Modified copper zeolite and method for using modified copper zeolite for treating NOx-containing gas streams.

Abstract

This disclosure provides catalyst compositions that may be useful in general for selective catalytic reduction. The catalyst compositions may include a zeolite containing copper and at least one additional metal. The catalyst compositions described herein may be used for NO in a gaseous stream. x Methods for reducing the amount of exhaust gas and exhaust gas treatment systems are also described.

Description

[Technical Field]

[0001] This disclosure relates to zeolite catalyst compositions for use in selective catalytic reduction (SCR) for reducing nitrogen oxides with minimal undesirable byproducts. Methods for treating gas flows using such catalyst compositions and exhaust gas treatment systems containing such catalyst compositions are also disclosed. [Background technology]

[0002] Nitrogen oxides (NO x The harmful components of NO are known to contribute to air pollution. x NO is found in exhaust gases from internal combustion engines (e.g., vehicles), combustion equipment (e.g., thermal power plants heated by natural gas, oil, or coal), and nitric acid production plants. Particularly difficult to find is NO, which is produced when operating at high compression ratios and burning fuel at high temperatures. x It is a modern diesel engine that produces emissions.

[0003] To reduce air pollution, NO x Various treatment methods are used to treat gaseous flows containing nitrogen oxides. One such treatment involves catalytic reduction of nitrogen oxides to form nitrogen gas and water. There are two processes: (1) a non-selective reduction process using carbon monoxide, hydrogen, or low molecular weight hydrocarbons as reducing agents, and (2) a selective reduction process using ammonia or ammonia precursors as reducing agents. In the selective reduction process, a high degree of nitrogen oxide removal can be achieved using small stoichiometric amounts of reducing agent.

[0004] The selective reduction process is called the SCR (Selective Catalytic Reduction) process. The SCR process uses catalytic reduction of nitrogen oxides with a reducing agent (e.g., ammonia) in the presence of excess oxygen, mainly resulting in the formation of nitrogen and water vapor. 4NO + 4NH3 + O2 → 4N2 + 6H2O (Standard SCR reaction) 2NO2 + 4NH3 + O2 → 3N2 + 6H2O (Slow SCR reaction) NO + NO2 + 2NH → 2N2 + 3H2O (fast SCR reaction) 4NO+4NH3+3O2→4N2O+6H2O(N2O formation)

[0005] In some cases, N2O is formed as a byproduct of SCR. N2O is a greenhouse gas, and its emissions are regulated. Therefore, it is desirable to minimize the formation of N2O in SCR. Thus, with minimal N2O formation, a potent NO x Identifying the SCR catalyst that induces the conversion is advantageous.

[0006] Catalysts used in SCR processes ideally need to be able to maintain good catalytic activity over a wide range of operating temperature conditions, such as 200°C to over 600°C, after aging under hydrothermal conditions. SCR catalysts used in exhaust gas control applications are exposed to high-temperature hydrothermal conditions during the regeneration of soot filters, which are components of exhaust gas treatment systems used for particulate removal. Molecular sieves such as zeolites have been used in selective catalytic reduction (SCR) of nitrogen oxides using reducing agents such as ammonia, urea, or hydrocarbons in the presence of oxygen. Zeolites are crystalline materials with uniform pore sizes ranging from approximately 3 to approximately 10 angstroms in diameter, depending on the type of zeolite and the type and amount of cations contained in the zeolite lattice. Recently, zeolites with 8-membered ring pore openings and double 6-membered ring secondary structural units, particularly those with cage-like structures, have been studied for use as SCR catalysts. A specific type of zeolite possessing these properties is chabazite (CHA), a microporous zeolite with eight-membered ring pore openings (approximately 3.8 angstroms) accessible through its three-dimensional porosity. The cage-like structure arises from the linkage of double six-membered ring units by four rings.

[0007] Metal-promoted zeolite catalysts for the selective catalytic reduction of nitrogen oxides by ammonia, especially iron-promoted and copper-promoted zeolite catalysts, etc. are known. It is always desirable to improve the performance of the catalyst, and thus, it is beneficial to provide an SCR catalyst with improved NO x conversion performance and reduced N2O formation. SUMMARY OF THE INVENTION

[0008] In some embodiments, the technology described herein is a catalyst composition comprising a zeolite, wherein the zeolite has a total amount of aluminum in sites T (n) (n≧2) of about 0.05 milliequivalents / g to about 5 milliequivalents / g; a silica-to-alumina ratio (SAR) of about 5 to about 120; copper, and at least one additional metal other than copper, and the additional metal has a charge-to-radius ratio (Z / r) of about 1.2 to about 3.0; the additional metal is not sodium or potassium; the zeolite has a copper content of about 0.05 milliequivalents / g to about 5.0 milliequivalents / g based on Cu 2+ ; the copper loading in milliequivalents / g based on the Cu 2+ standard is less than the total amount of aluminum equivalents in sites T (n) (n≧2); and the loading of the additional metal is selected to be no more than the total amount of aluminum equivalents in sites T (n) (n≧1), relating to a catalyst composition.

[0009] In some embodiments, the technology described herein relates to a catalyst composition in which the loading of the additional metal is selected such that the total metal loading in milliequivalents / g is no more than the total amount of aluminum equivalents in sites T (n) (n≧2).

[0010] In some embodiments, the technology described herein relates to a catalyst composition in which the loading of the additional metal is selected such that the total metal loading in milliequivalents / g is substantially equal to the total amount of aluminum equivalents in sites T (n) (n≧2).

[0011] In some embodiments, the techniques described herein relate to catalyst compositions in which copper and at least one additional metal ion are added to a zeolite by an ion exchange process.

[0012] In some embodiments, the techniques described herein relate to catalyst compositions in which copper and at least one additional metal ion are added to a zeolite by a co-exchange process.

[0013] In some embodiments, the techniques described herein relate to catalyst compositions in which the additional metal has a charge-to-radius ratio (Z / r) of about 2.0 to 2.5.

[0014] In some embodiments, the techniques described herein relate to catalyst compositions in which the additional metal has a charge-to-radius ratio (Z / r) of about 2.2 to about 2.4.

[0015] In some embodiments, the techniques described herein relate to catalyst compositions in which the additional metal comprises magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or a combination thereof.

[0016] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite has a SAR of about 10 to about 50.

[0017] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite has a SAR of about 15 to about 40.

[0018] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite is a micropore zeolite, a medium-pore zeolite, or a large-pore zeolite.

[0019] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite is a 10-membered ring zeolite or a 12-membered ring zeolite.

[0020] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite has a skeletal structure selected from AEI, AFT, CHA, LTA, AFX, ERI, UFI, KFI, AFV, AVL, SFW, SWY, or mixtures and / or intercrystals comprising one or more of these.

[0021] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite has a skeletal structure selected from MFI, MWW, FER, MSE, YFI, or mixtures and / or intercrystals comprising one or more of these.

[0022] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite has a skeletal structure selected from FAU, BEA, or mixtures and / or intercrystals comprising one or more of these.

[0023] In some embodiments, the techniques described herein relate to catalyst compositions in which the zeolite is CHA.

[0024] In some embodiments, the techniques described herein relate to catalyst compositions in which the catalyst composition is coated on a monolithic substrate in a wash coat layer, the substrate being a metal, cordierite, or silicon carbide (SiC) substrate.

[0025] In some embodiments, the technology described herein relates to a catalyst composition in which the substrate is a flow-through substrate or a wall-flow substrate.

[0026] In some embodiments, the techniques described herein involve a catalyst composition in the wash coat layer being approximately 0.1 g / in based on the bulk volume of the substrate. 3 ~Approximately 5.0g / in 3 This relates to a catalyst composition.

[0027] In some embodiments, the techniques described herein involve aging at a temperature of 550°C or higher for 60,000 hours. -1At the space velocity and temperatures above 250°C, at least 80% NO x The present invention relates to a catalyst composition that provides a conversion rate and, when used for selective catalytic reduction, yields a conversion rate of less than 1.0% of NO to N2O at temperatures below 400°C.

