Catalyst for selective catalytic reduction of NOx

Abstract

The present invention relates to a catalyst for selective catalytic reduction of NOx comprising a wall-flow filter substrate including a plurality of passages defined by an interior wall of the substrate extending therethrough, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end, wherein a porous wall of the substrate includes a coating, the coating comprising a zeolitic material, copper, and a first non-zeolitic oxide material comprising zirconium, the coating comprising a zeolitic material at a loading L(z) in g / in3 and a first non-zeolitic oxide material at a loading L1 in g / in3, the loading ratio L(z)(g / in3):L1(g / in3) being at most 10:1, and 90-100% by weight of the first non-zeolitic oxide material being ZrO 2 It consists of zirconium calculated as:

Description

[Technical field]

[0001] The present invention relates to a catalyst for the selective catalytic reduction of NOx, a process for preparing a catalyst for the selective catalytic reduction of NOx, as well as a catalyst obtainable by said process and the catalyst obtained.Furthermore, the present invention relates to an exhaust gas treatment system comprising said catalyst and the use of said catalyst. [Background technology]

[0002] GB 2528737 discloses a method for treating exhaust gas, which includes the use of a selective catalytic reduction catalyst composition containing a transition metal-exchanged small pore zeolite. Furthermore, WO 2020 / 040944 discloses a selective catalytic reduction catalyst composition containing a platinum group metal and a zeolite material promoted with a metal. However, these applications do not address cold flow backpressure or backpressure with soot loading, and it is known that the requirements for selective catalytic reduction catalyst technology are good DeNOx activity over the entire temperature range, good productivity, acceptable cold flow backpressure, good filtration efficiency, and good backpressure behavior with soot loading. In fact, different factors can have a strong influence on filter behavior with soot.

[0003] WO 2020 / 088531(A1) discloses a process for preparing a catalyst for selective catalytic reduction of NOx, comprising a copper ion-exchanged zeolite material. However, there is still a need to find new catalysts for selective catalytic reduction of NOx that exhibit high NOx conversion and reduced back pressure. Furthermore, there is still a need for catalysts that are highly thermally stable. Summary of the Invention

[0004] It was therefore an object of the present invention to provide a novel catalyst for selective catalytic reduction of NOx, which exhibits excellent NOx conversion, improved thermal stability and reduced backpressure. Surprisingly, it has been found that the catalyst of the present invention makes it possible to exhibit high NOx conversion and reduced backpressure. Furthermore, the catalyst has improved thermal stability compared to the prior art.

[0005] Thus, the present invention provides a catalyst for selective catalytic reduction of NOx, comprising: a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by interior walls of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; the porous wall of the substrate comprises a coating, the coating comprising a zeolitic material, copper, and a first non-zeolitic oxide material comprising zirconium; the coating comprises a zeolitic material at a loading L(z) in g / in3 and a first non-zeolitic oxide material at a loading L1 in g / in3, the loading ratio L(z) (g / in3):L1 (g / in3) being at most 10:1; and The catalyst comprises 90-100% by weight of the first non-zeolitic oxide material consisting of zirconium, calculated as ZrO2.

[0006] ABW, ACO, AEI 、AEL、AEN、AET、AFG、AFI、AFN、AFO、AFR、AFS、A FT、AFV、AFX、AFY、AHT、ANA、APC、APD、AST、ASV、ATN、ATO、ATS、ATT、ATV、AVL、AWO、AWW、BCT、 BEA、BEC、BIK、BOF、BOG、BOZ、BPH、BRE、BSV、CAN、CAS、CDO、CFI、CGF、CGS、CHA、-CHI、-CLO、C ON, CSV, CZP, DAC, DDR, DFO, DFT, DOH, DON, EAB, EDI, EEI, EMT, EON, EPI, ERI, ESV, ETR, EUO. * -EWT、EZT、FAR、FAU、FER、FRA、GIS、GIU、GME、GON、GOO、HEU、IFO、 IFR、-IFU、IFW、IFY、IHW、IMF、IRN、IRR、-IRY、ISV、ITE、ITG、ITH、 * -ITN、ITR、ITT、-ITV、ITW、IWR、IWS、IWV、IWW、JBW、JNT、JOZ、JRY、JSN、JSR、JST、JSW、LAKFI、LEV 、LIO、-LIT、LOS、LOV、LTA、LTF、LTJ、LTL、LTN、MAR、MAZ、MEI、MEL、MEP、MER、MFI、MFS、MON、MOR、MOZ * MRE、MSE、MSO、MTF、MTN、MTT、MTW、MVY、MWF、MWW、NAB、NAT、NES、NON、N PO、NPT、NSI、OBW、OFF、OKO、OSI、OSO、OWE、-PAR、PAU、PCR、PHI、PON、PO S、PSI、PUN、RHO、-RON、RRO、RSN、RTE、RTH、RUT、RWR、RWY、SAF、SAO、SA S、SAT、SAV、SBE、SBN、SBS、SBT、SEW、SFE、SFF、SFG、SFH、SFN、SFO、SFS、 * SFV、SFW、SGT、SIV、SOD、SOF、SOS、SSF、 * -SSO、SSY、STF、STI、 *More preferably, the zeolitic material contained in the coating has a framework type selected from the group consisting of STO, STT, STW, -SVR, SVV, SZR, TER, THO, TOL, TON, TSC, TUN, UEI, UFI, UOS, UOV, UOZ, USI, UTL, UWY, VET, VFI, VNI, VSV, WEI, -WEN, YUG, ZON, mixtures of two or more thereof, and mixed types of two or more thereof, more preferably selected from the group consisting of CHA, AEI, RTH, LEV, DDR, KFI, ERI, AFX, mixtures of two or more thereof, and mixed types of two or more thereof, more preferably selected from the group consisting of CHA, AEI, RTH, AFX, mixtures of two or more thereof, and mixed types of two or more thereof, more preferably selected from the group consisting of CHA and AEI. More preferably, the zeolitic material contained in the coating has framework type CHA.

[0007] The framework structure of the zeolite material is preferably composed of Si, Al and O in an amount of 95 to 100% by weight, more preferably 98 to 100% by weight, and even more preferably 99 to 100% by weight.

[0008] Preferably, in the framework structure of the zeolitic material comprised in the coating, the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, is in the range of 2:1 to 30:1, more preferably in the range of 5:1 to 25:1, more preferably in the range of 7:1 to 22:1, more preferably in the range of 8:1 to 20:1, more preferably in the range of 9:1 to 18:1, more preferably in the range of 10:1 to 17:1, more preferably in the range of 12:1 to 16:1.

[0009] Preferably, the zeolitic material included in the coating, more preferably a zeolitic material having framework CHA, has an average crystallite size as measured by scanning electron microscopy of at least 0.1 micrometers, more preferably in the range of 0.1 to 3.0 micrometers, more preferably in the range of 0.3 to 1.5 micrometers, more preferably in the range of 0.4 to 1.0 micrometers.

[0010] Preferably, the amount of copper contained in the coating, calculated as CuO, is in the range of 2 to 10 wt.%, preferably in the range of 2.5 to 5.5 wt.%, more preferably in the range of 3 to 5 wt.%, based on the weight of the zeolitic material.

[0011] Preferably, the zeolitic material included in the coating comprises copper.

[0012] Preferably, the coating comprises a loading of the zeolite material in the range of 0.5 to 5 g / in3, more preferably in the range of 0.75 to 3 g / in3, more preferably in the range of 1 to 2.5 g / in3, more preferably in the range of 1.25 to 2 g / in3.

[0013] Preferably, 95-100% by weight, more preferably 98-100% by weight, more preferably 99-100% by weight, more preferably 99.5-100% by weight of the first non-zeolitic oxide material contained in the coating consists of zirconium calculated as ZrO2. The first non-zeolitic oxide material is preferably zirconia (ZrO2). In other words, the first non-zeolitic oxide material contained in the coating preferably consists essentially of zirconia (ZrO2), more preferably consists of zirconia.

[0014] The coating comprises a zeolitic material at a loading L(z) in g / in3 and a first non-zeolitic oxide material, more preferably zirconia, at a loading L1 in g / in3, wherein the loading ratio L(z) (g / in3):L1 (g / in3) is in the range of 10:1 to 1.1:1, more preferably in the range of 9:1 to 1.25:1, more preferably in the range of 8:1 to 2:1, more preferably in the range of 7.5:1 to 2.5:1, more preferably in the range of 7:1 to 3.5:1, more preferably in the range of 5.5:1 to 4:1.

[0015] Thus, the present invention preferably provides a catalyst for selective catalytic reduction of NOx, comprising: a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by interior walls of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; The porous wall of the substrate includes a coating, the coating including a zeolitic material having a framework type CHA, copper, and a first non-zeolitic oxide material including zirconium. the coating comprises a zeolitic material at a loading L(z) in g / in3 and a first non-zeolitic oxide material at a loading L1 in g / in3, the loading ratio L(z) (g / in3):L1 (g / in3) being in the range of 9:1 to 1.25:1, more preferably in the range of 8:1 to 2:1, more preferably in the range of 7.5:1 to 2.5:1, more preferably in the range of 7:1 to 3.5:1, more preferably in the range of 5.5:1 to 4:1; and From 90 to 100% by weight of the first non-zeolitic oxide material consists of zirconium, calculated as ZrO2, more preferably from 95 to 100% by weight, more preferably from 98 to 100% by weight, more preferably from 99 to 100% by weight, more preferably from 99.5 to 100% by weight.

[0016] In the context of the present invention, it is preferred that the coating further comprises a second non-zeolitic oxide material, the second non-zeolitic oxide material being selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti and Ce, and mixtures of two or more thereof, preferably selected from the group consisting of alumina, silica and titania, mixed oxides comprising one or more of Al, Si and Ti, and mixtures of two or more thereof, more preferably selected from the group consisting of mixed oxides comprising one or more of alumina, silica, Al and Si, and mixtures of two or more thereof, more preferably a mixture of alumina and silica.

[0017] Preferably, 80 to 99% by weight, more preferably 85 to 98% by weight, more preferably 90 to 98% by weight of the mixture of alumina and silica is made of alumina, and preferably 1 to 20% by weight, preferably 2 to 15% by weight, more preferably 2 to 10% by weight of the mixture of alumina and silica is made of silica.

[0018] Preferably, the coating comprises the second non-zeolitic oxide material in an amount in the range of 2 to 20% by weight, more preferably in the range of 5 to 15% by weight, more preferably in the range of 7 to 13% by weight, based on the weight of the zeolitic material.

[0019] Preferably, 0-0.001% by weight, more preferably 0-0.0001% by weight, more preferably 0-0.00001% by weight of the coating consists of platinum group metal. In other words, the coating is preferably substantially free of platinum group metal, and more preferably free of platinum group metal.

[0020] Preferably, the coating extends over x% of the axial length of the substrate from the inlet end towards the outlet end, or from the outlet end towards the inlet end, of the substrate, where x is in the range 95-100, preferably in the range 98-100, more preferably in the range 99-100.

[0021] Preferably, 90-100% by weight, more preferably 95-100% by weight, more preferably 98-100% by weight of the coating is contained on the porous walls of the substrate.

[0022] Preferably, the coating of the catalyst of the present invention is present substantially only within the porous walls of the substrate, more preferably only within the porous walls of the substrate, and it is further contemplated that a small amount of the coating may be present on the surface of the inner walls in an intermediate zone of the substrate axial length.

[0023] Preferably, the coating is uniformly disposed along the axial length of the substrate.

[0024] It may also be preferred that the amount of coating is greater in a middle zone of the substrate axial length compared to the amount present at the inlet end of the substrate and the outlet end of the substrate, respectively, by one of the coating methods described below, in which the substrate is preferably first coated from the inlet end towards the outlet end, or from the outlet end towards the inlet end, over less than about 50-90%, more preferably about 60-80%, more preferably about 65-75% of the substrate axial length, and then the substrate is further coated from the other of the inlet end or the outlet end over less than about 50-90%, more preferably about 60-80%, more preferably about 65-75% of the substrate axial length.

[0025] In the context of the present invention, the substrate is preferably one or more of a cordierite wall-flow filter substrate, a silicon carbide wall-flow filter substrate, and an aluminum titanate wall-flow filter substrate, more preferably one or more of a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate.

[0026] Preferably, the substrate is a silicon carbide wall-flow filter substrate or an aluminum titanate wall-flow filter substrate.

