Ammonia oxidation catalyst with twc function for gasoline applications

Abstract

This invention relates to an exhaust gas treatment system for treating exhaust gas streams exiting a gasoline engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas streams into the exhaust gas treatment system, and wherein the exhaust gas treatment system comprises: (i) a first catalyst, which is a three-way conversion catalyst having an inlet end and an outlet end and comprising a coating disposed on a substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh, and mixtures of two or more thereof, supported on a carrier material; (ii) a second catalyst, which is a four-way conversion catalyst having an inlet end and an outlet end and comprising a coating disposed on a wall-flow filter substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh, and mixtures of two or more thereof, supported on a carrier material; or a gasoline particulate filter having an inlet end and an outlet end; (iii) a third catalyst having an inlet end and an outlet end, wherein the third catalyst comprises materials for ammonia oxidation (AMOx) and nitrogen oxidation. Substrates and coatings for chemical reduction, carbon monoxide oxidation, and hydrocarbon oxidation (TWC), wherein the coating of the third catalyst comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh, and mixtures of two or more of them, supported on a carrier material; wherein the coating of the third catalyst comprises one or more zeolite materials; and wherein the coating of the third catalyst comprises rhodium and / or an oxygen storage compound; wherein the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system, and wherein the inlet end of the first catalyst is arranged upstream of the outlet end of the first catalyst; wherein in the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and wherein the inlet end of the second catalyst is arranged upstream of the outlet end of the second catalyst; wherein in the exhaust gas treatment system, the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and wherein the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst.

Description

Technical Field

[0001] The present invention relates to an exhaust gas treatment system for treating exhaust gas streams leaving a gasoline engine and a method for treating exhaust gas streams leaving a gasoline engine using the exhaust gas treatment system. Background Technology

[0002] Emissions regulations for exhaust gases from mobile gasoline applications have become increasingly stringent in the past and may become even more stringent in the future. Therefore, more efficient exhaust treatment systems for automobiles will be needed in the coming years. Effective methods for removing major pollutants, including nitrogen oxides (NOx), unburned hydrocarbons (HC), carbon monoxide (CO), and particulate matter, from gasoline engines have been developed and commercialized in the past based on so-called three-way conversion catalysts (TWC) or four-way conversion catalysts (FWC).

[0003] However, future emissions regulations may also impose stricter restrictions on secondary emissions from exhaust gases. For example, stricter European emissions standards such as EURO 7 or comparable US regulations may impose restrictions on tailpipe emissions of ammonia (NH3), hydrocarbons (HC), and carbon monoxide (CO), substances that have been shown to have harmful effects on humans, ecosystems, and vegetation. Therefore, there is a need for improved exhaust gas treatment systems that allow for reductions in tailpipe emissions of ammonia (NH3), hydrocarbons (HC), and carbon monoxide (CO).

[0004] EP 3974059 A1 relates to a method for preparing a catalyst for ammonia oxidation, characterized by the following steps: grinding platinum black containing primary particles with a particle size of 2 nm to 7 nm into agglomerates of 30 nm to 150 nm, and then mixing it with a support material; or mixing platinum black containing primary particles with a particle size of 2 nm to 7 nm with a support material and grinding the mixture into platinum black agglomerates of 30 nm to 150 nm; and coating the mixture onto a support substrate.

[0005] EP 3310461 A1 relates to a catalyst article having an ammonia leakage catalyst (ASC) comprising a blend of platinum and a first SCR catalyst on a support having low ammonia storage, and a second catalyst (such as a diesel oxidation catalyst, a diesel exothermic catalyst (DEC)), a NOx absorbent, a selective catalytic reduction / passive NOx adsorbent (SCR / PNA), a cold start catalyst (CSC), or a three-way catalyst (TWC). Detailed Implementation

[0006] Therefore, the object of the present invention is to provide an improved exhaust gas treatment system for treating exhaust gas leaving a gasoline engine, which allows for reduced tailpipe emissions of ammonia (NH3), hydrocarbons (HC), and / or carbon monoxide (CO) compared to systems according to the prior art (e.g., EURO 6 or other systems). In addition to improved ammonia tailpipe emissions, the system of the present invention has been found to significantly contribute to the reduction of HC and CO emissions.

[0007] Therefore, the present invention relates to an exhaust gas treatment system for treating exhaust gas streams exiting a gasoline engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas streams into the exhaust gas treatment system, and wherein the exhaust gas treatment system includes...

[0008] (i) A first catalyst, which is a three-way conversion catalyst having an inlet end and an outlet end and comprising a coating disposed on a substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more thereof, supported on a support material.

[0009] (ii) A second catalyst, which is a four-way conversion catalyst having an inlet end and an outlet end and comprising a coating disposed on a wall-flow filter substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more thereof, supported on a carrier material; or a gasoline particulate filter having an inlet end and an outlet end.

[0010] (iii) A third catalyst having an inlet end and an outlet end, wherein the third catalyst comprises a substrate and a coating for ammonia oxidation (AMOx) and for nitrogen oxide reduction, carbon monoxide oxidation and hydrocarbon oxidation (TWC), wherein the coating of the third catalyst comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more of them supported on a support material, wherein the coating of the third catalyst comprises one or more zeolite materials, and wherein the coating of the third catalyst comprises rhodium and / or an oxygen storage compound;

[0011] Wherein the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system, and wherein the inlet end of the first catalyst is arranged upstream of the outlet end of the first catalyst.

[0012] In the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and the inlet end of the second catalyst is arranged upstream of the outlet end of the second catalyst.

[0013] In the exhaust gas treatment system, the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst.

[0014] Preferably, the outlet end of the first catalyst according to (i) is in fluid communication with the inlet end of the second catalyst according to (ii), and wherein there is no catalyst for treating the waste gas stream leaving the first catalyst located in the waste gas treatment system between the outlet end of the first catalyst according to (i) and the inlet end of the second catalyst according to (ii).

[0015] Preferably, the outlet end of the second catalyst according to (ii) is in fluid communication with the inlet end of the third catalyst according to (iii), and wherein there is no catalyst for treating the waste gas stream leaving the second catalyst located in the waste gas treatment system between the outlet end of the second catalyst according to (ii) and the inlet end of the third catalyst according to (iii).

[0016] Preferably, one or more platinum group metals in the coating of the first catalyst are selected from the group consisting of Pd, Rh, and mixtures thereof, and preferably wherein one or more platinum group metals in the coating of the first catalyst are Pd and Rh.

[0017] Preferably, the coating of the first catalyst comprises a loading of at least 1 g / ft of platinum group metals. 3 Up to 300g / ft 3 Within the range, preferably within 10 g / ft 3 Up to 290g / ft 3 More preferably within the range of 30g / ft 3 Up to 270g / ft 3 More preferably within the range of 50g / ft 3 Up to 260g / ft 3 More preferably within the range of 60 g / ft 3 Up to 250g / ft 3 One or more platinum group metals within the range.

[0018] Preferably, the support material of the platinum group metal component of the coating supporting the first catalyst is selected from the group consisting of alumina, cerium dioxide, silicon dioxide, zirconium oxide, titanium dioxide, mixtures of two or more thereof, and mixed oxides of two or more thereof. More preferably, it is selected from the group consisting of alumina, titanium dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof. More preferably, it is selected from the group consisting of alumina, zirconium oxide, mixtures of two thereof, and mixed oxides of two thereof. More preferably, it is alumina.

[0019] Preferably, the coating of the first catalyst further comprises an oxygen storage compound, which preferably comprises cerium, more preferably one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium. The mixed oxide comprising cerium more preferably further comprises one or more of zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of zirconium, yttrium, neodymium, lanthanum, and praseodymium, more preferably zirconium. When the first catalyst further comprises an oxygen storage agent, preferably, the coating of the first catalyst comprises an oxygen storage agent with a loading of 0.1 g / in. 3 Up to 10g / in 3 Within the range, preferably within 0.5 g / in 3 Up to 5g / in 3 More preferably within the range of 1.0 g / in 3 Up to 3g / in 3 Within the range, more preferably within 1.3 g / in 3 Up to 2.7g / in 3 More preferably, the oxygen storage compound is in the range of 1.5 g / in³ to 2.5 g / in³. Even further, preferably, in the coating of the first catalyst, the weight ratio of the support material to the oxygen storage compound is 0.1 g / in³. 3 Up to 5g / in 3 Within the range, preferably within 0.3 g / in 3 Up to 3g / in 3 More preferably within the range of 0.5 g / in 3 Up to 2g / in 3 More preferably within the range of 0.7 g / in 3 Up to 1.7g / in 3 More preferably within the range of 0.8 g / in 3 Up to 1.5g / in 3 Within the range.

[0020] Preferably, the coating of the first catalyst further comprises a non-zeolite oxide material, more preferably comprising one or more of zirconium oxide, alumina, cerium dioxide, titanium dioxide, and silicon dioxide, and a mixed oxide comprising two or more of Zr, Al, Ce, Ti, and Si, more preferably comprising one or more of zirconium oxide, alumina, cerium dioxide, and silicon dioxide, and more preferably comprising zirconium oxide. Further, preferably, based on the weight of the coating of the first catalyst, the coating of the first catalyst comprises a non-zeolite oxide material in an amount ranging from 95% to 100% by weight, preferably from 96% to 99.5% by weight, and more preferably from 97% to 99% by weight, calculated as an oxide.

[0021] Preferably, the coating of the first catalyst further comprises a NOx storage component, preferably wherein the NOx storage component comprises one or more of an oxide of an alkaline earth metal and an oxide of an alkali metal, more preferably wherein the NOx storage component comprises an oxide selected from the group consisting of Mg, Ca, Sr, Ba, Li, Na, K, Rb, and Cs, more preferably an oxide selected from the group consisting of Mg, Ca, Sr, and Ba, and more preferably wherein the NOx storage component comprises barium oxide, preferably composed of barium oxide. Further, preferably, based on the weight of the coating of the first catalyst, the coating of the first catalyst contains a NOx storage component in an amount ranging from 0.1 wt% to 15 wt%, preferably from 0.5 wt% to 15 wt%, and more preferably from 1 wt% to 10 wt%.

[0022] Preferably, 98% to 100% by weight, more preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the coating of the first catalyst are composed of one or more platinum group metals supported on a carrier material, preferably oxygen storage compounds as defined above, more preferably non-zeolite oxidizing materials as defined above, and even more preferably NOx storage components as defined above.

[0023] Preferably, the substrate of the first catalyst is a flow-through substrate, and more preferably a ceramic flow-through substrate.

[0024] Preferably, the first catalyst consists of a substrate and a coating.

[0025] Preferably, the coating of the second catalyst comprises one or more platinum group metals selected from the group consisting of Pd, Rh and mixtures thereof, and preferably wherein the one or more platinum group metals are Pd and Rh.

[0026] Preferably, the coating of the second catalyst contains a platinum group metal loading of 0.1 g / ft. 3 Up to 100g / ft 3 Within the range, preferably within 1 g / ft 3 Up to 80g / ft 3 More preferably within the range of 5g / ft 3 Up to 50g / ft 3 More preferably, one or more platinum group metals in the range of 10 g / ft³ to 30 g / ft³.

[0027] Preferably, the support material of the platinum group metal component of the coating supporting the second catalyst is selected from the group consisting of alumina, cerium dioxide, silicon dioxide, zirconium oxide, titanium dioxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, more preferably from the group consisting of alumina, titanium dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, more preferably from the group consisting of alumina, zirconium oxide, mixtures of two thereof, and mixed oxides of two thereof, and even more preferably alumina.