[0028] In some embodiments, the technology described herein is NO x NO in a gas stream containing NO x A method for reducing the amount of site T, comprising contacting a gas stream with a catalyst composition, wherein the catalyst composition comprises a zeolite, and the zeolite is present in an amount of about 0.05 milliequivalents / g to about 5 milliequivalents / g. (n) (n≧2) has a total amount of aluminum; a silica-to-alumina ratio (SAR) of about 5 to about 120; copper and at least one additional metal other than copper; the additional metal has a charge-to-radius ratio (Z / r) of about 1.2 to about 3.0; the additional metal is not sodium or potassium; the zeolite is Cu 2+ It has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g according to the standard; Cu 2+ The amount of copper loaded in milliequivalents / g at the standard site T (n) The total amount of aluminum equivalents at (n≧2) is less than the amount of additional metal loaded at site T (n) This relates to a method for selecting the total amount of aluminum equivalents for (n≧1) such that it is less than or equal to the total amount of aluminum equivalents.

[0029] In some embodiments, the techniques described herein involve a load of additional metal, where the total metal load in milliequivalents / g is site T (n) This relates to a method selected such that the total amount of aluminum equivalents is less than or equal to the amount of aluminum equivalents in (n≧2).

[0030] In some embodiments, the techniques described herein involve a load of additional metal, where the total metal load in milliequivalents / g is site T (n) This relates to a method selected such that the total amount of aluminum equivalents for (n≧2) is substantially equal.

[0031] In some embodiments, the techniques described herein relate to a method by which copper and at least one additional metal ion are added to a zeolite by an ion exchange process.

[0032] In some embodiments, the techniques described herein relate to a method by which copper and at least one additional metal ion are added to a zeolite by a co-exchange process.

[0033] In some embodiments, the techniques described herein relate to a method in which the additional metal has a charge-to-radius ratio (Z / r) of about 2.0 to 2.5.

[0034] In some embodiments, the techniques described herein relate to a method in which the additional metal has a charge-to-radius ratio (Z / r) of about 2.2 to about 2.4.

[0035] In some embodiments, the techniques described herein relate to methods in which the additional metal includes magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or combinations thereof.

[0036] In some embodiments, the techniques described herein relate to a method in which the zeolite has a SAR of about 10 to about 50.

[0037] In some embodiments, the techniques described herein relate to a method in which the zeolite has a SAR of about 15 to about 40.

[0038] In some embodiments, the techniques described herein relate to methods in which the zeolite is a micropore zeolite, a medium-pore zeolite, or a large-pore zeolite.

[0039] In some embodiments, the techniques described herein relate to methods in which the zeolite is a 10-membered ring zeolite or a 12-membered ring zeolite.

[0040] In some embodiments, the techniques described herein relate to a method in which the zeolite has a skeletal structure selected from AEI, AFT, CHA, LTA, AFX, ERI, UFI, KFI, AFV, AVL, SFW, SWY, or mixtures and / or intercrystals comprising one or more of these.

[0041] In some embodiments, the techniques described herein relate to a method in which the zeolite has a skeletal structure selected from MFI, MWW, FER, MSE, YFI, or mixtures and / or intercrystals comprising one or more of these.

[0042] In some embodiments, the techniques described herein relate to a method in which the zeolite has a skeletal structure selected from FAU, BEA, or a mixture and / or intercrystal containing one or more of these.

[0043] In some embodiments, the techniques described herein relate to a method in which the zeolite is CHA.

[0044] In some embodiments, the techniques described herein relate to a method in which a catalyst composition is coated on a monolithic substrate in a wash coat layer, wherein the substrate is a metal, cordierite, or silicon carbide (SiC) substrate.

[0045] In some embodiments, the techniques described herein relate to methods in which the substrate is a flow-through substrate or a wall-flow substrate.

[0046] In some embodiments, the techniques described herein involve a catalyst composition in the wash coat layer being approximately 0.1 g / in based on the bulk volume of the substrate. 3 ~Approximately 5.0g / in 3 This concerns the method.

[0047] In some embodiments, the techniques described herein involve a catalyst composition that, after aging at a temperature of 550°C or higher, undergoes aging for 60,000 hours. -1 At the space velocity and temperatures above 250°C, at least 80% NOx This invention relates to a method that provides a conversion rate and yields a conversion rate of less than 1.0% of NO to N2O at temperatures below 400°C when the catalyst composition is used for selective catalytic reduction.

[0048] In some embodiments, the technology described herein is an exhaust gas treatment system, NO x NO, which generates exhaust gas flows containing NO x A generator and a catalyst composition containing zeolite, wherein the zeolite is present at site T at approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. (n) (n≧2) has a total amount of aluminum; a silica-to-alumina ratio (SAR) of about 5 to about 120; copper and at least one additional metal other than copper; the additional metal has a charge-to-radius ratio (Z / r) of about 1.2 to about 3.0; the additional metal is not sodium or potassium; the zeolite is Cu 2+ It has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g according to the standard; Cu 2+ The amount of copper loaded in milliequivalents / g at the standard site T (n) The total amount of aluminum equivalents at (n≧2) is less than the amount of additional metal loaded at site T (n) A catalyst composition selected such that the total amount of aluminum equivalents in (n≧1) is less than or equal to the total amount of aluminum equivalents, and an injector configured to inject a reducing agent into the exhaust gas flow, wherein the catalyst composition is in fluid communication with the exhaust gas flow, and the reducing agent and the catalyst composition are NO x The conversion of the catalyst to a composition containing N2 and water is promoted, and the catalyst composition is aged at a temperature of 550°C or higher for 60,000 hours. -1 At the space velocity and temperatures above 250°C, at least 80% NO x This invention relates to an exhaust gas treatment system that provides a conversion rate and, when the catalyst composition is used for selective catalytic reduction, yields a conversion rate of less than 1.0% of NO to N2O at temperatures below 400°C.

[0049] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the NOx generator is an internal combustion engine, an external combustion engine, or a chemical reactor.

[0050] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the catalyst composition is in a tightly coupled position.

[0051] In some embodiments, the techniques described herein involve a load of additional metal, where the total metal load in milliequivalents / g is site T (n) This relates to an exhaust gas treatment system selected such that the total amount of aluminum equivalent is less than or equal to (n≧2).

[0052] In some embodiments, the techniques described herein involve a load of additional metal, where the total metal load in milliequivalents / g is site T (n) This relates to an exhaust gas treatment system selected to be substantially equal to the total amount of aluminum equivalents for (n≧2).

[0053] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which copper and at least one additional metal ion are added to a zeolite by an ion exchange process.

[0054] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which copper and at least one additional metal ion are added to a zeolite by a co-exchange process.

[0055] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the additional metal has a charge-to-radius ratio (Z / r) of about 2.0 to 2.5.

[0056] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the additional metal has a charge-to-radius ratio (Z / r) of about 2.2 to about 2.4.

[0057] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the additional metal includes magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or a combination thereof.

[0058] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite has a SAR of about 10 to about 50.

[0059] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite has a SAR of about 15 to about 40.

[0060] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite is a micropore zeolite, a medium-pore zeolite, or a coarse-pore zeolite.

[0061] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite is a 10-membered ring zeolite or a 12-membered ring zeolite.

[0062] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite has a skeletal structure selected from AEI, AFT, CHA, LTA, AFX, ERI, UFI, KFI, AFV, AVL, SFW, SWY, or a mixture and / or intercrystal comprising one or more of these.

[0063] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite has a skeletal structure selected from MFI, MWW, FER, MSE, YFI, or a mixture and / or intercrystal containing one or more of these.

[0064] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite has a skeletal structure selected from FAU, BEA, or a mixture and / or intercrystal comprising one or more of these.

[0065] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the zeolite is CHA.

[0066] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which a zeolite is coated on a monolithic substrate in a wash coat layer, the substrate being a metal, cordierite, or silicon carbide (SiC) substrate.

[0067] In some embodiments, the technology described herein relates to an exhaust gas treatment system in which the substrate is a flow-through substrate or a wall-flow substrate.

[0068] In some embodiments, the techniques described herein involve a catalyst composition in the wash coat layer being approximately 0.1 g / in based on the bulk volume of the substrate. 3 ~Approximately 5.0g / in 3 This concerns exhaust gas treatment systems.

