• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    SUBSTRATE MONOLITH, EXHAUST SYSTEM FOR AN INTERNAL COMBUSTION ENGINE OF POOR FIRE BURNING, INTERNAL COMBUSTION ENGINE OF POOR BURNING, COMPRESSION IGNITION ENGINE, VEHICLE, AND METHOD OF REDUCING OR PREVENTING PLATINUM METAL. A substrate monolith (6) having a length L and comprising a first zone (11) of substantially uniform length defined at one end by a first end of the substrate monolith, the first zone of which comprises a selective catalytic reduction catalyst (SCR) for reduce nitrogen oxides with a nitrogen reducer in exhaust gas emitted from an internal combustion engine and a second zone (8) of substantially uniform length less than L defined at one end by a second end of the substrate monolith, the second zone of which comprises (a) at least one particulate metal oxide or a mixture of any two or more of them to trap metal from the gas phase platinum group (PGM), which at least one particulate metal oxide does not act as a support for any other catalytic components; or (b) a component capable of trapping with gas phase PGM.
    公开号:BR112014013233B1
    申请号:R112014013233-0
    申请日:2012-12-11
    公开日:2020-10-27
    发明作者:Mario Jaime Castagnola；Andrew Francis Chiffey；Paul Richard Phillips；Raj RAJARAM；Andrew Walker
    申请人:Johnson Matthey Public Limited Company；
    IPC主号:
    专利说明:

    Field of the Invention
    [0001] The present invention relates to a substrate monolith comprising a selective catalytic reduction (SCR) catalyst to reduce nitrogen oxides with a nitrogenous reducer in exhaust gas emitted from an internal combustion engine, such as an engine vehicular internal combustion, whose substrate monolith is designed to reduce or prevent contamination of the SCR catalyst, and consequent loss of conversion of NOX activity, of the platinum group metal (PGM), particularly platinum that can be volatilized from catalysts containing PGM upstream. Fundamentals of the Invention
    [0002] In general, there are four classes of pollutants that are controlled by intergovernmental organizations worldwide: carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxides (NOX) and particulate matter (PM).
    [0003] As the emission standards for the permissible emission of such pollutants in vehicle engine exhaust gases become progressively tighter, a combination of engine management and multiple catalytic exhaust gas aftertreatment systems is being proposed and developed to meet these emission standards. For exhaust systems containing a particulate filter it is common for engine management to be used periodically (for example, every 500 km) to increase the temperature in the filter in order to burn substantially all the remaining soot kept in the filter thus returning the system to a baseline level. These engine-managed soot combustion events are often called “filter regeneration”. Although a primary focus of filter regeneration is to burn soot kept in the filter, an unintended consequence is that one or more catalyst coatings present in the exhaust system, for example, a filter coat on the filter itself (a so-called catalyzed soot (CSF)) an oxidation catalyst (such as a diesel oxidation catalyst (DOC)) or a NO2 adsorbent catalyst (NAC) located upstream or downstream of the filter (for example, a first DOC followed by a particulate diesel filter, followed by a second DOC and finally a SCR catalyst) can be regularly exposed to high exhaust gas temperatures, depending on the level of engine management control in the system, such conditions can also be experienced with occasional unintended engine compromise modes or uncontrolled or poorly controlled regeneration events. However, some diesel engines, particularly heavy dirt diesel engines that operate at high load, can still expose catalysts to significant temperatures, for example,> 600 ° C under normal operating conditions.
    [0004] As vehicle manufacturers develop their engines and engine management systems to meet emission standards, vehicle manufacturers have asked the Applicant / Inventor to propose catalytic components and catalytic component combinations to assist in the goal of meeting emission standards. Such components include DOCs to oxidize CO, HCs and optionally NO as well; CSFs to oxidize CO, HCs, optionally to oxidize NO as well, and to trap particulate matter for subsequent combustion; NACs to oxidize CO and HC and to oxidize nitrogen monoxide (NO) and absorb it from a poor exhaust gas and to desorb adsorbed NOX and to reduce it to N2 in a rich exhaust gas (see below) ; and selective catalytic reduction catalysts (SCR) to reduce NOXto N2 in the presence of a nitrogen reducer, such as ammonia (see below).
    [0005] In practice, catalyst compositions employed in DOCs and CSFs are very similar. In general, however, a major difference between the use of a DOC and a CSF is the substrate monolith on which the catalyst composition is coated: in the case of a DOC, the substrate monolith is typically a substrate monolith through the flow , comprising a metal or ceramic honeycomb monolith having an arrangement of elongated channels extending through it, whose channels are open at both ends; a CSF substrate monolith is a filter monolith, such as a wall flow filter, for example, a porous ceramic filter substrate comprising a plurality of input channels arranged in parallel with a plurality of output channels, where each Inlet channel and each outlet channel is defined in part by a porous ceramic wall, where each input channel is alternately separated from an outlet channel by a porous ceramic wall and vice versa. In other words, the wall flow filter is a honeycomb arrangement that defines a plurality of primary channels plugged at an upstream end and a plurality of secondary channels not plugged at the upstream end, but plugged at a downstream end. Channels vertically and laterally adjacent to a primary channel are plugged at one end downstream. When viewed from either end, the alternately plugged and open ends of the channels assume the appearance of a board.
    [0006] Very complicated multi-layer catalyst arrangements, such as DOCs and NACs, can be coated on a substrate monolith through flow. While it is possible to coat a surface of a filter monolith, for example, an inlet channel surface of a wall flow filter, with more than one layer of catalyst composition, a problem with coating filter monoliths is to avoid pressure of return that increases unnecessarily when in use, overloading the filter monolith with final catalyst finish, thus restricting the passage of gas through it. Thus, although coating a surface of a substrate filter monolith sequentially with one or more different layers of catalyst is not impossible, it is more common for different catalyst compositions to be segregated in any zones, for example, axially segregated front and half-rear zones of a filter monolith, or by coating an inlet channel of a substrate monolith wall flow filter with a primary catalyst composition and an outlet channel with a second catalyst composition. However, in particular embodiments of the present invention, the filter inlet is coated with one or more layers, the layers of which may be of the same or different catalyst composition. It has also been proposed to coat a NAC composition on a substrate filter monolith (see, for example, EP 0766993).
    [0007] In exhaust systems comprising multiple components of the catalyst, each comprising a separate substrate monolith, typically the SCR catalyst is located downstream of a DOC and / or a CSF and / or a NAC because it is known that oxidizing some nitrogen oxide (NO) in the exhaust gas to nitrogen dioxide (NO2) so there is a ratio of about 1: 1 of NO: NO2 coming out of the DOC and / or the CSF and / or the NAC, the SCR reaction the downstream is promoted (see below). It is also well known from EP341832 (the so-called Continuously Regerar Trap or CRT®) that NO2, generated by oxidation of NO in exhaust gas to NO2, can be used to passively burn soot in a downstream filter. In exhaust system arrangements where the EP341832 process is important, where the SCR catalyst must be located upstream of the filter, this can reduce or prevent the soot burning process trapped in NO2, due to a majority of the NOX used for burning the soot can probably be removed from the SCR catalyst.
    [0008] However, a preferred system arrangement for light dirt diesel vehicles is a diesel oxidation catalyst (DOC) followed by a nitrogen reducer injector, then an SCR catalyst and finally a catalyzed soot filter (CSF). A shortcut to an arrangement like this is “DOC / SCR / CSF”. This arrangement is preferred for light dirt diesel vehicles because an important consideration is to achieve conversion of NOx into an exhaust system as quickly as possible after a vehicle engine is started to enable (i) precursors to nitrogen reducers, such as as ammonia to be injected / decomposed in order to release ammonia for NOX conversion; and (ii) NOX conversion as high as possible. Where a large thermal mass filter to be placed upstream of the SCR catalyst, that is, between the DOC and the SCR catalyst (“DOC / CSF / SCR”), (i) and (ii) may take longer to reach and convert NOX as a whole of the emission pattern triggering cycle can be reduced. Particulate removal can be done using oxygen and occasional forced regeneration of the filter using engine management techniques.
    [0009] It has also been proposed to coat a final finish SCR catalyst on a substrate filter monolith itself (see, for example, WO 2005/016497), in which case an oxidation catalyst can be located upstream of the coated filter substrate with SCR (whether the oxidation catalyst is a component of a DOC, a CSF or a NAC) in order to modify the NO / NO2 ratio to promote NOX reduction activity in the SCR catalyst. It has also been proposed to locate a NAC upstream of an SCR catalyst disposed in a substrate monolith through the flow, whose NAC can generate NH3 in situ during NAC regeneration (see below). A proposal like this is described in GB 2375059.