[0028] Preferably, the coating of the second catalyst further comprises an oxygen storage compound (OSC), which preferably comprises cerium, more preferably cerium oxide, a mixture of oxides including cerium oxide, and a mixed oxide containing cerium, wherein the mixed oxide containing cerium more preferably also comprises one or more of zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably zirconium, yttrium, neodymium, lanthanum, and praseodymium, and more preferably zirconium. Where the coating of the second catalyst further comprises an oxygen storage compound (OSC), preferably, the coating of the second catalyst comprises an OSC with a loading of 0.1 g / in. 3 Up to 5g / in 3 Within the range, preferably within 0.1 g / in 3 Up to 2g / in 3 More preferably within the range of 0.2 g / in 3 Up to 1.5g / in 3 More preferably within the range of 0.3 g / in 3 The oxygen storage compound is in the range of 1 g / in³. Further, preferably, in the coating of the second catalyst, the weight ratio of the support material to the oxygen storage compound is 0.1 g / in³. 3 Up to 5g / in 3 Within the range, preferably within 0.2 g / in 3 Up to 3g / in 3 More preferably within the range of 0.25 g / in 3 Up to 2g / in 3 More preferably within the range of 0.3 g / in 3 Up to 1g / in 3 Within the range.

[0029] Preferably, the coating of the second catalyst further comprises a non-zeolite oxide material, which preferably comprises one or more of zirconium oxide, alumina, cerium dioxide, titanium dioxide, and silicon dioxide, and a mixed oxide comprising two or more of Zr, Al, Ce, Ti, and Si, more preferably comprising one or more of zirconium oxide, alumina, cerium dioxide, and silicon dioxide, and even more preferably comprising zirconium oxide; wherein, based on the weight of the coating of the first catalyst, the coating of the second catalyst preferably comprises a non-zeolite oxide material in an amount calculated as an oxide ranging from 10 wt% to 70 wt%, preferably from 20 wt% to 60 wt%, more preferably from 30 wt% to 50 wt%, and even more preferably from 35 wt% to 45 wt%.

[0030] Preferably, the coating of the second catalyst further comprises an oxide of an alkaline earth metal, preferably selected from the group consisting of barium, strontium, and magnesium, more preferably selected from the group consisting of barium and strontium, and even more preferably barium. Further, preferably, based on the weight of the coating of the second catalyst, the coating of the second catalyst contains an amount of alkaline earth metal oxide ranging from 0.1 wt% to 20 wt%, preferably from 1 wt% to 15 wt%, and more preferably from 5 wt% to 10 wt%.

[0031] Preferably, 98% to 100% by weight, more preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the coating of the second catalyst are composed of one or more platinum group metals supported on a carrier material, preferably oxygen storage compounds as defined above, more preferably non-zeolite oxidizing materials as defined above, and even more preferably alkaline earth metal oxides as defined above.

[0032] Preferably, the substrate of the second catalyst is a honeycomb wall flow filter substrate.

[0033] Preferably, the substrate of the second catalyst is a ceramic substrate, wherein the ceramic substrate preferably comprises cordierite, cordierite-α-alumina, aluminum titanate, silicon carbide, silicon nitride, zircon-mullite, spodumene, alumina-silica-magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, selenite, α-alumina, or aluminum silicate, and more preferably is composed of them.

[0034] Preferably, the second catalyst consists of a substrate and a coating.

[0035] When the exhaust system includes a gasoline particulate filter, the gasoline particulate filter is preferably a wall-flow filter, more preferably a honeycomb wall-flow filter. Further, preferably, the wall-flow filter is a ceramic wall-flow filter, wherein the ceramic wall-flow filter comprises cordierite, cordierite-α-alumina, aluminum titanate, silicon carbide, silicon nitride, zirconium mullite, spodumene, alumina-silica-magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, selenite, α-alumina, or aluminum silicate, preferably composed of these.

[0036] Preferably, one or more platinum group metals in the coating of the third catalyst are selected from the group consisting of Pt, Rh, and mixtures thereof, and preferably one or more platinum group metals in the AMOx coating of the third catalyst are Rh.

[0037] Alternatively, preferably the third catalyst is substantially free of palladium, and preferably wherein the third catalyst contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less palladium, more preferably wherein the third catalyst does not contain palladium.

[0038] As a second alternative, preferably, the coating of the third catalyst is substantially free of palladium, and preferably wherein the catalytic coating of the third catalyst contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less palladium, more preferably wherein the catalytic coating of the third catalyst is palladium-free.

[0039] Preferably, the loading of the third catalyst coating is 0.1 g / in. 3 Up to 20g / in 3 Within the range, preferably within 1 g / in 3 Up to 15g / in 3 More preferably within the range of 2.1 g / in 3 Up to 10g / in 3 More preferably within the range of 2.15 g / in 3 Up to 9.5g / in 3 More preferably within the range of 2.2 g / in 3 Up to 9g / in 3 More preferably, within the range of 2.25 g / in 3 Up to 8.5g / in 3 Within the range, more preferably within 2.3 g / in 3 Up to 8g / in 3More preferably within the range of 2.35 g / in 3 Up to 7.5g / in 3 More preferably within the range of 2.4 g / in 3 Up to 7g / in 3 More preferably within the range of 2.45 g / in 3 Up to 6g / in 3 More preferably within the range of 2.5 g / in 3 Up to 5g / in 3 More preferably within the range of 3.0 g / in 3 Up to 4.5g / in 3 Within the range.

[0040] Preferably, the support material for the coating of the third catalyst is selected from the group consisting of titanium dioxide, alumina, cerium dioxide, silicon dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, preferably from the group consisting of titanium dioxide, alumina, and silicon dioxide, and more preferably alumina. Further, preferably, the coating content of the third catalyst is 0.1 g / in. 3 Up to 5g / in 3 Within the range, preferably within 0.4 g / in 3 Up to 3g / in 3 More preferably within the range of 0.6 g / in 3 Up to 2g / in 3 More preferably within the range of 0.8 g / in 3 Up to 1.6g / in 3 More preferably within the range of 0.85 g / in 3 Carrier materials in the range of up to 1.5 g / in³.

[0041] Preferably, the coating of the third catalyst comprises an oxygen storage compound, preferably wherein the oxygen storage compound preferably comprises cerium, more preferably comprises one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium, wherein the mixed oxide comprising cerium more preferably also comprises one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, and praseodymium, more preferably aluminum. Further, preferably, based on the total weight of the oxygen storage compound in the coating of the third catalyst, the cerium content of the oxygen storage compound in the coating of the third catalyst is in the range of 5% by weight to 81.46% by weight, preferably 10% by weight to 80% by weight, more preferably 20% by weight to 75% by weight, more preferably 30% by weight to 70% by weight, more preferably 40% by weight to 60% by weight, more preferably 45% by weight to 55% by weight.

[0042] Within the meaning of this invention, the term "rare earth metals" refers to Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0043] Preferably, the support material of the coating of the third catalyst comprises one or more rare earth metals, wherein the one or more rare earth metals are selected from the group consisting of Sc, Y, La, Ce, Pr, Nd and mixtures of two or more thereof, preferably from the group consisting of La, Ce and mixtures thereof, and more preferably wherein the one or more rare earth metals is La.

[0044] In cases where the carrier material of the coating of the third catalyst contains one or more rare earth metals, preferably, based on the total weight of the carrier material of the coating of the third catalyst, the content of one or more rare earth metals in the carrier material of the coating of the third catalyst is in the range of 0.1 wt% to 80 wt%, preferably 0.5 wt% to 70 wt%, more preferably 1 wt% to 60 wt%, more preferably 3 wt% to 50 wt%, more preferably 5 wt% to 40 wt%, more preferably 10 wt% to 30 wt%, and more preferably 15 wt% to 25 wt%.

[0045] Alternatively, preferably, the one or more rare earth metals is lanthanum, and wherein the lanthanum content of the support material for the coating of the third catalyst is in the range of 0.1 wt% to 30 wt%, preferably 0.5 wt% to 20 wt%, more preferably 1 wt% to 15 wt%, more preferably 1.5 wt% to 10 wt%, more preferably 2 wt% to 8 wt%, more preferably 2.5 wt% to 6 wt%, more preferably 3 wt% to 5 wt%, and more preferably 3.5 wt% to 4.5 wt%.

[0046] As a second alternative, preferably, the one or more rare earth metals is cerium, and wherein the cerium content of the carrier material of the coating of the third catalyst is in the range of 1% to 80% by weight, preferably 5% to 70% by weight, more preferably 10% to 60% by weight, more preferably 20% to 50% by weight, and more preferably 30% to 40% by weight, based on the total weight of the carrier material of the coating of the third catalyst.

[0047] Preferably, the coating of the third catalyst includes one or more zeolite materials comprising one or more of Fe and Cu, preferably wherein the one or more zeolite materials comprise Fe. Where the coating of the third catalyst includes one or more zeolite materials comprising one or more of Fe and Cu, preferably, the coating of the third catalyst includes one or more zeolite materials that are 12-membered ring-porous zeolite materials, wherein the 12-membered ring-porous zeolite material preferably has a framework type selected from the group consisting of BEA, MOR, FAU, GME, OFF, mixtures of two or more of them, and mixtures of two or more of them, more preferably selected from the group consisting of BEA and FAU, and more preferably, the 12-membered ring-porous zeolite material included in the coating of the third catalyst has a framework type of BEA. Furthermore, preferably, 95% to 100% by weight, more preferably 98% to 100% by weight, more preferably 99% to 100% by weight, and more preferably 99.5% to 100% by weight of the 12-membered ring porous zeolite material framework structure included in the coating of the third catalyst is composed of Si, Al and O, wherein in the framework structure, the molar ratio of Si to Al calculated as molar SiO2:Al2O3 is more preferably in the range of 2:1 to 40:1, more preferably in the range of 3:1 to 30:1, more preferably in the range of 4:1 to 20:1, and more preferably in the range of 6:1 to 15:1.

[0048] Preferably, the coating of the third catalyst extends more than 98% to 100% of the axial length of the substrate, more preferably more than 99% to 100%, and even more preferably more than 99.5% to 100%.

[0049] Preferably, the substrate of the third catalyst is a ceramic wall-flow filter substrate.

[0050] Within the meaning of this invention, the term "alkaline earth metals" refers to the elements Mg, Ca, Sr, and Ba, and the term "alkali metals" refers to the elements Li, Na, K, Rb, Cs, and Fr.

[0051] Preferably, the coating of the third catalyst is substantially free of alkaline earth metal oxides and alkali metal oxides, wherein preferably the coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or fewer alkaline earth metal oxides and alkali metal oxides, more preferably wherein the coating of the third catalyst is free of alkaline earth metal oxides and alkali metal oxides.

[0052] Preferably, the coating of the third catalyst is substantially barium-free, wherein preferably the coating of the third catalyst contains 0.1 g / ft. 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less barium, more preferably wherein the coating of the third catalyst is barium-free.

[0053] Preferably, the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, the first catalytic coating comprising one or more platinum group metals supported on a support material, the second catalytic coating comprising one or more zeolite materials, wherein the first catalytic coating comprises rhodium and / or an oxygen storage compound.

[0054] In cases where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the first catalytic coating contains one or more platinum group metals selected from the group consisting of Pt, Rh, and mixtures thereof, more preferably, the first catalytic coating contains one or more platinum group metals that are Rh.

[0055] Furthermore, preferably, the first catalytic coating is substantially free of palladium, and preferably wherein the first catalytic coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less palladium, more preferably wherein the first catalytic coating is palladium-free.

[0056] Furthermore, preferably, the loading of the first catalytic coating is 0.1 g / in. 3 Up to 20g / in 3 Within the range, preferably within 1 g / in 3 Up to 15g / in 3 More preferably within the range of 2.1 g / in 3 Up to 10g / in 3 More preferably within the range of 2.15 g / in 3 Up to 9.5g / in 3 More preferably within the range of 2.2 g / in 3 Up to 9g / in 3 More preferably, within the range of 2.25 g / in 3 Up to 8.5g / in 3 Within the range, more preferably within 2.3 g / in 3 Up to 8g / in 3 More preferably within the range of 2.35 g / in 3 Up to 7.5g / in3 More preferably within the range of 2.4 g / in 3 Up to 7g / in 3 More preferably within the range of 2.45 g / in 3 Up to 6g / in 3 More preferably within the range of 2.5 g / in 3 Up to 5g / in 3 More preferably within the range of 3.0 g / in 3 Up to 4.5g / in 3 Within the range.