[0027] The catalyst preferably consists of a wall-flow filter substrate and a coating.

[0028] The present invention further relates to a process for preparing a catalyst for the selective catalytic reduction of NOx, preferably a catalyst according to the invention, comprising: (i) preparing a first aqueous mixture comprising water, a copper source, and a precursor of a first non-zeolitic oxide component comprising zirconium; (ii) preparing a second aqueous mixture comprising water and a zeolitic material, the zeolitic material being copper-free; (iii) mixing the first aqueous mixture obtained according to (i) with the second aqueous mixture obtained according to (ii) to obtain a third aqueous mixture, wherein the amount of precursor of the first non-zeolitic oxide component in the third aqueous mixture, calculated as oxide, is at least 10 wt.-% based on the weight of the zeolitic material; (iv) disposing the third aqueous mixture onto a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by an interior wall of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and optionally drying the substrate including the mixture; (v) calcining the substrate obtained in (iv).

[0029] Preferably, the copper source included in the first aqueous mixture prepared in (i) is selected from the group consisting of copper acetate, copper nitrate, copper sulfate, copper formate, copper oxide, and mixtures of two or more thereof, more preferably selected from the group consisting of copper acetate, copper oxide, and mixtures thereof, more preferably copper oxide, more preferably CuO.

[0030] Preferably, the precursor of the first non-zeolitic oxide component included in the first aqueous mixture prepared in (i) is a zirconium salt or zirconium oxide, more preferably a zirconium salt, more preferably zirconium acetate.

[0031] Preferably, the first aqueous mixture prepared in (i) comprises copper, calculated as CuO, in an amount in the range of 2 to 10 wt.%, more preferably in the range of 2.5 to 5.5 wt.%, more preferably in the range of 3 to 5 wt.%, based on the weight of the zeolitic material contained in the second aqueous mixture prepared in (ii).

[0032] In the first aqueous mixture, the amount of the precursor of the first non-zeolitic oxide material, calculated as oxide, is preferably in the range of 10 to 80 wt%, more preferably in the range of 11 to 80 wt%, more preferably in the range of 12.5 to 50 wt%, more preferably in the range of 13 to 40 wt%, more preferably in the range of 14.3 to 28.5 wt%, more preferably in the range of 18 to 25 wt%, based on the weight of the zeolitic material contained in the second aqueous mixture prepared in (ii). In the first aqueous mixture, the amount of zirconium acetate, calculated as ZrO2, is more preferably in the range of 10 to 80 wt%, more preferably in the range of 11 to 80 wt%, more preferably in the range of 12.5 to 50 wt%, more preferably in the range of 13 to 40 wt%, more preferably in the range of 14.3 to 28.5 wt%, more preferably in the range of 18 to 25 wt%, based on the weight of the zeolitic material contained in the second aqueous mixture prepared in (ii).

[0033] With regard to (i): (i.1) preparing a mixture comprising water and a copper source, the mixture further comprising an acid, more preferably an organic acid, more preferably acetic acid; (i.2) adding a precursor of a first non-zeolitic oxide component, more preferably zirconium acetate, to the mixture obtained according to (i.1) to obtain a first aqueous mixture.

[0034] Preferably, 90-100% by weight, more preferably 93-99% by weight, more preferably 96-99% by weight of the copper source is present in an undissolved state in the mixture prepared in (i.1).

[0035] Preferably, the copper particles in the mixture according to (i.1) have a Dv90 in the range of 0.1 to 15 micrometers, more preferably in the range of 0.5 to 10 micrometers, more preferably in the range of 1 to 8 micrometers, more preferably in the range of 3 to 7 micrometers, Dv90 being preferably determined as described in Reference Example 3.

[0036] Preferably, the copper particles in the mixture according to (i.1) have a Dv50 in the range of 0.1 to 5 micrometers, more preferably in the range of 0.5 to 3 micrometers, more preferably in the range of 0.75 to 2 micrometers, Dv50 being more preferably determined as described in Reference Example 3.

[0037] Preferably, the mixture obtained in (i.1) has a solids content in the range of 4 to 30% by weight, more preferably in the range of 4 to 21% by weight, based on the weight of the mixture obtained in (i.1).

[0038] Preferably, the second mixture obtained in (ii) has a solids content in the range of 15 to 50% by weight, more preferably in the range of 20 to 45% by weight, more preferably in the range of 30 to 40% by weight, based on the weight of the second mixture.

[0039] Preferably, the particles of the zeolitic material in the second mixture have a Dv90 in the range of 1 to 10 micrometers, more preferably in the range of 2 to 6 micrometers, with Dv90 more preferably determined as described in Reference Example 3.

[0040] In the second mixture obtained in (ii), the zeolitic material is preferably in its H form.

[0041] Preferably, the particles of the zeolitic material in the second mixture have a Dv50 in the range of 0.5 to 5 micrometers, more preferably in the range of 0.75 to 3 micrometers; Dv90 is preferably determined as described in Reference Example 3.

[0042] Regarding (iii): (iii.1) mixing the first aqueous mixture obtained according to (i) with a second aqueous mixture according to (ii); (iii.2) more preferably milling the obtained mixture (iii.1), more preferably until the particles of said mixture have a Dv90 in the range of 0.5 to 8 micrometers, more preferably in the range of 1 to 5 micrometers, more preferably in the range of 1.5 to 4 micrometers, the Dv90 being more preferably determined as described in Reference Example 3; (iii.3) preparing a mixture comprising water and a second non-zeolitic oxide material selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti, and Ce, and mixtures of two or more thereof; (iii.4) mixing the mixture obtained in (iii.3) with the mixture obtained in (iii.1), more preferably with the mixture obtained in (iii.2), to obtain a third aqueous mixture.

[0043] Preferably, the mixture prepared in (iii.3) has a solids content in the range of 15 to 60% by weight, more preferably in the range of 20 to 45% by weight, more preferably in the range of 25 to 40% by weight, based on the weight of the mixture.

[0044] Preferably, the particles of the second non-zeolitic oxide material in the mixture prepared in (iii.3) have a Dv90 in the range of 2 to 12 micrometers, more preferably in the range of 3 to 7 micrometers, Dv90 being more preferably determined as described in Reference Example 3.

[0045] Preferably, the particles of the zeolitic material in the second mixture have a Dv50 in the range of 0.75 to 6 micrometers, more preferably in the range of 1.5 to 4 micrometers, and a Dv90, more preferably determined as described in Reference Example 3.

[0046] Preferably, the second non-zeolitic oxide material contained in the mixture prepared in (iii.3) is selected from the group consisting of alumina, silica, and mixed oxides comprising one or more of titania, Al, Si, and Ti, and mixtures of two or more thereof, more preferably selected from the group consisting of mixed oxides comprising one or more of alumina, silica, Al, and Si, and mixtures of two or more thereof, more preferably a mixture of alumina and silica.

[0047] Preferably, 80 to 99% by weight, more preferably 85 to 98% by weight, more preferably 90 to 98% by weight of the mixture of alumina and silica consists of alumina, and more preferably 1 to 20% by weight, more preferably 2 to 15% by weight, more preferably 2 to 10% by weight of the mixture of alumina and silica consists of silica.

[0048] Preferably, the mixture prepared in (iii.3) comprises the second non-zeolitic oxide material in an amount in the range of 2 to 20 wt.%, more preferably in the range of 5 to 15 wt.%, more preferably in the range of 7 to 13 wt.%, based on the weight of the zeolitic material.

[0049] With regard to the third aqueous mixture obtained in (iii), preferably (iii.4)), it is preferred that said mixture has a solids content in the range of 15 to 50 wt.-%, more preferably in the range of 20 to 45 wt.-%, more preferably in the range of 25 to 40 wt.-%, based on the weight of the third aqueous mixture.

[0050] Preferably, 98-100% by weight, more preferably 99-100% by weight, more preferably 99.5-100% by weight, more preferably 99.9-100% by weight of the third aqueous mixture prepared in (iii) consists of water, the zeolitic material, the copper source, the precursor of the first non-zeolitic oxide material, more preferably zirconium acetate, more preferably the second non-zeolitic oxide material as defined above.

[0051] Preferably, the disposing of the mixture according to (iv) is carried out by spraying the mixture onto the substrate or by immersing the substrate in the mixture, more preferably by immersing the substrate in the mixture.

[0052] Preferably, the third aqueous mixture obtained according to (iii) is disposed over x% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, according to (iv), where x is in the range of 95 to 100, more preferably in the range of 98 to 100, more preferably in the range of 99 to 100.

[0053] The substrate in (iv) may be any substrate so long as it is a wall-flow filter substrate. However, the substrate in (iv) is preferably one or more of a cordierite wall-flow filter substrate, a silicon carbide wall-flow filter substrate, and an aluminum titanate wall-flow filter substrate, more preferably one or more of a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate, more preferably a silicon carbide wall-flow filter substrate or an aluminum titanate wall-flow filter substrate.

[0054] As regards the drying according to (iv), it is preferably carried out in a gas atmosphere having a temperature in the range of 60 to 300° C., more preferably in the range of 90 to 150° C., the gas atmosphere more preferably containing oxygen.

[0055] As regards drying according to (iv), it is preferably carried out in a gas atmosphere for a duration ranging from 10 minutes to 4 hours, more preferably ranging from 20 minutes to 2 hours, the gas atmosphere more preferably comprising oxygen.

[0056] With respect to the arrangement according to (iv), there is an alternative preferred method, according to which the arrangement according to (iv) preferably comprises (iv.1) disposing a first portion of the third aqueous mixture obtained in(iii) onto a wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by an interior wall of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and drying the substrate containing the first portion of the third aqueous mixture; (iv.2) disposing a second portion of the third aqueous mixture obtained in (iii) onto a substrate comprising the first portion of the third aqueous mixture obtained in (iv.1); and optionally drying the substrate comprising the first and second portions of the third aqueous mixture.

[0057] Preferably, the first portion of the third aqueous mixture according to (iii) is disposed over x1% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, in accordance with (iv.1), where x1 is in the range 95-100, more preferably in the range 98-100, more preferably in the range 99-100.

[0058] Preferably, the second portion of the third aqueous mixture according to (iii) is disposed over x2% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, in accordance with (iv.2), where x2 is in the range 95-100, more preferably in the range 98-100, more preferably in the range 99-100. It is more preferred that x1 is in the range 95-100, more preferably in the range 98-100, more preferably in the range 99-100, and x2=x1.

[0059] Alternatively, the first portion of the third aqueous mixture according to (iii) is preferably disposed over x1% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, in accordance with (iv.1), where x1 is in the range 50 to 90, more preferably in the range 60 to 80, more preferably in the range 65 to 75.

[0060] Preferably, the second portion of the third aqueous mixture according to (iii) is disposed over x2% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, in accordance with (iv.2), where x2 is in the range of 50 to 90, more preferably in the range of 60 to 80, more preferably in the range of 65 to 75. It is more preferred that x1 is in the range of 50 to 90, more preferably in the range of 60 to 80, more preferably in the range of 65 to 75, and x2=x1.

[0061] More preferably, a first portion of the third aqueous mixture according to (iii) is disposed over x1% of the substrate axial length from the outlet end to the inlet end of the substrate in accordance with (iv.1), and a second portion of the third aqueous mixture according to (iii) is disposed over x2% of the substrate axial length from the inlet end to the outlet end of the substrate in accordance with (iv.2). Other processes are contemplated.

[0062] Preferably, the drying according to (iv.1) is carried out in a gas atmosphere having a temperature in the range of from 60 to 300° C., more preferably in the range of from 90 to 150° C., the gas atmosphere more preferably comprising oxygen.

[0063] Preferably, the drying according to (iv.1) is carried out in a gas atmosphere for a duration ranging from 10 minutes to 4 hours, more preferably in the range from 20 minutes to 2 hours, the gas atmosphere more preferably comprising oxygen.

[0064] Preferably, the drying according to (iv.2) is carried out in a gas atmosphere having a temperature in the range of from 60 to 300° C., more preferably in the range of from 90 to 150° C., the gas atmosphere more preferably comprising oxygen.

[0065] Preferably, the drying according to (iv.2) is carried out in a gas atmosphere for a duration ranging from 10 minutes to 4 hours, more preferably in the range from 20 minutes to 2 hours, the gas atmosphere more preferably comprising oxygen.