    [00010] NACs are known, for example, from US 5,473,887 and are designed to adsorb NOX from the poor exhaust gas (lambda> 1) and to desorb the NOX when the oxygen concentration in the exhaust gas decreases. NOX desorbed can be reduced to N2 with a suitable reducer, for example engine fuel, promoted by a catalyst component, such as rhodium, from the NAC itself or located downstream from the NAC. In practice, control of the oxygen concentration can be adjusted to a desired redox composition intermittently in response to a calculated NAC remaining adsorption capacity of the NAC, for example, richer than normal (but still poor stoichiometric or engine running operation) lambda = 1 composition), stoichiometric or rich in stoichiometry (lambda <1). The oxygen concentration can be adjusted in a number of ways, for example, throttling, injecting additional hydrocarbon fuel into an engine cylinder, such as during the exhaust stroke or injecting hydrocarbon fuel directly into the exhaust gas downstream of a manifold the engine.
    [00011] A typical NAC formulation includes a catalytic oxidation component, such as platinum, a significant amount, (that is, substantially more that is required for use as a promoter, such as a promoter in a three-way catalyst), of a NOX storage component, such as barium, and a reduction catalyst, for example, rhodium. A commonly given mechanism for storing NOX from a poor exhaust gas for this formulation is:
    where in reaction (1), nitric oxide reacts with oxygen at active oxidation sites on platinum to form NO2. Reaction (2) involves adsorption of NO2 by the storage material in the form of an inorganic nitrate.
    [00012] At lower concentrations of oxygen and / or at high temperatures, nitrate species become thermodynamically unstable and decomposes, producing NO or NO2 according to the reaction (3) below. In the presence of a suitable reducer, these nitrogen oxides are subsequently reduced by carbon monoxide, hydrogen and hydrocarbons to N2, which can happen on the reduction catalyst (see reaction (4)).

    [00013] In the reactions of (l) - (4) including previously here, the reactive barium species are given as the oxide. However, it is understood that in the presence of air the majority of barium is in the form of carbonate or possibly 0 hydroxide. Versed can adapt the previous reaction schemes according to the barium species other than the oxide and catalytic coatings sequence in the exhaust stream.
    [00014] Oxidation catalysts promote oxidation of CO to CO2 and HCs not burned to CO2 and H2O. Typical oxidation catalysts include platinum and / or palladium on a high surface area support.
    [00015] The application of SCR technology to treat NOX emissions from vehicular internal combustion (IC) engines, particularly low-burn IC engines, is well known. Examples of nitrogenous reducers that can be used in the SCR reaction include compounds, such as nitrogen hydrides, for example, ammonia (NH3) or hydrazine, or an NH3 precursor.
    [00016] NH3 precursors are one or more compounds from which NH3 can be derived, for example, by hydrolysis. Decomposition of the precursor to ammonia and other by-products can be by hydrothermal or catalytic hydrolysis, NH3 precursors include urea (COCNPEh) as an aqueous solution or as a solid or ammonium carbamate (NH2COONH4). If urea is used as an aqueous solution, a eutectic mixture, for example, a 32.5% NH3 (aq) is preferred. Additives can be included in the aqueous solutions to reduce the crystallization temperature. Currently, urea is the preferred source of NH3 for mobile applications because it is less toxic than NH3, it is easy to transport and to handle and is inexpensive and commonly available. Incomplete urea hydrolysis can lead to higher PM emissions in tests to meet the relevant emission test cycle due to solids or droplets of partially hydrolyzed urea being trapped by the filter paper used in the PM legislative test and counted as PM mass . In addition, the release of certain incomplete urea hydrolysis products, such as cyanuric acid, is environmentally undesirable.
    [00017] SCR has three main reactions (shown below in reactions (5) - (7) inclusive) that reduce NOX to elemental nitrogen.

    [00018] A relevant undesirable, non-selective side reaction is:

    [00019] In practice, reaction (7) is relatively slow compared to reaction (5) and reaction (6) is the fastest of all. For this reason, when versed in technology they design exhaust after-treatment systems for vehicles, they often prefer to have an oxidation element catalyst (for example, a DOC and / or a CSF and / or a NAC) upstream of a SCR catalyst.
    [00020] When certain DOCs and / or NACs and / or CSFs are exposed to high temperatures encountered, for example, during filter regeneration and / or an engine compromise event and / or (in certain heavy dirt diesel applications) normal high temperature exhaust gas, sufficient time at high temperature is possible for low levels of platinum group metal components, particularly Pt, to volatilize from DOC and / or NAC and / or CSF components and subsequently for the platinum group metal to be trapped in an SCR catalyst downstream. This can have a highly detrimental effect on the performance of the SCR catalyst, since the presence of Pt leads to a high activity for competitive, non-selective ammonia oxidation, such as in reaction (9) (which shows the complete oxidation of NH3) , thus producing secondary emissions and / or not productively consuming NH3.

    [00021] A vehicle manufacturer reported the observation of this phenomenon on SAE 2009-01-0627 paper, which is entitled “Impact and Prevention of Ultra-Low Contamination of Metal of Platinum Groups on SCR Catalysts Due to DOC Design” and includes data that compare the NOX-to-temperature conversion activity for a Fe / zeolite SCR catalyst located in series behind four suppliers' DOCs containing platinum group metal (PGM) that have been brought into contact with a flow model exhaust gas at 850 ° C for 16 hours. The results presented show that the NOX conversion activity of a Fe / zeolite SCR catalyst disposed behind a DOC 20Pt: Pd at 70gff3 (2,499 g / m3) total PGM was negatively altered at higher evaluation temperatures compared to evaluation temperatures lower as a result of Pt contamination. Two 2Pt: Pd DOCs from different suppliers at total PGM 105gff3 (3,748.5 g / m3) were also tested. In a first DOC 2Pt: Pd, the activity of the SCR catalyst was affected to a similar extent as the test in the DOC 20Pt: Pd, whereas for the second DOC 2Pt: Pd the activity of the SCR catalyst was contaminated to a lesser extent, although the second DOC 2Pt: Pd still showed less conversion of NOX activity compared to the white control (no DOC, only one substrate discovered). The authors concluded that the supplier of the second DOC 2Pt: Pd, which showed more moderate conversion of NOX degradation, was more successful in stabilizing 70gff3 (2,499 g / m3) Pt present with 35gff3 (1,249.5 g / m3 ) Pd. A DOC of only Pd at 150 gff3 (5,355 g / m3) showed no impact on the SCR downstream with respect to the white control. Previous studies by the authors of SAE 2009-01-0627 have been published on SAE paper no. 2008-01-2488. Summary of the Invention
    [00022] Vehicle manufacturers began to ask the Applicant for means to resolve the volatilization problem of relatively low levels of component PGMs upstream of SCR catalysts. It would be highly desirable to develop strategies to prevent this movement of PGM in an SCR catalyst downstream at high temperatures. Numerous strategies have been developed to meet this need.
    [00023] It has been observed that platinum volatilization of a catalyst containing PGM comprising platinum and both platinum and palladium can occur under extreme temperature conditions. For example, in some experiments, Pt volatilization can occur when the weight ratio of Pt: Pd is greater than about 2: 1. It is also believed that where PGM consists of platinum, platinum volatilization can also be observed. A substrate monolith has been designed comprising an SCR catalyst and an exhaust system arrangement including this substrate monolith which avoids or reduces the PGM problem, particularly Pt, migrating from a relatively highly charged Pt catalyst upstream to an SCR catalyst at downstream.
    [00024] According to a first aspect, the invention provides a substrate monolith having a length L and comprising a first zone of substantially uniform length defined at one end by a first end of the substrate monolith, the first zone of which comprises a catalyst of selective catalytic reduction (SCR) to reduce nitrogen oxides with a nitrogenous reducer in exhaust gas emitted from an internal combustion engine and a second zone of substantially uniform length less than L defined at one end by a second end of the substrate monolith, whose second zone comprising (a) at least one particulate metal oxide or a mixture of any two or more of them to trap metal from the gas phase platinum group (PGM), which at least one particulate metal oxide does not act as a support for any other catalytic component; or (b) a component capable of trapping with gas phase PGM. The first zone or first end of the substrate monolith is generally different from the second zone or second end of the substrate monolith.
    [00025] In accordance with an additional aspect, the invention provides an exhaust system for a vehicle combustion combustion engine, whose system comprises a substrate monolith of the invention, and in which the second zone and / or the second end of the substrate monolith is oriented to an upstream side (for example, the first zone and / or the first end of the substrate monolith is oriented to a downstream side). Typically, the exhaust system further comprises a catalyzed substrate monolith, wherein the catalyzed substrate monolith comprises a catalyst comprising platinum, and in which the catalyzed substrate monolith and / or platinum is arranged upstream of the substrate monolith of the invention. .
    [00026] The invention further provides a low-burn internal combustion engine comprising an exhaust system of the invention. The internal combustion engine with poor burn can be a compression ignition engine.
    [00027] According to an additional aspect, a vehicle is provided comprising an exhaust system of the invention. Typically, the vehicle further comprises an engine (e.g., an internal combustion engine), such as a low-burn internal combustion engine, particularly an engine compression ignition.