[0057] Furthermore, preferably, the carrier material of the first catalytic coating is selected from the group consisting of titanium dioxide, alumina, cerium dioxide, silicon dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, preferably from the group consisting of titanium dioxide, alumina and silicon dioxide, and more preferably alumina.

[0058] Furthermore, preferably, the first catalytic coating contains 0.1 g / in 3 Up to 5g / in 3 Within the range, preferably within 1 g / in 3 Up to 3g / in 3 Within the range, more preferably within 1.3 g / in 3 Up to 2.7g / in 3 Within the range, more preferably within 1.5 g / in 3 Carrier materials in the range of up to 2.5 g / in³.

[0059] Furthermore, preferably, the first catalytic coating of the third catalyst comprises an oxygen storage compound, preferably wherein the oxygen storage compound preferably comprises cerium, more preferably comprises one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium, wherein the mixed oxide comprising cerium more preferably also comprises one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, and praseodymium, and more preferably aluminum.

[0060] When the oxygen storage compound contains cerium, preferably, based on the total weight of the oxygen storage compound in the coating of the third catalyst, the cerium content of the oxygen storage compound in the coating of the third catalyst is in the range of 5% to 81.46% by weight, preferably 10% to 80% by weight, more preferably 20% to 75% by weight, more preferably 30% to 70% by weight, more preferably 40% to 60% by weight, and more preferably 45% to 55% by weight.

[0061] In the case where the coating of the third catalyst includes the first catalytic coating and the second catalytic coating, preferably, the support material of the first catalytic coating of the third catalyst comprises one or more rare earth metals, wherein the one or more rare earth metals are selected from the group consisting of Sc, Y, La, Ce, Pr, Nd and mixtures of two or more thereof, preferably selected from the group consisting of La, Ce and mixtures thereof, and more preferably wherein the one or more rare earth metals is La.

[0062] In cases where the support material of the first catalytic coating of the third catalyst contains one or more rare earth metals, preferably, based on the total weight of the support material of the first catalytic coating of the third catalyst, the content of one or more rare earth metals in the support material of the first catalytic coating is in the range of 0.1 wt% to 80 wt%, preferably 0.5 wt% to 70 wt%, more preferably 1 wt% to 60 wt%, more preferably 3 wt% to 50 wt%, more preferably 5 wt% to 40 wt%, more preferably 10 wt% to 30 wt%, and more preferably 15 wt% to 25 wt%.

[0063] Alternatively, preferably, the one or more rare earth metals is lanthanum, and wherein the lanthanum content of the support material of the first catalytic coating based on the total weight of the third catalyst is in the range of 0.1 wt% to 30 wt%, preferably 0.5 wt% to 20 wt%, more preferably 1 wt% to 15 wt%, more preferably 1.5 wt% to 10 wt%, more preferably 2 wt% to 8 wt%, more preferably 2.5 wt% to 6 wt%, more preferably 3 wt% to 5 wt%, more preferably 3.5 wt% to 4.5 wt%.

[0064] As a second alternative, preferably, the one or more rare earth metals are cerium, and wherein the cerium content of the support material of the first catalytic coating based on the third catalyst is in the range of 1% to 80% by weight, preferably 5% to 70% by weight, more preferably 10% to 60% by weight, more preferably 20% to 50% by weight, and more preferably 30% to 40% by weight.

[0065] When the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the first catalytic coating is substantially free of zeolite material, and preferably wherein the first catalytic coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less zeolite material, more preferably wherein the first catalytic coating does not contain zeolite material.

[0066] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the first catalytic coating does not contain zeolite material, and wherein the zeolite material contained in the AMOx coating is completely contained in the second catalytic coating.

[0067] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the first catalytic coating is substantially free of alkaline earth metal oxides and alkali metal oxides, wherein preferably, the ammonia oxidation coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or fewer alkaline earth metal oxides and alkali metal oxides, more preferably wherein the ammonia oxidation coating of the third catalyst is free of alkaline earth metal oxides and alkali metal oxides.

[0068] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the first catalytic coating is substantially barium-free, wherein preferably the ammonia oxidation coating contains 0.1 g / ft. 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less barium, more preferably wherein the first catalytic coating is barium-free.

[0069] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the zeolite material contained in the second catalytic coating is selected from the group consisting of AFR, ATS, BEA, DFO, EMT, EON, FAU, GME, IWS, IWV, MEI, MSE, MOR, OFF, POS, SAO, SBE, SBS, SBT, SOR, SOV, and mixtures of two or more thereof and mixtures of two or more thereof, more preferably selected from the group consisting of AFR, BEA, DFO, EON, GME, IWS, IWV, MOR, OFF, SBE, SBS, SBT, and mixtures of two or more thereof and mixtures of two or more thereof, more preferably selected from the group consisting of BEA, MOR, OFF, and mixtures of two or more thereof and mixtures of two or more thereof, wherein more preferably, the 12-membered ring-porous zeolite material contained in the second catalytic coating of the third catalyst has the framework type BEA.

[0070] Furthermore, in the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, 95% to 100% by weight, more preferably 98% to 100% by weight, more preferably 99% to 100% by weight, and more preferably 99.5% to 100% by weight of the framework structure of the 12-membered ring-porous zeolite material contained in the second catalytic coating are composed of Si, Al and O, wherein in the framework structure, the molar ratio of Si to Al calculated as molar SiO2:Al2O3 is more preferably in the range of 1 to 100, more preferably in the range of 3 to 50, more preferably in the range of 5 to 20, more preferably in the range of 7 to 15, and more preferably in the range of 7.5 to 12.5.

[0071] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the zeolite material contained in the second catalytic coating comprises iron, wherein the amount of iron contained in the zeolite material, calculated as Fe2O3 based on the total weight of the zeolite material, is preferably in the range of 0.1 wt% to 10.0 wt%, more preferably in the range of 0.5 wt% to 8 wt%, and even more preferably in the range of 1.5 wt% to 7.5 wt%.

[0072] Furthermore, in the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, the second catalytic coating is substantially free of Cu, preferably wherein the second catalytic coating contains 0.1% by weight or less, more preferably 0.01% by weight or less, more preferably 0.001% by weight or less of Cu, and even more preferably wherein the second catalytic coating of the third catalyst is free of Cu.

[0073] Furthermore, in the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, the second catalytic coating preferably further comprises a non-zeolite oxidizing material, wherein the non-zeolite oxidizing material is selected from the group consisting of zirconium oxide, alumina, cerium dioxide, titanium dioxide, silicon dioxide, and mixtures thereof, preferably from the group consisting of zirconium oxide, alumina, cerium dioxide, silicon dioxide, and mixtures thereof, more preferably from the group consisting of zirconium oxide, alumina, or mixtures thereof, and even more preferably wherein the non-zeolite oxidizing material is zirconium oxide and alumina.

[0074] In cases where the second catalytic coating further comprises a non-zeolite oxidizing material, preferably, the second catalytic coating comprises a non-zeolite oxidizing material in a carrier coating loading based on the second catalytic coating, the amount calculated as an oxide ranging from 0.5 wt% to 12 wt%, preferably from 1 wt% to 10 wt%, and more preferably from 1 wt% to 6 wt%.

[0075] In the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, the second catalytic coating is substantially free of cerium dioxide, preferably wherein the second catalytic coating contains 0.1% by weight or less, more preferably 0.01% by weight or less, more preferably 0.001% by weight or less of cerium dioxide, and more preferably wherein the second catalytic coating is free of cerium dioxide.

[0076] Furthermore, in the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, the second catalytic coating is substantially free of platinum group metals, preferably wherein the second catalytic coating contains 0.1% by weight or less, more preferably 0.01% by weight or less, more preferably 0.001% by weight or less of platinum group metals, and more preferably wherein the second catalytic coating is free of platinum group metals.

[0077] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the second catalytic coating is free of platinum group metals, and wherein one or more platinum group metals contained in the AMOx coating are completely contained in the first catalytic coating.

[0078] Furthermore, in the case where the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, preferably, the loading of the second catalytic coating is 0.1 g / in. 3 Up to 20g / in 3 Within the range, preferably within 1 g / in 3 Up to 15g / in 3 More preferably within the range of 2g / in 3 Up to 10g / in 3 More preferably within the range of 2.5 g / in 3 Up to 8g / in 3 More preferably within the range of 3g / in 3 Up to 6g / in 3 More preferably within the range of 3.05 g / in 3 Up to 5.5g / in 3 Within the range, more preferably within 3.1 g / in 3 Up to 5g / in 3 More preferably within the range of 3.15 g / in 3 Up to 4.5g / in 3 More preferably within the range of 3.2 g / in 3 Up to 4g / in 3 More preferably within the range of 3.25 g / in 3 Up to 3.75g / in 3 Within the range, more preferably within 3.3 g / in 3Up to 3.5g / in 3 Within the range.

[0079] In the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, 98% to 100% by weight, more preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the second catalytic coating is composed of a zeolite material containing one or more of Fe and Cu, and preferably a non-zeolite oxidizing material as defined above.

[0080] Furthermore, in the case where the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, the first catalytic coating is disposed on the substrate of the third catalyst at more than 98% to 100%, preferably 99% to 100%, more preferably 99.5% to 100% of the axial length of the substrate, and the second catalytic coating is disposed on the first catalytic coating at 98% to 100%, preferably 99% to 100%, more preferably 99.5% to 100% of the axial length of the substrate.

[0081] Furthermore, preferably, the third catalyst includes an inlet region and an outlet region, the inlet region comprising a first catalytic coating, preferably composed of the first catalytic coating, and the outlet region comprising a second catalytic coating, preferably composed of the second catalytic coating.

[0082] In the case where the third catalyst includes an inlet region comprising a first catalytic coating and an outlet region comprising a second catalytic coating, preferably, the inlet region extends from the inlet end of the substrate toward the outlet end by more than x% of the axial length of the substrate, where x is in the range of 20 to 60, preferably in the range of 30 to 55, and more preferably in the range of 45 to 55. Further still, preferably, the outlet region extends from the outlet end of the substrate toward the inlet end by more than y% of the axial length of the substrate, where y = 100 - x. Further still, preferably, the second catalytic coating is disposed on the substrate of the third catalyst at more than 50% of the axial length of the substrate, thereby forming the inlet region. Further still, preferably, the first catalytic coating is disposed on the substrate of the third catalyst at more than 50% of the axial length of the substrate.

[0083] When the coating of the third catalyst includes a first catalytic coating and a second catalytic coating, preferably, 98% to 100% by weight, more preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the first catalytic coating of the third catalyst is composed of one or more platinum group metals, a support material supporting the platinum group metal, and one or more rare earth metals contained in the support material.

[0084] Preferably, the third catalyst consists of a substrate and an AMOx coating.

[0085] This invention further relates to a method for the simultaneous selective catalytic reduction of NOx, oxidation of hydrocarbons, oxidation of nitric oxide, and oxidation of ammonia, the method comprising:

[0086] (1) Provide exhaust gas flow from a gasoline engine, the exhaust gas flow containing one or more of NOx, ammonia, nitric oxide and hydrocarbons;

[0087] (2) Pass the exhaust gas provided in (1) through the exhaust gas system according to any of the embodiments disclosed herein.

[0088] The invention is further illustrated by the following set of embodiments and combinations thereof, derived from the indicated dependencies and reverse references. Specifically, it should be noted that in each instance where the scope of the embodiments is mentioned, for example in the context of terms such as “exhaust gas treatment system according to any one of embodiments 1 to 4,” each embodiment within this scope is meant to be explicitly disclosed to a person skilled in the art that the wording of this term should be understood by a person skilled in the art to be synonymous with “exhaust gas treatment system according to any one of embodiments 1, 2, 3, and 4.”

[0089] Furthermore, it should be clearly pointed out that the following set of embodiments represents a suitable structured portion of the general description of preferred aspects of the invention, and therefore appropriately supports but does not represent the claims of the invention.

[0090] 1. An exhaust gas treatment system for treating exhaust gas streams exiting a gasoline engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas streams into the exhaust gas treatment system, and wherein the exhaust gas treatment system includes...

