• 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:
    nitrogen oxide storage catalyst, treatment system for an automobile exhaust gas stream, and method for the treatment of automobile engine exhaust gas. The present invention relates to a nitrogen oxide storage catalyst comprising: a substrate; a first reactive coating layer applied to the substrate, the first reactive coating layer comprising a nitrogen oxide storage material, a second reactive coating layer applied to the first reactive coating layer, the second reactive coating layer comprising a material hydrocarbon capture material wherein the hydrocarbon capture material substantially contains no element or compound in a state in which it is capable of catalyzing selective catalytic reduction, preferably wherein the hydrocarbon capture material substantially does not contain element or compound in a state in which It is capable of catalyzing a reaction in which nitrogen oxide is reduced to n ~ 2 ~, said catalyst further comprising a nitrogen oxide conversion material which is equally contained in the second reactive coating layer and / or a coating layer. reactive applied between the first reactive coating layer and the second coating layer.
    公开号:BR112012031330B1
    申请号:R112012031330-4
    申请日:2011-06-09
    公开日:2018-12-11
    发明作者:Susanne Stiebels；Edith Schneider；Torsten Neubauer；Torsten Müller-Stach
    申请人:Basf Se；
    IPC主号:
    专利说明:

    (54) Title: NITROGEN OXIDE STORAGE CATALYST, TREATMENT SYSTEM FOR AN AUTOMOBILE EXHAUST GAS CHAIN, AND METHOD FOR THE TREATMENT OF AUTOMOBILE EXHAUST GAS (73) Holder: BASF SE, German Company. Address: 67056 Ludwigshafen, GERMANY (DE) (72) Inventor: SUSANNE STIEBELS; EDITH SCHNEIDER; TORSTEN NEUBAUER; TORSTEN MÜLLER-STACH.
    Validity Period: 20 (twenty) years from 06/09/2011, subject to legal conditions
    Issued on: 12/11/2018
    Digitally signed by:
    Liane Elizabeth Caldeira Lage
    Director of Patents, Computer Programs and Topographies of Integrated Circuits “NITROGEN OXIDE STORAGE CATALYST, TREATMENT SYSTEM FOR AN AUTOMOBILE ESCAPE GAS CHAIN, AND, METHOD FOR THE TREATMENT OF MOTOR ESCAPE GAS”
    TECHNICAL FIELD
    The present invention relates to a NO X storage catalyst with improved hydrocarbon conversion activity, also to a method for treating automobile exhaust gas and to a treatment system for an automobile exhaust gas stream.
    FUNDAMENTALS
    A major problem encountered in the treatment of automotive exhaust gas refers to the so-called “cold start” period of the treatment process, when the exhaust gas and also the exhaust gas treatment system have low temperatures. At these temperatures, exhaust gas treatment systems do not exhibit sufficient activity to effectively treat hydrocarbon, NO X and / or CO emissions. As a result, considerable efforts have been made to alleviate this problem, in particular by developing capturing systems that store emissions at low temperatures and subsequently release them at higher temperatures, in which the catalytic components present in the system have achieved sufficient activity to treat them.
    Thus, trapping materials have been developed to retain specific emissions during the cold start period of automotive combustion, in which hydrocarbons and NO X have received the most attention because of environmental concerns. To facilitate implementation, multi-component exhaust gas treatment articles have been developed which aim to combine the various capturing and catalytic activities in as few elements as possible. As a result of this, a large number of products incorporate both capture and catalytic activities, for example by adopting a multilayer structure in which different functions are located at different layers.
    Regarding NO X capturing components, for example, there is a tendency in your design to combine them with a hydrocarbon capture capable of catalyzing selective reduction. Thus, JP 11226415 A and JP 11300211 A respectively disclose a NO X storage catalyst comprising a first layer on a substrate containing a nitrogen oxide storage material, and a second layer applied on the first layer containing a hydrocarbon trap material. supporting a selective catalytic reduction catalyst. EP 935055 A, on the other hand, additionally teaches the introduction of an intermediate layer in these layers, wherein said layer essentially consists of alumina and / or silica and is free of noble metal, to improve the thermal stability of the active components of the first and third layers. However, the combination of different functions in such multi-component systems often leads to unwanted interactions between individual functionalities. Specifically, it has been found that the combination of selective catalytic reduction and hydrocarbon capture functionalities in the same component of a multilayer system produces unsatisfactory results with respect to NO X conversion.
    On the other hand, there are multicomponent systems that incorporate hydrocarbon and NO X capture without including elements or compounds capable of catalyzing selective catalytic reduction in the hydrocarbon capture material. Thus JP 2005169203 A reveals a multilayer NO X trap containing a hydrocarbon trap layer on a substrate and upper layers positioned on the hydrocarbon trap layer containing a nitrogen oxide storage material and a selective reduction catalyst. Said NO X captors, however, exhibit a decreased conversion rate with respect to hydrocarbons, NO X and CO during the cold start period of the exhaust gas treatment compared to NO X captors lacking capture capability. hydrocarbon.
    The object of the present invention is to obtain an improved NO X storage catalyst, as well as an improved method for the treatment of automobile exhaust gas and an improved treatment system for an automobile exhaust gas stream. Specifically, the objective of the present invention is to obtain a NO X storage catalyst with improved hydrocarbon conversion activity that does not impair the activity of the catalyst to convert CO and NO X.
    DESCRIPTION
    Thus, it has surprisingly been found that the NO X storage catalyst according to the present invention exhibits improved hydrocarbon conversion activity, in which the activity of the catalyst for the conversion of CO and NO X remains virtually unaffected. Specifically, it has been surprisingly found that by adopting a specific order of layers in a multilayer NO X storage catalyst, the objective of the present invention can be achieved.
    Thus, the present invention relates to a nitrogen oxide catalyst comprising:
    a substrate;
    a first layer of reactive coating applied on the substrate, the first layer of reactive coating comprising a nitrogen oxide storage material, a second layer of reactive coating applied on the first layer of reactive coating, the second layer of reactive coating comprising a material hydrocarbon trap, wherein the hydrocarbon trap material substantially does not contain element or compound in a state in which it is capable of catalyzing selective catalytic reduction, preferably in which the hydrocarbon trap material substantially does not contain element or compound in a state in which it is able to catalyze a reaction in which nitrogen oxide is reduced to N 2 , said catalyst additionally comprising a nitrogen oxide conversion material which is also contained in the second reactive coating layer and / or an applied reactive coating layer between the first bed of the reactive coating and the second layer of reactive coating.
    As the substrate, any material can be used as long as it can withstand the reactive coating layers of the nitrogen oxide storage catalyst and is resistant to the conditions that prevail during the exhaust gas treatment process. The substrate according to the present invention can be of any conceivable form, as long as it allows contact of the fluid with at least a portion of the reactive coating layers present thereon. Preferably, the substrate is a monolith, where more preferably the monolith is a direct flow monolith. Suitable substrates include any of those materials typically used to prepare catalysts, and will usually comprise a metal or ceramic favored structure. Consequently, the monolithic substrate contains parallel, thin gas flow passages extending from an inlet face to an outlet face of the substrate, such that the passages are open to the flow of fluid (called favored direct flow substrates) ). The passages, which are essentially straight paths from their fluid inlet to their fluid outlet, are defined by the walls on which the reactive liners are positioned, so that the gases flowing through the passages contact the catalytic material. The flow passages of the monolithic substrate are thin-walled channels, which can be of any shape in cross section and size such as trapezoidal, rectangular, square, sinusoidal, hexagonal, oval, or circular. Such structures can contain up to 900 gas inlet openings (ie, cells) per square inch (6.45 cm 2 ) of cross section, in which according to the present invention the structures preferably have 50 to 600 openings per square inch (6.45 cm), more preferably 300 to 500, and even more preferably 350 to 400.
    Thus, according to a preferred embodiment of the present invention, the nitrogen oxide storage catalyst comprises a substrate which is a monolith, preferably a direct-flow monolith, more preferably a direct-flow monolith having a favorable structure.
    According to another embodiment of the present invention, the nitrogen oxide storage catalyst incorporates the function of a catalyzed soot filter. For these embodiments, the substrate is preferably a soft wall flow filter, packaged or rolled fiber filter, open cell foam, or sintered metal filter, where wall flow filters are specifically preferred. Useful wall flow substrates have a plurality of thin, substantially parallel gas flow passages extending along the longitudinal axis of the substrate. Typically, each passage is blocked at one end of the substrate body, with alternating passages blocked at opposite end faces.
    Specifically preferred wall flow substrates for use in the present invention include thin porous wall faviform monoliths, through which the fluid stream passes without causing a very large increase in back pressure or pressure through the nitrogen oxide storage catalyst. Ceramic wall flow substrates used in the present invention are preferably formed from a material having a porosity of at least 40%, preferably from 40 to 70%, and having an average particle size of at least 5 micrometers, preferably from 5 to 30 micrometers. Additionally preferred are substrates having a porosity of at least 50% and having an average particle size of at least 10 micrometers.