    [00028] In an additional aspect a method is provided to reduce or prevent metal from the platinum group from positioning a selective catalytic reduction catalyst (SCR) to reduce nitrogen oxides with a nitrogenous reducer in exhaust gas emitted from a combustion engine internal in an exhaust system of a low-combustion internal combustion engine, whose platinum group metal (PGM) is present in a catalyzed substrate monolith of an exhaust system of a low-combustion internal combustion engine and, typically it is liable to volatilize when in use and migrate to a surface of a substrate monolith comprising the SCR catalyst, wherein a substrate monolith comprising an SCR catalyst is disposed downstream of the catalyzed substrate monolith, whose substrate monolith having a length L and comprising a first zone of substantially uniform length defined at one end by a first end of the substrate monolith, the first zone comprising a selective catalytic reduction catalyst (SCR) to reduce nitrogen oxides with a nitrogen reducer in exhaust gas emitted from an internal combustion engine and a second zone of substantially uniform length less than L defined at one end by a second end of the substrate monolith, the second zone of which comprises (a) at least one particulate metal oxide or a mixture of any two or more of them to trap gas phase PGM, which at least one particulate metal oxide does not act as a support for any other catalytic component; or (b) a component capable of trapping with gas phase PGM and in which the second zone is oriented to come into contact with exhaust gas leaving the catalyzed substrate monolith before the first zone, the method of which involves trapping PGM in the second zone .
    [00029] An additional aspect of the invention relates to the use of a particulate metal oxide (for example, at least a particulate metal oxide or a mixture of any two or more of them) or a component capable of trapping with gas group platinum group metal (PGM) to reduce or prevent poisoning of a selective catalytic reduction catalyst (SCR) by a platinum group metal (PGM), typically in an exhaust system of an internal combustion engine poor burn, wherein the exhaust system comprises a substrate monolith having a length L and comprising a first zone of substantially uniform length defined at one end by a first end of the substrate monolith, the first zone of which comprises a selective catalytic reduction catalyst (SCR) to reduce nitrogen oxides with a nitrogenous reducer in exhaust gas emitted from an internal combustion engine and a second zone of subst length initially uniformly smaller than L defined at one end by a second end of the substrate monolith, the second zone of which comprises (a) the particulate metal oxide to trap metal in the gas phase platinum group (PGM) and, preferably whose metal oxide particulate does not act as a support for any other catalytic component, or (b) the component capable of trapping with gas phase PGM. Typically, the second zone and / or the second end of the substrate monolith is oriented to an upstream side (for example, the first zone and / or the first end of the substrate monolith is oriented to a downstream side). Brief Description of Drawings
    [00030] In such a way that the invention can be more fully understood, reference is made to the following modality and Examples by way of illustration only and with reference to the attached drawings.
    [00031] Figure 1 is a schematic drawing of an exhaust system according to the present invention.
    [00032] Figure 2 is a schematic drawing of a laboratory reactor used to test platinum contamination on a Fe / Beta zeolite SCR catalyst or a Cu / CHA zeolite SCR catalyst.
    [00033] Figure 3 is a graph that compares the conversion of NOx activity as a temperature function of the three aged SCR catalyst cores, each of which was aged in a laboratory scale exhaust system configuration containing a flow filter. catalytic wall disposed upstream of the Fe / Beta zeolite SCR catalyst of example 1, a system comprising a coated filter in both the inlet and outlet channel with weight ratio Pt: Pd 1: 1 of example 3; a second system comprising a coated filter in both the input and output channels with a weight ratio Pt: Pd 5: 1 of example 4; and a third, comparative system comprising a filter coated both in the inlet and outlet channel with a Pt-only catalyst according to Comparative Example 2. The results of the aged SCR activity are plotted against the activity of a newly SCR catalyst prepared, that is, not aged.
    [00034] Figure 4 is a bar graph that compares the conversion of NOX activity as a function of temperature of the two aged SCR catalyst cores, each of which was aged in the laboratory scale exhaust system shown in Figure 1 containing samples of the diesel oxidation catalyst core of comparative example 3 and example 4 heated in a tube oven at 900 ° C for 2 hours in a synthetic exhaust gas flowing with the Cu / CHA zeolite SCR catalyst core maintained at 300 ° C located downstream. Detailed Description of the Invention
    [00035] Typically, particulate metal oxide (i.e., at least one particulate metal oxide from (a)) can be selected from the group consisting of optionally stabilized alumina, amorphous silica-alumina, optionally stabilized zirconia, ceria, titania , an optionally stabilized mixed ceriazirconium oxide and mixtures of either or more of the same. By "does not act as a support for any other catalytic component" here is meant that at least one particulate metal oxide does not support any of the catalyst compositions comprising alkali metals, alkaline earth metals or transition metals (including lanthanides) or elements of the group III A, IV A, VA or VIA (according to the Chemical Abstracts Service (c. 1999)) of the periodic table.
    [00036] The second zone can typically comprise a particulate metal oxide in a total amount of 0.1 to 5 g in3, preferably 0.2 to 4 g in-3 (for example, 0.5 to 3.5 g in-3), more preferably 1 to 2.5 g in-3.
    [00037] The component capable of trapping with gas phase PGM (for example, component (b)) typically comprises a metal selected from the group consisting of gold, palladium and silver. Preferably, component (b) comprises a mixture or an alloy of palladium and gold.
    [00038] Typically, the total amount of component (b) is 10 to 350 g ff3 (12,495 / m3). It is preferred that the total amount of component (b) is 20 to 300 g ff3 (174 to 10,710 g / m3), more preferably 30 to 250 g ff3 (1 74 to 8,925 g / m3), even more preferably 45 to 200 g ff3 (1,606.5 g / m3), and even more preferably 50 to 175 g ff3 (1,785 g / m3 to 6,247.5 g / m3).
    [00039] The second zone and the first zone comprising the SCR catalyst in the substrate monolith can be arranged in a number of different ways. For example, the first zone can extend over the entire length L, and the second zone can rest in the first zone. The SCR catalyst can be of the extruded type (also sometimes referred to as a "body catalyst"), or a coating to be applied to an inert substrate monolith. Component (b) capable of trapping with platinum in the gas phase, for example, palladium, gold, silver or palladium and gold, can be supported by the SCR catalyst per se, or component (b) comprises at least one metal oxide in the which component capable of trapping with gas phase PGM is supported. Methods of impregnating an SCR catalyst with a PGM to form a zone to selectively oxidize that slides on the SCR catalyst to dinitrogen are known, for example, from EP 1399246 and the opposition to it.
    [00040] Where the second zone comprises a coating, the zone is generally applied as a final finish coating comprising a support material. Supporting materials known in the art include optionally stabilized alumina, titania, ceria, optionally stabilized zirconia, mixed oxides containing ceria, such as ceriazirconia possibly still stabilized with one or more elements of rare metal, silica, amorphous silica alumina, etc.
    [00041] Substrate monolith for use in the present invention can be ceramic, such as cordierite, aluminum titanate, silicon carbide or the like; or metallic, made, for example, of thin metal sheets of ferritic iron-chromium-aluminum alloys. The arrangement of such a substrate monolith can be by non-filtration, such as then called monoliths through the flow in which open channels extend from a first end to a second end, or substrate filter monolith can be used having inlet surfaces and exit surfaces, where the entrance surfaces are separated from the exit surfaces by a porous structure. Preferred substrate filter monoliths are wall flow filters, as described above.
    [00042] Catalyzed filters, preferably wall flow filters, can be coated using the method described in Applicant / Inventor WO 2011/080525. That is, a method of coating a honeycomb monolith substrate comprising a plurality of channels with a liquid comprising a catalyst component, the method of which comprises the steps of: (i) maintaining a honeycomb substrate substantially vertically; (ii) introducing a predetermined volume of the liquid into the substrate through the open ends of the channels at a lower end of the substrate; (iii) to seal the liquid introduced into the substrate in a sealed manner; (iv) inverting the substrate containing the retained liquid; and (v) applying a vacuum to the open ends of the substrate channels at the inverted, lower end of the substrate to remove the liquid along the substrate channels. The catalyst composition can be coated on the filter channels of a first end, after which the coated filter can be dried.
    [00043] Use of a method like this can be controlled using, for example, vacuum resistance, vacuum duration, final finish viscosity, final finish solids, coating particle or agglomerate size and surface tension, in such a way that catalyst is coated predominantly on the entrance surfaces, but also optionally on the porous structure, but close to the entrance surfaces. Alternatively, the final finishing component can be ground to a size, for example, D90 <5pm, in such a way that they “permeate” the porous structure of the filter (see WO 2005/016497).
    [00044] The term "substantially uniform length" as used herein refers to the length of the layer that does not deviate by more than 10%, preferably does not deviate by more than 5%, more preferably does not deviate by more than 1%, from average layer length value.
    [00045] When the substrate monolith comprises (a) or (b), the SCR catalyst in the first zone may be present as a coating on the substrate monolith of substantially uniform length less than L. Typically, there is substantially no overlap between the first zone comprising (a) or (b) and the second zone. It is preferred that component (b) comprises at least one metal oxide in which the component capable of trapping with gas phase PGM is supported.
    [00046] When the substrate monolith is a wall flow filter, the SCR catalyst can be arranged in open channels at the first end of the wall flow filter and the second zone is arranged in open channels at the second end of it, where the porous structure defines a transition between the first final finishing zone and the second final finishing zone.