[0066] With regard to the firing according to (v), it is preferably carried out in a gas atmosphere having a temperature in the range of 300 to 900°C, more preferably in the range of 400 to 650°C, more preferably in the range of 400 to 500°C, the gas atmosphere more preferably containing oxygen.

[0067] As regards the calcination according to (v), it is preferably carried out in a gas atmosphere for a duration ranging from 0.1 to 4 hours, more preferably ranging from 0.5 to 2.5 hours, the gas atmosphere more preferably comprising oxygen.

[0068] In the context of the present invention, the process preferably consists of (i), (ii), (iii), (iv) and (v).

[0069] The present invention further relates to a catalyst for the selective catalytic reduction of NOx obtainable or obtained by the process obtained according to the invention and the process as defined above, the catalyst being preferably the catalyst of the invention and as defined above.

[0070] The invention further relates to an exhaust gas treatment system for treating exhaust gas from a compression ignition engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising a catalyst according to the invention and one or more of a diesel oxidation catalyst, a selective catalytic reduction catalyst, an ammonia oxidation catalyst, a NOx trap and a particulate filter as defined above. The compression ignition engine is preferably a diesel engine.

[0071] Preferably, the system comprises a catalyst according to the present invention, a diesel oxidation catalyst and a selective catalytic reduction catalyst, The diesel oxidation catalyst is more preferably located upstream of the selective catalytic reduction catalyst, which in turn is located upstream of the catalyst according to the invention.

[0072] Alternatively, the system preferably comprises a catalyst according to the present invention, a NOx trap and a selective catalytic reduction catalyst, The NOx trap is more preferably located upstream of the selective catalytic reduction catalyst, which in turn is located upstream of the catalyst according to the invention.

[0073] Alternatively, the system preferably comprises a catalyst according to the present invention, a diesel oxidation catalyst and a selective catalytic reduction catalyst, More preferably, the diesel oxidation catalyst is positioned upstream of the catalyst according to the invention, which in turn is located upstream of the selective catalytic reduction catalyst.

[0074] Alternatively, the system preferably comprises a catalyst according to the present invention, a NOx trap and a selective catalytic reduction catalyst, The NOx trap is more preferably located upstream of the catalyst according to the invention, which in turn is located upstream of the selective catalytic reduction catalyst. More preferably, the system further comprises an ammonia oxidation catalyst or a selective catalytic reduction / ammonia oxidation catalyst, more preferably located downstream of the selective catalytic reduction catalyst.

[0075] The present invention further relates to the use of a catalyst according to the invention and as defined above, for the selective catalytic reduction of NOx.

[0076] The present invention further provides a method for selective catalytic reduction of NOx, comprising the steps of: (1) providing an exhaust gas stream, more preferably an exhaust gas stream exiting a diesel engine; (2) contacting the exhaust gas stream provided in (1) with a catalyst for selective catalytic reduction of NOx according to the present invention.