    In general, the substrate can be made of materials commonly known in the art. For this purpose, porous materials are preferably used as the substrate material, specifically ceramic and similarly ceramic materials such as cordierite, aalumina, an aluminosilicate, cordierite-alumina, silicon carbide, aluminum titanate, silicon nitride, zirconia, mullite, zircon, mullite zircon, zircon silicate, sillimanite, a magnesium silicate, petalite, spodumene, silica-magnesia alumina and zirconium silicate, also their porous refractory oxides and metals. According to the present invention, "defective metal" refers to one or more metals selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Re. The substrate can also be formed from fibrous ceramic composite materials. According to the present invention, the substrate is preferably formed from cordierite, silicon carbide, and / or aluminum titanate. In general, materials that are able to withstand the high temperatures to which a NO X storage catalyst is exposed are preferred, specifically when used in the treatment of automotive exhaust gas. Furthermore, it will be understood that the loading of the catalytic composition onto a wall flow substrate will depend on the properties of the substrate such as porosity and wall thickness.
    The substrates useful for the catalysts of modalities of the present invention can also be of a metallic nature and be composed of one or more metals or one or more metal alloys. Metal substrates can be used in various forms such as corrugated sheet or monolithic form. Metallic supports include metals and heat-resistant metal alloys such as titanium and stainless steel as well as other alloys in which iron is a substantial or major component. Such alloys may contain one or more of nickel, chromium and / or aluminum, and the total amount of these metals may advantageously comprise at least 15% by weight of the alloy, eg, 10-25% by weight of chromium, 3-8% by weight. aluminum weight and up to 20% nickel weight. The alloys can also contain trace or small amounts of one or more other metals such as manganese, copper, vanadium, titanium and the like. The metal surface or substrates can be oxidized at high temperatures, e.g., 1000 ° C and higher, to improve the corrosion resistance of the alloys by forming an oxide layer on the substrate surfaces. Such high temperature-induced oxidation can enhance the subsequent adhesion of reactive coating compositions to the substrate.
    According to a preferred embodiment of the present invention, the first reactive coating layer additionally comprises an oxygen-storing component. In principle, any oxygen-storing component can be used, as long as it can reversibly store oxygen. Preferably, said oxygen storage component comprises at least one compound selected from the group consisting of zirconia, ceria, barium, lantana, praseodymia, neodymia, and mixtures thereof. According to a specifically preferred embodiment, the oxygen-storing component comprises ceria and / or zirconia, wherein even more preferably the oxygen-storing component comprises ceria.
    In principle, any possible loading of the oxygen storage component can be chosen in the first reactive coating layer, provided that sufficient oxygen can be stored for the oxidation processes to take place in the NO X storage catalyst and the function of the remaining components contained in the NO X catalyst is not impaired. In general, the loading of an oxygen storage component in the first layer of reactive coating can vary from 6.10 mg / cm to 183 mg / cm 3 , with respect to the weight of the metal contained in the respective compound, in which the loading of the component oxygen storage preferably ranges from 18.3 mg / cm to 122 mg / cm 3 , more preferably from 30.5 mg / cm to 91.5 □ mg / cm 3 , even more preferably from 42.7 mg / cm to 73.2 mg / cm 3 , even more preferably from 45.8 mg / cm to 70.2 mg / cm 3 , and even more preferably from 48.8 mg / cm 3 to 58.0 mg / cm 3 .
    According to the present invention it is further preferred that the first layer of reactive coating comprises at least one metal of the platinum group, wherein within the meaning of the present invention the metals of the platinum group are Ru, Rh, Pd, Os, Ir , and Pt. In another preferred embodiment, the at least one platinum group metal contained in the first reactive coating layer is Pt and / or Pd. The one or more metals in the platinum group will typically be present in the first reactive coating layer in an amount of up to 7.063 mg / cm 3 , preferably in an amount of 0.353 mg / cm to 5.297 mg / cm, more preferably of 0.530 mg / cm cm to 3.531 mg / cm, more preferably from 0.706 mg / cm 3 to 2.825 mg / cm 3 , more preferably from 1.059 mg / cm 3 to 2.482 mg / cm 3 , and even more preferably from 1.236 mg / cm 3 to 2.295 mg / cm 3 .
    In preferred embodiments of the present invention comprising Pt in the first layer of reactive coating, its loading into said layer is generally within the range of 0.353 mg / cm to 3.531 mg / cm, preferably within the range of 0.530 mg / cm to 2.825 mg / cm cm, more preferably within the range of 0.706 mg / cm to 2.472
    Q is mg / cm, and even more preferably within the range of 1.059 mg / cm to 2.118 mg / cm 3 .
    In addition, in preferred embodiments comprising Pd in the first layer of reactive coating, its loading in said layer is generally within the range of 0.0353 mg / cm to 1.0594 mg / cm, -ΊA preferably within the range of 0.0706 mg / cm to 0.530 mg / cm, more preferably within the range of 0.106 mg / cm to 0.353 mg / cm, more preferably within the range of 0.141 mg / cm to 0.282 mg / cm, more preferably within the range of 0.177 mg / cm to 0.247 mg / cm, and □ most preferably within the range of 0.212 mg / cm to 0.229 mg / cm.
    According to the modalities of the present invention in which a nitrogen oxide conversion material is at least contained in a reactive coating layer applied between the first and second reactive coating layers, it is specifically preferred that at least one metal from the group of the platinum is present in the first layer of the reactive coating, preferably in an amount of 0.530 mg / cm
    2.472 mg / cm, more preferably from 0.706 mg / cm to 1.766 mg / cm, plus QO preferably from 0.883 mg / cm to 1.589 mg / cm, and even more preferably from 1.059 mg / cm to 1.413 mg / cm. Furthermore, it is further preferred that with respect to its preferred modalities comprising Pt in the first layer of reactive coating, its loading in said layer is within the range of 0.353 mg / cm 3 to 1.766 mg / cm 3 , more preferably within the range 0.530 mg / cm 3 to 1.589 mg / cm 3 , more preferably within the range 0.706 mg / cm 3 to 1.413 mg / cm 3 , and even more preferably within the range 0.883 mg / cm 3 to 1.236 mg / cm 3 .
    According to other embodiments of the present invention in which a nitrogen oxide conversion material is at least contained in a reactive coating layer positioned between the first and second reactive coating layers, it is additionally specifically preferred that at least one metal in the group of the platinum is present in the first reactive coating layer, preferably in an amount of 1.059 mg / cm 3 to 3.531 mg / cm 3 , more preferably of 1.766 mg / cm 3 to 3.002 mg / cm 3 , more preferably of 1.942 mg / cm 3 to 2,825 mg / cm 3 , more preferably from 2,119 mg / cm to 2,649 mg / cm, and even more preferably from 2,295 mg / cm to 2,472 mg / cm. In addition, it is further preferred that with respect to its preferred modalities comprising Pt in the first layer of reactive coating, its loading in said layer is within the range of 0.883 mg / cm 3 to 3.355 mg / cm 3 , more preferably within the range 1,589 mg / cm 3 to 2,825 mg / cm 3 , more preferably within the range of 1,766 mg / cm 3 to 2,649 mg / cm 3 , more preferably within the range of 1,942 mg / cm 3 to 2,472 mg / cm 3 , and even more preferably within the range of 2,119 mg / cm 3 to 2,295 mg / cm 3 .
    According to embodiments of the present invention in which a nitrogen oxide conversion material is at least contained in the second reactive coating layer, it is specifically preferred that at least one metal of the platinum group is present in the first reactive coating layer, preferably in an amount of 1.059 mg / cm 3 to 3.531 mg / cm 3 , more preferably from 1.766 mg / cm 3 to 3.002 mg / cm 3 , more preferably from 1.942 mg / cm 3 to 2.825 mg / cm 3 , more preferably from 2.119 mg / cm 3 to 2.649 mg / cm 3 , and even more preferably from 2.295 mg / cm 3 to 2.472 mg / cm 3 . Furthermore, it is further preferred that with respect to its preferred embodiments comprising Pt in the first layer of reactive coating, its loading in said layer is comprised within the range of 0.883 mg / cm to 3.355 mg / cm, more preferably within the range of 1.589 mg / cm to 2,825 mg / cm, more preferably within the range of 1,766 mg / cm to 2,649 mg / cm, more preferably within the range of 1,942 mg / cm 3 to 2,472 mg / cm 3 , and even more preferably within the range from 2,119 mg / cm to 2,295 mg / cm.
    In preferred embodiments of the present invention according to which the first reactive coating layer comprises one or more metals of the platinum group, it is further preferred that said layer additionally comprises metal oxide support particles, wherein preferably at least part of the metal oxide support particles support at least part of the at least one metal of the platinum group.
    In general, the first reactive coating layer can contain any possible amount of metal oxide support particles, as long as the function of the remaining components contained in the NO X storage catalyst is not impaired. In general, the loading of the metal oxide component contained in the first reactive coating layer can vary from 61.0 mg / cm 3 to 305.1 mg / cm 3 , and preferably ranges from 91.5 mg / cm 3 to 274, 6 mg / cm 3 , more preferably from 122.0 mg / cm 3 to 256.3 mg / cm 3 , and even more preferably from 134.3 mg / cm 3 to 244.1 mg / cm 3 .