    [00047] The substrate monolith according to the invention comprises a catalyst to selectively catalyze the reduction of nitrogen oxides to dinitrogen with a nitrogen reducer, also known as a selective catalytic reduction (SCR) catalyst. The SCR catalyst can be coated as a coating on a substrate monolith, as described above. Alternatively, the SCR catalyst is supplied as an extrudate (also known as a “body catalyst”), that is, the catalyst is mixed with components of the substrate structure monolith, which are both extruded, so the catalyst is part of the walls of the substrate monolith. It is also possible to prepare a wall flow filter from an extruded SCR catalyst (see WO 2009/093071 and WO 201 1/092521 by Applicant / Inventor). SCR catalysts for use in the present invention can be selected from the group consisting of at least one of Cu, Hf, La, Au, Em, V, lanthanides and group VII transition metals, such as Fe, supported in a refractory oxide or molecular sieve. Preferred metals of particular interest are selected from the group consisting of Ce, Fe and Cu. Suitable refractory oxides include AI2O3, TiO2, CeCL, SiO2, ZrÜ2 and mixed oxides containing two or more of the same. Non-zeolite catalyst can also include tungsten oxide, for example, V2O5 / WO3 / TIOO2. Preferred metals of particular interest are selected from the group consisting of Ce, Fe and Cu. Molecular sieves can be exchanged ionically with the previous metals.
    [00048] In general, at least one molecular sieve is an aluminosilicate zeolite or a SAPO. At least one molecular sieve can be a small, medium or large pore molecular sieve, for example. By "small pore molecular sieve" here is meant molecular sieves containing a maximum ring size of 8 tetrahedral atoms, such as CHA; By "medium pore molecular sieve" here is meant a molecular sieve containing a maximum ring size of 10 tetrahedral atoms, such as ZSM-5; and by "large pore molecular sieve" here is meant a molecular sieve having a maximum ring size of 12 tetrahedral atoms, such as beta. Small pore molecular sieves are potentially advantageous for use in SCR catalysts - see, for example, Applicant / Inventor WO 2008/132452. Molecular sieves for use in SCR catalysts according to the invention include one or more metals incorporated in a molecular sieve frame for example, Fe "in the frame" Beta and Cu "in the frame" CHA.
    [00049] Particular molecular sieves for application in the present invention are selected from the group consisting of AEI, ZSM-5, ZSM-20, ERI including ZSM-34, mordenite, ferrierite, BEA including Beta, Y, CHA, LEV including Nu- 3, MCM-22 and EU-1, with CHA molecular sieves, for example, CHA aluminosilicate, currently preferred, particularly in combination with Cu as an ion exchange promoter.
    [00050] Typically, the exhaust system of the invention still comprises means (for example, an injector) for injecting a nitrogenous reducer into the exhaust gas. In general, the means for injecting a nitrogenous reducer is arranged upstream of the substrate monolith. Thus, a nitrogen reducer can be added to an exhaust gas and fed to an inlet, typically at a second end, of the substrate monolith.
    [00051] Nitrogen reducers and precursors thereof for use in the present invention include any of those mentioned above in conjunction with the fundamentals section. Thus, for example, the nitrogen reducer is preferably ammonia or urea.
    [00052] It is preferred that the means for injecting a nitrogen reducer (e.g., ammonia or a precursor thereof, such as urea) are arranged between the catalyzed substrate monolith and the substrate monolith comprising the SCR catalyst. Ammonia precursors can be any of those mentioned in the fundamentals section earlier.
    [00053] The catalyst comprising platinum can be a diesel oxidation catalyst or a NOX absorbent catalyst, optionally each having the composition described in the fundamentals section above. Where a diesel oxidation catalyst is disposed on a filtration substrate, for example, a wall flow filter, it is known here as a catalyzed soot filter or CSF.
    [00054] Typically, the catalyst (i.e., the catalyst comprising platinum) comprises both platinum and palladium.
    [00055] Since the substrate monolith according to the invention comprises a measure to reduce or prevent platinum from volatilizing and migrating from the catalyst comprising platinum to a downstream SCR catalyst, it is possible that relatively high Pt: Pd weight ratios are used in the catalyst comprising platinum for the purposes of, for example, generating NO2 to promote combustion downstream of filtered particulate matter, such as <10: 1, for example, 8: 1, 6: 1, 5: 1 or 4: 1 It is possible to use relatively high Pt: Pd weight ratios, even if PGM can volatilize from it because the design of the substrate monolith according to the first aspect of the invention substantially prevents PGM from volatilizing from contact with 0 SCR catalyst.
    [00056] The catalyst comprising platinum can be disposed immediately upstream of the substrate monolith comprising the SCR catalyst (i.e. without any intervention of the substrate monolith between the catalyzed substrate monolith and the substrate monolith of the present invention for example, comprising the SCR catalyst).
    [00057] In general, and especially when the catalyst comprising platinum is disposed immediately upstream of the substrate monolith (i.e., comprising the SCR catalyst), the catalyst (i.e., the catalyst comprising platinum) comprises both platinum and palladium in a weight ratio of Pt: Pd is <2, such as <1.5: 1, for example, about 1: 1. The significance of this characteristic is shown in the examples: it was observed that the weight ratios Pt: Pd preferred are less volatile, through empirical testing, than a similar catalyst having a Pt: Pd weight ratio of 4: 1. In layered catalyst arrangements, it is preferred that an outer layer has a Pt: Pd weight ratio of <2 , or optionally that the general Pt: Pd weight ratio of all combined layers is <2.
    [00058] Typically, the weight ratio of Pt: Pd is> 35:65 (for example,> 7: 13). It is preferred that the weight ratio Pt: Pd is> 40:60 (for example,> 2: 3), more preferably> 42.5: 57.5 (for example,> 17:23), particularly> 45:55 (for example ,> 9: 11), such as> 50:50 (e.g.> 1: 1), and even more preferably> 1.25: 1. The weight ratio of Pt: Pd is typically 10: 1 to 7: 13. It is preferred that the weight ratio of Pt: Pd is 8: 1 to 2: 3, more preferably 6: 1 to 17:23, even more preferably 5: 1 to 9: 11, such as 4: 1 to 1: 1, and even more preferably 2: 1 to 1.25: 1.
    [00059] In general, the total amount of the platinum group metal (PGM) (for example, the total amount of Pt and / or Pd) is 1 to 500 g ff3 (35.7 to 17,850 g / m3). Preferably, the total amount of PGM is 5 to 400 g ff3 (178.5 to 14.280 g / m3), more preferably 10 to 300 g ff3 (357 to 10.710 g / m3), even more preferably 25 to 250 g ff3 ( 892.5 to 8925 g / m3), and even more preferably 35 to 200 g ff3 (1,249.5 to 7,140 g / m3).
    [00060] The invention also provides a low-burn internal combustion engine comprising an exhaust system according to the invention. The low-burn internal combustion engine can be a positive ignition, for example, a spark ignition, engine that typically runs on gasoline fuel or combinations of gasoline fuel and other components, such as ethanol, but is preferably a compression ignition , for example, a diesel engine. Low combustion internal combustion engines include homogeneous charge compression ignition (HCCI) engines, powered by both gasoline etc. fuel or diesel fuel.
    [00061] Engine management means can be provided, when in use, to bring the catalyzed substrate monolith into contact with an enriched exhaust gas to generate ammonia in situ. Such an arrangement can be used in combination with exhaust systems comprising means for injecting a nitrogen reducer (eg, ammonia or a precursor thereof, such as urea) between the catalyzed substrate monolith and the substrate monolith comprising the SCR catalyst, or without such means. Engine management means are provided to enrich exhaust gas, such that ammonia gas is generated in situ by the reduction of NOX in the PGM catalyst of the catalyzed substrate monolith.
    [00062] In combination with a properly designed and managed diesel compression ignition engine, enriched exhaust gas, that is, exhaust gas containing increased amounts of carbon monoxide and hydrocarbon with respect to normal poor racing mode, comes into contact the NAC.
    [00063] Components in a NAC, such as ceria promoted by PGM or ceria-zirconia can promote the water-gas displacement reaction, that is, CO (g) + H20 (V) ^ CÜ2 (g) + H2 (g) evolving PE. Indeed, the footnote for side reaction for reactions (3) and (4) presented above, for example, Ba (N0s) 2 + 8H2— »BaO + 2NH3 + 5H2O, NH3 can be generated in situ and stored for reduction of NOX in the downstream SCR catalyst.
