is supported on a CuO-Al2O3 mixed oxide. 9. The catalyst of any of embodiments 1-5, wherein the first washcoat layer is substantially free of Ce, preferably the first washcoat layer is free of Ce. 10. The catalyst of embodiment 9, wherein the catalyst is substantially free of Ce, preferably the catalyst is free of Ce. 11. The catalyst of any of embodiments 1-10, wherein the first washcoat layer comprises Cu supported on a particulate support material, preferably the Cu is supported on a CuO-Al2O3 mixed oxide. 12. The catalyst of embodiment 11, wherein the loading of Cu supported on the particulate support material in the first washcoat layer, calculated as element, is in the range of 1 to 50 wt.%, preferably 2 to 30 wt.%, more preferably 5 to 20 wt.%, more preferably 8 to 12 wt.%, based on 100 wt.% of the first washcoat layer. 13. The catalyst of any of embodiments 1-10, wherein the first washcoat layer is substantially free of Cu not contained in the CuO—Al2O3 mixed oxide, preferably wherein the first washcoat layer is free of Cu not contained in the CuO—Al2O3 mixed oxide. 14. The catalyst of embodiment 13, wherein the catalyst is substantially free of Cu not contained in the CuO—Al2O3 mixed oxide, preferably wherein the catalyst is free of Cu not contained in the CuO—Al2O3 mixed oxide. 15. The catalyst of any of embodiments 1-14, wherein the substrate is a wall-flow substrate or a flow-through substrate, preferably a honeycomb wall-flow substrate or a honeycomb flow-through substrate, more preferably a honeycomb flow-through substrate, and the flow-through substrate is more preferably a flow-through substrate having highly porous walls. 16. The loading of the first washcoat layer is 0.5 to 5 g / in 3 , preferably 1 to 3 g / in 3 , more preferably 1.5 to 2.5 g / in 3 , more preferably 1.7 to 2 g / in 3 16. The catalyst of any of embodiments 1 to 15, wherein 17. The loading in the second washcoat layer is 0.25 to 6 g / in 3 , preferably 0.3 to 6 g / in 3 , more preferably 1 to 5 g / in 3 , more preferably 1.5 to 4 g / in 3 , more preferably 2 to 3.5 g / in 3 , more preferably 2.2 to 3.0 g / in 3 , more preferably 2.3 to 2.9 g / in 3 , more preferably 2.5 to 2.7 g / in 3 17. The catalyst of any of embodiments 1 to 16, wherein 18. The catalyst of any of embodiments 1-17, wherein the catalyst comprises one or more platinum group metals consisting of Pt, Pd, or Pt and Pd; preferably, the catalyst comprises Pt, or Pt and Pd as the one or more platinum group metals; more preferably, the catalyst comprises Pt and Pd as the one or more platinum group metals. 19. The catalyst, calculated as element, is 2 to 250 g / ft 3 , preferably 5 to 150 g / ft 3 , more preferably 10 to 125 g / ft 3 , more preferably 20 to 100 g / ft 3 , more preferably 25 to 85 g / ft 3 , more preferably 30 to 80 g / ft 3 , more preferably 40 to 60 g / ft 3 19. The catalyst of any of embodiments 1-18, comprising Pt at a loading in the range of 20. The catalyst, calculated as element, is 1 to 80 g / ft 3 , preferably 5 to 60 g / ft 3 , more preferably 10 to 50 g / ft 3 , more preferably 15 to 40 g / ft 3 , more preferably 20 to 30 g / ft 3 20. The catalyst of any of embodiments 1-19, comprising Pd at a loading in the range of 21. The catalyst, calculated as an element, is 2 to 250 g / ft 3 , preferably 5 to 200 g / ft 3 , more preferably 10 to 150 g / ft 3 , more preferably 20 to 130 g / ft 3 , more preferably 30 to 125 g / ft 3 , more preferably 40 to 110 g / ft 3 , more preferably 50 to 100 g / ft 3 , more preferably 60 to 90 g / ft 3 , more preferably 70 to 80 g / ft 3 21. The catalyst of any of embodiments 1-20, comprising Pt and Pd, with a total loading of Pt and Pd in ​​the range of 22. The catalyst of any of embodiments 1-21, wherein the catalyst comprises Pt and Pd in ​​a Pt:Pd weight ratio ranging from 30:70 to 90:10, preferably from 50:50 to 80:20, more preferably from 60:40 to 75:25, more preferably from 65:35 to 70:30. 23. The catalyst of any of embodiments 1-22, wherein the one or more platinum group metals are supported on a particulate support material, the particulate support material preferably being selected from the group consisting of Al2O3, SiO2, TiO2, SiO2-doped Al2O3, Mn-oxide-doped Al2O3, and mixtures of two or more thereof, and preferably the one or more platinum group metals are supported on Al2O3, and / or SiO2-doped Al2O3, and / or Mn-oxide-doped Al2O3, more preferably SiO2-doped Al2O3, or Al2O3, or Mn-oxide-doped Al2O3, the Mn-oxide-doped Al2O3 preferably containing 1 to 10 wt. %, more preferably 4 to 6 wt. %, Mn oxide, calculated as MnO2, based on 100 wt. % Mn-oxide-doped Al2O3. 24. The first washcoat layer comprises a hydrocarbon trap material, the hydrocarbon trap material comprising a molecular sieve, preferably a zeolite, more preferably a zeolite having a maximum pore size of 12-membered rings, more preferably zeolite beta, the molecular sieve, preferably the zeolite, preferably comprising SiO2 and Al2O3, the molecular sieve, preferably the zeolite, more preferably having a pore size of 10:1 to 500:1, more preferably 10:1 to 100:1, more preferably 10:1 to 40 24. The catalyst of any of embodiments 1-23, wherein the molecular sieve, preferably zeolite, preferably contains Fe, and the molecular sieve, preferably zeolite, more preferably contains Fe in an amount ranging from 1.0 to 7.0 wt. %, more preferably 3.0 to 5.0 wt. %, more preferably 4.0 to 4.5 wt. %, calculated as FeO, based on the weight of the molecular sieve. 25. The loading of the hydrocarbon trap material in the first washcoat layer is 0.01 to 2.0 g / in 3in the range of 0.05 to 1.0 g / in 3 in the range of 0.05 to 0.3 g / in 3 25. The catalyst of embodiment 24, wherein 26. The catalyst of any of embodiments 1-25, wherein the catalyst comprises a second washcoat layer, and the one or more platinum group metals are at least partially contained in the second washcoat layer, preferably, the one or more platinum group metals are completely contained in the second washcoat layer. 27. The second washcoat layer comprises a hydrocarbon trap material, the hydrocarbon trap material comprising a molecular sieve, preferably a zeolite, more preferably a zeolite having a maximum pore size of 12-membered rings, more preferably zeolite beta, the molecular sieve, preferably the zeolite, preferably comprising SiO2 and Al2O3, the molecular sieve, preferably the zeolite, more preferably having a pore size of 10:1 to 500:1, more preferably 10:1 to 100:1, more preferably 10:1 to 40 27. The catalyst of any of embodiments 1-26, wherein the molecular sieve, preferably zeolite, preferably contains Fe, and the molecular sieve, preferably zeolite, more preferably contains Fe in an amount ranging from 1.0 to 7.0 wt. %, more preferably 3.0 to 5.0 wt. %, more preferably 4.0 to 4.5 wt. %, calculated as FeO, based on the weight of the molecular sieve. 28. The loading of hydrocarbon trap material in the second washcoat layer is 0.01 to 2.0 g / in 3 in the range of 0.05 to 1.0 g / in 3 in the range of 0.05 to 0.3 g / in 3 28. The catalyst of embodiment 27, wherein 29. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibiting a layered arrangement of the first washcoat layer and the second washcoat layer, and the one or more platinum group metals are at least partially contained in the second washcoat layer. 30. The catalyst of embodiment 29, wherein a first washcoat layer is provided on the substrate, and a second washcoat layer is provided on the first washcoat layer. 31. The catalyst of embodiment 29 or 30, wherein a second washcoat layer is provided on the substrate, and the first washcoat layer is provided on the second washcoat layer. 