    In principle, any metal oxide particles can be used in the first reactive coating layer, as long as they can adequately support at least one metal in the platinum group and that they can withstand the conditions encountered during automotive exhaust gas treatment. , specifically with respect to the temperatures to which the NO X storage catalyst is exposed. Preferably, high surface area refractory metal oxide supports such as alumina support materials, also called "gamma-alumina" or "activated alumina", are used. Said materials typically exhibit a BET surface area ranging from 60 m 2 / g to 200 m 2 / g or greater. Such activated alumina is usually a mixture of the gamma and delta phases of alumina, but it can also contain substantial amounts of eta, cover and theta phases of alumina. Refractory metal oxides other than activated alumina can be used as a support for at least some of the catalytic components. For example, bulky ceria, zirconia, alpha-alumina and other materials are known for such use. Although many of these materials suffer from the disadvantage of having a considerably lower BET surface area than that of activated alumina, that disadvantage tends to be offset by a great durability of the resulting catalyst. “BE surface area” has its usual meaning of referring to the Brunauer, Emmett, Teller method to determine the surface area by N 2 adsorption. Pore diameter and pore volume can also be determined using BET-type N 2 adsorption. Preferably, the active alumina has a specific surface area contained within the range of 60 m 2 / g to 350 m 2 / g, and typically 90 m 2 / g to 250 m 2 / g.
    According to the present invention, it is preferred that at least part of the metal oxide support particles contain at least one compound selected from the group consisting of alumina, silica, titania, silica-alumina, titania-alumina, zirconia, zirconia-alumina , baria-alumina, ceria, ceria-alumina, baria-ceria-alumina, lantana-alumina, lantana-zirconia-alumina, baria-lantana-alumina, baria-lantana-neodymia-alumina, zirconia, titania-silica, titania-zirconia, and mixtures thereof, more preferably at least one compound selected from the group consisting of ceria, barium-alumina, ceria-alumina, barium-ceria-alumina, and mixtures thereof, wherein even more preferably at least part of the oxide support particles metal contains ceria and / or barium-ceria-alumina.
    According to specifically preferred embodiments of the present invention, the metal oxide support particles contained in the first reactive coating layer can be doped with one or more compounds. Thus, the metal oxide support, preferably alumina, contained in the first layer of reactive coating is preferably doped with ceria and / or barium, preferably with from 5% to 60% by weight of at least one of said compounds, more preferably with from 10% to 50% by weight, more preferably from 20% to 40% by weight, more preferably from 25% to 35% by weight, and even more preferably from 28% to 32% by weight.
    According to preferred embodiments in which the metal oxide support particles contain both barium and ceria, the ratio of barium to ceria generally ranges from 4: 1 to 1: 2, preferably from 3: 1 to 1: 1, more preferably from 5: 2 to 3: 2, and even more preferably from 2.2: 1 to 1.8: 1.
    According to the present invention, it is preferred that at least part of the one or more metals of the platinum group contained in the first reactive coating layer are supported on the metal oxide support particles that are preferred. More preferably, the one or more metals of the platinum group are supported on the preferred metal oxide support particles according to the present invention.
    Regarding the nitrogen oxide storage material contained in the first reactive coating layer, any conceivable element or compound can be used, either alone or in combination with other elements or compounds, provided that said element or compound is capable of reversibly fixing oxide of nitrogen. Specifically, the nitrogen oxide storage material is chosen in such a way that it is able to bind nitrogen oxide at lower temperatures and subsequently be able to release it at higher temperatures, specifically at temperatures at which its effective catalytic conversion can to be fulfilled. More specifically, lower temperatures as used in the present context refer to those found in automotive exhaust gas purification during cold start conditions, before which the engine is mostly at room temperature. Higher temperatures, on the other hand, refer to those temperatures found when the exhaust gas system has reached a temperature at which it is fully operative in relation to the treatment of exhaust gas, specifically with respect to the efficiency of converting emissions. nitrogen oxide.
    Within the meaning of the present invention, it is noted that the term "conversion" is used in the sense that it includes both chemical conversion of emissions to other components, and the capture of emissions by adsorbed and / or chemical bonding in an appropriate capture material. This applies specifically to cold start periods in the automotive exhaust gas treatment, because the effective capture of emissions ideally has the effect of temporarily storing them until their conversion can be carried out in the hottest exhaust gas treatment phases. . "Emissions" as used in the context of the present invention preferably refers to exhaust gas emissions, more preferably to exhaust gas emissions comprising NO X , CO, and hydrocarbons, and even more preferably to NO X , CO, and hydrocarbons contained in automotive exhaust gas.
    In accordance with the present invention, nitrogen oxide storage materials which contain at least one metal compound selected from the group consisting of alkali metal compounds, alkaline earth metal compounds, rare earth metal compounds, and mixtures are preferred of them, preferably of the group consisting of alkaline earth metal compounds, rare earth metal compounds, and mixtures thereof. Preferred alkaline earth metal compounds and rare earth metal compounds are the respective oxides of said compounds.
    Among the preferred nitrogen oxide storage materials of the present invention, those containing at least one element selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Ce, La, are additionally preferred. Pr, Nd, and mixtures thereof, preferably from the group consisting of Mg, Ba, Ce, and mixtures thereof, wherein the nitrogen oxide storage material preferably comprises Mg and / or Ba. Among alkaline earth and rare earth metals, these are preferably used as metal oxides, the nitrogen oxide storage material thus preferably comprising magnesia and / or barium.
    In principle, any possible loading of nitrogen oxide storage material can be chosen, as long as a sufficient amount of nitrogen oxide can be stored, and the function of the remaining components contained in the NO X storage catalyst is not impaired. In general, the loading of nitrogen oxide storage material in the first layer of reactive coating can vary from 3.05 mg / cm 3 to 61.02 mg / cm 3 , with respect to the weight of the metal contained in the respective compound, in which the loading preferably ranges from 6.10 mg / cm 3 to 48.82 mg / cm 3 , more preferably from 9.15 mg / cm 3 to 36.61 mg / cm 3 , more preferably from 12.20 mg / cm 3 at 33.56 mg / cm 3 , and even more preferably from 15.26 mg / cm 3 to 30.51 mg / cm 3 .
    Regarding the nitrogen oxide conversion material contained in the second reactive coating layer and / or a reactive coating layer positioned between the first and second reactive coating layers, any conceivable element or compound can be used, either alone or in combination with other elements or compounds, provided that said element or compound is capable of converting nitrogen oxide, preferably it is capable of converting nitrogen oxide into diatomic nitrogen. According to the present invention, the conversion of nitrogen oxide into the nitrogen oxide conversion material is mainly carried out by its chemical conversion to another compound, preferably to diatomic nitrogen. Preferably, the conversion of nitrogen oxide into the oxide conversion material of nitrogen is substantially accomplished by its chemical conversion to another compound.
    In relation to the nitrogen oxide conversion material, it is further preferred according to the present invention that said material comprises an oxygen-storing component. In principle, any oxygen-storing component can be used, as long as it can reversibly store oxygen. In accordance with preferred embodiments of the present invention, the oxygen-storing component of the nitrogen oxide conversion material comprises at least one compound selected from the group consisting of zirconia, ceria, barium, lantana, praseodymy, neodymia, and mixtures thereof. More preferably, the oxygen-storing component comprises ceria and / or zirconia, wherein even more preferably the oxygen-storing component comprises ceria.
    In principle, any possible loading of the oxygen storage component can be chosen, as long as a sufficient amount of oxygen can be stored for the oxidation processes to take place in the NO X storage catalyst and the function of the remaining components contained in the NO storage catalyst X is not affected. In general, the loading of an oxygen storage component into the second reactive coating layer can vary from 6.10 mg / cm 3 to 91.5 mg / cm 3 , where the loading of the oxygen storage component preferably ranges from 12, 2 mg / cm 3 to 73.2 mg / cm 3 , more preferably 18.3 mg / cm 3 to 61.0 mg / cm 3 , more preferably 24.4 mg / cm 3 to 54.9 mg / cm 3 , more preferably from 27.5 mg / cm 3 to 48.8 mg / cm 3 , and even more preferably from 30.5 mg / cm 3 to 45.8 mg / cm 3 .
    In accordance with the present invention it is further preferred that the nitrogen oxide conversion material comprises at least one platinum group metal. Preferably, the nitrogen oxide conversion material comprises at least one metal of the platinum group selected from the group consisting of Pt, Pd, Rh, and mixtures thereof, wherein more preferably the at least one metal of the platinum group is Pt and / or Rh, and even more preferably the nitrogen oxide conversion material comprises Pt and Rh, preferably, Pt, Pd, and Rh. According to the present invention, the one or more metals of the platinum group can be present in an amount of up to 7.06 mg / cm, preferably from 0.353 mg / cm 3 to 5.30 mg / cm 3 , more preferably from 0.706 mg / cm 3 to 4.23 mg / cm 3 , more preferably from 1.06 mg / cm to 3.53 mg / cm, more preferably from 1.41 mg / cm 3 to 3.18 mg / cm 3 , more preferably from 1.59 mg / cm 3 to 3.00 mg / cm 3 , and even more preferably from 1.76 mg / cm 3 to 2.82 mg / cm 3 .