[0077] The present invention is further described by the following set of embodiments and combinations of embodiments resulting from 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 "any one catalyst of embodiments 1-4", it is meant that all embodiments within this range are explicitly disclosed to those skilled in the art, that is, the expression of this term is understood by those skilled in the art to be synonymous with "any one catalyst 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 the preferred aspects of the present invention, and thus properly supports but does not represent the scope of the claims of the present invention. 1. A catalyst for selective catalytic reduction of NOx, a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by interior walls of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; the porous wall of the substrate comprises a coating, the coating comprising a zeolitic material, copper, and a first non-zeolitic oxide material comprising zirconium; the coating comprises a zeolitic material at a loading L(z) in g / in3 and a first non-zeolitic oxide material at a loading L1 in g / in3, the loading ratio L(z) (g / in3):L1 (g / in3) being at most 10:1; and The catalyst comprises 90-100% by weight of the first non-zeolitic oxide material consisting of zirconium, calculated as ZrO2. 2.The ABW 1,000,000,000,000,000 ABW 、ACO、AEI、AEL、AEN、AET、AFG、AFI、AFN、AFO、AF R, AFS, AFT, AFV, AFX, AFY, AHT, ANA, APC, APD, AST, ASV, ATN, ATO, ATS, ATT, ATV, AVL, AWO, AWW BCT, BEA, BEC, BIK, BOF, BOG, BOZ, BPH, BRE, BSV, CAN, CAS, CDO, CFI, CGF, CGS, CHA, CHI, CL O, CON, CSV, CZP, DAC, DDR, DFO, DFT, DOH, DON, EAB, EDI, EEI, EMT, EON, EPI, ERI, ESV, ETR, EUO * -EWT、EZT、FAR、FAU、FER、FRA、GIS、GIU、GME、GON、GOO、HEU、IFO、 IFR、-IFU、IFW、IFY、IHW、IMF、IRN、IRR、-IRY、ISV、ITE、ITG、ITH、 * -ITN、ITR、ITT、-ITV、ITW、IWR、IWS、IWV、IWW、JBW、JNT、JOZ、JRY、JSN、JSR、JST、JSW、LAKFI、LEV 、LIO、-LIT、LOS、LOV、LTA、LTF、LTJ、LTL、LTN、MAR、MAZ、MEI、MEL、MEP、MER、MFI、MFS、MON、MOR、MOZ * MRE、MSE、MSO、MTF、MTN、MTT、MTW、MVY、MWF、MWW、NAB、NAT、NES、NON、N PO、NPT、NSI、OBW、OFF、OKO、OSI、OSO、OWE、-PAR、PAU、PCR、PHI、PON、PO S、PSI、PUN、RHO、-RON、RRO、RSN、RTE、RTH、RUT、RWR、RWY、SAF、SAO、SA S、SAT、SAV、SBE、SBN、SBS、SBT、SEW、SFE、SFF、SFG、SFH、SFN、SFO、SFS、 * SFV、SFW、SGT、SIV、SOD、SOF、SOS、SSF、 * -SSO、SSY、STF、STI、 *STO, STT, STW, -SVR, SVV, SZR, TER, THO, TOL, TON, TSC, TUN, UEI, UFI, UOS, UOV, UOZ, USI, UTL, UWY, VET, VFI, VNI, VSV, WEI, -WEN, YUG, ZON, mixtures of two or more thereof, and mixed types of two or more thereof, preferably selected from the group consisting of CHA, AEI, RTH, LEV, DDR, KFI, ERI, AFX, mixtures of two or more thereof, and mixed types of two or more thereof, more preferably selected from the group consisting of CHA, AEI, RTH, AFX, mixtures of two or more thereof, and mixed types of two or more thereof, more preferably selected from the group consisting of CHA and AEI, and more preferably the zeolitic material comprised in the coating has framework type CHA. 3. The catalyst of embodiment 1 or 2, wherein 95-100% by weight, preferably 98-100% by weight, more preferably 99-100% by weight, of the framework structure of the zeolitic material consists of Si, Al and O, and the molar ratio of Si to Al, calculated as molar SiO2:Al2O3, in the framework structure is preferably in the range of 2:1 to 30:1, more preferably in the range of 5:1 to 25:1, more preferably in the range of 7:1 to 22:1, more preferably in the range of 8:1 to 20:1, more preferably in the range of 9:1 to 18:1, more preferably in the range of 10:1 to 17:1, more preferably in the range of 12:1 to 16:1. 4. The catalyst according to any one of the preceding embodiments, wherein the zeolitic material contained in the coating, preferably a zeolitic material having framework type CHA, has an average crystallite size, as measured by scanning electron microscopy, of at least 0.1 micrometers, preferably in the range of 0.1 to 3.0 micrometers, more preferably in the range of 0.3 to 1.5 micrometers, more preferably in the range of 0.4 to 1.0 micrometers. 5. The catalyst according to any one of the preceding embodiments, wherein the amount of copper contained in the coating, calculated as CuO, is in the range of 2 to 10 wt.%, preferably in the range of 2.5 to 5.5 wt.%, more preferably in the range of 3 to 5 wt.%, based on the weight of the zeolitic material. 6. The catalyst of any one of the preceding embodiments, wherein the zeolitic material contained in the coating comprises copper. 7. The catalyst of any one of the preceding embodiments, wherein the coating comprises a loading of zeolite material in the range of 0.5 to 5 g / in3, more preferably in the range of 0.75 to 3 g / in3, more preferably in the range of 1 to 2.5 g / in3, more preferably in the range of 1.25 to 2 g / in3. 8. The catalyst according to any one of the preceding embodiments, wherein 95-100% by weight, preferably 98-100% by weight, more preferably 99-100% by weight, more preferably 99.5-100% by weight of the first non-zeolitic oxide material contained in the coating consists of zirconium, calculated as ZrO2. 9. The catalyst according to any one of the preceding embodiments, wherein the coating comprises a zeolitic material at a loading L(z) in g / in3 and a first non-zeolitic oxide material, preferably zirconia, at a loading L1 in g / in3, the loading ratio L(z) (g / in3):L1 (g / in3) being in the range of 10:1 to 1.1:1, preferably in the range of 9:1 to 1.25:1, more preferably in the range of 8:1 to 2:1, more preferably in the range of 7.5:1 to 2.5:1, more preferably in the range of 7:1 to 3.5:1, more preferably in the range of 5.5:1 to 4:1. 10. The catalyst according to any one of the preceding embodiments, wherein the coating further comprises a second non-zeolitic oxide material selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti, and Ce, and mixtures of two or more thereof, preferably selected from the group consisting of alumina, silica, and titania, mixed oxides comprising one or more of Al, Si, and Ti, and mixtures of two or more thereof, more preferably selected from the group consisting of alumina, silica, Al, and Si, and mixtures of two or more thereof, more preferably a mixture of alumina and silica. 11. The catalyst according to embodiment 10, wherein 80 to 99% by weight, preferably 85 to 98% by weight, more preferably 90 to 98% by weight, of the mixture of alumina and silica is made of alumina, and 1 to 20% by weight, preferably 2 to 15% by weight, more preferably 2 to 10% by weight, of the mixture of alumina and silica is made of silica. 12. The catalyst according to embodiment 10 or 11, wherein the coating comprises a second non-zeolitic oxide material in an amount in the range of 2 to 20 wt.%, preferably in the range of 5 to 15 wt.%, more preferably in the range of 7 to 13 wt.%, based on the weight of the zeolitic material. 13. The catalyst according to any one of the preceding embodiments, wherein 0-0.001 wt.%, preferably 0-0.0001 wt.%, more preferably 0-0.00001 wt.% of the coating consists of a platinum group metal. 14. The catalyst of any one of the preceding embodiments, wherein the coating extends over x% of the substrate axial length from the inlet end towards the outlet end, or from the outlet end towards the inlet end, of the substrate, where x is in the range of 95-100, preferably in the range of 98-100, and more preferably in the range of 99-100. 15. The catalyst according to any one of the preceding embodiments, wherein 90-100 wt.%, preferably 95-100 wt.%, more preferably 98-100 wt.% of the coating is contained on the porous walls of the substrate. 16. The catalyst of any one of the preceding embodiments, wherein the coating is uniformly disposed along the axial length of the substrate or the amount of coating is greater in the intermediate zone of the axial length of the substrate compared to the amount present at the inlet end of the substrate and the outlet end of the substrate, respectively. 17. The catalyst according to any one of the preceding embodiments, wherein the substrate is one or more of a cordierite wall-flow filter substrate, a silicon carbide wall-flow filter substrate, and an aluminum titanate wall-flow filter substrate, preferably one or more of a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate. 18. The catalyst of embodiment 17, wherein the substrate is a silicon carbide wall-flow filter substrate or an aluminum titanate wall-flow filter substrate. 19. The catalyst of any one of the preceding embodiments, wherein the catalyst consists of a wall-flow filter substrate and a coating. 20. A process for preparing a catalyst for selective catalytic reduction of NOx, preferably according to any one of the first to 19 embodiments, comprising: (i) preparing a first aqueous mixture comprising water, a copper source, and a precursor of a first non-zeolitic oxide component comprising zirconium; (ii) preparing a second aqueous mixture comprising water and a zeolitic material, the zeolitic material being copper-free; (iii) mixing the first aqueous mixture obtained according to (i) with the second aqueous mixture obtained according to (ii) to obtain a third aqueous mixture, wherein the amount of precursor of the first non-zeolitic oxide component in the third aqueous mixture, calculated as oxide, is at least 10 wt.-% based on the weight of the zeolitic material; (iv) disposing the third aqueous mixture onto a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by an interior wall of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and optionally drying the substrate including the mixture; (v) calcining the substrate obtained in (iv). 21. The process of embodiment 20, wherein the copper source included in the first aqueous mixture prepared in (i) is selected from the group consisting of copper acetate, copper nitrate, copper sulfate, copper formate, copper oxide, and mixtures of two or more thereof, preferably selected from the group consisting of copper acetate, copper oxide, and mixtures thereof, more preferably copper oxide, more preferably CuO. 22. The process of embodiment 20 or 21, wherein the precursor of the first non-zeolitic oxide component contained in the first aqueous mixture prepared in (i) is a zirconium salt or zirconium oxide, preferably a zirconium salt, more preferably zirconium acetate. 23. The process of any one of embodiments 20 to 22, wherein the first aqueous mixture prepared in (i) contains copper, calculated as CuO, in an amount in the range of 2 to 10 wt.%, preferably in the range of 2.5 to 5.5 wt.%, more preferably in the range of 3 to 5 wt.%, based on the weight of the zeolitic material contained in the second aqueous mixture prepared in (ii). 24. The process according to any one of embodiments 20 to 23, wherein the amount of precursor of the first non-zeolitic oxide material in the first aqueous mixture, calculated as oxide, is in the range of 10 to 80 wt.%, more preferably in the range of 11 to 80 wt.%, more preferably in the range of 12.5 to 50 wt.%, more preferably in the range of 13 to 40 wt.%, more preferably in the range of 14.3 to 28.5 wt.%, more preferably in the range of 18 to 25 wt.%, based on the weight of the zeolitic material contained in the second aqueous mixture prepared in (ii). twenty five. (i.1) preparing a mixture comprising water and a copper source, the mixture preferably further comprising an acid, more preferably an organic acid, more preferably acetic acid; (i.2) adding a precursor of a first non-zeolitic oxide component to the mixture obtained according to (i.1) to obtain a first aqueous mixture; 25. The process according to any one of embodiments 20 to 24, comprising: 26. The process of embodiment 25, wherein 90 to 100 wt.%, preferably 93 to 99 wt.%, more preferably 96 to 99 wt.% of the copper source is present in an undissolved state in the mixture prepared in (i.1). 27. The process according to embodiment 26, wherein the copper particles in the mixture according to (i.1) have a Dv90 in the range of 0.1 to 15 micrometers, more preferably in the range of 0.5 to 10 micrometers, more preferably in the range of 1 to 8 micrometers, more preferably in the range of 3 to 7 micrometers, wherein Dv90 is preferably determined as described in Reference Example 3. 28. The process according to any one of embodiments 25 to 27, wherein the mixture obtained in (i.1) has a solids content in the range of 4 to 30% by weight, preferably in the range of 4 to 21% by weight, based on the weight of the mixture obtained in (i.1). 29. The process according to any one of embodiments 20 to 28, wherein the second mixture obtained in (ii) has a solids content in the range of 15 to 50% by weight, more preferably in the range of 20 to 45% by weight, more preferably in the range of 30 to 40% by weight, based on the weight of the second mixture. 30. The process of any one of embodiments 20 to 29, wherein the particles of the zeolite material in the second mixture have a Dv90 in the range of 1 to 10 micrometers, preferably in the range of 2 to 6 micrometers, and the Dv90 is preferably determined as described in Reference Example 3. 31. The process according to any one of embodiments 20 to 30, wherein the particles of the zeolite material in the second mixture have a Dv50 in the range of 0.5 to 5 micrometers, preferably in the range of 0.75 to 3 micrometers, and a Dv90 preferably determined as described in Reference Example 3. 32.(iii) is (iii.1) mixing the first aqueous mixture obtained according to (i) with a second aqueous mixture according to (ii); (iii.2) preferably milling the obtained mixture (iii.1), more preferably until the particles of said mixture have a Dv90 in the range of 0.5 to 8 micrometers, more preferably in the range of 1 to 5 micrometers, more preferably in the range of 1.5 to 4 micrometers, Dv90 preferably being determined as described in Reference Example 3; (iii.3) preparing a mixture comprising water and a second non-zeolitic oxide material selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti, and Ce, and mixtures of two or more thereof; (iii.4) mixing the mixture obtained in (iii.3) with the mixture obtained in (iii.1), preferably with the mixture obtained in (iii.2), to obtain a third aqueous mixture. 33. The process of embodiment 32, wherein the mixture prepared in (iii.3) has a solids content in the range of 15 to 60% by weight, preferably in the range of 20 to 45% by weight, more preferably in the range of 25 to 40% by weight, based on the weight of the mixture. 34. The process according to embodiment 32 or 33, wherein the particles of the second non-zeolitic oxide material in the mixture prepared in (iii.3) have a Dv90 in the range of 2 to 12 micrometers, preferably in the range of 3 to 7 micrometers, Dv90 being preferably determined as described in Example 3. 35. The process of any one of embodiments 32 to 34, wherein the particles of the second non-zeolitic oxide material in the second mixture have a Dv50 in the range of 0.75 to 6 micrometers, preferably in the range of 1.5 to 4 micrometers, and a Dv90, preferably determined as described in Reference Example 3. 36. The second non-zeolitic oxide material contained in the mixture prepared in (iii.3) is selected from the group consisting of alumina, silica, and titania, mixed oxides containing one or more of Al, Si, and Ti, and mixtures of two or more thereof, preferably selected from the group consisting of alumina, silica, mixed oxides containing one or more of Al, and Si, and mixtures of two or more thereof, more preferably a mixture of alumina and silica; 36. The process of any one of embodiments 32 to 35, wherein 80 to 99 wt.%, more preferably 85 to 98 wt.%, more preferably 90 to 98 wt.% of the mixture of alumina and silica consists of alumina, and more preferably 1 to 20 wt.%, more preferably 2 to 15 wt.%, more preferably 2 to 10 wt.% of the mixture of alumina and silica consists of silica. 37. The process of any one of embodiments 32 to 36, wherein the mixture prepared in (iii.3) comprises a second non-zeolitic oxide material in an amount in the range of 2 to 20 wt.%, preferably in the range of 5 to 15 wt.%, more preferably in the range of 7 to 13 wt.%, based on the weight of the zeolitic material. 38. The process of any one of embodiments 32 to 37, wherein in (iii), preferably the third aqueous mixture obtained in (iii.4), has a solids content in the range of 15 to 50 wt.%, more preferably in the range of 20 to 45 wt.%, more preferably in the range of 25 to 40 wt.%, based on the weight of the third aqueous mixture. 39. The process according to any one of embodiments 20 to 38, wherein 98 to 100 wt.%, preferably 99 to 100 wt.%, more preferably 99.5 to 100 wt.%, more preferably 99.9 to 100 wt.% of the third aqueous mixture prepared in (iii) consists of water, zeolitic material, a copper source, a precursor of the first non-zeolitic oxide material, and preferably a second non-zeolitic oxide material as defined in any one of embodiments 32 and 34 to 37. 40. The process of any one of embodiments 20 to 39, wherein the disposing of the mixture according to (iv) is carried out by spraying the mixture onto the substrate or by immersing the substrate in the mixture, preferably by immersing the substrate in the mixture. 41. The process of any one of embodiments 20 to 40, wherein the third aqueous mixture obtained according to (iii) is disposed according to (iv) over x% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, where x is in the range of 95 to 100, preferably in the range of 98 to 100, more preferably in the range of 99 to 100. 42. The process of any one of embodiments 20 to 41, wherein the substrate in (iv) is one or more of a cordierite wall-flow filter substrate, a silicon carbide wall-flow filter substrate, and an aluminum titanate wall-flow filter substrate, preferably one or more of a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate, more preferably a silicon carbide wall-flow filter substrate or an aluminum titanate wall-flow filter substrate. 43. The process according to any one of embodiments 20 to 42, wherein the drying according to (iv) is carried out in a gas atmosphere having a temperature in the range of 60 to 300 °C, preferably in the range of 90 to 150 °C, and the gas atmosphere preferably contains oxygen. 44. The process according to any one of embodiments 20 to 43, wherein the drying according to (iv) is carried out in a gas atmosphere for a duration in the range of 10 minutes to 4 hours, preferably in the range of 20 minutes to 2 hours, and the gas atmosphere preferably contains oxygen. 45.(iv) is to be placed in accordance with (iv.1) disposing a first portion of the third aqueous mixture obtained in(iii) onto a wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by an interior wall of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and drying the substrate containing the first portion of the third aqueous mixture; 45. The process of any one of embodiments 20 to 44, comprising: (iv.2) disposing a second portion of the third aqueous mixture obtained in (iii) on a substrate comprising the first portion of the third aqueous mixture obtained in (iv.1); and optionally drying the substrate comprising the first and second portions of the third aqueous mixture. 46. ​​The process of embodiment 45, wherein the first portion of the third aqueous mixture according to (iii) is disposed over x1% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate according to (iv.1), where x1 is in the range of 95 to 100, preferably in the range of 98 to 100, more preferably in the range of 99 to 100. 