32. The catalyst of embodiment 29 or 30, wherein the catalyst comprises a third washcoat layer, the catalyst exhibiting a zoned arrangement of the first washcoat layer, the second washcoat layer, and the third washcoat layer, the third washcoat layer being disposed on the substrate along its axial length starting from an inlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length starting from an outlet end of the substrate, and the second washcoat layer being disposed completely over the first washcoat layer, the length of the first washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the third washcoat layer and a downstream zone comprising the first washcoat layer and the second washcoat layer, and the one or more platinum group metals are at least partially contained in the third washcoat layer. 33. The catalyst of embodiment 29 or 31, wherein the catalyst comprises a third washcoat layer, the catalyst exhibiting a zoned arrangement of the first washcoat layer, the second washcoat layer, and the third washcoat layer, the third washcoat layer being disposed on the substrate along its axial length starting from an inlet end of the substrate, the second washcoat layer being disposed on the substrate along its axial length starting from an outlet end of the substrate, the first washcoat layer being disposed completely over the second washcoat layer, the length of the second washcoat layer being shorter than the axial length of the substrate to create an upstream zone comprising the third washcoat layer and a downstream zone comprising the first washcoat layer and the second washcoat layer, and the one or more platinum group metals are at least partially contained in the third washcoat layer. 34. The catalyst of embodiment 29 or 30, wherein the catalyst comprises a third washcoat layer, the catalyst exhibiting a zoned arrangement of the first washcoat layer, the second washcoat layer, and the third washcoat layer, the third washcoat layer being disposed on the substrate along its axial length starting from the outlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length starting from the inlet end of the substrate, and the second washcoat layer being disposed completely over the first washcoat layer, the length of the first washcoat layer being less than the axial length of the substrate so as to create a downstream zone comprising the third washcoat layer and an upstream zone comprising the first washcoat layer and the second washcoat layer, and the one or more platinum group metals are at least partially contained in the third washcoat layer. 35. The catalyst of embodiment 29 or 31, wherein the catalyst comprises a third washcoat layer, the catalyst exhibiting a zoned arrangement of the first washcoat layer, the second washcoat layer, and the third washcoat layer, the third washcoat layer being disposed on the substrate along its axial length starting from the outlet end of the substrate, the second washcoat layer being disposed on the substrate along its axial length starting from the inlet end of the substrate, the first washcoat layer being disposed completely over the second washcoat layer, the length of the second washcoat layer being shorter than the axial length of the substrate to create a downstream zone comprising the third washcoat layer and an upstream zone comprising the first washcoat layer and the second washcoat layer, and the one or more platinum group metals are at least partially contained in the third washcoat layer. 36. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer and the second washcoat layer, the second washcoat layer being disposed on the substrate along its axial length beginning at an inlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length beginning at an outlet end of the substrate, the length of the first washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 37. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer and the second washcoat layer, the second washcoat layer being disposed on the substrate along its axial length beginning at an inlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length beginning at an outlet end of the substrate, the length of the first washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 38. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer and the second washcoat layer, the second washcoat layer being disposed on the substrate along its axial length beginning at an inlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length beginning at an outlet end of the substrate, the length of the second washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 39. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer and the second washcoat layer, the second washcoat layer being disposed on the substrate along its axial length starting from an inlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length starting from an outlet end of the substrate, the length of the second washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 40. The catalyst of embodiment 36 or 38, wherein the catalyst comprises a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibiting a zoned arrangement of the second washcoat layer and the third washcoat layer, the second washcoat layer being disposed on the substrate along the axial length of the substrate starting from an inlet end of the substrate, and the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from an outlet end of the substrate, the length of the third washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer and the third washcoat layer. 41. The catalyst of embodiment 37 or 39, wherein the catalyst comprises a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibiting a zoned arrangement of the second washcoat layer and the third washcoat layer, the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from an inlet end of the substrate, and the second washcoat layer being disposed on the substrate along the axial length of the substrate starting from an outlet end of the substrate, the length of the third washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and the third washcoat layer, and a downstream zone comprising the second washcoat layer. 42. The catalyst of any of embodiments 32-41, wherein the first washcoat layer and the second washcoat layer are adjacent to each other. 43. The catalyst of any one of embodiments 32-42, wherein the second washcoat layer and the third washcoat layer are adjacent to one another. 44. The catalyst of any of embodiments 32-43, wherein a portion of the second washcoat layer overlaps at least a portion of the first washcoat layer, and preferably the second washcoat layer overlaps the first washcoat layer over a portion in the range of 10 to 100%, more preferably 15 to 80%, more preferably 20 to 50% of the axial length of the first washcoat layer. 45. The catalyst of any of embodiments 32-44, wherein a portion of the first washcoat layer overlaps at least a portion of the second washcoat layer, and preferably the first washcoat layer overlaps the second washcoat layer over a portion in the range of 10 to 100%, more preferably 15 to 80%, more preferably 20 to 50% of the axial length of the second washcoat layer. 46. ​​The catalyst of any of embodiments 32-45, wherein a portion of the third washcoat layer overlaps at least a portion of the first washcoat layer, and preferably the third washcoat layer overlaps the first washcoat layer over a portion in the range of 10 to 100%, more preferably 15 to 80%, more preferably 20 to 50% of the axial length of the first washcoat layer. 47. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer and the second washcoat layer, the second washcoat layer being disposed on the substrate along its entire length, the first washcoat layer being disposed on the second washcoat layer along its axial length starting from the outlet end of the substrate, the length of the first washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 48. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibits a zoned arrangement of the first washcoat layer and the second washcoat layer, the second washcoat layer being disposed on the substrate along its entire length, the first washcoat layer being disposed on the second washcoat layer along its axial length starting from the inlet end of the substrate, the length of the first washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 49. The catalyst of embodiment 47 or 48, wherein the length of the first washcoat layer is in the range of 10 to 90%, preferably 30 to 80%, and more preferably 50 to 70% of the axial length of the substrate. 50. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first washcoat layer and the second washcoat layer, the first washcoat layer being disposed on the substrate along its entire length, the second washcoat layer being disposed on the first washcoat layer along its axial length beginning at the inlet end of the substrate, the length of the second washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 51. The catalyst of embodiment 50, wherein the catalyst comprises a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibiting a zoned arrangement of the second washcoat layer and the third washcoat layer, the second washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the inlet end of the substrate, and the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the outlet end of the substrate, and the length of the third washcoat layer is shorter than the axial length of the substrate so as to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the third washcoat layer. 52. The catalyst of any of embodiments 1-28, wherein the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first washcoat layer and the second washcoat layer, the first washcoat layer being disposed on the substrate along its entire length, the second washcoat layer being disposed on the first washcoat layer along its axial length starting from the outlet end of the substrate, the length of the second washcoat layer being less than the axial length of the substrate so as to create an upstream zone comprising the first washcoat layer and a downstream zone comprising the second washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer. 53. The catalyst of embodiment 52, wherein the catalyst comprises a third washcoat layer, the third washcoat layer being disposed on the first layer, the catalyst exhibiting a zoned arrangement of the second and third washcoat layers, the third washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the inlet end of the substrate, and the second washcoat layer being disposed on the first washcoat layer along the axial length of the substrate starting from the outlet end of the substrate, and the length of the third washcoat layer is less than the axial length of the substrate so as to create an upstream zone comprising the third washcoat layer and a downstream zone comprising the second washcoat layer. 54. The catalyst of embodiment 51 or 53, wherein the second washcoat layer and the third washcoat layer are adjacent to each other. 55. The catalyst of embodiments 1-54, wherein the length of the first washcoat layer is in the range of 5-100% of the axial length of the substrate, preferably 10-90% of the axial length of the substrate, preferably 15-75%, more preferably 20-60%, more preferably 25-50%, more preferably 35-45%. 56. The catalyst of embodiments 29-55, wherein the length of the second washcoat layer is in the range of 5-100% of the axial length of the substrate, preferably 10-90% of the axial length of the substrate, more preferably 15-75%, more preferably 20-60%, more preferably 25-50%, more preferably 35-45%. 57. The catalyst of embodiments 32-56, wherein the length of the third washcoat layer is in the range of 5-100% of the axial length of the substrate, preferably 10-90% of the axial length of the substrate, preferably 15-75%, more preferably 20-60%, more preferably 25-50%, more preferably 35-45%. 58. The catalyst of any of embodiments 32-57, wherein the third washcoat layer is substantially free of sulfur trapping material, preferably, the third washcoat layer is free of sulfur trapping material. 59. The third layer comprises a hydrocarbon trap material, the hydrocarbon trap material comprising a molecular sieve, preferably a zeolite, more preferably a zeolite having a maximum pore size of 12 ring members, more preferably zeolite beta, the molecular sieve, preferably the zeolite, preferably comprising SiO2 and Al2O3, the molecular sieve, preferably the zeolite, more preferably having a pore ratio of 10:1 to 500:1, more preferably 10:1 to 100:1, more preferably 10:1 to 40:1, more preferably ... 59. The catalyst of any of embodiments 32-58, preferably having a molar ratio of SiO2 to Al2O3 in the range of 15:1 to 30:1, more preferably 20:1 to 25:1, and wherein the molecular sieve, preferably zeolite, preferably contains Fe, and the molecular sieve, preferably zeolite, more preferably contains Fe in an amount in the range of 1.0 to 7.0 wt. %, more preferably 3.0 to 5.0 wt. %, more preferably 4.0 to 4.5 wt. %, calculated as Fe2O3, based on the weight of the molecular sieve. 60. The loading of hydrocarbon trap material in the third washcoat layer is 0.01 to 2.0 g / in 3 in the range of 0.05 to 1.0 g / in 3 in the range of 0.05 to 0.3 g / in 3 60. The catalyst of embodiment 59, wherein 61. The catalyst of any of embodiments 32-60, wherein the one or more platinum group metals are at least partially contained in the third washcoat layer. 62. The catalyst of embodiment 61, wherein one or more platinum group metals are supported on a particulate support material, the particulate support material preferably being selected from the group consisting of Al2O3, SiO2, TiO2, SiO2-doped Al2O3, Mn-oxide-doped Al2O3, and mixtures of two or more thereof, and preferably the one or more platinum group metals are supported on Al2O3, and / or SiO2-doped Al2O3, and / or Mn-oxide-doped Al2O3, more preferably SiO2-doped Al2O3, or Al2O3, or Mn-oxide-doped Al2O3, the Mn-oxide-doped Al2O3 preferably containing 1 to 10 wt. %, more preferably 4 to 6 wt. %, of Mn oxide, calculated as MnO2, based on 100 wt. % of the Mn-oxide-doped Al2O3. 63. The catalyst of any of embodiments 32-62, wherein the catalyst comprises a second washcoat layer and a third washcoat layer, wherein the one or more platinum group metals are completely contained in the second washcoat layer and the third washcoat layer, wherein the weight ratio of the one or more platinum group metals in the second washcoat layer to the one or more platinum group metals in the third washcoat layer is in the range of 0.5:1 to 5.0:1, more preferably 1.0:1 to 2.0:1, more preferably 1.4:1 to 1.6:1, wherein the one or more platinum group metals in the second washcoat layer preferably comprise, more preferably consist of, Pt and Pd, and wherein the one or more platinum group metals in the third washcoat layer preferably comprise, more preferably consist of, Pt and Pd. 64. The catalyst of any of embodiments 29-63, wherein the one or more platinum group metals are contained entirely in the second washcoat layer, or in the second washcoat layer and the third washcoat layer. 