    In preferred embodiments of the present invention comprising Pt in the second layer of reactive coating and / or in a layer of reactive coating positioned between the first and second layers of reactive coating, their loading in said layers can respectively vary from 610 mg / cm 3 to 9,154 mg / cm 3 , wherein the loading of Pt is preferably from 1,220 mg / cm 3 to 6,102 mg / cm 3 , more preferably from 1,831 mg / cm 3 to 5,492 mg / cm 3 , more preferably from 2,136 mg / cm 3 at 4,882 mg / cm 3 , and even more preferably from 2,441 mg / cm 3 to 4,577 mg / cm 3 .
    Furthermore, in preferred embodiments comprising Pd and / or Rh in the second layer of reactive coating and / or in a layer of reactive coating positioned between the first and second layers of reactive coating, more preferably Rh, the respective loading of said metals from the group of the platinum in said layers is generally within the range of 61 mg / cm 3 to 915 mg / cm 3 , and preferably within the range of 92 mg / cm 3 to 732 mg / cm 3 , more preferably within the range of 122 mg / cm 3 to 610 mg / cm 3 , more preferably within the range of 153 mg / cm 3 to 549 mg / cm 3 , more preferably within the range of 183 mg / cm 3 to 488 mg / cm 3 , more preferably within the range of 214 mg / cm 3 to 427 mg / cm 3 , and even more preferably within the range of 244 mg / cm 3 to 397 mg / cm 3 .
    According to specifically preferred embodiments containing both Pd and Rh in the second reactive coating layer and / or in a reactive coating layer positioned between the first and second reactive coating layers, the amount of Pd is generally within □
    from the range of 61 mg / cm to 488 mg / cm 3 , and preferably within the range of 122 mg / cm 3 to 427 mg / cm 3 , more preferably from 153 mg / cm 3 to 366 mg / cm 3 , more preferably from 183 mg / cm 3 to 305 mg / cm 3 , and even more preferably 214 mg / cm 3 to 275 mg / cm 3 , and the amount of Rh is generally within the range of 61 mg / cm 3 to 915 mg / cm 3 , and preferably within the range of 122 mg / cm 3 to 732 mg / cm 3 , more preferably 183 mg / cm 3 to 610 mg / cm 3 , more preferably 244 mg / cm 3 to 549 mg / cm 3 , more preferably from 305 mg / cm 3 to 488 mg / cm 3 , and even more preferably from 366 mg / cm 3 to 427 mg / cm 3 .
    In preferred embodiments of the present invention, according to which the nitrogen oxide conversion material comprises one or more metals of the platinum group, it is additionally preferred that the nitrogen oxide conversion material comprises metal oxide support particles , wherein preferably at least part of the metal oxide support particles support at least part of the at least one metal of the platinum group.
    In principle, any metal oxide particles can be used, as long as they can adequately support at least one metal in the platinum group and that they can withstand the conditions encountered during automotive exhaust gas treatment, specifically with respect to temperatures to which the NO X storage catalyst is exposed. Preferably, high surface area sputtering metal oxide supports such as alumina support materials, also called "gamma-alumina" or "activated alumina", are used. Said materials typically exhibit a BET surface area ranging from 60 m 2 / g to 200 m 2 / g or greater. Such activated alumina is usually a mixture of the gamma and delta phases of alumina, but it can also contain substantial amounts of eta, cover and theta phases of alumina. Refractory metal oxides other than activated alumina can be used as a support for at least some of the catalytic components. For example, bulky ceria, zirconia, alpha-alumina and other materials are known for such use. Although many of these materials suffer from the disadvantage of having a considerably lower BET surface area than that of activated alumina, that disadvantage tends to be compensated for by the long life of the resulting catalyst. “BE surface area” has its usual meaning of referring to the Brunauer, Emmett, Teller method to determine the surface area by N 2 adsorption. Pore diameter and pore volume can also be determined using BET-type N 2 adsorption. Preferably, the active alumina has a specific surface area contained within the range of 60 m 2 / g to 350 m 2 / g, and typically 90 m 2 / g to 250 m 2 / g.
    According to the present invention, it is preferred that at least part of the metal oxide support particles contain at least one compound selected from the group consisting of alumina, silica, titania, silica-alumina, titania-alumina, zirconia, zirconia-alumina , baria-alumina, ceria, ceria-alumina, baria-ceria-alumina, lantana-alumina, lantana-zirconia-alumina, baria-lantana-alumina, baria-lantana-neodymia-alumina, zirconia, titania-silica, titania-zirconia, and mixtures thereof. In specifically preferred embodiments, at least part of the metal oxide support particles contains at least one compound selected from the group consisting of alumina, ceria, ceria-alumina, and mixtures thereof, wherein even more preferably at least part of the particles of metal oxide support comprises alumina and / or ceria.
    In general, the second reactive coating layer and / or a reactive coating layer positioned between the first and second reactive coating layers can contain any possible amount of metal oxide support particles, as long as the function of the remaining components contained in the NO X storage catalyst is not impaired. In embodiments of the present invention in which the second reactive coating layer comprises a nitrogen oxide conversion material, and preferably in embodiments that additionally do not contain a reactive coating layer positioned between the first and second reactive coating layers, the loading of the metal oxide component in the second reactive coating layer can vary from 6.1 mg / cm 3 to 305 mg / cm 3 , with respect to the weight of the metal contained in the respective compound, where the loading preferably varies from 30.5 mg / cm 3 cm 3 to 214 mg / cm 3 , more preferably from 49 mg / cm 3 to 183 mg / cm 3 , more preferably from 55 mg / cm 3 to 152 mg / cm 3 , more preferably from 61 mg / cm 3 to 140 mg / cm 3 , and even more preferably from 61 mg / cm 3 to 91.5 mg / cm 3 .
    According to preferred embodiments comprising metal oxide particles which contain ceria and also metal oxide particles which contain alumina, it is specifically preferred that the ratio of ceria to alumina is contained within the range of 1: 4 to 5: 1, more preferably from 1: 3 to 4: 1, more preferably from 2: 5 to 7: 2, and even more preferably from 1: 2 to 3: 1.
    According to other preferred embodiments, the platinum group metals supported on at least part of the metal oxide particles contain Rh and also at least one other platinum group metal being preferably Pt and / or Pd, more preferably Pt and Pd . With respect to said modalities, it is preferred that Rh is supported on other metal oxide support particles than Pt and / or Pd, preferably Pt and Pd, where Rh is preferably supported on metal oxide particles comprising ceria and / or ceria-alumina, even more preferably on metal oxide particles comprising ceria. Furthermore, in preferred embodiments comprising Pt and Pd, said platinum group metals are preferably supported on the same metal oxide support particles, wherein said metal oxide particles preferably comprise alumina.
    According to the present invention, it is further preferred that the second reactive coating layer and / or a reactive coating layer positioned between the first and second reactive coating layers substantially does not contain Mg and Ba. According to another preferred embodiment of the present invention, the second reactive coating layer and / or a reactive coating layer positioned between the first and second reactive coating layers substantially does not contain an element selected from the group consisting of Mg, Ca, Sr, Ba, and combinations thereof, wherein even more preferably, the second reactive coating layer and / or a reactive coating layer positioned between the first and second reactive coating layers substantially does not contain an alkaline earth element.
    Regarding the hydrocarbon trapping material contained in the nitrogen oxide storage catalyst of the present invention, any material can be used, as long as it has the ability to reversibly capture hydrocarbons, and specifically hydrocarbon emissions during the cold start period in treatment automotive exhaust gas. More specifically, the hydrocarbon-trapping materials that can be used in the present invention are capable of binding hydrocarbons at lower temperatures and subsequently releasing them at higher temperatures, specifically at temperatures at which their effective catalytic conversion can be carried out. More specifically, lower temperatures as used in the context of the present invention refer to those found in automotive exhaust gas purification during cold start conditions, before which the engine is mostly at room temperature. Higher temperatures, on the other hand, refer to those temperatures found when the exhaust gas system has reached a temperature at which it is fully operational with respect to the treatment of exhaust gas, specifically with regard to the catalytic conversion of hydrocarbon emissions. .
    Among the hydrocarbon trapping materials that can be used in the present invention, those containing a zeolite, preferably a zeolite selected from the group consisting of faujasite, chabazite, clinoptilolite, mordenite, silicalite, zeolite X, zeolite Y, ultra-stable Y zeolite are preferred , zeolite ZSM-5, zeolite ZSM-12, zeolite SSZ-3, zeolite SAPO 5, offetite, beta zeolite, and mixtures thereof. According to specifically preferred embodiments, the hydrocarbon trap material comprises beta zeolite, preferably H-beta zeolite.
    According to the present invention, it is specifically preferred that used zeolites have a high ratio of silica to alumina. Typically, such zeolites will have a silica / alumina molar ratio of at least about 25/1, preferably at least about 50/1, more preferably where the silica / alumina molar ratio ranges from 25/1 to 1,000 / 1, more preferably from 50/1 to 500/1. More preferred are zeolites whose molar ratio of silica / alumina ranges from 25/1 to 300/1, more preferably from about 100/1 to 250/1. According to an even more preferred embodiment of the present invention, the molar ratio of silica / alumina of the zeolites ranges from 35/1 to 180/1.