[0069] In some embodiments, the techniques described herein involve a catalyst composition that, after aging at a temperature of 550°C or higher, undergoes aging for 60,000 hours. -1 At the space velocity and temperatures above 250°C, at least 85% NO x This invention relates to an exhaust gas treatment system that provides a conversion rate and, when the catalyst composition is used for selective catalytic reduction, yields a conversion rate of less than 1.0% of NO to N2O at temperatures below 400°C. [Brief explanation of the drawing]

[0070] The aspects, features, benefits, and advantages of the embodiments described herein will become apparent with reference to the following description, the appended claims, and the appended drawings. [Figure 1] This is a diagram of the stereochemistry around different tetrahedral sites in the zeolite framework representing the T(n) site, where n represents the number of nearest neighbor tetrahedral sites occupied by aluminum atoms. [Figure 2] This graph shows the ion exchange capacity available at each site T(n) and the total ion exchange capacity available at sites T(2-4) for different SARs, assuming a random distribution of Al atoms. [Figure 3]This graph shows the N2O formation and NOx conversion rates of selected exemplary catalyst compositions according to embodiments described herein. [Figure 4] This graph shows the N2O formation and NOx conversion rates of selected exemplary catalyst compositions according to embodiments described herein. [Figure 5] This graph shows the NOx conversion rate and N2O formation of selected exemplary catalyst compositions containing different amounts of magnesium according to embodiments described herein. [Figure 6] This graph shows the NOx conversion rate and N2O formation of selected catalyst compositions containing different amounts of zinc according to embodiments described herein. [Figure 7] This is a graph of the NOx conversion rates of selected exemplary catalyst compositions of different SARs, coated on a ceramic monolith and aged under progressively harsher conditions, according to embodiments described herein. [Figure 8] This graph shows the NOx conversion rate and N2O formation of selected catalyst compositions aged for 50 hours at 650°C in 10% H2O / air according to embodiments described herein. [Figure 9] This graph shows the NOx conversion rate and N2O formation of selected catalyst compositions containing different amounts of copper, coated on a ceramic monolith according to embodiments described herein and aged for 50 hours at 650°C in 10% H2O / air. [Figure 10] This graph shows the N2O formation and NOx conversion rates of selected catalyst compositions coated on a ceramic monolith according to embodiments described herein, aged for 50 hours at 650°C in 10% H2O / air, and evaluated at NO2 / NOx = 0 or 0.5. [Figure 11] This graph shows the N2O formation and NOx conversion rates of selected catalyst compositions coated on a ceramic monolith according to embodiments described herein, aged for 50 hours at 650°C in 10% H2O / air, and evaluated at NO2 / NOx = 0 or 0.5. [Figure 12] This chart shows the NOx conversion rate and N2O selectivity of selected catalyst compositions coated on a ceramic monolith according to embodiments described herein and aged for 50 hours at 650°C in 10% H2O / air. [Figure 13] This chart shows the ΔdeNOx (NOx conversion rate in the degreened state - NOx conversion rate in the aged state) and N2O selectivity of selected catalyst compositions coated on a ceramic monolith according to the embodiments described herein, after aging. [Modes for carrying out the invention]

[0071] This disclosure describes catalyst compositions for use in the selective catalytic reduction of nitrogen oxides. The catalyst compositions generally comprise modified zeolites and can provide effective reduction of nitrogen oxides with minimal formation of undesirable byproducts.

[0072] In some embodiments, the catalyst composition comprises a zeolite, wherein the zeolite is present at site T at approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. (n) A catalyst composition is provided having a total amount of aluminum in (n≧2), a silica-to-alumina ratio (ration) (SAR) of about 5 to about 100, copper, and at least one additional metal. The zeolite is Cu 2+ The copper content may range from approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g on a standard basis. The additional metal is, in some embodiments, a metal having a charge-to-radius ratio (Z / r) of approximately 1.2 to approximately 3.0, and the additional metal is not sodium or potassium. The catalyst compositions of this disclosure are site T (n) Less than the total amount of aluminum in (n≧2), Cu 2+ It has a copper loading amount in milliequivalents / g of the standard. The amount of additional metals loaded in the catalyst composition is the total loading amount in milliequivalents / g, at site T (n) The amount of aluminum in (n≧2) is selected to be less than or equal to the total amount of aluminum in the sample.

[0073] For the purposes of this application, the following terms shall have the meanings set forth below.

[0074] As used herein, the term “milli-equivalent” means milligram equivalent. A milligram equivalent is one-thousandth of an equivalent, and for the purposes of this disclosure, an equivalent refers to an ion-exchange equivalent. The substitution of a single silicon atom by a single aluminum atom in a zeolite framework results in an ion-exchange equivalent of 1. Thus, a zeolite containing 1.0 mmol / g of aluminum in its framework contains an ion-exchange equivalent of 1.0 milli-equivalent / g. The amount of ion-exchanged metal in a zeolite can be defined in terms of the number of ion-exchange equivalents it can compensate for. For a given metal ion, the number of ion-exchange equivalents (in milli-equivalents / g) is defined as the product Z × C (where Z is the charge of the metal ion (unit of the elementary charge of an electron) and C is the concentration of the metal ion in the zeolite (in units of mmol / g)). For example, a zeolite containing 1.0 mmol / g of copper contains Cu 2+ It contains 2.0 milliequivalents / g of copper according to the standard.

[0075] As used herein, the term “selective catalytic reduction,” which may be abbreviated as “SCR,” refers to nitrogen oxide (NOx) reduction. x This refers to any catalytic process involving the reaction of NO with a reducing agent. In particular, SCR refers to NO x This refers to a reduction reaction that converts to its reduction product, preferably N2. The term "reductant" or "reducing agent" refers to any suitable reducing agent for SCR, which may preferably include ammonia or ammonia precursors such as urea and / or ammonium carbamate. The reducing agent may refer to ammonia, or hydrocarbon derivatives such as hydrocarbons and / or oxygenated hydrocarbons, for example, those that can be found in automotive fuels and / or automotive exhaust, such as diesel fuel and / or diesel exhaust.

[0076] The zeolites described herein are understood to be aluminosilicates having an open three-dimensional framework structure composed of TO4 tetrahedra (wherein T is Al or Si) sharing corners. Cationic cations that balance the charge of the anionic framework associate with the skeletal oxygen, while non-skeletal cations are generally interchangeable.

[0077] The zeolites described herein generally contain silica (SiO2) and alumina (Al2O3) in a molar ratio known as the "silica-to-alumina ratio," which can be abbreviated as "SAR."

[0078] As used herein, zeolites may be referred to as "small-pore zeolites," "medium-pore zeolites," or "large-pore zeolites." Small-pore zeolites are those whose maximum pore opening is defined by a macrocyclic molecule containing eight tetrahedral metal or metalloid atoms, and are also called eight-membered ring zeolites. Medium-pore zeolites are those whose maximum pore opening is defined by a macrocyclic molecule containing ten tetrahedral metal or metalloid atoms, and are also called ten-membered ring zeolites. Large-pore zeolites are those whose maximum pore opening is defined by a macrocyclic molecule containing twelve or more tetrahedral metal or metalloid atoms, and are also called twelve-membered ring zeolites.

[0079] As used herein, the ratio Z / r refers to the charge on a metal ion divided by its ionic radius. Charge is given in units of the elementary charge of electrons. For example, Na 1+ In this case, Z=1, Mg 2+In this case, Z=2. The ionic radius is given in angstroms, and the coordination number (CN) is assumed to be 6. The ionic radius values ​​used herein are taken from RDShannon, "Revised Effective Ionic Radii and Systematic Studies of Interatomic Distances in Halides and Chalcogenides," Acta Cryst. A32751-767 (1976). Such ratios are sometimes called the "charge-to-radius ratio." As an example, Cu 2+ The ion has a z-axis of 2 and an ionic radius of 0.87 angstroms. The charge-to-radius ratio Z / r is 2.30.