65. The catalyst of any of embodiments 29-64, wherein the one or more platinum group metals are at least partially contained in the first washcoat layer. 66. The catalyst of any of embodiments 1 to 65, wherein the substrate is a metallic substrate or a ceramic substrate, preferably the substrate is a ceramic substrate, more preferably the substrate comprises cordierite and / or SiC, preferably cordierite, more preferably the substrate consists of cordierite and / or SiC, preferably cordierite. 67. The catalyst of any of embodiments 32 to 66, wherein the substrate consists of two separate monoliths, the first monolith being provided upstream of the second monolith, and wherein the upstream zone washcoat layer or layers are contained on the first monolith and the downstream zone washcoat layer or layers are contained on the second monolith, preferably the first monolith containing the upstream zone washcoat layer or layers and the second monolith containing the downstream zone washcoat layer or layers are obtained or obtainable by compartmentalizing the catalyst according to any of embodiments 30 to 68 into two separate monoliths, wherein the upstream zone washcoat layer or layers are contained on the first monolith and the downstream zone washcoat layer or layers are contained on the second monolith. 68. The catalyst of any of embodiments 1-67, wherein the exhaust gas stream contains hydrocarbons, preferably C1 to C20 hydrocarbons, more preferably C2 to C10 hydrocarbons. 69. An exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit for exhaust gases from the internal combustion engine, wherein the exhaust gas conduit contains one or more catalysts according to any of embodiments 1 to 68, preferably one, two, three, or four catalysts according to any of embodiments 1 to 68. 70. The exhaust gas treatment system of embodiment 69, wherein the internal combustion engine is a compression ignition engine, preferably a diesel engine. 71. The exhaust gas treatment system of embodiment 69 or 70, wherein the internal combustion engine is a lean gasoline engine. 72. The exhaust gas treatment system of embodiment 69, wherein the internal combustion engine is powered by an oxygenated fuel, and the oxygenated fuel preferably comprises one or more of methanol and biofuel. 73. The exhaust gas treatment system of any of embodiments 69-72, wherein the system includes one or more of an electric heater, a fuel burner, a fuel injector, a selective catalytic reduction (SCR) catalyst, an ammonia oxidation (AMOX) catalyst, a catalyzed soot filter (CSF), a diesel particulate filter (DPF), a selective catalytic reduction catalyst on a filter (SCRoF), and a diesel exothermic catalyst (DEC). 74. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of exhaust gas, an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a diesel exothermic catalyst (DEC), a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst. 75. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a diesel exothermic catalyst (DEC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst. 76. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of exhaust gas, an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a diesel exothermic catalyst (DEC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 77. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of embodiments 1 to 68, a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst. 78. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of the exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, and wherein the substrate is a wall-flow substrate, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 79. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of the exhaust gas, an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and a selective catalytic reduction (SCR) catalyst. 80. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of the exhaust gas, an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 81. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of the exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of embodiments 1 to 68, and wherein the substrate is a wall-flow substrate, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 82. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of the exhaust gas, an electric heater or a fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction catalyst on a filter (SCRoF), and an ammonia oxidation (AMOX) catalyst. 83. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of the exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction catalyst on a filter (SCRoF), and an ammonia oxidation (AMOX) catalyst. 84. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of the exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyzed soot filter (CSF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 85. The exhaust gas treatment system of embodiment 73, comprising, in sequential order in the direction of the exhaust gas, optionally an electric heater or fuel burner and / or a fuel injector, a selective catalytic reduction (SCR) catalyst, an optional fuel injector, a catalyst according to any of embodiments 1 to 68, a catalyst according to any of embodiments 1 to 68, and wherein the substrate is a wall-flow substrate, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 86. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of exhaust gas, an electric heater or fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 87. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of the exhaust gas, an electric heater or a fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction catalyst on a filter (SCRoF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 88. The exhaust gas treatment system of embodiment 73, optionally comprising, in sequential order in the direction of the exhaust gas, an electric heater or a fuel burner and / or a fuel injector, a catalyst according to any of embodiments 1 to 68, a selective catalytic reduction (SCR) catalyst, a selective catalytic reduction catalyst on a filter (SCRoF), a selective catalytic reduction (SCR) catalyst, and an ammonia oxidation (AMOX) catalyst. 89. A method for the treatment of an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, comprising: (A) providing an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons; (B) directing the exhaust gas stream provided in (A) through the catalyst of any of embodiments 1-68. 90. The method of embodiment 89, wherein the exhaust gas stream provided in (A) comprises one or more sulfur-containing compounds, preferably SO2 and / or SO3. 91.(A) The exhaust gas flow provided by NO x 91. The method of embodiment 89 or 90, comprising: 92. The method of any of embodiments 89-91, wherein the exhaust gas stream provided in (A) comprises CO. 93. The method of any of embodiments 89-92, wherein the exhaust gas stream provided in (A) comprises hydrocarbons, preferably C1 to C20 hydrocarbons, more preferably C2 to C10 hydrocarbons. 94. Use of a catalyst according to any of embodiments 1-68 for the oxidation of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons in an exhaust gas stream, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons in the exhaust gas stream of an internal combustion engine, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons in the exhaust gas stream of a compression ignition engine, more preferably for the oxidation of one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons in the exhaust gas stream of a diesel engine.