[0091] (i) A first catalyst, which is a three-way conversion catalyst having an inlet end and an outlet end and comprising a coating disposed on a substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more thereof, supported on a support material.

[0092] (ii) A second catalyst, which is a four-way conversion catalyst having an inlet end and an outlet end and comprising a coating disposed on a wall-flow filter substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh, and mixtures of two or more thereof, supported on a carrier material; or

[0093] A gasoline particulate filter having an inlet end and an outlet end;

[0094] (iii) A third catalyst having an inlet end and an outlet end, wherein the third catalyst comprises a substrate and a coating for ammonia oxidation (AMOx) and for nitrogen oxide reduction, carbon monoxide oxidation and hydrocarbon oxidation (TWC), wherein the coating of the third catalyst comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more of them supported on a support material, wherein the coating of the third catalyst comprises one or more zeolite materials, and wherein the coating of the third catalyst comprises rhodium and / or an oxygen storage compound;

[0095] Wherein the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system, and wherein the inlet end of the first catalyst is arranged upstream of the outlet end of the first catalyst.

[0096] In the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and the inlet end of the second catalyst is arranged upstream of the outlet end of the second catalyst.

[0097] In the exhaust gas treatment system, the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst.

[0098] 2. The waste gas treatment system according to embodiment 1, wherein the outlet end of the first catalyst according to (i) is in fluid communication with the inlet end of the second catalyst according to (ii), and wherein there is no catalyst for treating the waste gas flow leaving the first catalyst located in the waste gas treatment system between the outlet end of the first catalyst according to (i) and the inlet end of the second catalyst according to (ii).

[0099] 3. The waste gas treatment system according to embodiment 1 or 2, wherein the outlet end of the second catalyst according to (ii) is in fluid communication with the inlet end of the third catalyst according to (iii), and wherein there is no catalyst for treating the waste gas flow leaving the second catalyst located in the waste gas treatment system between the outlet end of the second catalyst according to (ii) and the inlet end of the third catalyst according to (iii).

[0100] 4. The waste gas treatment system according to any one of embodiments 1 to 3, wherein the one or more platinum group metals of the coating of the first catalyst are selected from the group consisting of Pd, Rh and mixtures thereof, preferably wherein the one or more platinum group metals of the coating of the first catalyst are Pd and Rh.

[0101] 5. The exhaust gas treatment system according to any one of embodiments 1 to 4, wherein the coating of the first catalyst comprises a loading of platinum group metals at 1 g / ft. 3 Up to 300g / ft 3 Within the range, preferably within 10 g / ft 3 Up to 290g / ft 3 More preferably within the range of 30g / ft 3 Up to 270g / ft 3 More preferably within the range of 50g / ft 3 Up to 260g / ft 3 More preferably within the range of 60 g / ft 3 Up to 250g / ft 3 One or more platinum group metals within the range.

[0102] 6. The waste gas treatment system according to any one of embodiments 1 to 5, wherein the carrier material of the platinum group metal component of the coating supporting the first catalyst is selected from the group consisting of alumina, cerium dioxide, silicon dioxide, zirconium oxide, titanium dioxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, preferably selected from the group consisting of alumina, titanium dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, more preferably selected from the group consisting of alumina, zirconium oxide, mixtures of two thereof, and mixed oxides of two thereof, and more preferably alumina.

[0103] 7. The waste gas treatment system according to any one of embodiments 1 to 6, wherein the coating of the first catalyst further comprises an oxygen storage compound, which preferably comprises cerium, more preferably comprises one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium, wherein the mixed oxide comprising cerium more preferably further comprises one or more of zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of zirconium, yttrium, neodymium, lanthanum, and praseodymium, more preferably zirconium.

[0104] 8. The waste gas treatment system according to embodiment 7, wherein the coating of the first catalyst comprises an oxygen storage compound in a loading range of 0.1 g / in³ to 10 g / in³, preferably in a loading range of 0.5 g / in³ to 5 g / in³, more preferably in a loading range of 1.0 g / in³ to 3 g / in³, more preferably in a loading range of 1.3 g / in³ to 2.7 g / in³, and more preferably in a loading range of 1.5 g / in³ to 2.5 g / in³.

[0105] 9. The waste gas treatment system according to embodiment 7 or 8, wherein in the coating of the first catalyst, the weight ratio of the carrier material to the oxygen storage compound is 0.1 g / in. 3 Up to 5g / in 3 Within the range, preferably within 0.3 g / in 3 Up to 3g / in 3 More preferably within the range of 0.5 g / in 3 Up to 2g / in 3 More preferably within the range of 0.7 g / in 3 Up to 1.7g / in 3 More preferably within the range of 0.8 g / in 3 Up to 1.5g / in 3 Within the range.

[0106] 10. The waste gas treatment system according to any one of embodiments 1 to 9, wherein the coating of the first catalyst further comprises a non-zeolite oxidizing material, which preferably comprises one or more of zirconium oxide, aluminum oxide, cerium dioxide, titanium dioxide, and silicon dioxide, and a mixed oxide comprising two or more of Zr, Al, Ce, Ti, and Si, more preferably comprising one or more of zirconium oxide, aluminum oxide, cerium dioxide, and silicon dioxide, and more preferably comprising zirconium oxide.

[0107] 11. The waste gas treatment system according to embodiment 10, wherein, based on the weight of the coating of the first catalyst, the coating of the first catalyst comprises a non-zeolite oxidizing material, calculated as an oxide, in an amount ranging from 95% to 100% by weight, preferably from 96% to 99.5% by weight, and more preferably from 97% to 99% by weight.

[0108] 12. The waste gas treatment system according to any one of embodiments 1 to 11, wherein the coating of the first catalyst further comprises a NOx storage component, preferably wherein the NOx storage component comprises one or more of an oxide of an alkaline earth metal and an oxide of an alkali metal, more preferably wherein the NOx storage component comprises an oxide selected from the group consisting of Mg, Ca, Sr, Ba, Li, Na, K, Rb and Cs, more preferably an oxide selected from the group consisting of Mg, Ca, Sr and Ba, and more preferably wherein the NOx storage component comprises barium oxide, preferably composed of barium oxide.

[0109] 13. The exhaust gas treatment system according to embodiment 12, wherein the coating of the first catalyst contains a NOx storage component in an amount ranging from 0.1 wt% to 15 wt%, preferably from 0.5 wt% to 15 wt%, and more preferably from 1 wt% to 10 wt%, based on the weight of the coating of the first catalyst.

[0110] 14. The exhaust gas treatment system according to any one of embodiments 1 to 6, wherein 98% to 100% by weight, preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and more preferably 99.9% to 100% by weight of the coating of the first catalyst are composed of one or more platinum group metals supported on a carrier material, preferably an oxygen storage compound as defined in any one of embodiments 7 or 8, more preferably a non-zeolite oxidizing material as defined in embodiments 10 or 11, and more preferably a NOx storage component as defined in embodiments 12 or 13.

[0111] 15. The waste gas treatment system according to any one of embodiments 1 to 14, wherein the substrate of the first catalyst is a flow-through substrate, preferably a ceramic flow-through substrate.

[0112] 16. The waste gas treatment system according to any one of embodiments 1 to 15, wherein the first catalyst comprises a substrate and a coating.

[0113] 17. The exhaust gas treatment system according to any one of embodiments 1 to 16, wherein the one or more platinum group metals of the coating of the second catalyst are selected from the group consisting of Pd, Rh and mixtures thereof, preferably wherein the one or more platinum group metals are Pd and Rh.

[0114] 18. The exhaust gas treatment system according to any one of embodiments 1 to 17, wherein the coating of the second catalyst comprises a loading of at least 0.1 g / ft of platinum group metals. 3 Up to 100g / ft 3 Within the range, preferably within 1 g / ft 3 Up to 80g / ft 3 More preferably within the range of 5g / ft 3 Up to 50g / ft 3 More preferably, one or more platinum group metals in the range of 10 g / ft³ to 30 g / ft³.

[0115] 19. The waste gas treatment system according to any one of embodiments 1 to 18, wherein the carrier material of the platinum group metal component of the coating supporting the second catalyst is selected from the group consisting of alumina, cerium dioxide, silicon dioxide, zirconium oxide, titanium dioxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, preferably selected from the group consisting of alumina, titanium dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, more preferably selected from the group consisting of alumina, zirconium oxide, mixtures of two thereof, and mixed oxides of two thereof, and more preferably alumina.

[0116] 20. The waste gas treatment system according to any one of embodiments 1 to 19, wherein the coating of the second catalyst further comprises an oxygen storage compound (OSC), which preferably comprises cerium, more preferably comprises one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium, wherein the mixed oxide comprising cerium more preferably further comprises one or more of zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of zirconium, yttrium, neodymium, lanthanum, and praseodymium, and more preferably zirconium.

[0117] 21. The waste gas treatment system according to embodiment 20, wherein the coating of the second catalyst comprises an oxygen storage compound in a loading range of 0.1 g / in³ to 5 g / in³, preferably in a loading range of 0.1 g / in³ to 2 g / in³, more preferably in a loading range of 0.2 g / in³ to 1.5 g / in³, and even more preferably in a loading range of 0.3 g / in³ to 1 g / in³.

[0118] 22. The waste gas treatment system according to embodiment 20 or 21, wherein in the coating of the second catalyst, the weight ratio of the carrier material to the oxygen storage compound is 0.1 g / in. 3 Up to 5g / in 3 Within the range, preferably within 0.2 g / in 3 Up to 3g / in 3 More preferably within the range of 0.25 g / in 3 Up to 2g / in 3 More preferably within the range of 0.3 g / in 3 Up to 1g / in 3 Within the range.

[0119] 23. The waste gas treatment system according to any one of embodiments 1 to 22, wherein the coating of the second catalyst further comprises a non-zeolite oxidizing material, which preferably comprises one or more of zirconium oxide, alumina, cerium dioxide, titanium dioxide, and silicon dioxide, and a mixed oxide comprising two or more of Zr, Al, Ce, Ti, and Si, more preferably comprising one or more of zirconium oxide, alumina, cerium dioxide, and silicon dioxide, and more preferably comprising zirconium oxide; wherein, based on the weight of the coating of the first catalyst, the coating of the second catalyst preferably comprises a non-zeolite oxidizing material in an amount calculated as an oxide ranging from 10 wt% to 70 wt%, preferably from 20 wt% to 60 wt%, more preferably from 30 wt% to 50 wt%, and more preferably from 35 wt% to 45 wt%.

[0120] 24. The waste gas treatment system according to any one of embodiments 1 to 23, wherein the coating of the second catalyst further comprises an oxide of an alkaline earth metal, preferably selected from the group consisting of barium, strontium and magnesium, more preferably selected from the group consisting of barium and strontium, and even more preferably barium.

[0121] 25. The waste gas treatment system according to embodiment 24, wherein the coating of the second catalyst contains an amount of alkaline earth metal oxide in the range of 0.1 wt% to 20 wt%, preferably in the range of 1 wt% to 15 wt%, and more preferably in the range of 5 wt% to 10 wt%, based on the weight of the coating of the second catalyst.

[0122] 26. The waste gas treatment system according to any one of embodiments 1 to 19, wherein 98% to 100% by weight, preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the coating of the second catalyst are composed of one or more platinum group metals supported on a carrier material, preferably oxygen storage compounds as defined above, more preferably non-zeolite oxidizing materials as defined above, and even more preferably alkaline earth metal oxides as defined above.

[0123] 27. The waste gas treatment system according to any one of embodiments 1 to 26, wherein the substrate of the second catalyst is a honeycomb wall flow filter substrate.

[0124] 28. The waste gas treatment system according to any one of claims 1 to 27, wherein the substrate of the second catalyst is a ceramic substrate, wherein the ceramic substrate preferably comprises cordierite, cordierite-α-alumina, aluminum titanate, silicon carbide, silicon nitride, zircon-mullite, spodumene, alumina-silica-magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, selenite, α-alumina, or aluminum silicate, more preferably composed of the like.