[0080] This disclosure is T (n) The site is mentioned. The tetrahedral site in the zeolite skeleton is T (n) (wherein n is an integer from 0 to 4) are organized into different stereochemical configurations labeled as follows: Each T (n) As shown in Figure 1, the site has a silicon atom at the center and n aluminum atoms in its nearest neighbor position. A random distribution is assumed throughout the entire framework of aluminum atoms, and this distribution follows Loewenstein's law, which prohibits aluminum atoms from being in each other's nearest neighbor position. Furthermore, two or more T (n) If it is possible to assign an aluminum atom to a site, an additional constraint is imposed that the aluminum atom must be assigned to a higher-order site (i.e., a site with a larger n value). Assuming these simplifications, given SAR, T (n) Basic statistics can be applied to calculate the number of sites. Figure 2 shows each T (n) The chart shows the number of ion exchange equivalents associated with each site plotted against the zeolite SAR value, subject to the above assumptions and limitations.

[0081] A given metal ion is one whose charge can be most effectively neutralized. (n) It preferentially interacts with the site. Cu 2+ Regarding ions, T (2) The site is the preferred binding site. Generally, metal ions with higher charge density are preferred at the skeletal site with higher charge density, i.e., site T (2) , T (3) , and T (4) It prefers to interact with site T. The dotted line in Figure 2 represents site T. (2~4) This shows the sum of all ion exchange capacities related to T. Over most of the zeolite SAR range, (2) The site is the greatest contributing factor to high-density ion exchange sites. (3) and T (4) The site contributes significantly only to SARs less than approximately 10. Copper loading (by ion exchange equivalent) is T (2~4) Copper zeolite compositions with a number of ion exchange equivalents lower than the number associated with a site have a portion of the ion exchange capacity at those sites that is not compensated. As the copper load decreases, the "uncompensated" T (n) The number of sites (n≧2) increases. Although not bound by theory, the decomposition of the zeolite skeleton by dealuminization is T (n) The process is faster at sites (n≧2) (i.e., where aluminum atoms are in close proximity to each other). Furthermore, if uncompensated high-density ion exchange sites can be compensated with suitable alternative cations, it is thought that dealuminization of high-density ion exchange sites can be suppressed.

[0082] Uncompensated ion-exchange sites in zeolites exist as Brønsted acid sites, and a single negative charge introduced by substituting a single silicon atom with a single aluminum atom in the tetrahedral sites of the framework is balanced by hydrogen ions. When the catalyst is exposed to high temperatures and / or steam during aging, the substituted aluminum atoms may be removed from the tetrahedral sites (a process called dealuminization), which leads to the decomposition of the zeolite framework. Substituting hydrogen ions with copper(II) ions partially prevents the loss of aluminum atoms from the framework during aging. Although not bound by theory, it is also thought that substituting hydrogen ions with metal ions having similar charge and ionic radius to copper(II) ions would also partially prevent the loss of aluminum atoms from the framework during aging.

[0083] As used herein, “impregnated” or “impregnation” refers to the penetration of a catalytic substance or other substance into the porous structure of a carrier material.

[0084] As used herein, “ion exchange process” refers to any process after the synthesis of the zeolite in which some or all of the charge compensation ions in the zeolite are replaced with different charge compensation ions.

[0085] As used herein, “co-exchange process” refers to an ion exchange process in which, after the zeolite has been synthesized, some or all of the charge compensation ions in the zeolite are replaced in a single process step with a mixture of at least two different charge compensation ions.

[0086] As used herein, the term “substrate” refers to a monolithic material on which a catalyst composition is arranged, typically in the form of a washcoat containing a plurality of particles on which the catalyst composition is located. The washcoat is formed by preparing a slurry containing particles of a specific solid content (e.g., 30–90% by weight) in a liquid suspension, then coating this onto the substrate and drying, thereby providing a washcoat layer.

[0087] Where used herein, the term “wash coat” has its usual meaning in the art of a thin, adhesive coating of a catalyst or other substance applied from a slurry of substances to a substrate material. The act of wash coating refers to the application of such a slurry to a substrate.

[0088] Aging can be carried out under a variety of conditions, and as used herein, “aging” is understood to encompass a range of conditions (e.g., temperature, time, atmosphere). An exemplary aging protocol involves exposing a fired and coated substrate to a temperature of 650°C in a 10% water vapor / air mixture for about 50 hours, or to a temperature of 750°C in a 10% water vapor / air mixture for about 20 hours. However, these protocols are not intended to be limiting, and the temperature may be lower or higher (e.g., temperatures above 400°C, e.g., 400°C to 000°C, 600°C to 950°C, or 650°C to 800°C, but not limited thereto). The time may be shorter or longer (e.g., about 1 hour to about 200 hours or about 2 hours to about 50 hours, but not limited thereto). The atmosphere may also be modified (e.g., to have different amounts of water vapor and / or other components present in it).

[0089] As used herein, the terms “upstream” and “downstream” refer to the relative direction of the flow of engine exhaust gases from the engine to the exhaust pipe (tailpipe), with the engine being in the upstream position and the tailpipe and any contamination reduction items such as filters and catalysts being in the downstream position of the engine.

[0090] As used herein, the term “flow” broadly refers to any combination of flowing gases, which may also contain solid or liquid particulate matter. The terms “gas flow” or “exhaust flow” mean the flow of gaseous components, such as the exhaust of a lean-burn engine, which may contain non-gaseous entrainments, such as droplets and solid particulate matter. Lean-burn engine exhaust flows typically further include combustion products, incomplete combustion products, nitrogen oxides, combustible and / or carbonaceous particulate matter (soot), and unreacted oxygen and nitrogen.

[0091] In some embodiments, the catalyst composition comprises a zeolite, wherein the zeolite is present at site T at approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. (n) (n≧2) The zeolite has a total amount of aluminum, a silica-to-alumina ratio (SAR) of about 10 to about 100, copper, and at least one additional metal, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 1.2 to about 3.0, and the additional metal is not sodium or potassium, but the zeolite is Cu 2+ It has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g according to the standard, Cu 2+ The amount of copper loaded in milliequivalents / g at the standard site T (n) The total amount of aluminum in (n≧2) is less than the amount of additional metal loaded at site T (n) A catalyst composition is provided, selected such that the total amount of aluminum is less than or equal to the total amount of aluminum in (n≧2).

[0092] The catalyst compositions described herein are generally metal-enhanced zeolites, i.e., zeolites to which one or more components have been intentionally added rather than containing impurities that may be inherent to the zeolite. An enhancer is a component intentionally added to enhance the activity of a catalyst compared to a catalyst without an enhancer. The catalyst compositions of this disclosure contain a suitable metal replaced in the zeolite to promote the SCR of nitrogen oxides. The catalyst compositions of this disclosure contain copper, which is involved in the conversion of nitrogen oxides.

[0093] In some embodiments, the total amount of aluminum in the catalyst composition is about 0.05 milliequivalents / g to about 5 milliequivalents / g, for example, about 0.05 milliequivalents / g, about 0.1 milliequivalents / g, about 0.15 milliequivalents / g, about 0.2 milliequivalents / g, about 0.3 milliequivalents / g, about 0.4 milliequivalents / g, about 0.5 milliequivalents / g, about 0.6 milliequivalents / g, about 0.7 milliequivalents / g, about 0.8 milliequivalents / g, about 0.9 milliequivalents / g, about 1 milliequivalent / g, about 1.5 milliequivalents / g, about 2 milliequivalents / g, about 2.5 milliequivalents / g, about 3 milliequivalents / g, about 3.5 milliequivalents / g, about 4 milliequivalents / g, about 4.5 milliequivalents / g, about 5 milliequivalents / g, or any range or value that falls within any of the aforementioned values.

[0094] In some embodiments, the SAR of the catalyst composition is about 5 to about 100, for example, 5, about 10, about 15, about 20, about 25, about 30, about 35, about 40, about 45, about 50, about 55, about 60, about 65, about 70, about 75, about 80, about 85, about 90, about 95, about 100, or any range or value that falls within any of the aforementioned values.