47. The process of embodiment 45 or 46, wherein the second portion of the third aqueous mixture according to (iii) is disposed over x2% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate according to (iv.2), where x2 is in the range of 95 to 100, preferably in the range of 98 to 100, more preferably in the range of 99 to 100, and more preferably, insofar as embodiment 46 depends on embodiment 45, x2=x1. 48. The process of embodiment 45, wherein a first portion of the third aqueous mixture according to (iii) is disposed over x1% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate according to (iv.1), where x1 is in the range of 50 to 90, preferably in the range of 60 to 80, more preferably in the range of 65 to 75. 49. The process of embodiment 45 or 48, wherein the second portion of the third aqueous mixture according to (iii) is disposed over x2% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate in accordance with (iv.2), where x2 is in the range of 50 to 90, preferably in the range of 60 to 80, more preferably in the range of 65 to 75, and more preferably, insofar as embodiment 48 depends on embodiment 45, x2=x1. 50. The process according to any one of embodiments 45 to 49, wherein the drying according to (iv.1) is carried out in a gas atmosphere having a temperature in the range of 60 to 300 °C, preferably in the range of 90 to 150 °C, and the gas atmosphere preferably contains oxygen. 51. The process according to any one of embodiments 45 to 50, wherein the drying according to (iv.1) is carried out in a gas atmosphere for a duration in the range of 10 minutes to 4 hours, preferably in the range of 20 minutes to 2 hours, and the gas atmosphere preferably contains oxygen. 52. The process according to any one of embodiments 45 to 51, wherein the drying according to (iv.2) is carried out in a gas atmosphere having a temperature in the range of 60 to 300 °C, preferably in the range of 90 to 150 °C, and the gas atmosphere preferably contains oxygen. 53. The process according to any one of embodiments 45 to 52, wherein the drying according to (iv.2) is carried out in a gas atmosphere for a duration in the range of 10 minutes to 4 hours, preferably in the range of 20 minutes to 2 hours, and the gas atmosphere preferably contains oxygen. 54. The process according to any one of embodiments 20 to 53, wherein the calcination according to (v) is carried out in a gas atmosphere having a temperature in the range of 300 to 900 °C, preferably in the range of 400 to 650 °C, more preferably in the range of 400 to 500 °C, and the gas atmosphere preferably contains oxygen. 55. The process according to any one of embodiments 20 to 54, wherein the calcination according to (v) is carried out in a gas atmosphere for a duration in the range of 0.1 to 4 hours, preferably in the range of 0.5 to 2.5 hours, and the gas atmosphere preferably contains oxygen. 56. The process of any one of embodiments 19 to 54, comprising (i), (ii), (iii), (iv), and (v). 57. A process for preparing a catalyst for selective catalytic reduction of NOx, preferably according to any one of embodiments 1 to 19, comprising: (i') preparing a first aqueous mixture comprising water, a copper source, and a precursor of a first non-zeolitic oxide component comprising zirconium; (ii') mixing a copper-free zeolitic material with the first mixture obtained according to (i') to obtain a second aqueous mixture, wherein the amount of precursor of the first non-zeolitic oxide component in the second aqueous mixture, calculated as oxide, is at least 10 wt.-% based on the weight of the zeolitic material; (iii') disposing the second aqueous mixture onto a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by an interior wall of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and optionally drying the substrate including the mixture; (iv') calcining the substrate obtained in (iii'). 58. The process of embodiment 57, wherein the copper source contained in the first aqueous mixture prepared in (i') is selected from the group consisting of copper acetate, copper nitrate, copper sulfate, copper formate, copper oxide, and mixtures of two or more thereof, preferably selected from the group consisting of copper acetate, copper oxide, and mixtures thereof, more preferably copper oxide, more preferably CuO. 59. The process of embodiment 57 or 58, wherein the precursor of the first non-zeolitic oxide component contained in the first aqueous mixture prepared in (i') is a zirconium salt or zirconium oxide, preferably a zirconium salt, more preferably zirconium acetate. 60. The process of any one of embodiments 57 to 59, wherein the first aqueous mixture prepared in (i') contains copper, calculated as CuO, in an amount in the range of 2 to 10 wt.%, preferably in the range of 2.5 to 5.5 wt.%, more preferably in the range of 3 to 5 wt.%, based on the zeolitic material of the second aqueous mixture obtained according to (ii'). 61. The process according to any one of embodiments 57 to 60, wherein the amount of precursor of the first non-zeolitic oxide material in the first aqueous mixture, calculated as oxide, is in the range of 10 to 80 wt.-%, more preferably in the range of 11 to 80 wt.-%, more preferably in the range of 12.5 to 50 wt.-%, more preferably in the range of 13 to 40 wt.-%, more preferably in the range of 14.3 to 28.5 wt.-%, more preferably in the range of 18 to 25 wt.-%, based on the weight of the zeolitic material contained in the second aqueous mixture obtained according to (ii'). 62.(i') is (i'.1) preparing a mixture comprising water and a copper source, preferably the mixture further comprises an acid, more preferably an organic acid, more preferably acetic acid, more preferably the mixture comprises sucrose, more preferably the weight ratio of copper, calculated as CuO, to sucrose is in the range of 2:1 to 1:2, more preferably in the range of 1.5:1 to 1:1.5, more preferably in the range of 1.2:1 to 1:1.2; (i'.2) adding a precursor of a first non-zeolitic oxide component to the mixture obtained according to (i'.1) to obtain a first aqueous mixture; 62. The process according to any one of embodiments 57 to 61, comprising: 63. The process of embodiment 62, wherein 90 to 100 wt.%, preferably 93 to 99 wt.%, more preferably 96 to 99 wt.% of the copper source is present in an undissolved state in the mixture prepared in (i'.1). 64. The process according to embodiment 63, wherein the copper particles in the mixture according to (i'.1) have a Dv90 in the range of 0.1 to 15 micrometers, more preferably in the range of 0.5 to 10 micrometers, more preferably in the range of 1 to 8 micrometers, more preferably in the range of 3 to 7 micrometers, wherein Dv90 is preferably determined as described in Reference Example 3. 65. The process according to any one of embodiments 62 to 64, wherein the mixture obtained in (i'.1) has a solids content in the range of 4 to 30% by weight, preferably in the range of 4 to 21% by weight, based on the weight of the mixture obtained in (i'.1). 66. The process of any one of embodiments 57 to 65, wherein the second aqueous mixture obtained in (ii') has a solids content in the range of 15 to 50% by weight, more preferably in the range of 20 to 45% by weight, more preferably in the range of 30 to 40% by weight, based on the weight of the second mixture. 67. The process of any one of embodiments 57 to 66, wherein the particles of the zeolite material in the second aqueous mixture have a Dv90 in the range of 1 to 10 micrometers, preferably in the range of 2 to 6 micrometers, and the Dv90 is preferably determined as described in Reference Example 3. 68. The process of any one of embodiments 57 to 67, wherein the particles of the zeolite material in the second aqueous mixture have a Dv50 in the range of 0.5 to 5 micrometers, preferably in the range of 0.75 to 3 micrometers, and Dv90 is preferably determined as described in Reference Example 3. 69.(ii') (ii'.1) mixing a preferably Cu-free zeolitic material with the first aqueous mixture obtained according to (i'); (ii'.2) preferably milling the obtained mixture (ii'.1), more preferably until the particles of said mixture have a Dv90 in the range of 0.5 to 8 micrometers, more preferably in the range of 1 to 5 micrometers, more preferably in the range of 1.5 to 4 micrometers, Dv90 preferably being determined as described in Reference Example 3; (ii'.3) mixing the second mixture obtained in (ii'.1), preferably in (ii'.2), with a second non-zeolitic oxide material selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti, and Ce, and mixtures of two or more thereof, to obtain a second aqueous mixture; The process according to any one of embodiments 57 to 68, comprising: 70. The process of embodiment 69, wherein the mixture prepared in (ii'.3) has a solids content in the range of 15 to 60% by weight, preferably in the range of 20 to 45% by weight, more preferably in the range of 25 to 40% by weight, based on the weight of the mixture. 71. The process of embodiment 69 or 70, wherein the particles of the second non-zeolitic oxide material in the mixture prepared in (ii'.3) have a Dv90 in the range of 2 to 12 micrometers, preferably in the range of 3 to 7 micrometers, Dv90 being preferably determined as described in Reference Example 3. 72. The process according to any one of embodiments 69 to 71, wherein the particles of the second non-zeolitic oxide material in the mixture prepared in (ii'.3) have a Dv50 in the range of 0.75 to 6 micrometers, preferably in the range of 1.5 to 4 micrometers, and a Dv90, preferably determined as described in Reference Example 3. 73. The second non-zeolitic oxide material contained in the mixture prepared in (ii'.3) is selected from the group consisting of alumina, silica, and titania, mixed oxides containing one or more of Al, Si, and Ti, and mixtures of two or more thereof, preferably selected from the group consisting of alumina, silica, mixed oxides containing one or more of Al, and Si, and mixtures of two or more thereof, more preferably a mixture of alumina and silica; 73. The process of any one of embodiments 69 to 72, wherein the mixture of alumina and silica is more preferably 80 to 99% by weight, more preferably 85 to 98% by weight, more preferably 90 to 98% by weight, of the alumina and silica, and more preferably 1 to 20% by weight, more preferably 2 to 15% by weight, more preferably 2 to 10% by weight, of the alumina and silica mixture is silica. 74. The process of any one of embodiments 69 to 73, wherein the mixture prepared in (ii'.2) comprises a second non-zeolitic oxide material in an amount in the range of 2 to 20 wt.%, preferably in the range of 5 to 15 wt.%, more preferably in the range of 7 to 13 wt.%, based on the weight of the zeolitic material. 75. The process of any one of embodiments 57 to 74, wherein 98 to 100 wt.%, preferably 99 to 100 wt.%, more preferably 99.5 to 100 wt.%, more preferably 99.9 to 100 wt.% of the second aqueous mixture prepared in (ii') consists of water, zeolitic material, a copper source, a precursor of the first non-zeolitic oxide material, and preferably a second non-zeolitic oxide material as defined in any one of embodiments 69 and 71 to 74. 76. The process according to any one of embodiments 57 to 77, wherein the disposing of the mixture according to (iii') is carried out by spraying the mixture onto the substrate or by immersing the substrate in the mixture, preferably by immersing the substrate in the mixture. 77. The process of any one of embodiments 57 to 76, wherein the second aqueous mixture obtained according to (ii') is disposed according to (iii') over x% of the axial length of the substrate from the inlet end to the outlet end of the substrate, or from the outlet end to the inlet end of the substrate, where x is in the range of 95 to 100, preferably in the range of 98 to 100, more preferably in the range of 99 to 100. 78. The process of any one of embodiments 57 to 77, wherein the substrate in (iii') is one or more of a cordierite wall-flow filter substrate, a silicon carbide wall-flow filter substrate, and an aluminum titanate wall-flow filter substrate, preferably one or more of a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate, more preferably a silicon carbide wall-flow filter substrate or an aluminum titanate wall-flow filter substrate. 79. The process according to any one of embodiments 57 to 78, wherein the drying according to (iii') is carried out in a gas atmosphere having a temperature in the range of 60 to 300 °C, preferably in the range of 90 to 150 °C, and the gas atmosphere preferably contains oxygen. 80. The process according to any one of embodiments 57 to 79, wherein the drying according to (iii') is carried out in a gas atmosphere for a duration in the range of 10 minutes to 4 hours, preferably in the range of 20 minutes to 2 hours, and the gas atmosphere preferably contains oxygen. 81.(iii') (iii'.1) disposing a first portion of the second aqueous mixture obtained in (ii') onto a wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by an interior wall of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and drying the substrate containing the first portion of the second aqueous mixture. (iii'.2) disposing a second portion of the second aqueous mixture obtained in (ii') onto a substrate comprising the first portion of the third aqueous mixture obtained in (iii'.1) and optionally drying the substrate comprising the first and second portions of the second aqueous mixture; The process according to any one of embodiments 57 to 80, comprising: 82. The process of embodiment 81, wherein the first portion of the second aqueous mixture according to (ii') is disposed over x1% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate according to (iii'.1), where x1 is in the range of 95 to 100, preferably in the range of 98 to 100, more preferably in the range of 99 to 100. 83. The process of embodiment 81 or 82, wherein the second portion of the second aqueous mixture according to (ii') is disposed over x2% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate in accordance with (iii'.2), where x2 is in the range of 95 to 100, preferably in the range of 98 to 100, more preferably in the range of 99 to 100, and more preferably x2=x1. 84. The process of embodiment 81, wherein the first portion of the second aqueous mixture according to (ii') is disposed over x1% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate in accordance with (iii'.1), where x1 is in the range of 50 to 90, preferably in the range of 60 to 80, more preferably in the range of 65 to 75. 85. The process of embodiment 81 or 84, wherein the second portion of the second aqueous mixture according to (ii') is disposed over x2% of the substrate axial length from the inlet end to the outlet end of the substrate or from the outlet end to the inlet end of the substrate according to (iii'.2), where x2 is in the range of 50 to 90, preferably in the range of 60 to 80, more preferably in the range of 65 to 75, more preferably x2=x1. 86. The drying according to (iii'.1) is carried out in a gas atmosphere having a temperature in the range of 60 to 300 ° C, preferably in the range of 90 to 150 ° C, the gas atmosphere preferably containing oxygen; The process according to any one of embodiments 81 to 85, wherein the drying according to (iii'.1) is preferably carried out in a gas atmosphere for a duration in the range of from 10 minutes to 4 hours, more preferably in the range of from 20 minutes to 2 hours. 87. The drying according to (iii'.2) is carried out in a gas atmosphere having a temperature in the range of 60 to 300 ° C, preferably in the range of 90 to 150 ° C, the gas atmosphere preferably containing oxygen; The process according to any one of embodiments 81 to 86, wherein the drying according to (iii'.2) is preferably carried out in a gas atmosphere for a duration in the range of from 10 minutes to 4 hours, more preferably in the range of from 20 minutes to 2 hours. 88. The calcination according to (iv') is carried out in a gas atmosphere having a temperature in the range of 300 to 900 ° C, preferably in the range of 400 to 650 ° C, more preferably in the range of 400 to 500 ° C, the gas atmosphere preferably containing oxygen; The process according to any one of embodiments 57 to 87, wherein preferably, the calcination according to (iv') is carried out in a gas atmosphere for a duration in the range of 0.1 to 4 hours, more preferably in the range of 0.5 to 2.5 hours. 89. The process of any one of embodiments 57-88, comprising (i'), (ii'), (iii'), and (iv'). 90. A catalyst for selective catalytic reduction of NOx, obtained or obtainable according to the process of any one of embodiments 20 to 56 or 57 to 89. 91. An exhaust gas treatment system for treating exhaust gas from a compression ignition engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system including a catalyst as described in any one of embodiments 1-19 and 90, and one or more of a diesel oxidation catalyst, a selective catalytic reduction catalyst, an ammonia oxidation catalyst, a NOx trap, and a particulate filter. 92. The system of embodiment 91, comprising the catalyst of any one of embodiments 1-19 and 90, a diesel oxidation catalyst, and a selective catalytic reduction catalyst; A system in which a diesel oxidation catalyst is preferably located upstream of a selective catalytic reduction catalyst, and the selective catalytic reduction catalyst is located upstream of the catalyst according to any one of embodiments 1-19 and 90. 93. The system of embodiment 91, comprising the catalyst of any one of embodiments 1-19 and 90, a NOx trap, and a selective catalytic reduction catalyst; A system in which the NOx trap is preferably located upstream of a selective catalytic reduction catalyst, which is located upstream of the catalyst of any one of embodiments 1-19 and 90. 94. The system of embodiment 91, comprising the catalyst of any one of embodiments 1-19 and 90, a diesel oxidation catalyst, and a selective catalytic reduction catalyst; A diesel oxidation catalyst is more preferably located upstream of the catalyst according to any one of embodiments 1-19 and 90, and the catalyst according to any one of embodiments 1-19 and 90 is located upstream of the selective catalytic reduction catalyst. 95. The system of embodiment 91, comprising the catalyst of any one of embodiments 1-19 and 90, a NOx trap, and a selective catalytic reduction catalyst; A system in which the NOx trap is more preferably located upstream of the catalyst of any one of embodiments 1-19 and 90, and the catalyst of any one of embodiments 1-19 and 90 is located upstream of the selective catalytic reduction catalyst. 96. The system of embodiment 95, further comprising an ammonia oxidation catalyst or a selective catalytic reduction / ammonia oxidation catalyst, preferably located downstream of the selective catalytic reduction catalyst. 97. Use of a catalyst according to any one of embodiments 1 to 19 and 90 for the selective catalytic reduction of NOx. 98. A method for selective catalytic reduction of NOx, comprising: (1) providing an exhaust gas stream, preferably an exhaust gas stream exiting a diesel engine; (2) contacting the exhaust gas stream provided in (1) with a catalyst for selective catalytic reduction of NOx as described in any one of embodiments 1 to 19 and 90.