    [00064] An exhaust system of the present invention is illustrated in figure 1. Exhaust system 10 comprises, in a series arrangement of upstream and downstream, a wall flow filter 2 coated with an oxidation catalyst formulation comprising both platinum and palladium at a 4: 1 weight ratio (known in the art as a catalytic soot filter or “CSF”); an ammonia source 4 comprising an injector for an ammonia precursor, urea; and a substrate 6 monolith wall flow downstream filter coated in the second zone 8 in its inlet channels only with a mixed ceria: zirconia oxide having a 9: 1 weight ratio at a final finish load of 1.0 g / in3 and coated in a first zone 11 that extends the entire length of the wall flow filter with a SCR CuCHA catalyst that permeates a porous structure of the wall flow filter. That is, the second zone overlaps the first zone. Each substrate monolith 2, 6 is arranged in a metal or “can” container including cone diffusers and is connected by a series of conduits 3 with a smaller cross-sectional area than a cross-sectional area of substrate monolith 2, 4. The diffuser in cone acts to spread the flow of exhaust gas that enters a housing of a "canned" substrate monolith, in such a way that the exhaust gas as a whole is directed through substantially the entire front "touching" each monolith of substrate. Exhaust gas exiting the substrate monolith 4 is exhausted to the atmosphere in the “tail pipe” 5. EXAMPLES EXAMPLE .O 1 - Preparation of substrate monolith coated with 5 wt% Fe / Beta Zeolite
    [00065] Commercially available beta zeolite was added to an aqueous solution of Fe (NOs) 3 with stirring. After mixing, binders and rheology modifiers were added to form a final finish composition.
    [00066] A cordierite substrate monolith through the flow of 400 cells per square inch (1 square inch = 645.2 cm2) was coated with a 5% aqueous weight of Fe / Beta zeolite sample using the method described in
    [00067] Applicant / Inventor WO 99/47260, that is, comprising the steps of (a) locating a containment medium on top of a support, (b) dosing a predetermined amount of a component liquid in said containment medium, either in the order (a) then (b) or (b) then (a), and (c) applying pressure or vacuum, removing said component liquid in at least a portion of the support, and retaining substantially all said amount in the support. This coated product (coated on one end only) is dried and then calcined and this process is repeated from the other ends, in such a way that substantially every substrate monolith is coated, with a minor overlap in the axial direction at the joint between the two. coatings. A 1 inch (2.54 cm) diameter x 3 inch long core was cut from the finished article. COMPARATIVE EXAMPLE 2 - Preparation of wall flow filter catalyzed only with Pt
    [00068] A final finish composition comprising a mixture of crushed alumina particles at a relatively high particle size distribution, platinum nitrate, binders and rheology modifiers in deionized water was prepared. An aluminum titanate wall flow filter was coated with the catalyst composition at a final finishing load of 0.2 g / in3 at a final total Pt load of 5g / ff 3 (178.5 g / m3) using the method and apparatus described in Applicant / Inventor WO 2011/080525, in which channels to a first end intended for orientation to an upstream side were coated by 75% of their full length size with a final finish comprising platinum nitrate and particulate alumina destined for the upstream end thereof; and channels at the opposite end and intended to be oriented to a downstream side are coated to 25% of their total length size with the same final finish as the inlet channels. That is, the method comprised the steps of: (i) maintaining a hive monolith substrate substantially vertically; (ii) introducing a predetermined volume of the liquid into the substrate through the open ends of the channels at a lower end of the substrate; (iii) to seal the liquid to be introduced into the substrate in a sealed manner; (iv) inverting the substrate containing the retained liquid; and (v) applying a vacuum to the open ends of the substrate channels at the inverted, lower end of the substrate to remove the liquid along the substrate channels. The catalyst composition was coated on the filter channels of a first end, after which the coated filter was dried. The dry coated filter of the first end was then spun and the method was repeated to coat the same catalyst with filter channels of the second end, followed by drying and calcination.
    [00069] A 1 inch (2.54 cm) diameter x 3 inch (7.62 cm) long core was cut from the finished article. The resulting part is described as “freshly prepared”, that is, not aged. EXAMPLE 3 - Preparation of catalyzed wall flow filter containing 1: 1% by weight of Pt: Pd
    [00070] A coated filter was prepared using the same method as in comparative example 2, except that no final finish applied to both the inlet and outlet channels of the filter included palladium nitrate other than platinum nitrate. The final finishing load in the input and output channels was conducted in such a way as to reach a load of Pd a 5g / ft3 (178.5 g / m3) Pt, 5g / ft3 (178.5 g / m3) both on the inlet and outlet surfaces, that is, a total PGM load of 10 g / ft3 (357 g / m3).
    [00071] A 1 inch (2.54 cm) diameter x 3 inch (7.6 cm) long core was cut from the finished article. The resulting part is described as “freshly prepared”, that is, not aged. EXAMPLE 4 - Preparation of catalyzed wall flow filter containing 5: 1% by weight of Pt: Pd
    [00072] A coated filter was prepared using the same method as in comparative example 2, except that no final finish applied to both the inlet and outlet channels of the filter included palladium nitrate other than platinum nitrate. The final finishing load in the input and output channels was conducted in such a way as to reach a load of 5g / ft3 (178.5 g / m3), 1 g / ft3 (35.7 g / m3) of Pd both on the inlet and outlet surfaces, that is, a total PGM load of 6g / ft3 (214.2 g / m3).
    [00073] A core 1 inch (2.54 cm) in diameter x 3 inches (7.6 cm) in length was cut from the finished article. The resulting part is described as “freshly prepared”, that is, not aged. EXAMPLE 5 - System tests
    [00074] The tests were carried out in a first synthetic catalyst activity test (SCAT) reactor illustrated in figure 1, in which a freshly prepared core of the coated Fe / Beta zeolite SCR catalyst of example 1 is arranged in a conduit downstream of a core of either of the catalyzed wall flow filter of comparative example 2 or example 3, 4, 5, 6, 7 or 8. A mixture of synthetic gas was passed through the conduit to a volume of catalyst oscillation of 30,000 h1. An oven was used to heat (or "age") the sample of the catalyzed wall flow filter to a steady state temperature at an inlet temperature of 900 ° C for 60 minutes, during which time the temperature of the SCR catalyst inlet was 300 ° C. A cooling mechanism with air (heat exchanger) or water was used to effect the temperature drop between the filter and the SCR catalyst. The gas mixture during aging was 10% O2, 6% H2O, 6% CO2, 100 ppm CO, 400 ppm NO, 100 ppm HC as C I, N2 balance.
    [00075] After aging, the aged SCR catalysts were removed from the first SCAT reactor and inserted into a second SCAT reactor specifically to test the NH3-SCR activity of the aged samples. The aged SCR catalysts were then tested for SCR activity at 150, 200, 250, 300, 350, 450, 550 and 650 ° C using a mixture of synthetic gas (O2 = 14%; H2O = 7%; CO2 = 5%; NH3 = 250ppm; NO = 250ppm; NO2 = 0 ppm; N2 = equilibrium) and the resulting NOX conversion for examples 3, 5 and 6 were plotted against temperature for each setting of temperature data in figure 2 against activity of freshly prepared SCR catalyst and against an aged SCR catalyst behind comparative example 2. The graph shown in figure 3 plots the resulting NOX conversion for examples 4 and 7 using the same comparisons. This graph essentially measures the competition between reaction (9) and reaction (5) and just as reaction (9) affects the conversion of NOX by the consumption of NH3 available for the SCR reaction (reaction (5)) -
    [00076] The results are shown in figures 2 and 3. It can be seen that SCR catalysts for use in the exhaust system according to the present invention retain more activity than the SCR catalyst in comparative example 2, although they retain less activity SCR than a freshly prepared catalyst. This result was interpreted showing that the loss in SCR activity is caused in part by the deposition of the low Pt levels of the upstream catalyzed wall flow filter on the downstream SCR catalyst. Substantially no loss in activity was seen between a freshly prepared Fe / Beta catalyst and an Fe / Beta catalyst aged at 300 ° C for 1 hour with no catalyst present upstream (results not shown). EXAMPLE 6 - Preparation of substrate monolith coated with 3 wt% Cu / CHA Zeolite
    [00077] Commercially available CHA aluminosilicate zeolite was added to an aqueous solution of Cu (NOs) 2 with stirring. The sludge was filtered, then washed and dried. The procedure can be repeated to achieve a desired metal charge. The final product was calcined. After mixing, binders and rheology modifiers were added to form a final finish composition.
    [00078] A cordierite substrate monolith through the flow of 400 cpsi (1 in2 = 645.2 cm2) was coated with an aqueous slurry of 3% by weight of Cu / CHA zeolite sample using the method described in WO 99 / 47260 of the Applicant / Inventor described in example 1 above. The coated substrate monolith was aged in an air oven at 500 ° C for 5 hours. A 1 inch (2.54 cm) diameter x 3 inch long (7.62 cm) core was cut from the finished article. EXAMPLE 7 - Additional Pt: Pd weight ratio studies
    [00079] Two diesel oxidation catalysts were prepared as follows: Diesel oxidation catalyst A
    [00080] A single layer DOC was prepared as follows. Platinum nitrate and palladium nitrate were added to a silica-alumina slurry. Beta zeolite was added to the mud, in such a way that it comprised <30% of the solids content as zeolite by mass. The final finishing sludge was dosed on a substrate through the flow of 400 cpsi (1 in2 = 645.2 cm2) using the method of example 1 previously. The dosed part was dried and then calcined at 500 ° C. The total metal load of the platinum group in the final finish coating was 60gft '3 (2,142 g / m3) and the weight ratio of total Pt: Pd was 4: 1. A 1 inch (2.54 cm) diameter x 3 inch (7.62 cm) long core was cut from the finished article. The resulting part can be described as “freshly prepared”, that is, not aged. Diesel oxidation catalyst B
    [00081] A single layer DOC was prepared as follows. Platinum nitrate and palladium nitrate were added to a silica-alumina slurry. Beta zeolite was added to the mud, in such a way that it comprised <30% of the solids content as zeolite by mass. The final finishing sludge was dosed on a substrate through the flow of 400 cpsi (1 in2 = 645.2 cm2) using the same method as used for DOC A. The dosed part was dried and then calcined at 500 ° C. The total PGM load in the single-layer DOC was 120 g / ft3 (4,284 g / m3) and the Pt: Pd weight ratio was 2: 1. A 1-inch (2.54 cm) diameter x 3-inch core ( 7.62 cm) in length was cut from the finished article. The resulting part can be described as “freshly prepared”, that is, not aged.