[0110] The present invention is further illustrated by the following examples and comparative examples.

[0111] Experimental Section Comparative Example 1: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons The catalysts were prepared by separately coating platinum group metal (PGM)-containing front zone segments and base metal oxide (BMO)-containing rear zone segments onto 1-inch diameter cordierite honeycomb substrates, then sequentially combining the coated cores for subsequent S-aging and testing. First, a solution containing Pt (using an aqueous solution containing an amine-stabilized hydroxo Pt(IV) complex, with a Pt content ranging from 10 to 20 wt. %, Pd (using Pd nitrate), beta zeolite, and 5 wt. % silica was prepared using techniques known in the art. Approximately 150 ml of Pt was added. 2 / g and a BET surface area of ​​approximately 0.6 cm 3The anterior zone segment was prepared by combining a commercially available alumina support powder with a pore volume of 10 ... 3 The washcoat loading of the PGM-containing layer was 2.9 g / in 3 The BMO-containing aft zone segment was first prepared by adding 9 wt. % La2O3 and approximately 75 m 2 A commercially available zirconia support powder with a BET surface area of ​​1.83 g / in of monolith volume was prepared by mixing it with a solution of Mn nitrate, Ce nitrate, and Cu nitrate in deionized (DI) water. The resulting mixture was ground to a particle size suitable for coating, after which a boehmite-alumina binder was added. The resulting slurry was then coated onto a 1-inch diameter x 1.8-inch long cordierite substrate, which was dried and then fired at 590°C for 1 hour. The total washcoat loading of the BMO-containing layer was 1.83 g / in of monolith volume, containing 8.8 wt% Mn, 8.8 wt% Ce, 8.8 wt% Cu, 3 wt% Al2O3 binder, and the balance La2O3-stabilized ZrO2. 3 It was.