[0078] Furthermore, it should be clearly noted that the above series of embodiments represents a properly structured portion of the general description directed to preferred aspects of the present invention and thus properly supports the claims of the present invention, but does not represent the same.

[0079] Systems according to the present invention are listed in the table below.

[0080] [Table 1]

[0081] Catalyst 1 is placed upstream of catalyst 2, which is located upstream of catalyst 3, which is located upstream of catalyst 4. In the above table, "Cat." denotes a catalyst according to the invention, preferably where the substrate is a wall-flow filter substrate. Also, "DOC" denotes diesel oxidation catalyst, "SCR" denotes selective catalytic reduction catalyst, "AMOx" denotes ammonia oxidation catalyst. "Cat." denotes selective catalytic reduction catalyst on filter "SCRoF". In the context of the present invention, systems 1 and 3 are preferred.

[0082] In the context of the present invention, the term "SCR" denotes a selective catalytic reduction catalyst and the term "SCRoF" denotes a selective catalytic reduction catalyst on a wall-flow filter substrate.

[0083] In the context of the present invention, the term "the porous walls of the substrate comprise a coating" means that at least a portion of the coating is located within the pores of the walls of the wall-flow filter substrate.

[0084] Furthermore, in the context of the present invention, the term "loading of a given component / coating" (expressed in g / in3 or g / ft3) means: It refers to the mass of that component / coating per volume of substrate, the volume of the substrate being the volume defined by the cross section of the substrate multiplied by the axial length of the substrate on which that component / coating resides. For example, when referring to a loading of a first coating that extends across x% of the substrate axial length and has a loading of X g / in3, the loading refers to X grams of first coating per x% of the total substrate volume (in cubic inches).

[0085] Furthermore, in the context of the present invention, the term "based on the weight of the zeolitic material" means the weight of the zeolitic material alone, not including copper. Further, in the context of the present invention, the term "based on the weight of the chabazite" means the weight of the chabazite alone, not including copper.

[0086] Furthermore, in the context of the present invention, the term "X is one or more of A, B, and C" (X is a given feature and each of A, B, and C represents a specific realization of that feature) should be understood as disclosing that X is either A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. In this regard, it should be noted that a person skilled in the art can translate the above abstract terms into concrete examples. For example, X is a chemical element and A, B, and C are specific elements such as Li, Na, and K, or X is a temperature and A, B, and C are specific temperatures such as 10°C, 20°C, and 30°C. In this regard, it is further noted that one of skill in the art may extend the above terms to less specific recognition of the feature (e.g., "X is one or more of A and B" discloses that X is either A, or B, or A and B), or more specific recognition of the feature (e.g., "X is one or more of A, B, C, and D" discloses that X is either A, or B, or C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C, or A and B and D, or B and C and D, or A and B and C and D).

[0087] The present invention is further illustrated by the following examples. EXAMPLES

[0088] Reference Example 1 Measurement of BET specific surface area and micropore surface area (ZSA) The BET specific surface area and the ZSA were determined according to DIN 66131 or DIN-ISO 9277 using liquid nitrogen.

[0089] Reference Example 2 Measurement of the average porosity and average pore size of porous wall-flow substrates The average porosity of the porous wall-flow substrates was determined by mercury intrusion using mercury porosimetry according to DIN 66133 and ISO 15901-1.

[0090] Reference Example 3 Determination of volumetric particle size distribution The particle size distribution was determined by static light scattering method using a Sympatec HELOS (3200) & QUIXEL instrument, and the optical density of the samples ranged from 6 to 10%.

[0091] Reference Example 4: Process for preparing a catalyst containing a copper-containing zeolite material not according to the present invention CuO powder having a Dv50 of 1.1 micrometers and a Dv90 of 5.8 micrometers was added to the water. The amount of CuO was calculated such that the total amount of copper in the coating after firing, calculated as CuO, was 4.15 wt% based on the weight of the chabazite. Sucrose was further added to the Cu mixture, and the amount of sucrose was calculated to be 4.15 wt% based on the weight of the chabazite. Acetic acid was added to the resulting slurry. The amount of acetic acid was calculated to be 1.7 wt% based on the weight of the Cu-chabazite. The resulting slurry had a solids content of 5 wt% based on the weight of the slurry. An aqueous zirconium acetate solution was added to the CuO-containing mixture to form a slurry. The amount of zirconium acetate was calculated such that the amount of zirconia in the coating, calculated as ZrO2, was 5 wt% based on the weight of the chabazite. H-chabazite (Dv10 of 0.7 micrometers, Dv50 of 1.5 micrometers, and Dv90 of 3.9 micrometers, SiO2:Al2O3 of 15.7:1, BET specific surface area of ​​590 m 2 / g, and a micropore surface area (ZSA) of 580 m 2 / g) was added to the copper-containing slurry to form the mixture with a solid content of 37 wt. % based on the weight of the mixture. The amount of chabazite was calculated such that the loading of chabazite after calcination was 85% of the loading of the coating in the catalyst after calcination. The resulting slurry was milled using a continuous milling device such that the particles had a Dv90 value of about 2.5 micrometers and the particles had a Dv50 value of about 1.35 micrometers.

[0092] Alumina powder (178m 2 94 wt% Al2O3 with 6 wt% SiO2, having a BET specific surface area of ​​1.2 g / g, Dv10 of 1.1 micrometers, Dv50 of 2.5 micrometers, and Dv90 of about 5.2 micrometers, was added to the Cu / CHA containing slurry. The amount of alumina+silica was calculated such that the amount of alumina+silica after calcination was 10 wt% based on the weight of the calcined chabazite in the final catalyst.

[0093] Additionally, the solids content of the final slurry was adjusted to 34% by weight based on the weight of the slurry by the addition of water.

[0094] Porous uncoated wall-flow filter substrate, silicon carbide (volume: 0.428 L, average porosity 63%, average pore size 20 micrometers and 300 cpsi and wall thickness 12 mils, diameter: 2.3 inches * A 100% axial length substrate (length: 6.4 inches) was coated twice with the final slurry from the inlet end to the outlet end. To do so, the substrate was immersed in the final slurry from the inlet end until the slurry reached the top of the substrate. Further, a pressure pulse was applied to the inlet end to distribute the slurry evenly in the substrate. The coated substrate was then dried at 140° C. for 30 minutes and calcined at 450° C. for 1 hour. This was repeated once.

[0095] The final coating loading after calcination was about 2.0 g / in3, which contained about 1.7 g / in3 of chabazite, 0.17 g / in3 of alumina+silica, 0.085 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating was 20:1.

[0096] Reference Example 5: Process for preparing a catalyst containing a copper-containing zeolite material not according to the present invention The catalyst of Example 5 was prepared similarly to the catalyst of Example 4, except that the amount of zirconium acetate was calculated such that the amount of zirconia in the coating, calculated as ZrO2, was 2.5 wt% based on the weight of chabazite. The final coating loading after calcination was about 2.05 g / in3, which contained about 1.75 g / in3 of chabazite, 0.175 g / in3 of alumina+silica, 0.044 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 40:1.

[0097] Example 1: Process for preparing a catalyst comprising a copper-containing zeolitic material according to the present invention The catalyst of Example 1 was prepared similarly to the catalyst of Reference Example 4, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 10 wt% based on the weight of chabazite. The final coating loading after calcination was about 2.0 g / in3, which contained about 1.65 g / in3 of chabazite, 0.165 g / in3 of alumina+silica, 0.165 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 10:1.

[0098] Example 2: Performance test of the catalysts prepared in Reference Examples 4, 5, and Example 1 Cold flow back pressure measurements were performed on the tested catalysts and soot back pressure measurements were performed on the engine bench with fresh catalyst. For analysis of DeNOx activity technology, the tested catalysts were oven aged at 850°C for 16 hours with 10% H2O and 20% O2. Engine bench tests were performed at steady state conditions for evaluation. The tested catalysts are listed in Table 1.

[0099] [Table 2] * Based on weight of chabazite

[0100] 1 and 2 show the test results for NOx performance (1a), NOx performance breakthrough at 20 ppm NH3 (1b), and backpressure behavior under steady state conditions.

[0101] Example 1 shows comparable DeNOx activity and reduced back pressure compared to Reference Examples 4 and 5. Thus, the catalyst of the present invention makes it possible to maintain excellent catalytic performance such as DeNOx while reducing back pressure.

[0102] Figure 3 shows the test results in back pressure under soot conditions from the engine bench. Example 1 (10 wt% ZrO2) shows the most promising results, especially in back pressure with soot behavior. It shows nearly 25% lower back pressure in soot compared to Reference Example 1.

[0103] Reference Example 6: Process for preparing a catalyst containing a copper-containing zeolite material not according to the present invention The catalyst of Example 6 was prepared similarly to the catalyst of Example 4, except that a full-sized substrate was added. In particular, the substrate used was a porous uncoated wall-flow filter substrate, silicon carbide (volume: 3 L, average porosity 63%, average pore size 20 micrometers and 300 cpsi and wall thickness of 12 mils, diameter: 6.43 inches). *Length: 6.387 inches). The final coating loading after firing was about 2 g / in3, which contained about 1.71 g / in3 of chabazite, 0.171 g / in3 of alumina+silica, 0.085 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating was 20:1.

[0104] Example 3: Process for preparing a catalyst comprising a copper-containing zeolitic material according to the present invention The catalyst of Example 3 was prepared similarly to the catalyst of Example 1, except for the addition of a full-sized substrate. In particular, the substrate used was a porous uncoated wall-flow filter substrate, silicon carbide (volume: 3 L, average porosity 63%, average pore size 20 micrometers and 300 cpsi and wall thickness of 12 mils, diameter: 6.43 inches). * Length: 6.387 inches). The final coating loading after firing was about 2 g / in3, which contained about 1.63 g / in3 of chabazite, 0.163 g / in3 of alumina+silica, 0.163 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating was 10:1.

[0105] Example 4: Process for preparing a catalyst comprising a copper-containing zeolitic material according to the present invention The catalyst of Example 4 was prepared similarly to the catalyst of Example 3, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 20 wt% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.51 g / in3 of chabazite, 0.151 g / in3 of alumina+silica, 0.302 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 5:1.

[0106] Example 5: Performance test of the catalysts prepared in Reference Example 6, and Examples 3 and 4 Backpressure measurements with soot loading were performed at laboratory conditions with fresh catalyst (not aged). For analysis of DeNOx activity and NH3 storage capacity, the catalyst was oven aged at 850°C for 16 hours with 10% H2O and 20% O2 (Figure 6), the catalyst was oven aged at 850°C for 16 hours with 10% H2O and 20% O2, then at 800°C for 16 hours, and finally at 850°C for 16 hours (Figure 7). For evaluation, engine bench tests at steady state conditions were performed. The catalysts tested are listed in Table 2.