    In principle, the second layer of reactive coating can contain any possible amount of hydrocarbon-trapping material, as long as the function of the remaining components contained in the NO X storage catalyst is not impaired. In general, the loading of the hydrocarbon-trapping material into the reactive coating layer can vary from 6.10 mg / cm 3 to 91.5 mg / cm 3 , preferably from 9.15 mg / cm 3 to 61 mg / cm 3 , more preferably from 12.2 mg / cm 3 to 42.7 mg / cm 3 , more preferably from 15.2 mg / cm 3 to 36.6 mg / cm 3 , and even more preferably from 18.3 mg / cm 3 at 30.5 mg / cm 3 .
    According to the present invention, it is additionally preferred that the hydrocarbon trap material additionally comprises Pt and / or Pd, more preferably Pt, wherein the platinum group metals in the hydrocarbon trap material will typically be present in an amount of up to 1 , 77 mg / cm, preferably from 0.00177 mg / cm 3 to 0.706 mg / cm 3 , more preferably from 0.00353 mg / cm 3 to 0.530 mg / cm 3 , more preferably from 0.0177 mg / cm 3 to 0.424 mg / cm 3 , plus □ preferably from 0.0353 mg / cm to 0.353 mg / cm, and even more preferably from 0.0706 mg / cm 3 to 0.282 mg / cm 3 .
    According to the modalities of the present invention in which the NO X storage catalyst comprises a reactive coating layer positioned between the first and second reactive coating layers, and preferably in which in addition the second reactive coating layer does not contain a conversion material of nitrogen oxide, it is preferred that the second layer of reactive coating comprises metal oxide support particles. In their embodiments additionally comprising one or more metals of the platinum group in the second reactive coating layer, it is additionally preferred that the metal oxide support particles support at least part of at least one metal of the platinum group. In principle, any metal oxide particles can be used, as long as they can adequately support at least one metal in the platinum group and that they can withstand the conditions encountered during automotive exhaust gas treatment, specifically with respect to temperatures to which the NO X storage catalyst is exposed during the treatment of exhaust gas. In specifically preferred embodiments, the metal oxide support particles contain alumina.
    According to said preferred embodiments, the second layer of reactive coating may contain any possible amount of metal oxide support particles, provided that the function of the remaining components contained in the NO X storage catalyst is not impaired. In general, the loading of the metal oxide component in the second layer of reactive coating of said preferred embodiments can vary from 0.610 mg / cm 3 to 183 mg / cm 3 , wherein the loading preferably ranges from 3.05 mg / cm 3 to 122 mg / cm 3 , more preferably from 6.10 mg / cm 3 to 61 mg / cm 3 , more preferably from 9.15 mg / cm 3 to 30.5 mg / cm 3 , and even more preferably from 12.2 mg / cm 3 to 18.33 mg / cm 3 .
    An essential feature of the present invention is that the hydrocarbon-trapping material substantially does not contain an element or compound in a state in which it would be able to catalyze selective catalytic reduction. According to the present invention, the term "selective catalytic reduction" refers to a catalytic treatment of exhaust gas from a gasoline engine, in which the nitrogen oxide is reduced to diatomic nitrogen by the reaction with reducing emissions present in the exhaust gas . Preferably, the term refers to the catalytic treatment of automotive exhaust gas in general. According to the present invention, it is specifically preferred that the term "selective catalytic reduction" refers to a catalyzed reaction in which gaseous nitrogen oxide is reduced to diatomic nitrogen.
    Thus, according to the present invention, the hydrocarbon-trapping material substantially does not catalyze the selective catalytic reduction of nitrogen oxide. Preferably, this refers to hydrocarbon trapping materials whose catalytic activity for the selective catalytic reduction of nitrogen oxide within the meaning of the present invention does not exceed the catalytic activity of a hydrocarbon trapping material substantially free of Cu and / or Co, more preferably of a hydrocarbon-trapping material substantially free of Cu, Co, Mn, Ag, In, Ir, and / or Rh, and even more preferably substantially free of Cu, Co, Fe, Mn, Ag, In, Ir, and / or Rh. According to the present invention, it is specifically preferred that the hydrocarbon trap material does not exhibit a catalytic activity for selective catalytic reduction within the meaning of the present invention that would exceed the activity of a hydrocarbon trap material which substantially does not contain a transition metal element except Pt and / or Pd, preferably of a hydrocarbon trap material which substantially does not contain transition metal element except Pt, and more preferably of a hydrocarbon trap material which substantially does not contain transition metal element, wherein the hydrocarbon trap material is preferably refers to the respectively preferred hydrocarbon trapping materials of the present invention.
    Within the meaning of the present invention, a material is defined as not containing a substantial amount of a specific element when it contains less than 1% by weight or less of said element, preferably 0.5% by weight or less, more preferably 0 , 01% by weight or less, more preferably 0.005% by weight or less, and even more preferably 0.001% by weight or less of the same.
    The nitrogen oxide storage catalyst according to the present invention can be readily prepared by processes well known in the prior art. A representative process is described below. As used herein, the term "reactive coating" has its usual meaning in the technique of an adherent, thin coating of a catalytic material or other material applied to a substrate support material, such as a favored support member, which is preferably sufficiently porous to allow the passage through it of the gas stream being treated.
    The various components of the nitrogen oxide storage catalyst material can be applied to the substrate as mixtures of one or more components in sequential steps that will be readily apparent to those skilled in the catalyst manufacturing technique. A typical method of manufacturing the nitrogen oxide storage catalyst of the present invention is to obtain the nitrogen oxide storage material, the nitrogen oxide conversion material, respectively, and the hydrocarbon trap material as a coating layer or coating layer. reactive on the walls of the gas flow passages of a suitable support member. According to some embodiments of the present invention, the nitrogen oxide conversion material and the hydrocarbon trap material are obtained in a single reactive coating on the substrate.
    According to the present invention, the components of the individual reactive coating layers can be respectively processed into a slurry, preferably into an aqueous slurry. The substrate can then be sequentially immersed in the respective pastes for the individual reactive coatings, after which the excess paste is removed to obtain a thin coating of the two or more pastes on the walls of the substrate gas flow passages. The coated substrate is then dried and calcined to obtain an adherent coating of the respective component on the walls of the passages. Thus, after applying the first layer of reactive coating on the substrate, the coated substrate can then be immersed in another paste of the nitrogen oxide conversion material or a mixture of the nitrogen oxide conversion material and the nitrogen capture material. hydrocarbon to form a second layer of reactive coating deposited on the first layer of reactive coating. The substrate is then dried and / or calcined and finally coated with a third layer of reactive coating comprising the hydrocarbon trap material, which is subsequently dried and / or calcined again to obtain a finished nitrogen oxide storage catalyst according to a embodiment of the present invention.
    In addition to the nitrogen oxide storage catalyst mentioned above, the present invention is also directed to treatment systems for an automobile exhaust gas stream. Specifically, the treatment system of the present invention comprises a combustion engine, preferably a diesel engine, an exhaust gas duct in fluid communication with the engine, and a nitrogen oxide storage catalyst as described herein that is positioned within the exhaust gas flue. In principle, any conceivable combustion engine can be used in the treatment system of the present invention, wherein preferably a poor combustion engine is used such as a diesel engine or a poorly combustion gasoline engine, more preferably a diesel engine .
    Thus, the present invention also relates to a treatment system for an automobile exhaust gas stream comprising:
    a combustion engine, preferably a diesel engine or a low combustion gasoline engine, more preferably a diesel engine, an exhaust gas duct in fluid communication with the engine, and a nitrogen oxide storage catalyst according to the present invention positioned within the exhaust gas line.
    According to a preferred embodiment, the treatment system additionally comprises a soot filter component and / or a selective catalytic reduction component,
    SCR). In said embodiments, the nitrogen oxide storage catalyst can be located upstream or downstream of the soot filter and / or the selective catalytic reduction component. According to a specifically preferred embodiment, the soot filter is a catalyzed soot filter, CSF. Any suitable CSF can be used in accordance with the present invention. Preferably, the CSF of the present invention comprises a substrate coated with a reactive coating layer containing one or more catalysts for burning captured soot and / or oxidizing exhaust gas stream emissions. In general, the soot-burning catalyst can be any known soot combustion catalyst. For example, CSF may be coated with one or more high surface area refractory oxides (such as eg alumina, silica, silica alumina, zirconia, and zirconia alumina) and / or with an oxidation catalyst (such as eg ceria- zirconia) for the combustion of unburned hydrocarbons and in some degree of particulate matter. However, preferably the soot-burning catalyst is an oxidation catalyst comprising one or more precious metal catalysts (platinum, palladium, and / or rhodium).
    According to a more preferred embodiment, the treatment system of the present invention additionally comprises a selective catalytic reduction (SCR) component. The SCR component is preferably located downstream of the nitrogen oxide storage catalyst and upstream or downstream of the soot filter. An SCR catalyst component suitable for use in the emission treatment system is able to effectively catalyze the reduction of the NO X component at temperatures below 600 ° C, so that adequate levels of NO X can be treated even under low load conditions that they are typically associated with lower exhaust temperatures. Preferably, the catalyst article is capable of converting at least 50% of the NO X component to N 2 , depending on the amount of a reducing agent such as NH3 which is preferably added to the system. In this regard, another desirable attribute for the composition is that it has the ability to catalyze the reaction of O 2 with any excess of NH 3 to N 2 and H 2 O, so that NH 3 is not emitted into the atmosphere. Useful SCR catalyst compositions used in the emission treatment system must also have thermal resistance at temperatures greater than 650 ° C. Such high temperatures can be found during regeneration of the upstream catalyzed soot filter.