    [00082] Both catalysts were tested according to the protocols presented in example 12. The results are shown in figure 5 with reference to a control (aged SCR catalyst that has not yet been aged downstream of either DOC A or DOC B ). EXAMPLE 8 - System tests
    [00083] The tests were carried out in a first synthetic catalyst activity test reactor (SCAT) in the laboratory illustrated in figure 1, in which an aged core of the SCR catalyst coated with zeolite Cu / CHA of example 10 was disposed in a conduit downstream of a core of any diesel oxidation catalyst (DOC) A or B (according to Example 10). A mixture of synthetic gas was passed through the flue at a rate of 6 liters per minute. An oven was used to heat (or "age") the DOC samples to a steady state temperature at a catalyst outlet temperature of 900 ° C for 2 hours. The SCR catalyst was disposed downstream of the DOC sample and was maintained at a catalyst temperature of 300 ° C during the aging process by adjusting the length of the tube between the furnace outlet and the SCR inlet, although a heat exchanger jacket water-cooled can also be used. Temperatures were determined using appropriately positioned thermocouples (Ti and T2). The gas mixture used during aging was 40% air, 50% N2, 10% H2O.
    [00084] After DOC aging, SCR catalysts were removed from the first SCAT reactor and inserted into a second SCAT reactor specifically to test H3-SCR activity of the aged samples. SCR catalysts were then tested for SCR activity at 500 ° C using a synthetic gas mixture (O2 = 10%; H2O = 5%; CO2 = 7.5%; CO = 330ppm; NH3 = 400ppm; NO = 500ppm; NO2 = 0 ppm; N2 = equilibrium, that is, an alpha value of 0.8 was used (NH ^ NOx ratio), so that the maximum possible conversion of NOX available was 80%) and the resulting NOX conversion was plotted against temperature in the bar graph attached in figure 5. This graph essentially measures the competition between reaction (9) and reaction (5) and how much reaction (9) affects the conversion of NOx by the consumption of available NH3 required for the SCR reaction (reaction (5)). Weight ratio study Pt: Pd - Conclusions
    [00085] Taken as a whole, the results of example 5 shown in figure 3 together with Examples 3 and 4 and Comparative example 2 indicate that a Pt: Pd weight ratio between 1: 1 and 5: 1 is beneficial in reducing the problem of loss of NOX activity conversion through volatilization of the platinum group metal, mainly platinum, from a platinum group metal containing catalyst to a downstream SCR catalyst; and
    [00086] The results of example 8 shown in figure 4 in conjunction with diesel oxidation catalysts A and B show that for aged SCR catalyst downstream of a DOC having a weight ratio 2: 1 Pt: Pd overall, loss of conversion of NOX activity is relatively slight to 67% conversion of NOX activity compared to control to 72% conversion of NOX activity (an aged SCR catalyst behind a 1: 1 weight ratio Pt: overall DOC pd (not described) here) using the same protocol had a NOX activity conversion of 69%). However, when the general weight ratio Pt: Pd was increased to 4: 1, SCR activity was significantly reduced to 48%.
    [00087] It is concluded, therefore, that there is a limit to about a 2: 1 Pt: general weight ratio Pd above which Pt volatility is more likely to happen. Thus, limiting to a general weight ratio Pt: Pd of 2: 1 in the DOC as a whole, and the <weight ratio 2: 1 Pt: Pd in the second layer of final finish coating, Pt in the DOC is less likely to volatilize and migrate to an SCR catalyst downstream.
    [00088] To avoid any doubt, all the contents of any and all documents cited here are incorporated by reference in this patent application.
    权利要求:
    Claims (11)
    [0001]
    1. Exhaust system (10) for an internal combustion engine with poor vehicle burning, characterized by the fact that it comprises: (i) a catalyzed substrate monolith (2); and (ii) a substrate monolith (6) having a length L and comprising a first zone of uniform length (11) defined at one end by a first end of the substrate monolith (6), the first zone of which comprises a reduction catalyst selective catalytic (SCR) to reduce nitrogen oxides with a nitrogenous reducer in exhaust gas emitted from an internal combustion engine and a second zone (8) of uniform length less than L defined at one end by a second end of the substrate monolith (6), whose second zone (8) consists of at least one particulate metal oxide or a mixture of any two or more of them to trap metal in the gas phase platinum group (PGM), in which at least one particulate metal oxide is selected from the group consisting of optionally stabilized alumina, amorphous silica-alumina, optionally stabilized zirconia, titania, and mixtures of any two or more of the same, where n at least one particulate metal oxide acts as a support for any other catalytic component; wherein the catalyzed substrate monolith (2) comprises a catalyst comprising at least one platinum group metal (PGM) disposed upstream of the substrate monolith (6) and wherein the second end of the substrate monolith (6) is oriented to an upstream side; and wherein the catalyst comprising at least one platinum group metal (PGM) comprises both platinum (Pt) and palladium (Pd) in a weight ratio of Pt: Pd> 1.25: 1.
    [0002]
    2. Exhaust system according to claim 1, characterized by the fact that the weight ratio of Pt: Pd is greater than 2: 1.
    [0003]
    Exhaust system according to either of claims 1 or 2, characterized in that the catalyst comprising PGM is a diesel oxidation catalyst or an NOX absorbent catalyst.
    [0004]
    Exhaust system according to any one of claims 1 to 3, characterized in that the catalyzed substrate monolith (2) is a substrate filter monolith.
    [0005]
    Exhaust system according to claim 4, characterized by the fact that the substrate filter monolith is a wall flow filter.
    [0006]
    Exhaust system according to any one of claims 1 to 5, characterized in that it comprises means (4) for injecting ammonia or a precursor thereof between the catalyzed substrate monolith (2) and the substrate monolith (6) comprising the SCR catalyst.
    [0007]
    Exhaust system according to any of claims 1 to 6, characterized in that the first zone (11) extends over the entire length L and the second zone (8) overlaps the first zone.
    [0008]
    Exhaust system according to any one of claims 1 to 7, characterized in that the SCR catalyst in the first zone (11) is present as a coating on the substrate monolith of uniform length less than L, and in which no there is overlap between the first zone (11) and the second zone (8).
    [0009]
    Exhaust system according to any one of claims 1 to 8, characterized in that the SCR catalyst in the first zone (11) is present as a coating on the substrate monolith.
    [0010]
    Exhaust system according to any one of claims 1 to 9, characterized by the fact that the substrate monolith (6) is a substrate filter monolith having inlet and outlet surfaces, in which the inlet surfaces are separated from the outlet surfaces by a porous structure.