[0125] 29. The waste gas treatment system according to any one of embodiments 1 to 28, wherein the second catalyst comprises a substrate and a coating.

[0126] 30. The exhaust gas treatment system according to any one of claims 1 to 16, wherein the gasoline particulate filter is a wall-flow filter, preferably a honeycomb wall-flow filter.

[0127] 31. The waste gas treatment system according to claim 30, wherein the wall-flow filter is a ceramic wall-flow filter, wherein the ceramic wall-flow filter comprises cordierite, cordierite-α-alumina, aluminum titanate, silicon carbide, silicon nitride, zircon-mullite, spodumene, alumina-silica-magnesium oxide, zirconium silicate, sillimanite, magnesium silicate, zircon, selenite, α-alumina, or aluminum silicate, preferably composed of these.

[0128] 32. The exhaust gas treatment system according to any one of embodiments 1 to 31, wherein the one or more platinum group metals of the coating of the third catalyst are selected from the group consisting of Pt, Rh and mixtures thereof, preferably wherein the one or more platinum group metals of the AMOx coating of the third catalyst are Rh.

[0129] 33. The waste gas treatment system according to any one of embodiments 1 to 31, wherein the third catalyst is substantially free of palladium, preferably wherein the third catalyst contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less palladium, more preferably wherein the third catalyst does not contain palladium.

[0130] 34. The waste gas treatment system according to any one of embodiments 1 to 31, wherein the coating of the third catalyst is substantially free of palladium, preferably wherein the catalytic coating of the third catalyst contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less palladium, more preferably wherein the catalytic coating of the third catalyst is palladium-free.

[0131] 35. The waste gas treatment system according to any one of embodiments 1 to 34, wherein the loading of the coating of the third catalyst is 0.1 g / in 3 Up to 20g / in 3 Within the range, preferably within 1 g / in 3 Up to 15g / in 3 More preferably within the range of 2.1 g / in 3 Up to 10g / in 3 More preferably within the range of 2.15 g / in 3 Up to 9.5g / in 3 More preferably within the range of 2.2 g / in 3 Up to 9g / in 3 More preferably, within the range of 2.25 g / in 3 Up to 8.5g / in 3 Within the range, more preferably within 2.3 g / in 3 Up to 8g / in 3 More preferably within the range of 2.35 g / in 3 Up to 7.5g / in 3 More preferably within the range of 2.4 g / in 3 Up to 7g / in 3 More preferably within the range of 2.45 g / in 3 Up to 6g / in 3 More preferably within the range of 2.5 g / in 3 Up to 5g / in 3 More preferably within the range of 3.0 g / in 3 Up to 4.5g / in 3 Within the range.

[0132] 36. The waste gas treatment system according to any one of embodiments 1 to 35, wherein the carrier material of the coating of the third catalyst is selected from the group consisting of titanium dioxide, alumina, cerium dioxide, silicon dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, preferably selected from the group consisting of titanium dioxide, alumina and silicon dioxide, more preferably alumina.

[0133] 37. The waste gas treatment system according to embodiment 36, wherein the coating of the third catalyst contains an amount in the range of 0.1 g / in³ to 5 g / in³.

[0134] Preferably, it is between 0.4 g / in³ and 3 g / in³. 3 More preferably, it is within the range of 0.6 g / in³ to 2 g / in³. 3More preferably, it is within the range of 0.8 g / in³ to 1.6 g / in³. 3 More preferably, the carrier material is in the range of 0.85 g / in³ to 1.5 g / in³.

[0135] 38. The waste gas treatment system according to any one of embodiments 1 to 37, wherein the coating of the third catalyst comprises an oxygen storage compound, preferably wherein the oxygen storage compound preferably comprises cerium, more preferably comprises one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium, wherein the mixed oxide comprising cerium more preferably further comprises one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, and praseodymium, more preferably aluminum.

[0136] 39. The waste gas treatment system according to embodiment 38, wherein the cerium content of the oxygen storage compound in the coating of the third catalyst is in the range of 5% to 81.46% by weight, preferably 10% to 80% by weight, more preferably 20% to 75% by weight, more preferably 30% to 70% by weight, more preferably 40% to 60% by weight, and more preferably 45% to 55% by weight, based on the total weight of the oxygen storage compound in the coating of the third catalyst.

[0137] 40. The exhaust gas treatment system according to any one of embodiments 1 to 39, wherein the carrier material of the coating of the third catalyst comprises one or more rare earth metals, and wherein the one or more rare earth metals are selected from the group consisting of Sc, Y, La, Ce, Pr, Nd and mixtures of two or more thereof, preferably selected from the group consisting of La, Ce and mixtures thereof, more preferably wherein the one or more rare earth metals is La.

[0138] 41. The waste gas treatment system according to embodiment 40, wherein the total weight of the carrier material of the coating of the third catalyst, the content of one or more rare earth metals of the carrier material of the coating of the third catalyst is in the range of 0.1 wt% to 80 wt%, preferably 0.5 wt% to 70 wt%, more preferably 1 wt% to 60 wt%, more preferably 3 wt% to 50 wt%, more preferably 5 wt% to 40 wt%, more preferably 10 wt% to 30 wt%, and more preferably 15 wt% to 25 wt%.

[0139] 42. The waste gas treatment system according to embodiment 40, wherein the total weight of the carrier material of the coating of the third catalyst, the lanthanum content of the carrier material of the coating of the third catalyst is in the range of 0.1 wt% to 30 wt%, preferably 0.5 wt% to 20 wt%, more preferably 1 wt% to 15 wt%, more preferably 1.5 wt% to 10 wt%, more preferably 2 wt% to 8 wt%, more preferably 2.5 wt% to 6 wt%, more preferably 3 wt% to 5 wt%, more preferably 3.5 wt% to 4.5 wt%.

[0140] 43. The waste gas treatment system according to embodiment 40, wherein the one or more rare earth metals is cerium, and wherein the cerium content of the carrier material of the coating of the third catalyst is in the range of 1% to 80% by weight, preferably 5% to 70% by weight, more preferably 10% to 60% by weight, more preferably 20% to 50% by weight, and more preferably 30% to 40% by weight, based on the total weight of the carrier material of the coating of the third catalyst.

[0141] 44. The waste gas treatment system according to any one of embodiments 1 to 43, wherein the coating of the third catalyst contains one or more zeolite materials comprising one or more of Fe and Cu, preferably wherein the one or more zeolite materials comprise Fe.

[0142] 45. The waste gas treatment system according to embodiment 44, wherein the coating of the third catalyst contains one or more zeolite materials that are 12-membered ring-porous zeolite materials, wherein the 12-membered ring-porous zeolite materials preferably have a framework type selected from the group consisting of BEA, MOR, FAU, GME, OFF, mixtures of two or more thereof, and mixtures of two or more thereof, more preferably selected from the group consisting of BEA and FAU, and even more preferably selected from the group consisting of BEA and FAU, wherein the 12-membered ring-porous zeolite materials contained in the coating of the third catalyst have a framework type of BEA.

[0143] 46. ​​The waste gas treatment system according to embodiment 44 or 45, wherein 95% to 100% by weight, preferably 98% to 100% by weight, more preferably 99% to 100% by weight, and more preferably 99.5% to 100% by weight of the 12-membered ring porous zeolite material skeleton structure contained in the coating of the third catalyst is composed of Si, Al and O, wherein in the skeleton structure, the molar ratio of Si to Al calculated as molar SiO2:Al2O3 is more preferably in the range of 2:1 to 40:1, more preferably in the range of 3:1 to 30:1, more preferably in the range of 4:1 to 20:1, and more preferably in the range of 6:1 to 15:1.

[0144] 47. The exhaust gas treatment system according to any one of embodiments 1 to 46, wherein the coating of the third catalyst extends more than 98% to 100% of the axial length of the substrate, more preferably more than 99% to 100%, and even more preferably more than 99.5% to 100%.

[0145] 48. The waste gas treatment system according to any one of embodiments 1 to 47, wherein the substrate of the third catalyst is a ceramic wall-flow filter substrate.

[0146] 49. The waste gas treatment system according to any one of embodiments 1 to 48, wherein the coating of the third catalyst is substantially free of alkaline earth metal oxides and alkali metal oxides, wherein preferably the coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or fewer alkaline earth metal oxides and alkali metal oxides, more preferably wherein the coating of the third catalyst is free of alkaline earth metal oxides and alkali metal oxides.

[0147] 50. The exhaust gas treatment system according to any one of embodiments 1 to 49, wherein the coating of the third catalyst is substantially barium-free, wherein preferably the coating of the third catalyst contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less barium, more preferably wherein the coating of the third catalyst is barium-free.

[0148] 51. The waste gas treatment system according to any one of embodiments 1 to 50, wherein the coating of the third catalyst comprises a first catalytic coating and a second catalytic coating, the first catalytic coating comprising one or more platinum group metals supported on a carrier material, the second catalytic coating comprising one or more zeolite materials, wherein the first catalytic coating comprises rhodium and / or an oxygen storage compound.

[0149] 52. The exhaust gas treatment system according to embodiment 51, wherein the one or more platinum group metals included in the first catalytic coating are selected from the group consisting of Pt, Rh and mixtures thereof, more preferably wherein the one or more platinum group metals included in the first catalytic coating are Rh.

[0150] 53. The waste gas treatment system according to embodiment 51 or 52, wherein the first catalytic coating is substantially free of palladium, preferably wherein the first catalytic coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less palladium, more preferably wherein the first catalytic coating is palladium-free.

[0151] 54. The exhaust gas treatment system according to any one of embodiments 51 to 53, wherein the loading of the first catalytic coating is 0.1 g / in. 3 Up to 20g / in 3 Within the range, preferably within 1 g / in 3 Up to 15g / in 3 More preferably within the range of 2.1 g / in 3 Up to 10g / in 3 More preferably within the range of 2.15 g / in 3 Up to 9.5g / in 3 More preferably within the range of 2.2 g / in 3 Up to 9g / in 3 More preferably, within the range of 2.25 g / in 3 Up to 8.5g / in 3 Within the range, more preferably within 2.3 g / in 3 Up to 8g / in 3 More preferably within the range of 2.35 g / in 3 Up to 7.5g / in 3 More preferably within the range of 2.4 g / in 3 Up to 7g / in 3 More preferably within the range of 2.45 g / in 3 Up to 6g / in 3 More preferably within the range of 2.5 g / in 3 Up to 5g / in 3 More preferably within the range of 3.0 g / in 3 Up to 4.5g / in 3 Within the range.

[0152] 55. The waste gas treatment system according to any one of embodiments 51 to 54, wherein the carrier material of the first catalytic coating is selected from the group consisting of titanium dioxide, alumina, cerium dioxide, silicon dioxide, zirconium oxide, mixtures of two or more thereof, and mixed oxides of two or more thereof, preferably selected from the group consisting of titanium dioxide, alumina and silicon dioxide, more preferably alumina.

[0153] 56. The waste gas treatment system according to any one of embodiments 51 to 55, wherein the first catalytic coating contains 0.1 g / in 3 Up to 5g / in 3 Within the range, preferably within 1 g / in 3 Up to 3g / in 3 Within the range, more preferably within 1.3 g / in 3 Up to 2.7g / in 3 Within the range, more preferably within 1.5 g / in 3 Up to 2.5g / in 3 Carrier materials within the specified range.

[0154] 57. The waste gas treatment system according to any one of embodiments 51 to 56, wherein the first catalytic coating of the third catalyst comprises an oxygen storage compound, preferably wherein the oxygen storage compound preferably comprises cerium, more preferably comprises one or more of cerium oxide, a mixture of oxides comprising cerium oxide, and a mixed oxide comprising cerium, wherein the mixed oxide comprising cerium more preferably further comprises one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, hafnium, samarium, and praseodymium, more preferably one or more of aluminum, zirconium, yttrium, neodymium, lanthanum, and praseodymium, more preferably aluminum.