    Suitable SCR catalyst compositions are described, for example, in US 4,961,917 and US 5,516,497. Suitable compositions include one or both a copper and an iron promoter present in a zeolite in an amount of about 0.1 to 30 weight percent, preferably about 1 to 5 weight percent, of the total weight of the most promoter zeolite. In addition to its ability to catalyze the reduction of NO X with NH 3 to N 2 , the disclosed compositions can also promote the oxidation of excess NH 3 with O 2 , especially for those compositions having higher concentrations of promoter.
    In addition to these embodiments, the present invention also relates to a method for treating automobile engine exhaust gas using the nitrogen oxide storage catalyst of the present invention. More specifically, the method of the present invention includes driving a car engine exhaust gas over and / or through the nitrogen oxide storage catalyst, wherein the car engine exhaust gas is preferably only conducted through the car storage catalyst. nitrogen oxide.
    Thus, the present invention also relates to a method for treating automobile engine exhaust gas comprising:
    (i) obtaining a nitrogen oxide storage catalyst according to the present invention, and (ii) conducting an automobile engine exhaust gas stream over and / or through the nitrogen oxide storage catalyst.
    In the method of the present invention, it is preferred that the automobile engine exhaust gas is from a low-combustion combustion engine, preferably from a diesel engine or a low-combustion gasoline engine, more preferably a diesel engine.
    Description of the Figures
    Fig. 1 shows test results of the NO X storage catalysts of Example 1 and Comparative Examples 1 and 2 with respect to the conversion of hydrocarbon, carbon monoxide, and NO X emissions contained in automotive exhaust gas under cold start conditions . The "Conversion /%" values indicate the percentage of the respective substances originally contained in the automotive exhaust gas that have been converted after the exhaust gas has been passed through the NO X storage catalyst according to said examples.
    Fig. 2 shows test results of the NO X catalysts storing Example 3 and Comparative Example 3 with respect to the conversion of hydrocarbon, carbon monoxide, and NO X emissions contained in automotive exhaust gas under cold start conditions. The “Conversion /%” values have the same meaning as described above for Figure 1.
    Examples
    Example 1
    On top of a direct flow monolithic faviform substrate (14.38 cm x 7.62 cm; 1.2 L; 62 cells per square centimeter / 152.4 micrometers), a first layer of reactive coating containing 146.5 mg was applied / cm of activated alumina containing 10% by weight of ceria and 20% by weight of barium oxide, 12.2 mg / cm of Ce as cerium nitrate, ο
    30.5 mg / cm of Ba as barium oxide and 6.1 mg / cm of Zr as zirconium oxide, said layer additionally containing 1.02 mg / cm of Pt and 0.21 mg / cm 3 of Pd.
    A second layer of reactive coating was then applied over the first layer, said second layer containing 15.3 mg / cm 3 of AI2O3 and 45.8 mg / cm 3 of ceria, said layer additionally containing a loading of 2.66 mg / cm 3 of Pt and 0.21 mg / cm 3 of Rh.
    Finally, a third layer of reactive coating was applied on the second layer, said third layer containing 15.26 mg / cm 3 of AI2O3 and 30.51 mg / cm 3 of H-beta zeolite, said layer additionally containing 0.14 mg / cm 3 of Pt.
    The resulting layered NO X capture catalyst contained a total of 3.81 mg / cm 3 of Pt, 0.21 mg / cm 3 of Pd and 0.21 mg / cm 3 of Rh.
    Example 2
    The layered NO X capture catalyst was positioned on a direct flow monolithic substrate having a volume of
    1,199 cm 3 (1.2 L), a cell density of 62 cells per square centimeter, and a wall thickness of approximately 100 pm.
    The first coating applied on the substrate contained a reactive coating of 234 mg / cm 3 of activated alumina containing 10% by weight of ceria and 18% by weight of barium oxide, 67.37 mg / cm of ceria (87% of ceria) being in particulate form), 14.65 mg / cm 3 of Mg as magnesium oxide, and 5.86 mg / cm of Zr as zirconium oxide, said layer 1 additionally comprising 2.22 mg / cm of Pt and 0 , 23 mg / cm of Pd.
    The second layer applied on the first coating contained a reactive coating of 42.7 mg / cm of activated alumina having 1.41 mg / cm of Pt and 0.14 mg / cm of Pd, 30.5 mg / cm of ceria. having 0.23 mg / cm 3 of Rh, substantially without an alkaline earth component being present in the second layer of reactive coating.
    The third coating applied on the second coating contained a reactive coating of 15.26 mg / cm 3 AI2O3 and 30.5 mg / cm 3 of H-beta zeolite having 0.14 mg / cm 3 of Pt.
    The resulting layered NO X capture catalyst contained a total of 3.78 mg / cm 3 of Pt, 0.371 mg / cm 3 of Pd and 0.23 mg / cm 3 of Rh.
    Example 3
    The layered NO X capture catalyst was positioned on a direct flow monolithic substrate having a volume of
    1,199 cm 3 (1.2 L), a cell density of 62 cells per square centimeter, and a wall thickness of approximately 100 pm.
    The first coating positioned on the substrate contained a reactive coating of 225 mg / cm of activated alumina containing 10% barium weight and 18% barium oxide, 64.68 mg / cm ceria (87% of the ceria being in the form particulate), 14.0 mg / cm of Mg as magnesium oxide, and 5.61 mg / cm of Zr as zirconium oxide, said layer additionally containing 2.15 mg / cm of Pt and 0.23 mg / cm of Pd.
    The second layer applied on the first coating contained a reactive coating of 36.6 mg / cm 3 of activated alumina having 1.41 mg / cm 3 of Pt and 0.14 mg / cm 3 of Pd, 30.5 mg / cm 3 ceria having 0.23 mg / cm 3 of Rh, and 18.3 mg / cm 3 of zeolite H-beta having 0.071 mg / cm of Pt, substantially without alkaline earth component being present in the second layer of reactive coating.
    The resulting layered NOx capture catalyst contained a total of 3.64 mg / cm 3 of Pt, 0.37 mg / cm 3 of Pd and 0.23 mg / cm 3 of Rh.
    Comparative Example 1
    The layered NO X capture catalyst was positioned on a direct flow monolithic substrate having a volume of
    1,199 cm 3 (1.2 L), a cell density of 62 cells per square centimeter, and a wall thickness of approximately 100 pm.
    The first coating positioned on the substrate contained a reactive coating of 15.3 mg / cm 3 of AI2O3 and 30.5 mg / cm 3 of zeolite H-beta having 0.14 mg / cm of Pt.
    The second layer applied to the first coating contained a reactive coating of 146.5 mg / cm of activated alumina containing 10% by weight of ceria and 20% by weight of barium oxide, 12.2 mg / cm 3 of Ce as cerium nitrate, 30.5 mg / cm 3 of Ba as barium oxide and 6.1 mg / cm 3 of Zr as zirconium oxide, said layer additionally containing 1.02 mg / cm 3 of Pt and 0.21 mg / cm 3 of Pd.
    The third coating positioned on the second coating contained a reactive coating of 15.26 mg / cm of activated alumina 2 * 2 □ having 2.65 mg / cm of Pt and 45.8 mg / cm of ceria having 0.21 mg / cm of Rh, substantially without alkaline earth component being present in said second layer of reactive coating.
    The resulting layered NO X capture catalyst * 2 “2 contained a total of 3.81 mg / cm Pt, 0.21 mg / cm Pd and 0.21 mg / cm Rh.
    Comparative Example 2
    The layered NO X capture catalyst was positioned on a direct flow monolithic substrate having a volume of
    1,199 cm 3 (1.2 L), a cell density of 62 cells per square centimeter, and a wall thickness of approximately 100prn.
    The first coating positioned on the substrate contained a reactive coating of 146.5 mg / cm of activated alumina □
    containing 10% by weight ceria and 20% by weight barium oxide, 12.2 mg / cm <2
    Ce as cerium nitrate, 30.5 mg / cm of Ba as barium oxide and 6.1 mg / cm 3 of Zr as zirconium oxide, said layer additionally containing 1.36 mg / cm 3 of Pt and 0.14 mg / cm 3 of Pd.
    The second layer applied over the first coating contained a reactive coating of 91.5 mg / cm of activated alumina 0 o * 3 having 3.52 mg / cm of Pt and 30.5 mg / cm of ceria having 0.28 mg / cm cm of Rh, substantially without alkaline earth component being present in the second layer of reactive coating.
    The resulting layered NO X capture catalyst contained a total of 4.73 mg / cm 3 Pt, 0.14 mg / cm 3 Pd and 0.28 mg / cm 3 Rh. Comparative Example 3
    The layered NOx-capturing catalyst was positioned on a direct flow faviform monolithic substrate having a volume of
    1,199 cm 3 (1.2 L), a cell density of 62 cells per square centimeter, and a wall thickness of approximately 100 gm.