[0107] [Table 3] * Based on weight of chabazite

[0108] Figure 4 shows the test results in cold flow conditions and the back pressure behavior with soot loading from a laboratory reactor. It is noted that the back pressure with soot loading is significantly reduced when using the catalyst of the present invention containing a higher proportion of zirconia compared to the catalyst of Reference Example 6. In particular, the catalyst with 20 wt% ZrO2 shows reduced cold flow back pressure (about 15%) and reduced soot loading back pressure of about 44% at 4 g / L soot compared to Reference Example 6.

[0109] Engine bench evaluation shows comparable DeNOx activity for inventive examples 3 and 4 vs. reference example 6 after aging at 850°C for 16 hours (Figures 5a-5b). The reduced NH3 storage capacity seen in Figure 6 is a result of reduced zeolite material amount, but does not impair DeNOx activity. Without wishing to be bound by any theory, it is believed that the zeolite material is stabilized by increasing the amount of zirconia when the thermal aging conditions are increased to longer times (three aging steps as above) and more severe conditions (higher flow rates from 5 to 25 l / h during the aging steps, more H2O). This is shown by better SCR activity and higher NH3 storage capacity after strong hydrothermal aging (see Figures 6-7).

[0110] Example 6 A) a process for preparing a catalyst comprising a copper-containing zeolitic material according to the invention: The catalyst of Example 6A was prepared similarly to the catalyst of Example 4, except that the substrate used was a porous uncoated wall-flow filter substrate, silicon carbide (volume: 3.4 L, average porosity 63%, average pore size 20 micrometers and 300 cpsi and wall thickness of 12.5 mils, diameter: 163.4 mm x length: 162.1 mm). The final coating loading after calcination was about 2 g / in3, which contained about 1.51 g / in3 of chabazite, 0.151 g / in3 of alumina + silica, 0.302 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 5:1. - B) A process for preparing a catalyst comprising a copper-containing zeolitic material according to the invention: The catalyst of Example 6B was prepared similarly to the catalyst of Example 6A, except that the amount of CuO was calculated such that the total amount of copper in the coating after calcination, calculated as CuO, was 4.5 wt.% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.51 g / in3 of chabazite, 0.151 g / in3 of alumina+silica, 0.302 g / in3 of zirconia, and 4.5 wt.% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 5:1.

[0111] Reference example 7 A) a process for preparing a catalyst comprising a copper-containing zeolitic material not according to the invention: The catalyst of Reference Example 7A was prepared similarly to the catalyst of Reference Example 6, except that the substrate used was a porous uncoated wall-flow filter substrate, silicon carbide (NGK) (volume: 3.4 L, average porosity 63%, average pore size 20 micrometers and 300 cpsi and wall thickness of 12.5 mils, diameter: 163.4 mm x length: 162.1 mm). The final coating loading after calcination was about 2 g / in3, containing about 1.71 g / in3 of chabazite, 0.171 g / in3 of alumina + silica, 0.085 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 20:1. - B) A process for preparing a catalyst comprising a copper-containing zeolitic material not according to the invention The catalyst of Example 7B was prepared similarly to the catalyst of Example 6, except that the substrate used was a porous uncoated wall-flow filter substrate, aluminum titanate (volume: 3.6 L, average porosity 59%, average pore size 18 micrometers and 350 cpsi and wall thickness of 12 mils, diameter: 163.4 mm x length: 162.1 mm). The final coating loading after calcination was 2 g / in3, containing approximately 1.71 g / in3 of chabazite, 0.171 g / in3 of alumina + silica, 0.085 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 20:1.

[0112] Example 7 A) a process for preparing a catalyst comprising a copper-containing zeolitic material according to the invention: The final slurry of Example 7A was prepared similarly to Example 4. Additionally, a porous uncoated wall-flow filter substrate, silicon carbide (volume: 3.4 L, average porosity 63%, average pore size 20 micrometers and wall thickness of 300 cpsi and 12.5 mils, diameter: 163.4 mm *A substrate having a length of 162.1 mm (length: 162.1 mm) was coated with the final slurry from the inlet end to the outlet end over 70% of the substrate axial length. To do so, the substrate was immersed in the final slurry from the outlet end until the slurry reached 70% of the substrate axial length. Further, a pressure pulse was applied to the inlet end to distribute the slurry evenly in the substrate. Further, the coated substrate was dried at 140° C. for 30 minutes and calcined at 450° C. for 1 hour to form a first coat (inlet coat) with a loading of 1.43 g / in 3 . Further, the coated substrate was coated with the final slurry from the inlet end to the outlet end over 70% of the substrate axial length. To do so, the substrate was immersed in the final slurry from the inlet end until the slurry reached 70% of the substrate axial length. Further, a pressure pulse was applied to the outlet end to distribute the slurry evenly in the substrate. The coated substrate was then dried at 140° C. for 30 minutes and calcined at 450° C. for 1 hour to form a second coat (outlet coat) with a loading of 1.43 g / in 3 .

[0113] The final coating loading after firing (inlet coat + outlet coat) was about 2 g / in3, which contained about 1.51 g / in3 of chabazite, 0.151 g / in3 of alumina + silica, 0.302 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating was 5:1. - B) A process for preparing a catalyst comprising a zeolitic material containing copper according to the invention:

[0114] The catalyst of Example 7B was prepared similarly to the catalyst of Example 7A, except that the substrate used was a porous uncoated wall-flow filter substrate, aluminum titanate (volume: 3.6 L, average porosity 59%, average pore size 18 micrometers and 350 cpsi and wall thickness of 12 mils, diameter: 163.4 mm x length: 162.1 mm). The final coating loading (inlet coat + outlet coat) after calcination was about 2 g / in3, which contained about 1.51 g / in3 of chabazite, 0.151 g / in3 of alumina + silica, 0.302 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 5:1.

[0115] Example 8 A) a process for preparing a catalyst comprising a copper-containing zeolitic material according to the invention: The final slurry of Example 8 was prepared similarly to Example 4, except that the amount of CuO was calculated such that the total amount of copper in the coating after firing, calculated as CuO, was 4.5 wt.% based on the weight of the chabazite. In addition, a porous uncoated wall-flow filter substrate, silicon carbide (volume: 3.4 L, average porosity 59%, average pore size 18 micrometers and wall thickness of 350 cpsi and 12 mils, diameter: 163.4 mm) was added. *A 100% axial length substrate (length: 162.1 mm) was coated once with the final slurry from the inlet end to the outlet end. To do so, the substrate was immersed in the final slurry from the inlet end until the slurry reached the top of the substrate. A pressure pulse was then applied to the inlet end to distribute the slurry evenly throughout the substrate. The coated substrate was then dried at 140° C. for 30 minutes and calcined at 450° C. for 1 hour. The final coating loading after calcination was about 2 g / in 3 , which included about 1.51 g / in 3 chabazite, 0.151 g / in 3 alumina+silica, 0.302 g / in 3 zirconia, and 4.5 wt % Cu, calculated as Cu, based on the weight of the chabazite. The weight ratio of zeolite material to zirconia in the coating is 5:1. - B) A process for preparing a catalyst comprising a copper-containing zeolitic material according to the invention:

[0116] The catalyst of Example 8B was prepared similarly to the catalyst of Example 8A, except that the substrate used was a porous uncoated wall-flow filter substrate, silicon carbide (volume: 3.4 L, average porosity 63%, average pore size 20 micrometers and 300 cpsi and wall thickness of 12 mils, diameter: 163.4 mm x length: 162.1 mm). The final coating loading after calcination was about 2 g / in3, which contained about 1.51 g / in3 of chabazite, 0.151 g / in3 of alumina + silica, 0.302 g / in3 of zirconia, and 4.5 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 5:1.

[0117] Example 9: Performance testing of the catalysts prepared in Reference Examples 7A-B, and Examples 6A-B, 7A-B, and 8 Cold flow back pressure measurements were performed under laboratory conditions using fresh (unaged) catalysts of Reference Examples 7A and 7B, and Examples 6A, 7A, 7B, and 8A. The results are shown in Table 3 below. For the analysis of DeNOx activity, the catalysts of Reference Example 7A, and Examples 6A, 6B, and 8B were oven-aged at 850°C for 16 hours with 10% H2O and 20% O2 (Figures 8 and 9). For evaluation, engine bench tests at steady-state conditions were performed.

[0118] [Table 4]

[0119] 8 and 9 show the results from engine bench evaluation. Example 6A shows comparable maximum DeNOx activity and DeNOx activity at 20 ppm NH3 breakthrough compared to Comparative Example 7A over the entire temperature window, but the cold flow back pressure of the catalyst of Example 6A is reduced. Therefore, without wishing to be bound by any theory, it is believed that the reduction of the amount of zeolite by increasing the amount of Zr does not impair the DeNOx activity and even allows the back pressure to be reduced. Example 6B and Example 8B show slightly higher low temperature DeNOx activity and slightly higher DeNOx activity at 20 ppm NH3 breakthrough due to higher CuO loading. High temperature performance is comparable to Comparative Example 7A and Example 6A.

[0120] Example 10: Process for preparing a catalyst comprising a copper-containing zeolitic material according to the present invention - Preparation of the catalyst: The catalyst of Example 10.1 was prepared similarly to the catalyst of Example 1, except that the amount of zirconium acetate was increased in the process such that the amount of zirconia in the coating, calculated as ZrO2, was 20 wt.% based on the weight of chabazite, and the amount of CuO was calculated such that the total amount of copper in the coating after calcination, calculated as CuO, was 4.5 wt.% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.49 g / in3 of chabazite, 0.149 g / in3 of alumina+silica, 0.3 g / in3 of zirconia, and 4.5 wt.% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 4.9:1.

[0121] The catalyst of Example 10.2 was prepared similarly to the catalyst of Example 1, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 25 wt% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.44 g / in3 of chabazite, 0.144 g / in3 of alumina+silica, 0.36 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 4:1.

[0122] The catalyst of Example 10.3 was prepared similarly to the catalyst of Example 1, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 40 wt% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.3 g / in3 of chabazite, 0.13 g / in3 of alumina+silica, 0.52 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 2.5:1.

[0123] [Table 5] * Based on weight of chabazite -Testing the catalytic performance of the prepared catalyst: Backpressure measurements were performed under laboratory conditions using fresh (unaged) catalysts of Examples 10.1, 10.2, and 10.3. Backpressure was also measured for a reference catalyst not according to the invention (Example 4'), prepared similarly to Example 4, except that the Cu content was 4.5 wt. % based on the weight of the zeolite material. The results are shown in FIG.

[0124] For the analysis of DeNOx activity, the catalysts of Reference Example 4 and Examples 10.1, 10.2, and 10.3 were oven-aged at 850° C. for 16 hours with 10% HO and 20% O (see FIGS. 13 and 14). For evaluation, engine bench tests at steady-state conditions were conducted.

[0125] As can be seen from Figures 12, 13 and 14, Example 10.1 shows significantly reduced backpressure behavior with respect to soot compared to Comparative Example 4'. Additional zeolite reduction to Example 10.1 results in further reduction of backpressure. Reduced zeolite loading, especially in Example 10.3, affects maximum DeNOx activity and DeNOx activity at 20 ppm NH3 breakthrough due to lower NH3 storage capacity, but remains acceptably good performance related to the amount of zeolite used.

[0126] Example 11: Process for preparing a catalyst containing copper-containing zeolitic material according to the present invention - Preparation of the catalyst: The catalyst of Example 11.1 was prepared similarly to the catalyst of Example 1, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 20 wt% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.49 g / in3 of chabazite, 0.149 g / in3 of alumina+silica, 0.3 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 4.9:1.

[0127] The catalyst of Example 11.2 was prepared similarly to the catalyst of Example 1, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 50 wt% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.22 g / in3 of chabazite, 0.122 g / in3 of alumina+silica, 0.61 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 2:1.

[0128] The catalyst of Example 11.3 was prepared similarly to the catalyst of Example 1, except that the amount of zirconium acetate was increased in the process so that the amount of zirconia in the coating, calculated as ZrO2, was 80 wt% based on the weight of chabazite. The final coating loading after calcination was about 2 g / in3, which contained about 1.09 g / in3 of chabazite, 0.109 g / in3 of alumina+silica, 0.872 g / in3 of zirconia, and 4.15 wt% Cu, calculated as Cu, based on the weight of chabazite. The weight ratio of zeolite material to zirconia in the coating is 1.25:1.