[0112] Example 2: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons The catalysts were prepared by separately coating the PGM-containing front zone segment and the BMO-containing rear zone segment onto 1-inch diameter cordierite honeycomb substrates and then combining the coated cores consecutively for subsequent sulfur aging (S-aging) and testing. The front zone segment was prepared as described in Comparative Example 1. The rear zone segment was first prepared by coating approximately 200 m of PGM-containing front zone segment and BMO-containing rear zone segment, containing 17 wt. % CuO. 2 / g and a BET surface area of ​​approximately 0.8 cm 3 An Al2O3 support powder with a pore volume of 1.1 g / g was prepared by mixing it with a solution of Mn nitrate and Ce nitrate in deionized (DI) water. The resulting mixture was ground to a particle size suitable for coating, after which a boehmite-alumina binder was added. The resulting slurry was then coated onto a 1-inch diameter x 1.8-inch long cordierite substrate, which was dried and then fired at 590°C for 1 hour. The total washcoat loading of the BMO-containing layer was 2.1 g / in of monolith volume, containing 9.3 wt% Mn, 9.3 wt% Ce, 3 wt% Al2O3 binder, and the remainder CuO-doped Al2O3. 3 It was.

[0113] Example 3: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons A catalyst was prepared in the same manner as in Example 2, except that Ce was not included. The total washcoat loading of the BMO-containing layer was 1.9 g / in of monolith volume, containing 9.4 wt. % Mn, 3 wt. % Al2O3 binder, and the remainder CuO-doped Al2O3. 3 It was.