    The first coating positioned on the substrate contained a reactive coating of 234 mg / cm of activated alumina containing 10% by weight of ceria and 18% by weight of barium oxide, 67.37 mg / cm 3 of ceria (87% of ceria being in particulate form), 14.6 mg / cm 3 of Mg as magnesium oxide, and 5.86 mg / cm of Zr as zirconium oxide, said layer additionally comprising 2.22 mg / cm 3 of Pt and 0.23 mg / cm 3 of Pd.
    The second layer applied on the first coating contained a reactive coating of 42.7 mg / cm 3 of activated alumina having 1.41 mg / cm 3 of Pt and 0.14 mg / cm 3 of Pd, 30.5 g / cm 3 of ceria having 397 mg / cm of Rh, substantially without alkaline earth component being present in the second layer of reactive coating.
    The resulting NO X capture catalyst contained a total of 3.64 mg / cm 3 of Pt, 0.371 mg / cm 3 of Pd and 0.23 mg / cm 3 of Rh.
    Catalyst Test
    All catalysts were oven-matured under hydrothermal conditions with 10% water vapor and 10% oxygen. Maturation was carried out for 5 h at 750 ° C. After maturation, the catalysts were tested on a dynamic engine bench under MVEG direction cycle conditions (cold start) using a transient test cell with an OM 646 engine.
    In the European steering cycle, hydrocarbons have to be stored in low temperature conditions during cold starting. For this purpose, the hydrocarbon / carbon monoxide and DeNOx activity was assessed during the certification cycle (New European Driving Cycle, EU2000).
    Figure 1 shows results of the test of Example 2 and Comparative Examples 1 and 2 with respect to the conversion of hydrocarbons, carbon monoxide and NO X under cold start conditions according to the test procedure described above. Specifically, the conversion value reflects the amount of emissions that have been removed from the exhaust gas stream through capture and / or conversion to a different chemical compound. In this regard, the test results in Figure 1 show that a hydrocarbon trapping layer as a top / top layer for a NO X trapping catalyst as present in Example 2 is able to lower hydrocarbon emissions while maintaining a rate of conversion of sufficient carbon monoxide and NO X compared to a NO X storage catalyst that does not contain hydrocarbon trap material (Comparative Example 2). When the hydrocarbon layer is used as an internal coating as in Comparative Example 1, it may not effectively lower hydrocarbon emissions from cold starting compared to the NO X trapping formulation that does not contain a hydrocarbon trapping material (Comparative Example 2). Furthermore, as can be deduced from Figure 2, the capacity of such a NO X storage catalyst containing an internal hydrocarbon coating is considerably worsened compared to the NO X storage catalyst of Comparative Example 2 which does not contain a hydrocarbon capturing component. .
    The same applies to the results shown in
    Figure 2 of the Example 3 test with the hydrocarbon trapping layer as a top / topcoat compared to the test results of Comparative Example 3 which does not contain a hydrocarbon trapping component. Thus, as for Example 2, the NO X storage catalyst according to Example 3 exhibits an improved hydrocarbon conversion capacity due to the presence of the hydrocarbon trap material in the top layer. Specifically, as can be deduced from the results in Figure 2, the capacity of the NO X catalyst to convert carbon monoxide and to store NO X under cold start conditions is not impaired by the additional presence of the hydrocarbon capturing element. in the top layer, because comparable results are achieved in this respect for both the NO X storage catalyst according to Example 3, which contains a hydrocarbon capturing element, and also for the catalyst according to Comparative Example 3, which does not contain such a hydrocarbon capturing element.
    权利要求:
    Claims (19)
    [1]
    1. Nitrogen oxide storage catalyst, characterized by the fact that it comprises:
    a substrate;
    a first layer of reactive coating applied on the substrate, the first layer of reactive coating comprising a nitrogen oxide storage material, a second layer of reactive coating applied on the first layer of reactive coating, the second layer of reactive coating comprising a material hydrocarbon trap, wherein the hydrocarbon trap material substantially contains no element or compound in a state in which it is capable of catalyzing selective catalytic reduction, said catalyst additionally comprising a nitrogen oxide conversion material that is also contained in the second layer reactive coating and / or in a reactive coating layer applied between the first reactive coating layer and the second reactive coating layer, in which the nitrogen oxide conversion material comprises Rh and Pt, in which the nitrogen conversion material nitrogen oxide additionally comp bends metal oxide support particles, where at least part of the metal oxide support particles support at least part of the Pt and Rh, where, in the nitrogen oxide conversion material, Rh is supported on other particles of metal oxide support than Pt.
    [2]
    2. Nitrogen oxide storage catalyst according to claim 1, characterized in that the first reactive coating layer additionally comprises a component
    Petition 870180124974, of 9/3/2018, p. 12/15 oxygen storage.
    [3]
    Nitrogen oxide storage catalyst according to claim 1 or 2, characterized in that the first reactive coating layer additionally comprises at least one platinum group metal.
    [4]
    Nitrogen oxide storage catalyst according to claim 3, characterized in that the first reactive coating layer additionally comprises metal oxide support particles.
    [5]
    Nitrogen oxide storage catalyst according to any one of claims 1 to 4, characterized in that the nitrogen oxide storage material comprises at least one metal compound selected from the group consisting of alkali metal compounds, composed of alkaline earth metal, rare earth metal compounds, and mixtures thereof.
    [6]
    6. Nitrogen oxide storage catalyst according to claim 5, characterized by the fact that the nitrogen oxide storage material comprises at least one element of the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Ce, La, Pr, Nd, and mixtures thereof.
    [7]
    Nitrogen oxide storage catalyst according to any one of claims 1 to 6, characterized in that the nitrogen oxide conversion material comprises an oxygen storage component.
    [8]
    Nitrogen oxide storage catalyst according to any one of claims 1 to 7, characterized in that the nitrogen oxide conversion material comprises at least one platinum group metal.
    [9]
    9. Nitrogen oxide storage catalyst according to
    Petition 870180124974, of 9/3/2018, p. 13/15 with any one of claims 1 to 8, characterized in that at least part of the metal oxide support particles comprises at least one compound selected from the group consisting of alumina, titania, titania-alumina, zirconia, zirconia- alumina, barium-alumina, ceria, ceria-alumina, baria-ceria-alumina, lantana-alumina, lantana-zirconia-alumina, titania-zirconia, and mixtures thereof.
    [10]
    10. Nitrogen oxide storage catalyst according to claim 9, characterized in that in the nitrogen oxide conversion material, Rh is supported on metal oxide support particles other than Pt and Pd.
    [11]
    11. Nitrogen oxide storage catalyst according to claim 10, characterized by the fact that Pt and Pd are supported on the same metal oxide support particles.
    [12]
    Nitrogen oxide storage catalyst according to any one of claims 1 to 11, characterized in that the one or more layers of reactive coating comprising a nitrogen oxide conversion material substantially do not contain Mg and Ba.
    [13]
    13. Nitrogen oxide storage catalyst according to any one of claims 1 to 12, characterized in that the hydrocarbon-capturing material comprises a zeolite.
    [14]
    Nitrogen oxide storage catalyst according to any one of claims 1 to 13, characterized in that the hydrocarbon capture material additionally comprises Pt and / or Pd.
    [15]
    Nitrogen oxide storage catalyst according to any one of claims 1 to 14, characterized in that the hydrocarbon capture material substantially does not contain Cu, Co, Mn, Ag, In, Ir, and / or Rh.
    [16]
    16. Nitrogen oxide storage catalyst according to
    Petition 870180124974, of 9/3/2018, p. 14/15 with any one of claims 1 to 15, characterized by the fact that the substrate is a monolith.
    [17]
    17. Treatment system for an automobile exhaust gas stream, characterized by the fact that it comprises:
    a combustion engine, an exhaust gas conduit in fluid communication with the engine, and a nitrogen oxide storage catalyst as defined in any one of claims 1 to 16 positioned within the exhaust gas conduit.
    [18]
    18. Method for treating car engine exhaust gas, characterized by the fact that it comprises:
    (i) obtaining a nitrogen oxide storage catalyst as defined in any of claims 1 to 16, and (ii) conducting an automobile engine exhaust gas stream over and / or through the nitrogen oxide storage catalyst.
    [19]
    19. Method according to claim 18, characterized in that the exhaust gas stream of the automobile engine is from a poorly combustion engine.