[0129] [Table 6] * Based on weight of chabazite -Testing the catalytic performance of the prepared catalyst: Backpressure measurements were performed under laboratory conditions using fresh (unaged) catalysts of Examples 11.1, 11.2, and 11.3. The results are shown in Figure 17(a). For the analysis of DeNOx activity, the catalysts of Examples 11.1, 11.2, and 11.3 were oven aged for 16 hours at 850°C with 20% O2 and 2.42 mL / min H2O at a flow rate of 25 L (see Figures 15 and 16). Backpressure was also measured under fresh conditions with the catalysts (see Figure 17(b)). For evaluation, engine bench tests at steady state conditions were performed. As can be seen from Figures 15-17, the backpressure measured for the catalysts of Examples 11.1, 11.2, and 11.3 is reduced compared to the catalyst of Reference Example 4', and the catalysts of Examples 11.1, 11.2, and 11.3 show high NOx conversion. [Brief description of the drawings]

[0130] [Figure 1] 1 shows the NOx conversion maxima obtained at different temperatures for the aged catalysts of Comparative Examples 1, 2, and Example 1 (a), and the NOx conversion at 20 ppm ammonia slip (b). [Diagram 2] 4 shows the NH3 storage capacity (a) and back pressure (b) obtained at different temperatures for the aged catalysts of Comparative Examples 1, 2, and Example 1. [Diagram 3] 1 shows the back pressure at soot loadings in the range of 0 to 2 g / L obtained using the fresh catalysts of Reference Example 1 and Example 1. [Figure 4] 1 shows the cold flow backpressure obtained using fresh catalysts of Comparative Example 6, and Examples 3 and 4, as well as the backpressure with soot loadings of 2, 4, and 6 g / L. [Diagram 5] 1 shows the NOx conversion maxima obtained at different temperatures for the aged catalysts of Comparative Example 6, and Examples 3 and 4 (a), and the NOx conversion at 20 ppm ammonia slip (b). [Figure 6] 1 shows the NOx conversion maxima obtained at different temperatures for the aged catalysts (aged three times) of Comparative Example 6, and Examples 3 and 4 (a), and the NOx conversion at 20 ppm ammonia slip (b). [Figure 7] NH3 storage capacities obtained for aged catalysts (aged three times) of Reference Example 6, and Examples 3 and 4 are shown. [Figure 8] 1 shows the NOx conversion (max) obtained for the aged catalysts of Comparative Example 7A, and Examples 6A, 6B, and 8B at different temperatures. [Figure 9] 1 shows the NOx conversion at 20 ppm ammonia slip achieved at different temperatures for the aged catalysts of Comparative Example 7A, and Examples 6A, 6B, and 8B. [Figure 10] 1 shows SEM images (a) and (b) of the catalyst of Reference Example 4. [Figure 11] 1 shows SEM images (a) and (b) of the catalyst of Example 6A. [Figure 12] 1 shows the backpressure measured for fresh catalysts of Reference Example 4', Examples 10.1, 10.2, and 10.3. [Figure 13]1 shows the NOx conversion maxima obtained at different temperatures (a) and NOx conversion at 20 ppm ammonia slip (b) for the aged catalysts of Comparative Example 4, and Examples 10.1, 10.2, and 10.3. [Figure 14] NH3 storage capacities obtained for aged catalysts of Reference Example 4, and Examples 10.1, 10.2, and 10.3 are shown. [Figure 15] Figure 1 shows the maximum NOx conversion obtained for the aged catalysts of Examples 11.1, 11.2, and 11.3 (a), and the NOx conversion at 20 ppm ammonia slip (b). [Figure 16] Figure 1 shows the NH3 storage capacities obtained for the aged catalysts of Examples 11.1, 11.2, and 11.3. [Figure 17] 1 shows the backpressure measured for Comparative Example 4', the fresh catalysts of Examples 11.1, 11.2, and 11.3 (a), and the aged catalysts of Examples 11.1, 11.2, and 11.3 (b).

[0131] References - International Publication No. 2020 / 040944(A1) -UK Patent No. 2528737(B) - International Publication No. 2020 / 088531(A1)

Claims

1. A catalyst for selective catalytic reduction of NOx, comprising: a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by interior walls of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; the porous walls of the substrate include a coating, the coating including a zeolitic material, copper, and a first non-zeolitic oxide material including zirconium; the coating comprises the zeolitic material at a loading L(z) in g / in 3 and the first non-zeolitic oxide material at a loading L1 in g / in 3 , wherein the loading ratio L(z) (g / in 3 ):L1 (g / in 3 ) is at most 10:1; and 90-100 wt. % of the first non-zeolitic oxide material is ZrO ２ A catalyst comprising zirconium calculated as

2. 95 to 100 wt. %, preferably 98 to 100 wt. %, more preferably 99 to 100 wt. % of the framework structure of the zeolite material contained in the coating is composed of Si, Al and O, and in the framework structure, the molar SiO ２ :Al ２ O ３ 2. The catalyst of claim 1, wherein the molar ratio of Si to Al, calculated as: is preferably in the range of from 2:1 to 30:1, more preferably in the range of from 5:1 to 25:1, more preferably in the range of from 7:1 to 22:1, more preferably in the range of from 8:1 to 20:1, more preferably in the range of from 9:1 to 18:1, more preferably in the range of from 10:1 to 17:1, more preferably in the range of from 12:1 to 16:

1.

3. 3. The catalyst according to claim 1 or 2, wherein the amount of copper contained in the coating, calculated as CuO, is in the range of 2 to 10 wt.%, preferably in the range of 2.5 to 5.5 wt.%, more preferably in the range of 3 to 5 wt.%, based on the weight of the zeolitic material.

4. 95 to 100 wt. %, preferably 98 to 100 wt. %, more preferably 99 to 100 wt. %, more preferably 99.5 to 100 wt. % of the first non-zeolitic oxide material in the coating is ZrO ２ 3. The catalyst of claim 1, wherein the zirconium is calculated as:

5. 3. A catalyst according to claim 1 or 2, wherein the coating comprises the zeolitic material at a loading L(z) in g / in 3 and the first non-zeolitic oxide material, preferably zirconia, at a loading L1 in g / in 3 , wherein the loading ratio L(z) (g / in 3 ):L1 (g / in 3 ) is in the range of 10:1 to 1.1:1, preferably in the range of 9:1 to 1.25:1, more preferably in the range of 8:1 to 2:1, more preferably in the range of 7.5:1 to 2.5:1, more preferably in the range of 7:1 to 3.5:1, more preferably in the range of 5.5:1 to 4:

1.

6. the coating further comprises a second non-zeolitic oxide material, the second non-zeolitic oxide material being selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti, and Ce, and mixtures of two or more thereof, preferably selected from the group consisting of alumina, silica, and titania, mixed oxides comprising one or more of Al, Si, and Ti, and mixtures of two or more thereof, more preferably selected from the group consisting of mixed oxides comprising one or more of alumina, silica, Al, and Si, and mixtures of two or more thereof, more preferably a mixture of alumina and silica; 3. A catalyst according to claim 1 or 2, wherein preferably 80 to 99 wt.%, more preferably 85 to 98 wt.%, more preferably 90 to 98 wt.% of said mixture of alumina and silica consists of alumina, and 1 to 20 wt.%, preferably 2 to 15 wt.%, more preferably 2 to 10 wt.% of said mixture of alumina and silica consists of silica.

7. 7. The catalyst of claim 6, wherein the coating comprises the second non-zeolitic oxide material in an amount in the range of 2 to 20 wt.%, preferably in the range of 5 to 15 wt.%, more preferably in the range of 7 to 13 wt.%, based on the weight of the zeolitic material.

8. 3. The catalyst according to claim 1 or 2, wherein 90 to 100 wt. %, preferably 95 to 100 wt. %, more preferably 98 to 100 wt. % of said coating is contained on said porous walls of said substrate.

9. 3. The catalyst of claim 1 or 2, wherein the substrate is one or more of a cordierite wall-flow filter substrate, a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate, preferably one or more of a silicon carbide wall-flow filter substrate and an aluminum titanate wall-flow filter substrate.

10. A process for preparing a catalyst for the selective catalytic reduction of NOx, preferably a catalyst according to claim 1 or 2, comprising: (i') preparing a first aqueous mixture comprising water, a copper source, and a precursor of a first non-zeolitic oxide component comprising zirconium; (ii') mixing a copper-free zeolitic material with the first mixture obtained according to (i') to obtain a second aqueous mixture, wherein the amount of the precursor of the first non-zeolitic oxide component, calculated as oxide, in the second aqueous mixture is at least 10 wt. % based on the weight of the zeolitic material; (iii') disposing the second aqueous mixture onto a wall-flow filter substrate including an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by interior walls of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and optionally drying the substrate containing the mixture; (iv') calcining the substrate obtained in (iii').

11. 11. The process of claim 10, wherein the precursor of the first non-zeolitic oxide component contained in the first aqueous mixture prepared in (i') is a zirconium salt or zirconium oxide, preferably a zirconium salt, more preferably zirconium acetate.

12. (i'.1) preparing a mixture comprising water and said copper source, preferably said mixture further comprising an acid, more preferably an organic acid, more preferably acetic acid, more preferably said mixture comprising sucrose, more preferably wherein the weight ratio of copper, calculated as CuO, to sucrose is in the range of 2:1 to 1:2, more preferably in the range of 1.5:1 to 1:1.5, more preferably in the range of 1.2:1 to 1:1.2; (i'.2) adding said precursor of said first non-zeolitic oxide component to the mixture obtained according to (i'.1) to obtain said first aqueous mixture; The process of claim 10, comprising:

13. 13. The process of claim 12, wherein 90 to 100 wt.-%, preferably 93 to 99 wt.-%, more preferably 96 to 99 wt.-% of the copper source is present in undissolved state in the mixture prepared in (i'.1), and wherein the copper particles in the mixture according to (i'.1) have a Dv90 in the range of 0.1 to 15 micrometers, preferably in the range of 0.5 to 10 micrometers, more preferably in the range of 1 to 8 micrometers, more preferably in the range of 3 to 7 micrometers.

14. (ii') is (ii'.1) mixing a preferably Cu-free zeolitic material with said first aqueous mixture obtained according to (i'); (ii'.2) preferably milling said obtained mixture (ii'.1), more preferably until the particles of said mixture have a Dv90 in the range of 0.5 to 8 micrometers, more preferably in the range of 1 to 5 micrometers, more preferably in the range of 1.5 to 4 micrometers; (ii'.3) mixing the second mixture obtained in (ii'.1), preferably in (ii'.2), with a second non-zeolitic oxide material selected from the group consisting of alumina, silica, titania, ceria, mixed oxides comprising one or more of Al, Si, Ti, and Ce, and mixtures of two or more thereof, to obtain a second aqueous mixture; The process of claim 10, comprising:

15. (iii') (iii'.1) disposing a first portion of the second aqueous mixture obtained in (ii') onto a wall-flow filter substrate comprising an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end, and a plurality of passages defined by interior walls of the substrate extending through the substrate, the plurality of passages including an inlet passage having an open inlet end and a closed outlet end, and an outlet passage having a closed inlet end and an open outlet end; and drying the substrate containing the first portion of the second aqueous mixture. (iii'.2) disposing a second portion of the second aqueous mixture obtained in (ii') onto the substrate comprising the first portion of the third aqueous mixture obtained in (iii'.1), and optionally drying the substrate comprising the first and second portions of the second aqueous mixture; The process of claim 10, comprising:

16. 10. An exhaust gas treatment system for treating exhaust gases from a compression ignition engine, the exhaust gas treatment system having an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, the exhaust gas treatment system comprising the catalyst of claim 1 or 2 and one or more of a diesel oxidation catalyst, a selective catalytic reduction catalyst, an ammonia oxidation catalyst, a NOx trap, and a particulate filter; The system preferably comprises a catalyst according to claim 1 or 2, a diesel oxidation catalyst and a selective catalytic reduction catalyst, The diesel oxidation catalyst is more preferably located upstream of the selective catalytic reduction catalyst, which is located upstream of the catalyst according to claim 1 or 2; or 3. An exhaust gas treatment system, wherein the diesel oxidation catalyst is more preferably located upstream of the catalyst according to claim 1 or 2, which in turn is located upstream of the selective catalytic reduction catalyst.

17. 3. Use of the catalyst according to claim 1 or 2 for the selective catalytic reduction of NOx.

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