[0095] In some embodiments, the copper content of the catalyst composition is approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g, for example, 0.05 milliequivalents / g, approximately 0.1 milliequivalents / g, approximately 0.15 milliequivalents / g, approximately 0.2 milliequivalents / g, approximately 0.3 milliequivalents / g, approximately 0.4 milliequivalents / g, approximately 0.5 milliequivalents / g, approximately 0.6 milliequivalents / g, approximately 0.7 milliequivalents / g, approximately 0.8 milliequivalents / g, approximately 0.9 milliequivalents / g, approximately 1 milliequivalent / g, approximately 1.5 milliequivalents / g, approximately 2 milliequivalents / g, approximately 2.5 milliequivalents / g, approximately 3 milliequivalents / g, approximately 3.5 milliequivalents / g, approximately 4 milliequivalents / g, approximately 4.5 milliequivalents / g, approximately 5 milliequivalents / g, or any range or value that falls within any of the aforementioned values.

[0096] In some embodiments, the additional metals include magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or combinations thereof. In some embodiments, the additional metal has a charge-to-radius ratio (Z / r) of about 1.2 to about 3.0, for example, 1.2, about 1.3, about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, about 2.1, about 2.2, about 2.3, about 2.4, about 2.5, about 2.6, about 2.7, about 2.8, about 2.9, about 3.0, or any range or value that falls within any of the aforementioned values. In some embodiments, the total metal loading refers to the total amount of metals such as copper and additional metals contained in the catalyst composition described herein.

[0097] In some embodiments, the zeolite is a small-pore zeolite, a medium-pore zeolite, or a large-pore zeolite. The zeolite skeleton is not particularly limited, and thereafter, 8-membered ring zeolites, 10-membered ring zeolites, and 12-membered ring zeolites are within the scope of this disclosure. The zeolite may have a skeleton selected from AEI, AFT, CHA, LTA, AFX, MFI, MWW, FER, FAU, BEA, ERI, UFI, KFI, AFV, AVL, SFW, SWY, MSE, YFI, etc., or a twin crystal containing one of these skeletons as a terminal member. In some embodiments, the zeolite is CHA.

[0098] In some embodiments, the catalyst composition is coated onto a monolithic substrate in a wash coat layer. The substrate is not particularly limited, and exemplary substrates include, but are not limited to, metals and metal alloys such as titanium and stainless steel, alloys including manganese, copper, vanadium, and titanium, and ceramic materials such as cordierite, mullite, cordierite-α-alumina, silicon nitride, zircon mullite, spodumene, alumina-silica-magnesia, zircon silicate, magnesium silicate, zircon, petalite, α-alumina, and aluminosilicates. In some embodiments, the substrate is a metal substrate, a cordierite substrate, or a silicon carbide (SiC) substrate.

[0099] The substrate may be a flow-through substrate or a wall-flow substrate. A flow-through substrate may have multiple fine parallel gas flow channels extending from the inlet surface to the outlet surface of the substrate, thereby allowing the channels to open and the fluid to flow. The channels, which are essentially straight paths from inlet to outlet, are defined by walls coated with a catalyst material as a wash coat, so that the gas flowing through the channels comes into contact with the catalyst material. The channels of a monolithic substrate are thin-walled channels that can be any preferred cross-sectional shape, such as trapezoidal, rectangular, square, sinusoidal, hexagonal, elliptical, or circular. Such structures may contain about 60 to about 1200 or more gas inlet openings (i.e., "cells") (cpsi) per square inch of cross-section, more typically about 300 to 600 cpsi. The wall thickness of a flow-through substrate can vary, with a typical range being 0.002 to 0.1 inches.

[0100] In some embodiments, the substrate may be a wall flow substrate, each flow channel is blocked by a non-porous plug at one end of the substrate body, and alternating flow channels are blocked at the opposing end faces. This requires the gas to flow through the porous walls of the wall flow substrate to reach the outlet. Such a monolithic substrate can contain from a maximum of about 700 cpsi or more, such as from about 100 - 400 cpsi, more typically from about 200 - about 300 cpsi. The cross-sectional shape of the cells can be various as described above. The wall flow substrate typically has a wall thickness of 0.002 - 0.1 inches.

[0101] When describing the amount of a washcoat or a catalytic metal component or other components of a composition, it is convenient to use the unit of weight of the component per unit volume of the catalyst substrate. Thus, the units gram per cubic inch ("g / in 3 ") and gram per cubic foot ("g / ft 3 ") are used herein to mean the weight of the component per volume of the substrate, including the volume of the voids of the substrate. Other units of weight per volume, such as g / L, may also be used. The total loading of catalytic articles (i.e., both ion-exchanged metals on a zeolite support material) on a catalyst substrate, such as a monolithic flow-through substrate, is typically from about 0.1 g / in 3 to about 5 g / in 3 . These weights per unit volume are typically calculated by weighing the catalyst substrate before and after treatment in a catalytic washcoat composition, because the treatment process involves drying and calcining the catalyst substrate at high temperature and essentially all of the water in the washcoat slurry has been removed, so it should be noted that these weights represent a catalyst coating essentially free of solvent. In some embodiments, the washcoat layer contains from about 0.1 g / in 3 to about 5.0 g / in 3 of the catalyst composition, based on the bulk volume of the substrate. For example, the washcoat layer can be about 0.1 g / in 3 , about 0.2 g / in 3 , about 0.3 g / in 3 , about 0.4 g / in3 , about 0.5 g / in 3 , about 1.0 g / in 3 , about 1.5 g / in 3 , about 2.0 g / in 3 , about 2.5 g / in 3 , about 3.0 g / in 3 , about 3.5 g / in 3 , about 4.0 g / in 3 , about 4.5 g / in 3 , or about 5.0 g / in 3 , or may include a catalyst composition of any range or value included in any of the foregoing values.

[0102] The catalyst compositions described herein can exhibit good SCR activity in some embodiments. Without being bound by theory, it is believed that the improvement in SCR activity achieved by the disclosed catalyst compositions may, in some embodiments, be due to an improvement in the hydrothermal stability of the zeolite component. Catalyst compositions containing metal-promoted zeolites typically undergo significant deactivation during aging (e.g., at a temperature of about 800 °C for about 16 hours) and thus exhibit a low NO x conversion rate after aging. Surprisingly, the catalyst compositions disclosed herein have been found to maintain high activity (i.e., NO x conversion rate) under such aging conditions. This high activity has been demonstrated in fact during use at both high and low temperatures, i.e., over the entire test window of 200 °C to 600 °C.

[0103] In certain embodiments, the disclosed catalyst compositions more advantageously exhibit a reduction in N2O formation without a significant decrease in NO x conversion performance. Without being bound by theory, the presence of additional metals in the copper zeolite is thought to result in improved NO conversion rates in combination with lower N2O formation compared to zeolites without the additional metals.

[0104] In some embodiments, the catalyst compositions of this disclosure are used in SCR. In some embodiments, the catalyst compositions are aged at a temperature of 550°C or higher for 60,000 hours. -1 At the space velocity and temperatures above 250°C, at least about 80% NO x The conversion rate is given. Using the catalyst compositions for selective catalytic reduction described herein, in some embodiments, the NO2 / NO2 in the feed gas x When the ratio is approximately 0, at temperatures below 400°C, this results in conversion rates of NO to N2O of approximately 3%, 2.5%, 2%, 1.5%, and 1.0%, respectively. In some embodiments, the catalyst composition is aged at temperatures above 550°C for 60,000 hours. -1 At the space velocity and temperatures above 250°C, at least about 80%, for example, at least about 85%, at least about 90%, at least about 95%, or about 100%, or any range or value contained therein, NO x It provides a conversion rate of NO2 / NO2 in the supply gas. In some embodiments, by using the catalyst composition of the present disclosure, the NO2 / NO2 in the supply gas is converted. x When the ratio is approximately 0, at temperatures below 400°C, this results in a conversion rate of less than approximately 1.0%, for example, less than 1%, less than 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, less than 0.1%, or about 0.0% of NO to N2O.