[0114] Example 4: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons The catalyst was prepared similarly to Comparative Example 1, except that the Pt-Pd loading in the front zone was 240 g / ft 3 (4:1 Pt-Pd) and the total washcoat loading of the BMO-containing layer was 2.2 g / in of monolith volume, containing 8.9 wt.% Mn, 8.9 wt.% Ce, 8.9 wt.% Cu, 3 wt.% Al2O3 binder, and the balance La2O3-stabilized ZrO2. 3 It was.

[0115] Example 5: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons The carrier used for Mn, Ce and Cu in the rear zone is approximately 150 m 2 / g and a BET surface area of ​​approximately 0.9 cm 3 The catalyst was prepared similarly to Comparative Example 4, except that the BMO-containing layer consisted of alumina with a pore volume of 2.2 g / g of monolith volume. The total washcoat loading of the BMO-containing layer was 2.2 g / g of monolith volume, containing 8.9 wt. % Mn, 8.9 wt. % Ce, 8.9 wt. % Cu, 3 wt. % Al2O3 binder, and the balance Al2O3. 3 It was.

[0116] Example 6: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons Forward zone Pt-Pd loading of 180g / ft 3 The catalyst was prepared similarly to Comparative Example 1, except that:

[0117] Example 7: Preparation of a catalyst for the treatment of exhaust gas streams containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons The catalyst was prepared similarly to Comparative Example 6, except that Cu was not included. The total washcoat loading of the BMO-containing layer was 1.9 g / in of monolith volume, containing 9.0 wt. % Mn, 9.0 wt. % Ce, 3 wt. % Al2O3 binder, and the balance La2O3-stabilized ZrO2. 3 It was.

[0118] Example 8: Catalyst Aging and Catalytic Testing Sulfur aging (S-aging) of the catalysts of Comparative Examples 1, 4, and 5, and Examples 2-3, was carried out in a laboratory reactor at 300°C in a feed containing 15 ppm SO, 150 ppm NO, 10% O, and 5% HO. The flow through the catalyst, measured as space velocity, was 35,000 / hr. The exposure time under these conditions was 88 minutes, corresponding to a target S exposure of 1 g(S) / L of monolith volume. Desulfation was achieved at 750°C for 30 minutes under isothermal conditions in a feed containing 10% O and 5% HO. The flow through the catalyst, measured by space velocity, was 32,000 / hr.

[0119] After sulfation and desulfation, 180 ppm NO, 1000 ppm CO, 25 ppm HCHO, 100 ppm C1 from C2H4, C 10 H 22 The samples were tested for formaldehyde (HCHO) light-off performance using a feed containing 190 ppm Cl, 10% O, 10% HO, and 10% CO from a catalyst. The flow through the catalyst, as measured by space velocity, was 50,000 / hr. The samples were placed in a reactor and first equilibrated in flowing air at 80°C. The formaldehyde-containing feed was then introduced, and a temperature ramp to 300°C was initiated at a rate of 15°C / min. Formaldehyde concentration was monitored by FTIR during the light-off ramp, and conversion performance versus temperature was then calculated from these measurements.

[0120] The results for the catalysts of Comparative Example 1 and Examples 2 and 3 are shown in Figure 1. Formaldehyde oxidation performance was higher for both samples according to the present invention after sulfation and desulfation at 750°C, confirming higher sulfur tolerance for the Cu-containing formaldehyde oxidation catalyst containing a CuO-Al2O3 support. CuO-Al2O3, when combined with Cu, appears to help mitigate the adverse effects of sulfur on Mn supported on La2O3-stabilized ZrO2. As shown in Figure 2, improved stability before and after sulfur exposure was also found for the catalyst of Example 3 prepared with CuO-Al2O3. Notably, performance remained almost unchanged after sulfation and desulfation at 750°C. In fact, after sulfation / desulfation, HCHO oxidation performance was higher for the sample containing Mn supported on a CuO / Al2O3 support relative to Mn, Cu, and Ce supported on a La2O3 / ZrO2 support.

[0121] As can be inferred from the results, HCHO oxidation performance was unexpectedly high when using a combination of Mn and a support containing CuO-doped alumina in the catalyst. This is particularly surprising because alumina is well known to be a poor Mn support for HCHO oxidation compared to zirconia, even when freshly tested before exposure to the deleterious effects of sulfur (see Figure 3). In addition, even when copper was added to Mn supported on 9 wt% La2O3-stabilized ZrO2, HCHO oxidation performance was lower for catalysts containing only Mn and Ce when tested after hydrothermal aging at 800 °C before any exposure to the deleterious effects of sulfur (Figure 4). In particular, the HCHO oxidation performance of Mn and Mn-Ce supported on CuO-Al2O3 was surprisingly higher than that of Mn, Ce, and Cu supported on 9 wt% La2O3-stabilized ZrO2 after sulfated and desulfated. [Brief explanation of the drawings]

[0122] [Figure 1] Figure 1 shows formaldehyde (HCHO) oxidation performance after sulfation and 750°C desulfation for the catalysts of Comparative Example 1 and Examples 2 and 3. All samples contained a front zone of 2:1 Pt-Pd at 75 g / ft. The rear zone of the Comparative Example 1 catalyst contained Mn, Ce, and Cu supported on 9 wt% LaO-ZrO, while the catalysts of Examples 2 and 3 contained either Mn-Ce or Mn supported on CuO-AlO, respectively. [Figure 2] Figure 1 shows formaldehyde (HCHO) oxidation performance before and after sulfation and 750°C desulfation for the catalysts of Comparative Example 1 and Example 3. Both samples contained a front zone of 2:1 Pt-Pd at 75 g / ft3. The rear zone of the Comparative Example 1 catalyst contained Mn, Ce, and Cu supported on 9 wt% La2O3-ZrO2, while the Example 3 catalyst contained Mn supported on CuO-Al2O3 in the rear zone. [Figure 3]Figure 1 shows formaldehyde (HCHO) oxidation performance for samples containing 8.9 wt% Mn, 8.9 wt% Cu, and 8.9 wt% Ce supported on either fresh AlO (Comparative Example 5) or 9 wt% LaO-stabilized ZrO (Comparative Example 4) after calcination at 590°C. [Figure 4] Figure 1 shows the formaldehyde (HCHO) oxidation performance of a sample containing 8.9 wt% Mn, 8.9 wt% Cu, and 8.9 wt% Ce supported on 9 wt% LaO-stabilized ZrO (Comparative Example 6) or a sample containing 9.0 wt% Mn and 9.0 wt% Ce supported on 9 wt% LaO-stabilized ZrO (Comparative Example 7) after hydrothermal aging at 800°C for 16 hours in the presence of 10% water vapor in air.