[0155] 58. The waste gas treatment system according to embodiment 57, wherein the cerium content of the oxygen storage compound in the coating of the third catalyst is in the range of 5% to 81.46% by weight, preferably 10% to 80% by weight, more preferably 20% to 75% by weight, more preferably 30% to 70% by weight, more preferably 40% to 60% by weight, and more preferably 45% to 55% by weight, based on the total weight of the oxygen storage compound in the coating of the third catalyst.

[0156] 59. The waste gas treatment system according to any one of embodiments 51 to 58, wherein the carrier material of the first catalytic coating of the third catalyst comprises one or more rare earth metals, and wherein the one or more rare earth metals are selected from the group consisting of Sc, Y, La, Ce, Pr, Nd and mixtures of two or more thereof, preferably selected from the group consisting of La, Ce and mixtures thereof, more preferably wherein the one or more rare earth metals is La.

[0157] 60. The waste gas treatment system according to embodiment 59, wherein, based on the total weight of the carrier material of the first catalytic coating of the third catalyst, the content of one or more rare earth metals of the carrier material of the first catalytic coating is in the range of 0.1 wt% to 80 wt%, preferably 0.5 wt% to 70 wt%, more preferably 1 wt% to 60 wt%, more preferably 3 wt% to 50 wt%, more preferably 5 wt% to 40 wt%, more preferably 10 wt% to 30 wt%, and more preferably 15 wt% to 25 wt%.

[0158] 61. The waste gas treatment system according to embodiment 59, wherein the lanthanum content of the support material of the first catalytic coating based on the third catalyst is in the range of 0.1 wt% to 30 wt%, preferably 0.5 wt% to 20 wt%, more preferably 1 wt% to 15 wt%, more preferably 1.5 wt% to 10 wt%, more preferably 2 wt% to 8 wt%, more preferably 2.5 wt% to 6 wt%, more preferably 3 wt% to 5 wt%, and more preferably 3.5 wt% to 4.5 wt%.

[0159] 62. The waste gas treatment system according to embodiment 59, wherein the one or more rare earth metals is cerium, and wherein the cerium content of the carrier material of the first catalytic coating, based on the total weight of the carrier material of the third catalyst, is in the range of 1% to 80% by weight, preferably 5% to 70% by weight, more preferably 10% to 60% by weight, more preferably 20% to 50% by weight, and more preferably 30% to 40% by weight.

[0160] 63. The waste gas treatment system according to any one of embodiments 51 to 62, wherein the first catalytic coating is substantially free of zeolite material, preferably wherein the first catalytic coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less zeolite material, more preferably wherein the first catalytic coating does not contain zeolite material.

[0161] 64. The exhaust gas treatment system according to any one of embodiments 51 to 63, wherein the first catalytic coating is free of zeolite material, and wherein the zeolite material contained in the AMOx coating is completely contained in the second catalytic coating.

[0162] 65. The waste gas treatment system according to any one of embodiments 51 to 64, wherein the first catalytic coating is substantially free of alkaline earth metal oxides and alkali metal oxides, wherein preferably the ammonia oxidation coating contains 0.1 g / ft 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or fewer alkaline earth metal oxides and alkali metal oxides, more preferably wherein the ammonia oxidation coating of the third catalyst is free of alkaline earth metal oxides and alkali metal oxides.

[0163] 66. The waste gas treatment system according to any one of embodiments 51 to 65, wherein the first catalytic coating is substantially barium-free, and preferably the ammonia oxidation coating contains 0.1 g / ft. 3 Or less, more preferably 0.01 g / ft 3 Or less, more preferably 0.001 g / ft 3 Or less barium, more preferably wherein the first catalytic coating is barium-free.

[0164] 67. The exhaust gas treatment system according to any one of embodiments 51 to 66, wherein the zeolite material included in the second catalytic coating is selected from the group consisting of AFR, ATS, BEA, DFO, EMT, EON, FAU, GME, IWS, IWV, MEI, MSE, MOR, OFF, POS, SAO, SBE, SBS, SBT, SOR, SOV, and mixtures of two or more thereof and mixed types thereof, more preferably selected from the group consisting of AFR, BEA, DFO, EON, GME, IWS, IWV, MOR, OFF, SBE, SBS, SBT, and mixtures of two or more thereof and mixed types thereof, even more preferably selected from the group consisting of BEA, MOR, OFF, and mixtures of two or more thereof and mixed types thereof, wherein more preferably, the 12-membered ring-porous zeolite material included in the second catalytic coating of the third catalyst has a framework type BEA.

[0165] 68. The waste gas treatment system according to embodiments 51 to 67, wherein 95% to 100% by weight, preferably 98% to 100% by weight, more preferably 99% to 100% by weight, and even more preferably 99.5% to 100% by weight of the 12-membered ring-porous zeolite material skeleton structure contained in the second catalytic coating is composed of Si, Al and O, wherein in the skeleton structure, the molar ratio of Si to Al calculated as molar SiO2:Al2O3 is more preferably in the range of 1 to 100, more preferably in the range of 3 to 50, more preferably in the range of 5 to 20, more preferably in the range of 7 to 15, and even more preferably in the range of 7.5 to 12.5.

[0166] 69. The waste gas treatment system according to any one of embodiments 51 to 68, wherein the zeolite material contained in the second catalytic coating contains iron, wherein the amount of iron contained in the zeolite material, calculated as Fe2O3 based on the total weight of the zeolite material, is preferably in the range of 0.1 wt% to 10.0 wt%, more preferably in the range of 0.5 wt% to 8 wt%, and even more preferably in the range of 1.5 wt% to 7.5 wt%.

[0167] 70. The exhaust gas treatment system according to any one of embodiments 51 to 69, wherein the second catalytic coating is substantially free of Cu, preferably wherein the second catalytic coating contains 0.1% by weight or less, more preferably 0.01% by weight or less, more preferably 0.001% by weight or less of Cu, and even more preferably wherein the second catalytic coating of the third catalyst is free of Cu.

[0168] 71. The waste gas treatment system according to any one of embodiments 51 to 70, wherein the second catalytic coating further comprises a non-zeolite oxidizing material, wherein the non-zeolite oxidizing material is selected from the group consisting of zirconium oxide, alumina, cerium dioxide, titanium dioxide, silicon dioxide, and mixtures thereof, preferably selected from the group consisting of zirconium oxide, alumina, cerium dioxide, silicon dioxide, and mixtures thereof, more preferably selected from the group consisting of zirconium oxide, alumina, or mixtures thereof, and even more preferably wherein the non-zeolite oxidizing material is zirconium oxide and alumina.

[0169] 72. The waste gas treatment system according to embodiment 71, wherein, based on the carrier coating loading of the second catalytic coating, the second catalytic coating comprises a non-zeolite oxidizing material in an amount calculated as an oxide ranging from 0.5 wt% to 12 wt%, preferably from 1 wt% to 10 wt%, and more preferably from 1 wt% to 6 wt%.

[0170] 73. The exhaust gas treatment system according to any one of embodiments 51 to 72, wherein the second catalytic coating is substantially free of cerium dioxide, preferably wherein the second catalytic coating contains 0.1% by weight or less, more preferably 0.01% by weight or less, more preferably 0.001% by weight or less of cerium dioxide, and even more preferably wherein the second catalytic coating is free of cerium dioxide.

[0171] 74. The exhaust gas treatment system according to any one of embodiments 51 to 73, wherein the second catalytic coating is substantially free of platinum group metals, preferably wherein the second catalytic coating contains 0.1% by weight or less, more preferably 0.01% by weight or less, more preferably 0.001% by weight or less of platinum group metals, and more preferably wherein the second catalytic coating is free of platinum group metals.

[0172] 75. The exhaust gas treatment system according to any one of embodiments 51 to 74, wherein the second catalytic coating is free of platinum group metals, and wherein the one or more platinum group metals contained in the AMOx coating are completely contained in the first catalytic coating.

[0173] 76. The exhaust gas treatment system according to any one of embodiments 51 to 75, wherein the loading of the second catalytic coating is 0.1 g / in. 3 Up to 20g / in 3 Within the range, preferably within 1 g / in 3 Up to 15g / in 3 More preferably within the range of 2g / in 3 Up to 10g / in 3 More preferably within the range of 2.5 g / in 3 Up to 8g / in 3 More preferably within the range of 3g / in 3 Up to 6g / in 3 More preferably within the range of 3.05 g / in 3 Up to 5.5g / in 3 Within the range, more preferably within 3.1 g / in 3 Up to 5g / in 3 More preferably within the range of 3.15 g / in 3 Up to 4.5g / in 3 More preferably within the range of 3.2 g / in 3 Up to 4g / in 3 More preferably within the range of 3.25 g / in 3 Up to 3.75g / in 3 Within the range, more preferably within 3.3 g / in 3 Up to 3.5g / in 3 Within the range.

[0174] 77. The exhaust gas treatment system according to any one of embodiments 51 to 70, wherein 98% to 100% by weight, preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the second catalytic coating is composed of a zeolite material comprising one or more of Fe and Cu, and preferably a non-zeolite oxidizing material as defined in embodiment 71 or 72.

[0175] 78. The waste gas treatment system according to any one of embodiments 51 to 77, wherein the first catalytic coating is disposed on the substrate of the third catalyst at more than 98% to 100%, preferably 99% to 100%, more preferably 99.5% to 100% of the axial length of the substrate, and the second catalytic coating is disposed on the substrate of the third catalyst at more than 98% to 100%, preferably 99% to 100%, more preferably 99.5% to 100% of the axial length of the substrate.

[0176] 79. The waste gas treatment system according to any one of embodiments 51 to 77, wherein the third catalyst includes an inlet region and an outlet region, the inlet region comprising the first catalytic coating, preferably composed of the first catalytic coating, and the outlet region comprising a second catalytic coating, preferably composed of the second catalytic coating.

[0177] 80. The exhaust gas treatment system according to embodiment 79, wherein the inlet area extends from the inlet end of the substrate toward the outlet end by more than x% of the axial length of the substrate, wherein x is in the range of 20 to 60, preferably in the range of 30 to 55, and more preferably in the range of 45 to 55.

[0178] 81. The exhaust gas treatment system according to embodiment 79 or 80, wherein the outlet area extends from the outlet end of the substrate toward the inlet end by more than y% of the axial length of the substrate, where y = 100 - x.

[0179] 82. The exhaust gas treatment system according to any one of embodiments 79 to 81, wherein the second catalytic coating is disposed on the substrate of the third catalyst at a length of more than 50% of the axial length of the substrate, thereby forming the inlet region.

[0180] 83. The exhaust gas treatment system according to any one of embodiments 79 to 82, wherein the first catalytic coating is disposed on the substrate of the third catalyst at a length of more than 50% of the axial length of the substrate.

[0181] 84. The waste gas treatment system according to any one of embodiments 51 to 83, wherein 98% to 100% by weight, preferably 99% to 100% by weight, more preferably 99.5% to 100% by weight, and even more preferably 99.9% to 100% by weight of the first catalytic coating of the third catalyst is composed of one or more platinum group metals, a support material supporting the platinum group metals, and one or more rare earth metals contained in the support material.

[0182] 85. The exhaust gas treatment system according to any one of embodiments 1 to 84, wherein the third catalyst comprises a substrate and an AMOx coating.

[0183] 86. A method for the simultaneous selective catalytic reduction of NOx, oxidation of hydrocarbons, oxidation of nitric oxide, and oxidation of ammonia, said method comprising:

[0184] (1) Provide exhaust gas flow from a gasoline engine, the exhaust gas flow containing one or more of NOx, ammonia, nitric oxide and hydrocarbons;

[0185] (2) The exhaust gas provided in (1) is passed through the exhaust gas system according to any one of embodiments 1 to 85.

[0186] The present invention is further illustrated by the following reference examples, embodiments and comparative examples.

[0187] Example

[0188] Reference Example 1: Determination of volume-based particle size distribution Dv90

[0189] Particle size distribution was determined using a Sympatec HELOS / BR-OM & QUIXEL wet dispersion apparatus via static light scattering. This apparatus is equipped with a laser (HeNe) diffraction sensor with a 31-channel multi-element detection range, comprising five modules covering 0.1 micrometers to 875 micrometers.