[0105] The catalyst compositions of this disclosure can be characterized by analytical tools and methods well known to those skilled in the art. The inclusion of additional metals in the zeolite, as described herein, is not theoretically bound but may affect these or other properties. The stabilizing effect of these additional metals on the material can be tested by analytical tools such as X-ray diffraction (XRD), N2 adsorption / desorption, infrared (IR) spectroscopy, and nuclear magnetic resonance (NMR) on the material before and after hydrothermal aging. An example of such an analytical tool is XRD. While not theoretically bound, the unit cell size is expected to expand upon the introduction of additional ions into the unit cell, which can be determined from the position of the peaks in the X-ray diffraction pattern. Another example of such an analytical tool is IR spectroscopy. While not theoretically bound, the TOT bond vibrations observed in the IR spectrum are expected to be perturbed to different degrees by the presence of different cations close to these bonds, from which further influence on the properties of the copper sites can be inferred. Analytical tools, including but not limited to XRD and IR spectroscopy, can be used to test for the effects of the presence or absence of additional metals as described herein.

[0106] In this specification, NO x NO in a gas stream containing NO x A method for reducing the amount of site T, comprising contacting a gas stream with a catalyst composition, wherein the catalyst composition comprises a zeolite, and the zeolite is present in an amount of about 0.05 milliequivalents / g to about 5 milliequivalents / g. (n) (n≧2) The total amount of aluminum in the zeolite is approximately 5 to approximately 120 silica-to-alumina ratio (SAR), and it contains copper and at least one additional metal, wherein the additional metal has a charge-to-radius ratio (Z / r) of approximately 1.2 to approximately 3.0, and the additional metal is not sodium or potassium, and the zeolite has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g based on Cu2, and the copper loading amount in milliequivalents / g based on Cu2+ is at site T (n)The total number of aluminum atoms in (n≧2) is less than the total amount of additional metals, and the amount of additional metals loaded is less than the total amount of metals loaded in milliequivalents / g at site T (n) A method is provided that is selected such that the total number of aluminum atoms (n≧2) is less than or equal to the total number of aluminum atoms.

[0107] In some embodiments, NO x NO in a gas stream containing NO x A method for reducing the amount includes contacting the gas flow with a catalyst composition according to any embodiment or combination of embodiments described herein.

[0108] An exhaust gas treatment system that generates an exhaust gas flow containing NOx x A generator and a catalyst composition containing zeolite, wherein the zeolite is present at site T at approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. (n) (n≧2) has a total amount of aluminum, a silica-to-alumina ratio (SAR) of about 5 to about 120, copper, and at least one additional metal, wherein the copper content is Cu 2+ The standard is approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g, the additional metal has a charge-to-radius ratio (Z / r) of approximately 1.2 to approximately 3.0, and the additional metal is Cu, not sodium or potassium. 2+ The amount of copper loaded in milliequivalents / g at the standard site T (n) The total number of aluminum atoms in (n≧2) is less than the total number of aluminum atoms at site T. (n) A flue gas treatment system is provided, comprising a catalyst composition selected such that the total number of aluminum atoms in (n≧2) is less than or equal to the total number of aluminum atoms. The flue gas treatment system further comprises an injector configured to inject a reducing agent into the gas stream. In some embodiments, NO x The generator is an internal combustion engine, an external combustion engine, or a chemical reactor.

[0109] In some embodiments, the catalyst composition is in fluid communication with the exhaust gas flow, and the reducing agent and catalyst composition are NO xThis facilitates the conversion of to a composition containing N2 and water. In some embodiments, the exhaust gas treatment system includes a catalyst composition according to any embodiment or combination of embodiments described herein. In some embodiments, the exhaust gas treatment system includes a second catalyst composition, which may be a catalyst composition described herein, such as a catalyst for SCR, or any other catalyst composition known to those skilled in the art. In some embodiments, the catalyst composition is in a tightly coupled position and is located directly at the exhaust outlet of the engine. In some embodiments, there are no catalytic exhaust system components located upstream of the catalyst composition. In other embodiments, there are one or more catalytic exhaust system components located upstream of the catalyst composition. In some embodiments, there are one or more catalytic exhaust system components located downstream of the catalyst composition.

[0110] The embodiments described herein may be combined in any way to form new embodiments. The catalyst compositions, methods, and exhaust gas treatment systems described herein are intended to be used together in some embodiments. For example, when the catalyst composition disclosed herein is used in the exhaust gas treatment system disclosed herein, after aging at a temperature of 550°C or higher, it will last for 60,000 hours. -1 At the space velocity and temperatures above 250°C, at least 85% NO x It gives a conversion rate of less than 1.0% of NO to N2O at temperatures below 400°C when the catalyst composition is used for selective catalytic reduction. [Examples]

[0111] The following examples were carried out in accordance with the embodiments described herein. The compositions of the examples are listed in Table 1.

[0112] Example 1: Copper-exchanged CHA zeolite Chabazite-type zeolite with SAR=16 was pre-calcined at 600°C for 1 hour. After calcination, the zeolite was impregnated with an aqueous copper acetate solution with a copper / zeolite ratio of 0.25 mmol / g by initial wetting impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. Next, the powder was dried at 100°C and then calcined in air at 600°C for 1 hour to produce powder B1.

[0113] Example 2: Copper-exchanged CHA zeolite with additional magnesium or zinc, prepared by sequential impregnation. Copper-exchanged zeolite powder with a copper load of 0.25 mmol / g was prepared as described in Example 1. This copper-exchanged zeolite was impregnated with an aqueous magnesium acetate solution with a magnesium / zeolite ratio of 0.15 mmol / g by initial wetting impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. The powder was then dried at 100°C and subsequently calcined in air at 600°C for 1 hour to obtain powder C2. The preparation was repeated with a magnesium / zeolite ratio of 0.30 mmol / g to obtain powder D2. The preparation was repeated with a magnesium / zeolite ratio of 0.45 mmol / g to obtain powder E2.

[0114] Copper-exchanged zeolite powder with a copper load of 0.25 mmol / g was prepared as described in Example 1. This copper-exchanged zeolite was impregnated with an aqueous zinc acetate solution with a zinc / zeolite ratio of 0.15 mmol / g by initial wetting impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. Next, the powder was dried at 100°C and then calcined in air at 600°C for 1 hour to obtain powder F2. The preparation was repeated with a zinc / zeolite ratio of 0.30 mmol / g to obtain powder G2. The preparation was repeated with a zinc / zeolite ratio of 0.45 mmol / g to obtain powder H2.

[0115] Example 3: Copper-exchanged CHA zeolite with additional magnesium or zinc, prepared by sequential impregnation. Chabazite-type zeolite with SAR=16 was impregnated with an aqueous magnesium acetate solution with a magnesium / zeolite ratio of 0.15 mmol / g by initial wet impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. Next, the powder was dried at 100°C and then calcined in air at 600°C for 1 hour. Magnesium-exchanged zeolite was impregnated with an aqueous copper acetate solution with a copper / zeolite ratio of 0.25 mmol / g by initial wet impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. Next, the powder was dried at 100°C and then calcined in air at 600°C for 1 hour to obtain powder C3. The preparation was repeated with a magnesium / zeolite ratio of 0.30 mmol / g to obtain powder D3. The preparation was repeated with a magnesium / zeolite ratio of 0.45 mmol / g to obtain powder E3.

[0116] Chabazite-type zeolite with SAR=16 was impregnated with an aqueous zinc acetate solution with a zinc / zeolite ratio of 0.15 mmol / g by initial wet impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. Next, the powder was dried at 100°C and then calcined in air at 600°C for 1 hour. Zinc-exchanged zeolite was impregnated with an aqueous copper acetate solution with a copper / zeolite ratio of 0.25 mmol / g by initial wet impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. Next, the powder was dried at 100°C and then calcined in air at 600°C for 1 hour to obtain powder F3. The preparation was repeated with a zinc / zeolite ratio of 0.30 mmol / g to obtain powder G3. The preparation was repeated with a zinc / zeolite ratio of 0.45 mmol / g to obtain powder H3.