    Petition 870180124974, of 9/3/2018, p. 15/15
    1/2
    Fig. 1
    CONVERSION%
    EXAMPLE 1
    EXAMPLE EXAMPLE
    COMPARATIVE 1 COMPARATIVE 2
    2/2
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112012031330B1|2018-12-11|nitrogen oxide storage catalyst, treatment system for an automobile exhaust gas stream, and method for the treatment of automobile engine exhaust gas
    US8734743B2|2014-05-27|NOx storage catalyst with improved hydrocarbon conversion activity
    KR101800028B1|2017-11-21|Diesel oxidation catalyst with layer structure for improved hydrocarbon conversion
    KR101380058B1|2014-04-01|Palladium-supported catalyst composites
    KR102331809B1|2021-12-01|Diesel oxidation catalyst composites
    US9242242B2|2016-01-26|Catalyst for gasoline lean burn engines with improved NO oxidation activity
    JP5647623B2|2015-01-07|Diesel oxidation catalyst composite with layer structure for carbon monoxide and hydrocarbon conversion
    JP2013528119A5|2014-07-24|
    JP6134708B2|2017-05-24|Catalytic substrate and exhaust system for internal combustion engine
    JP5996538B2|2016-09-21|Catalyst for lean-burn gasoline engines with improved NO oxidation activity
    US8950174B2|2015-02-10|Catalysts for gasoline lean burn engines with improved NH3-formation activity
    EP2387463B1|2016-04-20|Layered diesel oxidation catalyst composites
    EP3277406A1|2018-02-07|LEAN NOx TRAP WITH ENHANCED HIGH AND LOW TEMPERATURE PERFORMANCE
    CA3021156A1|2017-10-26|Platinum group metal catalysts supported on large pore alumina support
    BR112013005099B1|2019-04-30|CATALYST, METHOD FOR PRODUCING A CATALYST, PROCESS FOR TREATING A GAS CURRENT, AND USING THE CATALYST
    JP6910353B2|2021-07-28|Diesel oxidation catalyst combining platinum group metal and base metal oxide
    同族专利:
    公开号 | 公开日
    WO2011154913A1|2011-12-15|
    KR101846593B1|2018-04-06|
    BR112012031330A2|2016-10-25|
    JP2013528119A|2013-07-08|
    EP2579985A4|2015-01-21|
    EP2579985A1|2013-04-17|
    JP5937579B2|2016-06-22|
    CN103052444A|2013-04-17|
    KR20130109093A|2013-10-07|
    CN103052444B|2016-05-11|
    EP3403722A1|2018-11-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US2577258A|1946-06-13|1951-12-04|Ohio Commw Eng Co|Alternating-current welder|
    US4961917A|1989-04-20|1990-10-09|Engelhard Corporation|Method for reduction of nitrogen oxides with ammonia using promoted zeolite catalysts|
    US5024981A|1989-04-20|1991-06-18|Engelhard Corporation|Staged metal-promoted zeolite catalysts and method for catalytic reduction of nitrogen oxides using the same|
    JP3799651B2|1995-04-28|2006-07-19|マツダ株式会社|Exhaust gas purification catalyst|
    JPH0910594A|1995-04-28|1997-01-14|Mazda Motor Corp|Catalyst for purifying exhaust gas|
    JPH10165819A|1996-12-12|1998-06-23|Nissan Motor Co Ltd|Catalyst for cleaning of exhaust gas and its use method|
    GB9713428D0|1997-06-26|1997-08-27|Johnson Matthey Plc|Improvements in emissions control|
    EP0935055B1|1998-02-05|2006-01-11|Nissan Motor Company, Limited|Method for purifying oxygen rich exhaust gas|
    JPH11226415A|1998-02-19|1999-08-24|Nissan Motor Co Ltd|Catalyst for purification of exhaust gas and purifying method of exhaust gas|
    JPH11300211A|1998-04-24|1999-11-02|Nissan Motor Co Ltd|Catalyst for and method of cleaning exhaust gas|
    DE19854794A1|1998-11-27|2000-05-31|Degussa|Catalyst for the purification of the exhaust gases of a diesel engine|
    US7022646B2|2003-01-31|2006-04-04|Engelhard Corporation|Layered catalyst composite|
    JP2005169203A|2003-12-09|2005-06-30|Nissan Motor Co Ltd|Catalyst for purifying exhaust gas and its manufacturing method|
    JP2005205302A|2004-01-22|2005-08-04|Hitachi Ltd|Exhaust gas cleaning catalyst and apparatus for combustion engine|
    US7795172B2|2004-06-22|2010-09-14|Basf Corporation|Layered exhaust treatment catalyst|
    JP2008100152A|2006-10-18|2008-05-01|Cataler Corp|Catalyst for cleaning exhaust gas|
    US9540980B2|2008-07-31|2017-01-10|Basf Se|NOx storage materials and traps resistant to thermal aging|
    EP2531280B1|2010-02-01|2014-12-24|Johnson Matthey Public Limited Company|NOx ABSORBER CATALYSTS|GB201021649D0|2010-12-21|2011-02-02|Johnson Matthey Plc|NOx Absorber catalyst|
    EP2844388B1|2012-04-06|2019-07-17|BASF Corporation|LEAN NOx TRAP DIESEL OXIDATION CATALYST WITH HYDROCARBON STORAGE FUNCTION|
    GB201220912D0|2012-11-21|2013-01-02|Johnson Matthey Plc|Oxidation catalyst for treating the exhaust gas of a compression ignition engine|
    EP2769760A1|2013-02-21|2014-08-27|Umicore AG & Co. KG|Catalyst for reducing nitrogen oxides|
    RU2667911C2|2013-03-12|2018-09-25|Басф Корпорейшн|Catalyst materials for no oxidation|
    GB2514177A|2013-05-17|2014-11-19|Johnson Matthey Plc|Oxidation catalyst for a compression ignition engine|
    JP5994730B2|2013-05-27|2016-09-21|マツダ株式会社|Method for producing exhaust gas purifying catalyst|
    JP5949662B2|2013-05-27|2016-07-13|マツダ株式会社|Exhaust gas purification catalyst and method for producing the same|
    JP6236995B2|2013-08-28|2017-11-29|マツダ株式会社|Exhaust gas purification catalyst, method for producing the same, and exhaust gas purification method using the same|
    DE102014113304B4|2013-09-16|2017-06-29|Johnson Matthey Public Limited Company|Exhaust system with a modified lean NOx trap|
    CN104667914A|2013-11-29|2015-06-03|陈社云|Diesel engine tail gas denitration catalyst and preparation method thereof|
    EP3077084B1|2013-12-06|2019-02-06|Johnson Matthey Public Limited Company|Cold start catalyst and its use in exhaust systems|
    EP2985068A1|2014-08-13|2016-02-17|Umicore AG & Co. KG|Catalyst system for the reduction of nitrogen oxides|
    CN107405606B|2015-02-09|2021-09-10|巴斯夫公司|Diesel oxidation catalyst|
    KR20170120698A|2015-03-03|2017-10-31|바스프 코포레이션|Lean NOx trap with improved high temperature and low temperature performance|
    MX2018000142A|2015-06-29|2018-02-19|Corning Inc|Porous ceramic body to reduce emissions.|
    GB2546164A|2015-09-30|2017-07-12|Johnson Matthey Plc|Gasoline particulate filter|
    EP3476480A4|2016-06-23|2020-03-04|N.E. Chemcat Corporation|Catalyst for lean burn|
    GB2557673A|2016-12-15|2018-06-27|Johnson Matthey Plc|NOx adsorber catalyst|
    GB2560941A|2017-03-29|2018-10-03|Johnson Matthey Plc|NOx Adsorber catalyst|
    GB2560944A|2017-03-29|2018-10-03|Johnson Matthey Plc|NOx adsorber catalyst|
    GB2560942A|2017-03-29|2018-10-03|Johnson Matthey Plc|NOx Adsorber catalyst|
    GB2560939A|2017-03-29|2018-10-03|Johnson Matthey Plc|NOx Adsorber catalyst|
    GB2560940A|2017-03-29|2018-10-03|Johnson Matthey Plc|Three layer NOx Adsorber catalyst|
    US20210283580A1|2018-06-12|2021-09-16|Basf Corporation|TWC SYSTEM FOR FUEL CUT NOx CONTROL|
    EP3623047B1|2018-09-17|2021-02-24|Umicore Ag & Co. Kg|Catalyst for reducing nitrogen oxides|
    EP3912719A1|2019-01-15|2021-11-24|Hitachi Zosen Corporation|Catalyst for exhaust gas purification use|
    EP3695902B1|2019-02-18|2021-09-01|Umicore Ag & Co. Kg|Catalyst for reducing nitrogen oxides|
    EP3824988A1|2019-11-20|2021-05-26|UMICORE AG & Co. KG|Catalyst for reducing nitrogen oxides|
    法律状态:
    2018-05-29| B07A| Technical examination (opinion): publication of technical examination (opinion) [chapter 7.1 patent gazette]|
    2018-10-02| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2018-12-11| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 09/06/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    2021-04-13| B21F| Lapse acc. art. 78, item iv - on non-payment of the annual fees in time|Free format text: REFERENTE A 10A ANUIDADE. |
    2021-08-10| B24J| Lapse because of non-payment of annual fees (definitively: art 78 iv lpi, resolution 113/2013 art. 12)|Free format text: EM VIRTUDE DA EXTINCAO PUBLICADA NA RPI 2623 DE 13-04-2021 E CONSIDERANDO AUSENCIA DE MANIFESTACAO DENTRO DOS PRAZOS LEGAIS, INFORMO QUE CABE SER MANTIDA A EXTINCAO DA PATENTE E SEUS CERTIFICADOS, CONFORME O DISPOSTO NO ARTIGO 12, DA RESOLUCAO 113/2013. |
    优先权:
    申请号 | 申请日 | 专利标题
    EP10165484|2010-06-10|
    EP10165484.6|2010-06-10|
    PCT/IB2011/052512|WO2011154913A1|2010-06-10|2011-06-09|Nox storage catalyst with improved hydrocarbon conversion activity|
    [返回顶部]