[0190] Reference Example 2: Three-way conversion (TWC) catalyst

[0191] An aqueous mixture of palladium and rhodium precursors was impregnated onto highly porous alumina and cerium dioxide-zirconia. The resulting Pd / Rh mixture (solid content: 60% to 75% by weight) on alumina and cerium dioxide-zirconia was calcined at 400°C to 600°C for 2 to 4 hours.

[0192] A mixture was prepared by mixing water, n-octanol, a barium oxide precursor, and zirconium oxide. The amount of barium oxide precursor was calculated such that the final BaO loading in the calcined catalyst was 1% to 10% by weight based on the coating weight, and the amount of zirconium oxide precursor was calculated such that the ZrO2 loading from the source in the calcined catalyst was 1% to 5% by weight based on the coating weight. The obtained calcined Pd / Rh on alumina and / or cerium dioxide-zirconia was added to the mixture containing n-octanol to obtain a slurry. The slurry solids content was adjusted to 30% to 50% by weight to enhance pH and viscosity measurements and wet milling. After milling, the pH of the slurry was adjusted to 3 to 5 by adding nitric acid. The particle size distribution (Dv90) of the milled slurry was 10 to 20 micrometers.

[0193] The obtained slurry was applied over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 4.66 inches × length: 4.5 inches, cylindrical substrate with 750 / (2.5)² cells per square centimeter and a wall thickness of 0.0635 mm (2.5 mils)), dried at 120°C to 180°C, and further calcined in air at 400°C to 600°C. The final coating comprised highly porosity alumina, cerium dioxide-zirconia, Pd, Rh, zirconium oxide, and barium oxide. The coating loading ranged from 1.5 g / in³ to 4 g / in³.

[0194] Reference Example 3: Four-way power conversion (FWC) catalyst

[0195] An aqueous mixture of palladium and rhodium precursors was impregnated onto highly porous alumina and cerium dioxide-zirconia. The resulting Pd / Rh mixture (solid content: 50% to 80% by weight) on alumina and cerium dioxide-zirconia was calcined at 400°C to 600°C for 2 to 4 hours.

[0196] A mixture was prepared by mixing water, n-octanol, a barium oxide precursor, and zirconium oxide. The amount of barium oxide precursor was calculated such that the final BaO loading in the calcined catalyst was 1% to 5% by weight based on the coating weight, and the amount of zirconium oxide precursor was calculated such that the ZrO2 loading from the source in the calcined catalyst was 1% to 5% by weight based on the coating weight. The obtained calcined Pd / Rh on alumina and / or cerium dioxide-zirconia was added to the mixture containing n-octanol to obtain a slurry. The slurry solids content was adjusted to 30% to 50% by weight to enhance pH and viscosity measurements and wet milling. After milling, the pH of the slurry was adjusted to 3 to 5 by adding nitric acid. The particle size distribution (Dv90) of the milled slurry was 7 to 18 micrometers.

[0197] The obtained slurry was applied over the entire length of an uncoated ceramic honeycomb wall flow substrate (diameter: 4.66 inches × length: 4.26 inches, cylindrical substrate with 300 / (2.54)² cells per square centimeter and a wall thickness of 0.2 mm (8 mils)), dried at 120°C to 180°C, and further calcined in air at 400°C to 600°C. The final coating comprised highly porosity alumina, cerium dioxide-zirconia, Pd, Rh, zirconium oxide, and barium oxide. The coating loading ranged from 1 g / in³ to 3 g / in³.

[0198] Reference Example 4: Three-Way Conversion (TWC) Catalyst

[0199] An aqueous mixture of palladium and rhodium precursors was impregnated onto highly porous alumina and cerium dioxide-zirconia. The resulting Pd / Rh mixture (solid content: 60% to 75% by weight) on alumina and cerium dioxide-zirconia was calcined at 400°C to 600°C for 2 to 4 hours.

[0200] A mixture was prepared by mixing water, n-octanol, a barium oxide precursor, and zirconium oxide. The amount of barium oxide precursor was calculated such that, based on the weight of the coating, the final loading of BaO in the calcined catalyst was 5% to 10% by weight, and the amount of zirconium oxide precursor was calculated such that, based on the weight of the coating, the loading of ZrO2 from the source in the calcined catalyst was 1% to 5% by weight. The obtained calcined Pd / Rh on alumina and / or cerium dioxide-zirconia was added to the mixture containing n-octanol to obtain a slurry. The slurry solids content was adjusted to 35% to 45% by weight to enhance pH and viscosity measurements and wet milling. After milling, the pH of the slurry was adjusted to 3 to 5 by adding nitric acid. The particle size distribution (Dv90) of the milled slurry was 15 to 22 micrometers.

[0201] The obtained slurry was applied over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 5.66 inches × length: 3.0 inches, cylindrical substrate with 750 / (2.5)² cells per square centimeter and a wall thickness of 0.0635 mm (2.5 mils)), dried at 120°C to 180°C, and further calcined in air at 400°C to 600°C. The final coating comprised highly porosity alumina, cerium dioxide-zirconia, Pd, Rh, zirconium oxide, and barium oxide. The coating loading ranged from 1.5 g / in³ to 3 g / in³.

[0202] Comparative Example 1: Exhaust gas treatment system not based on the present invention

[0203] The exhaust gas treatment system of Comparative Example 1 includes a catalyst (TWC catalyst) from Reference Example 1 as catalyst 1, a catalyst (FWC catalyst) from Reference Example 2 as catalyst 2, and a catalyst (TWC catalyst) from Reference Example 4 as catalyst 3, wherein catalyst 1 is located upstream of catalyst 2 and catalyst 2 is located upstream of catalyst 3. There is no catalyst between catalyst 1 and catalyst 2, or between catalyst 2 and catalyst 3, and catalyst 1 is a tightly coupled catalyst. This system in... Figure 1 As shown in the image.

[0204] Reference Example 5: Ammonia Oxidation (AMOx) Catalyst

[0205] PGM-containing bottom coating :

[0206] Aqueous mixtures of Pt precursors were impregnated in an aqueous medium onto high-surface-area and porous lanthanum-doped alumina (La content in the doped alumina was 4% by weight). The resulting mixture had a solid content of 50% to 70%. The slurry was wet-milled to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 5.66 inches × length: 3 inches, cylindrical substrate with 400 / (2.54)² cells per square centimeter and a wall thickness of 0.1 mm (4 mils)), dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM coating was 2.5 g / in. 3 Up to 4.5g / in 3 .

[0207] PGM-free top coating :

[0208] A mixture of distilled water and Fe-BEA zeolite was prepared (Fe content, calculated as Fe2O3: 1.5 wt% to 7.5 wt% based on the weight of the zeolite, and a molar ratio of silica to alumina of 6-15:1). Zirconia and alumina (1 wt% to 5 wt%) were added to the mixture under constant mixing conditions. The resulting slurry had a solid content of 30% to 50%. The slurry was dispersed and mixed to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of a substrate coated with a PGM-containing undercoat, dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM-free coating was 2.5 g / in. 3 Up to 3.5g / in 3 .

[0209] Comparative Example 2: Exhaust gas treatment system not based on the present invention

[0210] The exhaust gas treatment system of Comparative Example 1 includes the catalyst of Reference Example 1 (TWC catalyst) as catalyst 1, the catalyst of Reference Example 2 (FWC catalyst) as catalyst 2, and the catalyst of Reference Example 5 (AMOx catalyst) as catalyst 3, wherein catalyst 1 is located upstream of catalyst 2 and catalyst 2 is located upstream of catalyst 3. There is no catalyst between catalyst 1 and catalyst 2, or between catalyst 2 and catalyst 3, and catalyst 1 is a tightly coupled catalyst. This system in... Figure 1 As shown in the image.

[0211] Reference Example 6: Ammonia Oxidation (TWC / AMOx) Catalyst

[0212] PGM-containing bottom coating :

[0213] Aqueous mixtures of Pt precursors were impregnated onto a high-surface-area, porous cerium dioxide-alumina mixture (30% by weight CeO2 content) in an aqueous medium. The resulting mixture had a solid content of 50% to 70%. The slurry was wet-milled to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then applied over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 5.66 inches × length: 3 inches, cylindrical substrate with 400 / (2.54)² cells per square centimeter and a wall thickness of 0.1 mm (4 mils)), dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM coating was 2.5 g / in. 3 Up to 4.5g / in 3 .

[0214] PGM-free top coating :

[0215] A mixture of distilled water and Fe-BEA zeolite was prepared (Fe content, calculated as Fe2O3: 1.5 wt% to 7.5 wt% based on the weight of the zeolite, and a molar ratio of silica to alumina of 6-15:1). Zirconia and alumina (1 wt% to 5 wt%) were added to the mixture under constant mixing conditions. The resulting slurry had a solid content of 30% to 50%. The slurry was dispersed and mixed to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of a substrate coated with a PGM-containing undercoat, dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM-free coating was 2.5 g / in. 3 Up to 3.5g / in 3 .

[0216] Example 1: Waste gas treatment system according to the present invention

[0217] The exhaust gas treatment system of Comparative Example 1 includes the catalyst of Reference Example 1 (TWC catalyst) as catalyst 1, the catalyst of Reference Example 2 (FWC catalyst) as catalyst 2, and the catalyst of Reference Example 6 ((TWC / AMOx) catalyst) as catalyst 3, wherein catalyst 1 is located upstream of catalyst 2 and catalyst 2 is located upstream of catalyst 3. There is no catalyst between catalyst 1 and catalyst 2, or between catalyst 2 and catalyst 3, and catalyst 1 is a tightly coupled catalyst. This system in... Figure 1 As shown in the image.

[0218] Reference Example 7: Ammonia Oxidation (TWC / AMOx) Catalyst

[0219] PGM-containing bottom coating :

[0220] An aqueous mixture of Pt precursors was impregnated onto a high-surface-area, porous cerium dioxide-alumina (70 wt% CeO2) medium in an aqueous medium. The resulting mixture had a solid content of 50% to 70%. The slurry was wet-milled to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 5.66 inches × length: 3 inches, cylindrical substrate with 400 / (2.54)² cells per square centimeter and a wall thickness of 0.1 mm (4 mils)), dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM coating was 2.5 g / in. 3 Up to 4.5g / in 3 .

[0221] PGM-free top coating :

[0222] A mixture of distilled water and Fe-BEA zeolite was prepared (Fe content, calculated as Fe2O3: 1.5 wt% to 7.5 wt% based on the weight of the zeolite, and a molar ratio of silica to alumina of 6-15:1). Zirconia and alumina (1 wt% to 5 wt%) were added to the mixture under constant mixing conditions. The resulting slurry had a solid content of 30% to 50%. The slurry was dispersed and mixed to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of a substrate coated with a PGM-containing undercoat, dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM-free coating was 2.5 g / in. 3 Up to 3.5g / in 3 .

[0223] Example 2: Waste gas treatment system according to the present invention

[0224] The exhaust gas treatment system of Comparative Example 1 includes the catalyst of Reference Example 1 (TWC catalyst) as catalyst 1, the catalyst of Reference Example 2 (FWC catalyst) as catalyst 2, and the catalyst of Reference Example 7 ((TWC / AMOx) catalyst) as catalyst 3, wherein catalyst 1 is located upstream of catalyst 2 and catalyst 2 is located upstream of catalyst 3. There is no catalyst between catalyst 1 and catalyst 2, or between catalyst 2 and catalyst 3, and catalyst 1 is a tightly coupled catalyst. This system in... Figure 1 As shown in the image.

[0225] Reference Example 8: Ammonia Oxidation (TWC / AMOx) Catalyst

[0226] PGM-containing bottom coating :

[0227] An aqueous mixture of Rh precursors was impregnated onto a high-surface-area, porous lanthanum oxide-doped alumina (La content of 4 wt%) in an aqueous medium. The resulting mixture had a solid content of 50% to 70%. The slurry was wet-milled to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 5.66 inches × length: 3 inches, cylindrical substrate with 400 / (2.54)² cells per square centimeter and a wall thickness of 0.1 mm (4 mils)), dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The PGM coating loading was 2.5 g / in. 3 Up to 4.5g / in 3 .