[0117] Example 4: Copper-exchanged CHA zeolite with additional magnesium or zinc, prepared by co-impregnation. Chabazite-type zeolite with SAR=16 was pre-calcined at 600°C for 1 hour. After calcination, the zeolite was impregnated with an aqueous solution containing copper acetate (copper / zeolite ratio = 0.25 mmol / g) and magnesium acetate (magnesium / zeolite ratio = 0.15 mmol / g) by initial wetting impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. The powder was then dried at 100°C and subsequently calcined in air at 600°C for 1 hour to obtain powder C4. The preparation was repeated with a magnesium / zeolite ratio of 0.30 mmol / g to obtain powder D4. The preparation was repeated with a magnesium / zeolite ratio of 0.45 mmol / g to obtain powder E4.

[0118] Chabazite-type zeolite with SAR=16 was pre-calcined at 600°C for 1 hour. After calcination, the zeolite was impregnated with an aqueous solution containing copper acetate (copper / zeolite ratio = 0.25 mmol / g) and zinc acetate (zinc / zeolite ratio = 0.15 mmol / g) by initial wetting impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. The powder was then dried at 100°C and subsequently calcined in air at 600°C for 1 hour to obtain powder F4. The preparation was repeated with a zinc / zeolite ratio of 0.30 mmol / g to obtain powder G4. The preparation was repeated with a zinc / zeolite ratio of 0.45 mmol / g to obtain powder H4.

[0119] Example 5: Evaluation of powder's SCR activity after aging at 550°C Each zeolite powder was suspended in deionized water at a concentration of 30% by weight (based on solid content). Zirconium acetate was added to obtain 5% by weight of zirconium (based on ZrO2) relative to the zeolite solid content. The suspension was homogenized and dried under stirring to obtain pellets. The pellets were calcined at 500°C for 1 hour. The calcined pellets were crushed and sieved into a size range of 250-500 μm. The sieved fractions were aged at 550°C for 50 hours in a 10% water vapor / air atmosphere. 120 mg of the aged material was diluted with corundum to obtain a total packing volume of 1.0 cm³. 3The material was obtained and filled into a cylindrical microreactor. A flow consisting of 500 ppm NO, 500 ppm NH3, 5% H2O, 10% O2, and the remainder N2 was introduced into the microreactor at a flow velocity of 1333 cm². 3 The supply was at a rate of [number] minutes. The amounts of NO, NO2, NH3, and N2O in the effluent gas were monitored by FTIR spectroscopy at T=175, 200, 225, 250, 300, 400, 550, and 575°C.

[0120] Table 1 lists each zeolite formulation evaluated for SCR activity. Under the conditions applied to the evaluation of SCR activity, the maximum N2O formation was observed at T=300°C. The bars in Figure 3 show the concentration of N2O measured at T=300°C at the reactor outlet. An important result is that all zeolite formulations (C2-H4) containing magnesium or zinc give lower N2O formation than the copper-only control sample B1 with a common copper load (0.25 mmol / g). The average reduction in formed N2O is 79% compared to the amount of N2O produced by control sample B1. The amount of N2O formed by the SCR catalyst can be reduced by means of reducing the overall conversion rate of NOx, which is well understood to present an undesirable trade-off between activity and selectivity. Therefore, it is important that all zeolite formulations A1-H4 give an NO conversion rate of over 96% at 300°C, resulting in the conversion of the same amount of NO in all cases. This indicates that lower N2O formation for formulations containing magnesium and zinc cannot be explained on the basis of less NO conversion. The dotted line in Figure 3 shows the trend of NO conversion rate at 200°C. At this temperature, the inventors operated with NO conversion rates of less than 50% under specified test conditions, and the inventors were able to distinguish formulations based on NO conversion activity. The data show that all zeolite formulations (C2-H4) containing magnesium or zinc give equivalent or higher NO conversion activity compared to the copper-only control sample B1. The inventors simultaneously achieved increased NO conversion activity and decreased N2O formation activity after a model accelerated aging procedure by adding certain additional metals (e.g., magnesium and / or zinc) to copper-zeolite formulations.

[0121] Example 6: Evaluation of powder's SCR activity after aging at 650°C A subset of the sieved powder was aged at 650°C for 50 hours in a 10% vapor / air atmosphere. 120 mg of the aged material was diluted with corundum to create a total packing volume of 1.0 cm³. 3The material was obtained and filled into a cylindrical microreactor. A flow consisting of 500 ppm NO, 500 ppm NH3, 5% H2O, 10% O2, and the remainder N2 was introduced into the microreactor at a flow velocity of 1333 cm². 3 The supply was at a rate of [number] minutes. The amounts of NO, NO2, NH3, and N2O in the effluent gas were monitored by FTIR spectroscopy at T=175, 200, 225, 250, 300, 400, 550, and 575°C.

[0122] The bars in Figure 4 show the concentration of N2O measured at T=300°C at the reactor outlet. After the aging procedure at 650°C, all zeolite formulations (C2-H4) containing magnesium or zinc yielded lower N2O formation than the copper-only control sample B1, with a common copper load (0.25 mmol / g). The average decrease in formed N2O was 70% of the amount of N2O produced by control sample B1. These data indicate that the positive effect of co-cations on N2O formation persists after more stringent aging protocols. Simultaneously, the dotted line in Figure 4 shows that the NO conversion rate at 200°C increased by an average of 64% for the magnesium-containing and zinc-containing formulations compared to the copper-only control sample B1. The average NO conversion rate for formulations containing additional metals was 38% after aging at 550°C and 37% after aging at 650°C. For comparison, the NO conversion rate of a control formulation containing only copper was 29% after aging at 550°C and 22% after aging at 650°C. As a result, the improvement in the NO conversion rate of formulations containing co-cations becomes more pronounced after more severe aging. These data indicate that the addition of co-cations has the effect of increasing the material's stability against hydrothermal aging.

[0123] Example 7: Effect of magnesium load amount Chabazite-type zeolite with SAR=16 was pre-calcined at 600°C for 1 hour. After calcination, the zeolite was co-impregnated with an aqueous solution containing a copper / zeolite ratio of 0.25 mmol / g and various amounts of magnesium acetate by initial wetting impregnation. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. The powder was then dried at 100°C and subsequently calcined in air at 600°C for 1 hour. The resulting powder contained 0.25 mmol / g of copper and a variable amount of magnesium. The formulations are listed in Table 2 (C4~L4). The powder was hydrothermally aged at 550°C for 50 hours in 10% H2O / air and evaluated by a steady-state SCR test as described in Example 6.

[0124] Figure 5 shows that the NOx conversion rate at 200°C passes its maximum value as the magnesium load increases, with the maximum conversion rate occurring at a magnesium load of 0.48 mmol / g. At this point, the total copper + magnesium load is 0.71 mmol / g, which is very close to the value estimated to occupy all paired aluminum sites when SAR=16. Further increasing the magnesium load leads to some of the copper ions reaching the optimal T (2) I left the site, and as a result, NO x The conversion activity decreases. Figure 5 shows that as the magnesium load increases to 0.30 mmol / g, the formation of N2O at 300°C decreases sharply. When the magnesium load is further increased, there is no significant change in N2O formation. Therefore, when SAR = 16 and copper load = 0.25 mmol / g, high NO x The optimal performance for conversion rate and low N2O formation is found when the magnesium load is 0.4 mmol / g to 0.5 mmol / g.

[0125] Example 8: Effect of zinc loading Chabazite-type zeolite with SAR=16 was pre-calcined at 600°C for 1 hour. After calcination, the zeolite was co-impregnated by initial wetting with an aqueous solution containing copper acetate with a copper / zeolite ratio of 0.25 mmol / g and varying amounts of zinc acetate. The impregnated zeolite powder was left in a sealed container at 50°C for 24 hours. The powder was then dried at 100°C and subsequently calcined in air at 600°C for 1 hour. The resulting powder contained 0.25 mmol / g of copper and a variable amount of zinc. The formulations are listed in Table 2 (F4~P4). The powder was hydrothermally aged at 550°C for 50 hours in 10% H2O / air and evaluated by a steady-state SCR test as described in Example 6.