    [0011]
    11. Exhaust system according to claim 10, characterized by the fact that the substrate filter monolith (6) is a wall flow filter, in which the SCR catalyst is arranged in open channels at the first end of the flow filter wall and the second zone is arranged in open channels at the second end thereof, where the porous structure defines a transition between the first zone of final finishing and the second zone of final finishing.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112014013233B1|2020-10-27|exhaust system for an internal combustion engine with a poor combustion
    US10688475B2|2020-06-23|Catalysed substrate monolith
    JP2017214930A|2017-12-07|Exhaust system for lean-burn internal combustion engine including scr catalyst
    EP2790815B1|2020-05-13|Exhaust system for a lean-burn ic engine comprising a pgm component and a scr catalyst
    BR112014008228B1|2019-12-24|catalyzed substrate monolith, exhaust system for a poor burning internal combustion engine, poor burning internal combustion engine, and method for reducing or preventing a selective catalytic reduction catalyst from poisoning with platinum
    GB2497598A|2013-06-19|Catalysed substrate monolith and its use in an exhaust system for a lean burn ic engine
    同族专利:
    公开号 | 公开日
    RU2608998C2|2017-01-30|
    EP2790826A2|2014-10-22|
    BR112014013233A2|2017-06-13|
    WO2013088129A3|2013-12-27|
    KR101951515B1|2019-02-22|
    CN103974768B|2016-06-29|
    GB201200783D0|2012-02-29|
    RU2014128568A|2016-02-10|
    GB2497656A|2013-06-19|
    KR20140105554A|2014-09-01|
    EP2790826B1|2019-08-21|
    WO2013088129A2|2013-06-20|
    US20130149207A1|2013-06-13|
    GB2497656B|2015-09-16|
    US9333461B2|2016-05-10|
    JP2015505723A|2015-02-26|
    DE102012222804A1|2013-06-27|
    CN103974768A|2014-08-06|
    GB201222229D0|2013-01-23|
    JP6173336B2|2017-08-02|
    DE102012222804B4|2021-05-20|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB8516333D0|1985-06-28|1985-07-31|Johnson Matthey Plc|Nitric oxide|
    JPS6268544A|1985-09-20|1987-03-28|Toyota Motor Corp|Monolithic catalyst for purifying exhaust gas|
    US4902487A|1988-05-13|1990-02-20|Johnson Matthey, Inc.|Treatment of diesel exhaust gases|
    ES2104943T5|1991-10-03|2005-04-16|Toyota Jidosha Kabushiki Kaisha|PURIFICATION DEVICE OF EXHAUST GASES OF AN INTERNAL COMBUSTION ENGINE.|
    DE69422938T2|1993-04-28|2000-07-20|Toyota Motor Co Ltd|Catalytic converter for cleaning exhaust gases from diesel engines|
    US6667018B2|1994-07-05|2003-12-23|Ngk Insulators, Ltd.|Catalyst-adsorbent for purification of exhaust gases and method for purification of exhaust gases|
    US5478549A|1994-12-15|1995-12-26|E. I. Du Pont De Nemours And Company|Production of nitric oxide|
    GB9511412D0|1995-06-06|1995-08-02|Johnson Matthey Plc|Improvements in emission control|
    JP3387290B2|1995-10-02|2003-03-17|トヨタ自動車株式会社|Exhaust gas purification filter|
    JPH09271674A|1996-04-04|1997-10-21|Toyota Motor Corp|Oxidizing catalyst for diesel exhaust gas|
    EP0842700B1|1996-11-11|1999-03-24|Degussa Ag|Exhaust gas purifying catalyst with improved hydrocarbon conversion|
    US6093378A|1997-05-07|2000-07-25|Engelhard Corporation|Four-way diesel exhaust catalyst and method of use|
    US6348430B1|1997-06-20|2002-02-19|Degussa Ag|Exhaust gas treatment catalyst for internal combustion engines with two catalytically active layers on a carrier structure|
    GB9805815D0|1998-03-19|1998-05-13|Johnson Matthey Plc|Manufacturing process|
    WO2000059630A1|1998-07-10|2000-10-12|Asec Manufacturing|Improved catalyzed adsorber system for treating internal combustion engine exhaust gas and method of making same|
    GB9919013D0|1999-08-13|1999-10-13|Johnson Matthey Plc|Reactor|
    JP4022707B2|2000-04-28|2007-12-19|ヤマトミシン製造株式会社|Sewing machine looper drawer|
    US6835689B1|2000-10-10|2004-12-28|Corning Incorporated|NH3 generation catalysts for lean-burn and diesel applications|
    DE10113947B4|2001-03-22|2004-03-25|Daimlerchrysler Ag|Process for reducing the nitrogen oxide content in the exhaust gas of a running in lean-fat change internal combustion engine|
    EP1264628A1|2001-06-09|2002-12-11|OMG AG & Co. KG|Redox catalyst fot the selective catalytic reduction of nitrogen oxides in the exhaust gases of diesel engines with ammoniac and preparation process thereof|
    PL1493484T3|2003-07-02|2007-05-31|Topsoe Haldor As|Process and filter for the catalytic treatment of diesel exhaust gas|
    US7229597B2|2003-08-05|2007-06-12|Basfd Catalysts Llc|Catalyzed SCR filter and emission treatment system|
    US7722829B2|2004-09-14|2010-05-25|Basf Catalysts Llc|Pressure-balanced, catalyzed soot filter|
    GB2406803A|2004-11-23|2005-04-13|Johnson Matthey Plc|Exhaust system comprising exotherm-generating catalyst|
    JP2006272064A|2005-03-28|2006-10-12|Mazda Motor Corp|Oxidation catalyst|
    US20070157607A1|2006-01-11|2007-07-12|Pfefferle William C|Clean air system|
    JP4711860B2|2006-03-03|2011-06-29|エヌ・イーケムキャット株式会社|Exhaust gas purification oxidation catalyst, exhaust gas purification catalyst structure, and exhaust gas purification method|
    US7576031B2|2006-06-09|2009-08-18|Basf Catalysts Llc|Pt-Pd diesel oxidation catalyst with CO/HC light-off and HC storage function|
    WO2008000449A2|2006-06-29|2008-01-03|Umicore Ag & Co. Kg|Three-way catalyst|
    US7550124B2|2006-08-21|2009-06-23|Basf Catalysts Llc|Layered catalyst composite|
    US7758834B2|2006-08-21|2010-07-20|Basf Corporation|Layered catalyst composite|
    JP5037888B2|2006-09-26|2012-10-03|株式会社キャタラー|Exhaust gas purification catalyst|
    GB0620883D0|2006-10-20|2006-11-29|Johnson Matthey Plc|Exhaust system for a lean-burn internal combustion engine|
    KR20080047950A|2006-11-27|2008-05-30|나노스텔라 인코포레이티드|Engine exhaust catalysts containing palladium-gold|
    US7534738B2|2006-11-27|2009-05-19|Nanostellar, Inc.|Engine exhaust catalysts containing palladium-gold|
    US7601662B2|2007-02-27|2009-10-13|Basf Catalysts Llc|Copper CHA zeolite catalysts|
    EP3300791B1|2007-04-26|2019-03-27|Johnson Matthey Public Limited Company|Transition metal/zeolite scr catalysts|
    JP2008279352A|2007-05-10|2008-11-20|Asahi Kasei Corp|Catalyst for removing nitrogen oxide discharged from lean burn automobile|
    GB2457651A|2008-01-23|2009-08-26|Johnson Matthey Plc|Catalysed wall-flow filter|
    US20090196812A1|2008-01-31|2009-08-06|Basf Catalysts Llc|Catalysts, Systems and Methods Utilizing Non-Zeolitic Metal-Containing Molecular Sieves Having the CHA Crystal Structure|
    AT460973T|2008-04-11|2010-04-15|Umicore Ag & Co Kg|EMISSION CONTROL SYSTEM FOR THE TREATMENT OF ENGINE GASES BY SCR CATALYST|
    US8776498B2|2008-04-16|2014-07-15|Ford Global Technologies, Llc|Air-injection system to improve effectiveness of selective catalytic reduction catalyst for gasoline engines|
    GB0808427D0|2008-05-09|2008-06-18|Johnson Matthey Plc|Apparatus|
    JP5323093B2|2008-12-19|2013-10-23|株式会社キャタラー|Exhaust gas purification catalyst|
    KR101477338B1|2008-12-24|2014-12-29|바스프 코포레이션|Emissions treatment systems and methods with catalyzed scr filter and downstream scr catalyst|
    WO2010077843A2|2008-12-29|2010-07-08|Basf Catalysts Llc|Oxidation catalyst with low co and hc light-off and systems and methods|
    US8844274B2|2009-01-09|2014-09-30|Ford Global Technologies, Llc|Compact diesel engine exhaust treatment system|
    US8252258B2|2009-01-16|2012-08-28|Basf Corporation|Diesel oxidation catalyst with layer structure for improved hydrocarbon conversion|
    US9440192B2|2009-01-16|2016-09-13|Basf Corporation|Diesel oxidation catalyst and use thereof in diesel and advanced combustion diesel engine systems|
    US8211392B2|2009-01-16|2012-07-03|Basf Corporation|Diesel oxidation catalyst composite with layer structure for carbon monoxide and hydrocarbon conversion|
    US8415269B2|2009-01-21|2013-04-09|WGCH Technology Limited|Palladium-gold catalyst synthesis|
    US10773209B2|2009-02-20|2020-09-15|Basf Corporation|Aging-resistant catalyst article for internal combustion engines|
    US8920759B2|2009-03-02|2014-12-30|GM Global Technology Operations LLC|Method and apparatus for reducing NOx emissions from a lean burning hydrocarbon fueled power source|
    US9662611B2|2009-04-03|2017-05-30|Basf Corporation|Emissions treatment system with ammonia-generating and SCR catalysts|