[0228] PGM-free top coating :

[0229] A mixture of distilled water and Fe-BEA zeolite was prepared (Fe content, calculated as Fe2O3: 1.5 wt% to 7.5 wt% based on the weight of the zeolite, and a molar ratio of silica to alumina of 6-15:1). Zirconia and alumina (1 wt% to 5 wt%) were added to the mixture under constant mixing conditions. The resulting slurry had a solid content of 30% to 50%. The slurry was dispersed and mixed to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of a substrate coated with a PGM-containing undercoat, dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM-free coating was 2.5 g / in. 3 Up to 3.5g / in 3 .

[0230] Example 3: Waste gas treatment system according to the present invention

[0231] The exhaust gas treatment system of Comparative Example 1 includes the catalyst of Reference Example 1 (TWC catalyst) as catalyst 1, the catalyst of Reference Example 2 (FWC catalyst) as catalyst 2, and the catalyst of Reference Example 8 ((TWC / AMOx) catalyst) as catalyst 3, wherein catalyst 1 is located upstream of catalyst 2 and catalyst 2 is located upstream of catalyst 3. There is no catalyst between catalyst 1 and catalyst 2, or between catalyst 2 and catalyst 3, and catalyst 1 is a tightly coupled catalyst. This system in... Figure 1 As shown in the image.

[0232] Reference Example 9: Ammonia Oxidation (TWC / AMOx) Catalyst

[0233] PGM-containing bottom coating :

[0234] An aqueous mixture of Rh precursors was impregnated onto a high-surface-area, porous cerium dioxide-alumina mixture (30% by weight CeO2 content) in an aqueous medium. The resulting mixture had a solid content of 50% to 70%. The slurry was wet-milled to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of an uncoated ceramic honeycomb flow-through substrate (diameter: 5.66 inches × length: 3 inches, cylindrical substrate with 400 / (2.54)² cells per square centimeter and a wall thickness of 0.1 mm (4 mils)), dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The PGM coating loading was 2.5 g / in. 3 Up to 4.5g / in 3 .

[0235] PGM-free top coating :

[0236] A mixture of distilled water and Fe-BEA zeolite was prepared (Fe content, calculated as Fe2O3: 1.5 wt% to 7.5 wt% based on the weight of the zeolite, and a molar ratio of silica to alumina of 6-15:1). Zirconia and alumina (1 wt% to 5 wt%) were added to the mixture under constant mixing conditions. The resulting slurry had a solid content of 30% to 50%. The slurry was dispersed and mixed to obtain a Dv90 of 5 to 15 micrometers. The resulting slurry was then placed over the entire length of a substrate coated with a PGM-containing undercoat, dried at 120°C to 180°C, and calcined in air at 400°C to 600°C. The loading of the PGM-free coating was 2.5 g / in. 3 Up to 3.5g / in 3 .

[0237] Example 4: Waste gas treatment system according to the present invention

[0238] The exhaust gas treatment system of Comparative Example 1 includes the catalyst of Reference Example 1 (TWC catalyst) as catalyst 1, the catalyst of Reference Example 2 (FWC catalyst) as catalyst 2, and the catalyst of Reference Example 9 ((TWC / AMOx) catalyst) as catalyst 3, wherein catalyst 1 is located upstream of catalyst 2 and catalyst 2 is located upstream of catalyst 3. There is no catalyst between catalyst 1 and catalyst 2, or between catalyst 2 and catalyst 3, and catalyst 1 is a tightly coupled catalyst. This system in... Figure 1 As shown in the image.

[0239] Example 5: Testing of the system according to Examples 1 to 5 and Comparative Example 1

[0240] In different systems, catalyst 1 (TWC) and catalyst 2 (FWC) are located in the same tank as different downstream component combinations in Comparative Example 1 and Examples 1 to 4. The comparative system containing TWC and FWC, as well as downstream of TWC, represents a standard Euro 6 configuration, while the system of the present invention, consisting of AMOx or TWC-AMOx in a floor-down position downstream of TWC+FWC, represents a Euro 7 gasoline application.

[0241] The evaluated systems were aged on an engine bench using a 2L Euro 6 engine, with the can containing TWC+FWC placed in the CC position, while the components under evaluation (TWC, AMOx, or TWC / AMOx) were placed downstream in separate cans. Five replicates were performed upstream using the same CC unit for all systems studied. Aging was of type λ1 with periodic fuel cut-off or lean / rich combustion disturbances, with a downstream catalyst inlet temperature of 850°C. The aging duration was 50 hours. Thermocouples placed at different locations along the exhaust line recorded the temperatures at the engine outlet, catalyst inlet, and bed and outlet.

[0242] System and therefore component evaluation (WLTC) was conducted on the Euro 6 2l GTDI engine bench test unit. The latter is equipped with thermoelectric elements and FT-IR units at the engine outlet / catalyst inlet, catalyst bed, and outlet locations, allowing for accurate recording of temperature and gas emissions along the exhaust line.

[0243] Figures 2 to 6 The cumulative NH3, CO, and HC emissions of each test system using WLTC cycles collected on the aforementioned media are presented.

[0244] As from Figure 2 As can be seen, the comparative systems exhibit significantly higher cumulative NH3 emissions compared to the systems of the present invention in Examples 1, 3, and 4. The best results were obtained using the system of Example 1, which contains Pt on Ce-doped alumina.

[0245] As from Figure 3 It can be seen that, during the WLTC cycle, the cumulative CO emissions of the comparative system and the system of the present invention are comparable over a period of up to 600 seconds. At higher speeds and temperatures, the CO emissions of the comparative system are higher than those of the system of the present invention. The best results were obtained using the system of Example 1, which contains Pt on Ce-doped alumina.

[0246] Furthermore, such as from Figure 4 As can be seen, the cumulative HC emissions obtained with the comparative system are significantly higher than those of the system of the present invention, especially at low speeds and temperatures up to 220 seconds during WLTC cycling. The best results were obtained with the system of Example 3, which contains Rh on La-doped alumina.

[0247] The cumulative NH3 emissions of Comparative Examples 1 and 2, as well as Examples 1 and 2, are shown in Figure 5 In addition, as the cerium dioxide content of the carrier material increases, the cumulative NH3 emissions in Examples 1 and 2 of the present invention decrease.

[0248] Finally, as from Figure 6 It can be seen that the cumulative CO emissions obtained decrease with the increase of cerium dioxide content in the carrier material of Examples 1 and 2 of the present invention. Attached Figure Description

[0249] Figure 1 A schematic diagram of the exhaust gas treatment system according to Examples 1 to 4 and Comparative Examples 1 and 2 is shown.

[0250] Figure 2 The cumulative NH3 obtained after aging using the systems of Examples 1, 3, and 4, as well as Comparative Examples 1 and 2, is shown.

[0251] Figure 3 The cumulative CO obtained after aging using the systems of Example 1, Example 3, Example 4, and Comparative Example 1 and Comparative Example 2 is shown.

[0252] Figure 4 The cumulative HC obtained after aging using the systems of Examples 1, 3, 4, and Comparative Examples 1 and 2 is shown.

[0253] Figure 5 The cumulative NH3 obtained after aging using the systems of Examples 1 and 2, as well as Comparative Examples 1 and 2, is shown.

[0254] Figure 6 The cumulative CO obtained after aging using the systems of Examples 1 and 2, as well as Comparative Examples 1 and 2, is shown.

[0255] References

[0256] -EP 3974059 A1

[0257] -EP 3310461 A1

Claims

1. An exhaust gas treatment system for treating an exhaust gas stream exiting a gasoline engine, wherein the exhaust gas treatment system has an upstream end for introducing the exhaust gas stream into the exhaust gas treatment system, and wherein the exhaust gas treatment system comprises (i) a first catalyst, which is a three-way conversion catalyst, having an inlet end and an outlet end and comprising a coating disposed on a substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more thereof supported on a carrier material; (ii) a second catalyst, which is a four-way conversion catalyst, having an inlet end and an outlet end and comprising a coating disposed on a wall-flow filter substrate, wherein the coating comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more thereof supported on a carrier material; or a gasoline particulate filter having an inlet end and an outlet end; (iii) a third catalyst having an inlet end and an outlet end, wherein the third catalyst comprises a substrate and a coating for ammonia oxidation (AMOx) and for nitrogen oxide reduction, carbon monoxide oxidation and hydrocarbon oxidation (TWC), wherein the coating of the third catalyst comprises one or more platinum group metals selected from the group consisting of Pt, Pd, Rh and mixtures of two or more thereof supported on a carrier material, wherein the coating of the third catalyst comprises one or more zeolitic materials, and wherein the coating of the third catalyst comprises rhodium and / or an oxygen storage compound; wherein the first catalyst according to (i) is the first catalyst of the exhaust gas treatment system downstream of the upstream end of the exhaust gas treatment system, and wherein the inlet end of the first catalyst is arranged upstream of the outlet end of the first catalyst; wherein in the exhaust gas treatment system, the second catalyst according to (ii) is located downstream of the first catalyst according to (i), and wherein the inlet end of the second catalyst is arranged upstream of the outlet end of the second catalyst; wherein in the exhaust gas treatment system, the third catalyst according to (iii) is located downstream of the second catalyst according to (ii), and wherein the inlet end of the third catalyst is arranged upstream of the outlet end of the third catalyst.

2. The exhaust gas treatment system according to claim 1, wherein the coating of the first catalyst further comprises an oxygen storage compound (OSC).

3. The exhaust gas treatment system according to claim 1 or 2, wherein the coating of the first catalyst further comprises a NOx storage component.

4. The exhaust gas treatment system according to any one of claims 1 to 3, wherein the coating of the second catalyst further comprises an oxygen storage compound (OSC).

5. The exhaust gas treatment system according to any one of claims 1 to 4, wherein the coating of the second catalyst further comprises a non-zeolitic oxidic material.

6. The exhaust treatment system of any one of claims 1 to 5, wherein the washcoat of the second catalyst further comprises an oxide of an alkaline earth metal.

7. The exhaust treatment system of any one of claims 1 to 6, wherein the third catalyst is substantially free of palladium.

8. The exhaust treatment system of any one of claims 1 to 7, wherein the washcoat of the third catalyst comprises an oxygen storage compound (OSC).

9. The exhaust treatment system of claim 8, wherein a cerium content of the oxygen storage compound in the washcoat of the third catalyst is in a range of 5 wt% to 81.46 wt%, based on a total weight of the oxygen storage compound of the washcoat of the third catalyst.

10. The exhaust treatment system of any one of claims 1 to 9, wherein the support material of the washcoat of the third catalyst comprises one or more rare earth metals, and wherein the one or more rare earth metals are selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, and mixtures of two or more thereof.

11. The exhaust treatment system of any one of claims 1 to 10, wherein the one or more zeolite materials comprised in the washcoat of the third catalyst comprises one or more of Fe and Cu.

12. The exhaust treatment system of any one of claims 1 to 11, wherein the washcoat of the third catalyst comprises a first catalytic washcoat comprising one or more platinum group metals supported on a support material and a second catalytic washcoat comprising one or more zeolite materials, wherein the first catalytic washcoat comprises rhodium and / or an oxygen storage compound.

13. The exhaust treatment system of claim 12, wherein the first catalytic washcoat is disposed on the substrate of the third catalyst for more than 98% to 100% of a substrate axial length.

14. The exhaust treatment system of claim 12, wherein the third catalyst comprises an inlet zone comprising the first catalytic washcoat and an outlet zone comprising a second catalytic washcoat.

15. A method for simultaneous selective catalytic reduction of NOx, oxidation of hydrocarbons, oxidation of nitrogen monoxide, and oxidation of ammonia, the method comprising (1) providing an exhaust gas stream from a gasoline engine, the exhaust gas stream comprising one or more of NOx, ammonia, nitrogen monoxide, and hydrocarbons; (2) passing the exhaust gas stream provided in (1) through an exhaust system according to any one of claims 1 to 14.

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