[0123] References -International Publication No. 2022 / 047132(A1) -US Patent No. 10,598,061(B2) -US Patent No. 10,392,980(B2) -U.S. Patent Application Publication No. 2018 / 333677(A1) -U.S. Patent Application Publication No. 2018 / 318805(A1) -MCAlvarez-Galvan et al.in Applied Catalysis B.2004,51,83-91

Claims

1. 1. A catalyst for the treatment of an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, said catalyst comprising: CuO-Al ２ O ３ a first washcoat layer comprising Mn supported on a mixed oxide; a substrate; the substrate has an inlet end through which the exhaust gas stream can enter the catalyst and an outlet end through which the exhaust gas stream can exit the catalyst; The catalyst further comprises one or more platinum group metals including Pt, Pd, or Pt and Pd, wherein the one or more platinum group metals are: (a) the first washcoat layer, and (b) an optional second washcoat layer; or (c) a catalyst at least partially contained in one or more of the optional second and third washcoat layers.

2. 2. The catalyst of claim 1, wherein the loading of Mn in the first washcoat layer, calculated as element, ranges from 1 to 50 wt %, based on 100 wt % of the first washcoat layer.

3. The catalyst of claim 1 or 2, wherein the first washcoat layer comprises Ce.

4. Ce is the CuO—Al ２ O ３ 4. The catalyst of claim 3 supported on a mixed oxide.

5. The catalyst of any one of claims 1 to 4, wherein the first washcoat layer comprises Cu supported on a particulate support material.

6. 6. A catalyst according to any one of claims 1 to 5, wherein the catalyst comprises a loading of Pt, calculated as element, in the range of 2 to 250 g / ft3.

7. 7. A catalyst according to any one of claims 1 to 6, wherein the catalyst comprises a loading of Pd, calculated as element, in the range of 1 to 80 g / ft3.

8. 8. A catalyst according to any one of claims 1 to 7, wherein the one or more platinum group metals are supported on a particulate support material.

9. 9. The catalyst of claim 1, wherein the catalyst comprises a second washcoat layer, and the one or more platinum group metals are at least partially contained in the second washcoat layer.

10. The catalyst of any one of claims 1 to 9, wherein the second washcoat layer comprises a hydrocarbon trapping material, the hydrocarbon trapping material comprising a molecular sieve.

11. 11. The catalyst according to any one of claims 1 to 10, wherein the catalyst comprises a second washcoat layer, the catalyst exhibiting a layered arrangement of the first washcoat layer and the second washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer.

12. 11. The catalyst of claim 1, wherein the catalyst comprises a second washcoat layer, the catalyst exhibiting a zoned arrangement of the first and second washcoat layers, the second washcoat layer being disposed on the substrate along its axial length beginning at the inlet end of the substrate, the first washcoat layer being disposed on the substrate along its axial length beginning at the outlet end of the substrate, the length of the first washcoat layer being less than the axial length of the substrate to create an upstream zone comprising the second washcoat layer and a downstream zone comprising the first washcoat layer, and the one or more platinum group metals being at least partially contained in the second washcoat layer.

13. 13. An exhaust gas treatment system comprising an internal combustion engine and an exhaust gas conduit for exhaust gases from said internal combustion engine, said exhaust gas conduit containing a catalyst according to any one of claims 1 to 12.

14. 14. The exhaust gas treatment system of claim 13, wherein the system includes one or more of an electric heater, a fuel burner, a fuel injector, a selective catalytic reduction (SCR) catalyst, an ammonia oxidation (AMOX) catalyst, a catalyzed soot filter (CSF), a diesel particulate filter (DPF), a selective catalytic reduction catalyst on a filter (SCRoF), and a diesel exothermic catalyst (DEC).

15. 1. A method for the treatment of an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons, comprising: (A) providing an exhaust gas stream containing one or more of formaldehyde, nitrogen oxides (NO), and hydrocarbons; (B) directing the exhaust gas stream provided in (A) through the catalyst of any one of claims 1 to 12.

16. Use of the catalyst according to any one of claims 1 to 12 for the oxidation of one or more of formaldehyde, nitrogen oxides (NO) and hydrocarbons.

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