    US8246923B2|2009-05-18|2012-08-21|Umicore Ag & Co. Kg|High Pd content diesel oxidation catalysts with improved hydrothermal durability|
    DE102009033635B4|2009-07-17|2020-11-05|Umicore Ag & Co. Kg|Catalytically active particle filter with hydrogen sulfide barrier function, its use and method for removing nitrogen oxides and particles|
    US20110064633A1|2009-09-14|2011-03-17|Ford Global Technologies, Llc|Multi-Functional Catalyst Block and Method of Using the Same|
    US20110064632A1|2009-09-14|2011-03-17|Ford Global Technologies, Llc|Staged Catalyst System and Method of Using the Same|
    US8557203B2|2009-11-03|2013-10-15|Umicore Ag & Co. Kg|Architectural diesel oxidation catalyst for enhanced NO2 generator|
    US8765625B2|2009-12-10|2014-07-01|Shubin, Inc.|Engine exhaust catalysts containing copper-ceria|
    EP2519718A4|2009-12-31|2013-09-11|Nanostellar Inc|Engine exhaust catalysts doped with bismuth or manganese|
    GB201000019D0|2010-01-04|2010-02-17|Johnson Matthey Plc|Coating a monolith substrate with catalyst component|
    EP2531280B1|2010-02-01|2014-12-24|Johnson Matthey Public Limited Company|NOx ABSORBER CATALYSTS|
    US8263033B2|2010-02-23|2012-09-11|Ford Global Technologies, Llc|Palladium-contaning oxidation catalyst|
    BR112012027087A2|2010-04-20|2016-07-26|Unicore Ag & Co Kg|oxide mixtures for selective catalytic reduction of nitrogen oxides in exhaust gases|
    US8293182B2|2010-05-05|2012-10-23|Basf Corporation|Integrated SCR and AMOx catalyst systems|
    US20110286900A1|2010-05-21|2011-11-24|Basf Corporation|PGM-Zoned Catalyst for Selective Oxidation of Ammonia in Diesel Systems|
    WO2011162030A1|2010-06-24|2011-12-29|エヌ・イー ケムキャット株式会社|Exhaust gas catalytic purging unit using selective reduction catalyst, exhaust gas purging method, and diesel automobile equipped with exhaust gas catalytic purging unit|
    EP2535102A1|2010-06-30|2012-12-19|N.E. Chemcat Corporation|Flue gas-cleaning device and flue gas-cleaning method that use selective catalytic reduction catalyst|
    US8137648B2|2010-10-12|2012-03-20|Ford Global Technologies, Llc|Diesel engine exhaust treatment system and method including a platinum group metal trapping device|
    US8323599B2|2010-11-22|2012-12-04|Umicore Ag & Co. Kg|Three-way catalyst having an upstream multi-layer catalyst|
    JP5310767B2|2011-03-29|2013-10-09|トヨタ自動車株式会社|Exhaust gas purification catalyst|
    WO2012147376A1|2011-04-28|2012-11-01|エヌ・イー ケムキャット株式会社|Off gas purification device|
    EP2707118B1|2011-05-13|2019-12-04|Basf Se|Catalyzed soot filter with layered design|
    EP2718010A1|2011-06-05|2014-04-16|Johnson Matthey Public Limited Company|Platinum group metal catalyst for treating exhaust gas|
    GB2492175B|2011-06-21|2018-06-27|Johnson Matthey Plc|Exhaust system for internal combustion engine comprising catalysed filter substrate|
    US9044734B2|2011-09-23|2015-06-02|Basf Se|Diesel oxidation catalyst with layered structure containing ceria composition as palladium support material for enhanced HC and CO gas conversion|
    JP5938819B2|2011-10-06|2016-06-22|ジョンソン、マッセイ、パブリック、リミテッド、カンパニーＪｏｈｎｓｏｎ Ｍａｔｔｈｅｙ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ|Oxidation catalyst for exhaust gas treatment|
    GB201200784D0|2011-12-12|2012-02-29|Johnson Matthey Plc|Exhaust system for a lean-burn internal combustion engine including SCR catalyst|
    GB2497597A|2011-12-12|2013-06-19|Johnson Matthey Plc|A Catalysed Substrate Monolith with Two Wash-Coats|
    GB201200781D0|2011-12-12|2012-02-29|Johnson Matthey Plc|Exhaust system for a lean-burn ic engine comprising a pgm component and a scr catalyst|JP5938819B2|2011-10-06|2016-06-22|ジョンソン、マッセイ、パブリック、リミテッド、カンパニーＪｏｈｎｓｏｎ Ｍａｔｔｈｅｙ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ|Oxidation catalyst for exhaust gas treatment|
    GB2497597A|2011-12-12|2013-06-19|Johnson Matthey Plc|A Catalysed Substrate Monolith with Two Wash-Coats|
    GB201200784D0|2011-12-12|2012-02-29|Johnson Matthey Plc|Exhaust system for a lean-burn internal combustion engine including SCR catalyst|
    GB201200781D0|2011-12-12|2012-02-29|Johnson Matthey Plc|Exhaust system for a lean-burn ic engine comprising a pgm component and a scr catalyst|
    GB201207313D0|2012-04-24|2012-06-13|Johnson Matthey Plc|Filter substrate comprising three-way catalyst|
    EP2657474A1|2012-04-26|2013-10-30|Bernhard Kahlert|Coated particulate filter, catalyst and device with same|
    KR20150090176A|2012-11-29|2015-08-05|바스프 에스이|Diesel oxidation catalyst comprising palladium, gold and ceria|
    US8992869B2|2012-12-20|2015-03-31|Caterpillar Inc.|Ammonia oxidation catalyst system|
    GB2512648B|2013-04-05|2018-06-20|Johnson Matthey Plc|Filter substrate comprising three-way catalyst|
    GB2513364B|2013-04-24|2019-06-19|Johnson Matthey Plc|Positive ignition engine and exhaust system comprising catalysed zone-coated filter substrate|
    GB2514177A|2013-05-17|2014-11-19|Johnson Matthey Plc|Oxidation catalyst for a compression ignition engine|
    RU2018143245A3|2013-07-30|2021-11-18|
    EP2875863A1|2013-11-25|2015-05-27|Umicore AG & Co. KG|SCR catalytic converter|
    FR3017899A1|2014-02-24|2015-08-28|Peugeot Citroen Automobiles Sa|GAS FILTRATION STRUCTURE AND REDUCTION OF NITROGEN OXIDES|
    US9662636B2|2014-04-17|2017-05-30|Basf Corporation|Zoned catalyst composites|
    US20150361842A1|2014-06-11|2015-12-17|Homayoun Ahari|Exhaust system for a vehicle|
    US9708949B2|2014-06-14|2017-07-18|GM Global Technology Operations LLC|Exhaust aftertreatment system for a compression-ignition engine|
    CN104258899B|2014-10-27|2016-08-31|四川绵阳华元航升环保科技有限公司|Urea scr catalyst based on Ion exchange-Size exclusion|
    GB201504658D0|2015-03-19|2015-05-06|Johnson Matthey Plc|Exhaust system for a compression ignition engine having a capture face for volatilised platinum|
    US9616386B2|2015-03-23|2017-04-11|Kabushiki Kaisha Toyota Chuo Kenkyusho|Catalyst for purification of exhaust gas, NOx storage-reduction catalyst, and method for purifying exhaust gas|
    JP6436824B2|2015-03-23|2018-12-12|日本碍子株式会社|Honeycomb structure|
    GB201521123D0|2015-11-30|2016-01-13|Johnson Matthey Plc|Diesel oxidation catalyst having a capture region for exhaust gas impurities|
    DE102015225579A1|2015-12-17|2017-06-22|Umicore Ag & Co. Kg|Method for preventing the contamination of an SCR catalyst with platinum|
    US20190145298A1|2016-05-03|2019-05-16|Khalifa University of Science and Technology|Catalytic converter substrates comprising triply periodic minimal surfaces|
    GB201613849D0|2016-08-12|2016-09-28|Johnson Matthey Plc|Exhaust system for a compression ignition engine having a capture region for volatilised platinum|
    GB201614677D0|2016-08-30|2016-10-12|Johnson Matthey Plc|Oxidation catalyst for a diesel engine exhaust|
    JP6458827B2|2017-06-05|2019-01-30|マツダ株式会社|Engine exhaust gas treatment device|
    US10456746B2|2018-02-12|2019-10-29|GM Global Technology Operations LLC|Selective catalytic reduction filter for reducing nitrous oxide formation and methods of using the same|
    US11161098B2|2018-05-18|2021-11-02|Umicore Ag & Co. Kg|Three-way catalyst|
    CN110560056A|2019-08-30|2019-12-13|无锡威孚环保催化剂有限公司|Universal small gasoline engine tail gas catalyst and preparation method thereof|
    EP3936221A1|2020-07-07|2022-01-12|UMICORE AG & Co. KG|Catalysed particulate filter with enhanced passive soot functionality|
    法律状态:
    2019-04-30| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-06-04| B07A| Technical examination (opinion): publication of technical examination (opinion) [chapter 7.1 patent gazette]|
    2020-02-04| B06A| Notification to applicant to reply to the report for non-patentability or inadequacy of the application [chapter 6.1 patent gazette]|
    2020-08-25| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2020-10-27| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 11/12/2012, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US201161569535P| true| 2011-12-12|2011-12-12|
    US61/569535|2011-12-12|
    GBGB1200783.7A|GB201200783D0|2011-12-12|2012-01-18|Substrate monolith comprising SCR catalyst|
    GB1200783.7|2012-01-18|
    PCT/GB2012/053083|WO2013088129A2|2011-12-12|2012-12-11|Substrate monolith comprising scr catalyst|
    [返回顶部]