[0126] Figure 6 shows NO at 200°C. x The conversion rate passes its maximum value as the zinc load increases, with the maximum conversion rate occurring at a zinc load of 0.45 mmol / g. At this point, the total copper + zinc load is 0.71 mmol / g, which is very close to the value estimated to occupy all paired aluminium sites when SAR=16. Further increasing the zinc load leads to some of the copper ions reaching the optimal T (2) I left the site, and as a result, NO x The conversion activity decreases. Figure 6 shows that as the zinc load increases to 0.30 mmol / g, N2O formation at 300°C decreases sharply. When the magnesium load is further increased, there is no significant change in N2O formation. Therefore, for SAR=16 and copper load=0.25 mmol / g, the optimal performance for high NOx conversion rate and low N2O formation is found when the zinc load is 0.4 mmol / g to 0.5 mmol / g. The similarity in the trends of magnesium load and zinc load in Figures 5 and 6 indicates that zinc and magnesium ions have a common role in stabilizing the zeolite structure and suppressing N2O formation.

[0127] Example 9: Preparation and evaluation of a monolithic sample having a zeolite copper loading of 0.25 mmol / g. CHA zeolite having SAR=16 or SAR=10 was pre-calcined at 550°C to generate a protonate form. The calcined zeolite powder was impregnated with a solution containing copper acetate and magnesium acetate or zinc acetate. The copper / zeolite ratio was fixed at 0.25 mmol / g. The amount of magnesium or zinc used varied depending on the zeolite SAR, as shown in Table 3. After impregnation, the wet powder was immersed in a sealed jar at 25°C for 24 hours, then dried and calcined at 550°C. The resulting zeolite powder was suspended in DI water, and D 90 The particles were milled to a particle size of <9 μm. The resulting slurry was processed with a channel density of 400 / inch. 2 The coating was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and then fired at 550°C for 1 hour. The composition of the samples is shown in Table 3. Each sample composition was degreened at 550°C for 4 hours in 10% H2O / air, and then aged for 200 hours at 550°C in 10% H2O / air, or for 50 hours at 650°C in 10% H2O / air, or for 20 hours at 750°C in 10% H2O / air.

[0128] Degreened and aged samples were evaluated for SCR activity using a standard SCR protocol, i.e., 1000 ppm NH3, 1000 ppm NO, 8% CO2, 7% H2O, 10% O2, the remainder N2, and SV = 60,000 / hour. Figure 7 shows NO activity after degreening and aging at continuously increasing temperatures for a formulation with SAR = 16, containing 0.25 mmol / g copper and 0.44 mmol / g magnesium or zinc. x This indicates the conversion rate. Compounds containing magnesium or zinc will undergo NO after degreening. x It does not demonstrate any advantages. After aging, formulations containing magnesium or zinc show at least twice as high NO at 200°C compared to formulations containing copper alone. x This shows the conversion rate. This is the NO conversion rate in copper-only formulations during aging. xThis is due to a significant decrease in the conversion rate, which is not observed in formulations further containing magnesium or zinc. This data is for zeolite NO when the overall Cu / Al atomic ratio is 0.13. x This shows how additional magnesium or zinc helps stabilize the conversion activity. NO at 200°C for the six catalyst formulations in Table 3 after aging at 650°C for 50 hours. x The conversion rate and N2O formation at 300°C are shown in Figure 8. This chart demonstrates that the favorable effect of adding magnesium or zinc is observed in chabazite-type zeolites with SAR=16 or 10, but that zeolites with SAR=10 can accommodate much higher loadings of magnesium or zinc when copper is fixed at 0.25 mmol / g. This results in a further significant reduction in N2O formation at SAR=10 due to the greater possible loading of magnesium or zinc.

[0129] Example 10: Preparation and evaluation of a monolithic sample having a zeolite copper loading of 0.12 mmol / g. CHA zeolite with SAR=16 was pre-calcined at 550°C to generate a protonate form. The calcined zeolite powder was impregnated with a solution containing copper acetate and either magnesium acetate or zinc acetate. The copper / zeolite ratio was fixed at 0.12 mmol / g. Additional amounts of magnesium or zinc were added to the impregnation solution to a level corresponding to a magnesium / zeolite ratio or zinc / zeolite ratio of 0.57 mmol / g. The calcined zeolite was then impregnated with this solution. The resulting wet powder was immersed in a sealed jar at 25°C for 24 hours, then dried and calcined at 550°C. The resulting zeolite powder was suspended in DI water, and D 90 The particles were milled to a particle size of <9 μm. The resulting slurry was processed with a channel density of 400 / inch. 2 The material was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and then fired at 550°C for 1 hour. The composition of the samples is shown in Table 4. Each sample composition was aged in 10% H2O / air at 650°C for 50 hours.

[0130] The aged samples were evaluated for SCR activity using a standard SCR protocol, i.e., 1000 ppm NH3, 1000 ppm NO, 8% CO2, 7% H2O, 10% O2, the remainder N2, and SV = 60,000 / hour. Figure 9 shows the NO activity at 250°C and 300°C after aging at 650°C for a copper loading of 0.12 mmol / g. x Conversion rate, residual T (2~4) Figure 9 shows that N2O formation increases by adding an amount of magnesium or zinc corresponding to the site sufficiency. N2O formation also decreases by adding magnesium or zinc. Figure 9 also shows that N2O formation decreases when the copper load is reduced from 0.25 mmol / g to 0.12 mmol / g, but as expected, NO x This indicates that the conversion rate also decreases. x This section shows how formulations can be adjusted for different applications, depending on whether conversion rate or low N2O formation is a more important requirement.

[0131] Example 11: Different NO2 / NO x Evaluation of coated monoliths under supplied composition The coated monolith is coated with a 1:1 mixture of NO and NO2 (NO2 / NO2). x NOx conversion activity was evaluated under supply conditions including (=0.5), i.e., 1000 ppm NH3, 500 ppm NO, 500 ppm NO2, 8% CO2, 7% H2O, 10% O2, the remainder N2, with SV = 60,000 / hour. Figure 10 shows the results for CHA zeolite (SAR=16) containing 0.12 mmol / g copper and 0.57 mmol / g magnesium or zinc after aging for 50 hours at 650°C in 10% H2O / air. NO2 / NO x As the ratio increases from zero to 0.5 as expected, the net NO x An increase in the conversion rate can be observed. For this reason, NO2 / NO x Supply conditions including =0.5 are generally called "fast" SCR conditions. Figure 10 shows NO2 / NO2. xAs the ratio increases from zero to 0.5 as expected, it indicates an increase in N2O formation. Compounds containing magnesium or zinc have a NO2 / NO2 / NO2 ratio. x Even at higher ratios, N2O formation remains lower than in the comparative formulation without magnesium or zinc. Figure 11 shows the results for CHA zeolite (SAR=16) containing 0.25 mmol / g copper and an additional 0.44 mmol / g magnesium or zinc after aging for 50 hours at 650°C in 10% H2O / air. The results indicate that the addition of magnesium or zinc reduces N2O formation under "fast" SCR conditions at higher copper loads. The addition of replacement magnesium or zinc to copper-exchanged zeolite results in a reduction of N2O formation activity, even when the supply gas contains NO2.

[0132] Example 12: Preparation and evaluation of a monolithic sample having a zeolite copper loading of 0.44 mmol / g. A CHA zeolite with SAR=16 is suspended in DI water, and D 90 The material was milled to a particle size <9 μm. CuO powder was added at a copper / zeolite ratio of 0.44 mmol / g. The slurry was stirred for 24 hours, and then the channel density was set to 400 / inch. 2 The coating was applied to a 1"OD×3"L ceramic monolith. The coated monolith was dried and fired at 550°C for 1 hour to obtain sample L30 (Table 5). The sample was degreened in still air at 650°C for 2 hours or aged in 10% H2O / air at 650°C for 50 hours. The degreened and aged samples were evaluated for SCR activity using a standard SCR protocol, i.e., 500 ppm NH3, 500 ppm NO, 8% CO2, 7% H2O, 10% O2, the remainder N2, and SV = 80,000 / hour.

[0133] Example 13: Preparation and evaluation of monolithic samples with zeolite copper loading = 0.44 mmol / g and different loading amounts of magnesium or zinc. CHA zeolite with SAR=16 was pre-calcined at 550°C to generate a protonate form. The calcined zeolite powder was impregnated with a solution containing copper acetate and either magnesium acetate or zinc acetate. The copper / zeolite ratio was fixed at 0.44 mmol / g. For the magnesium-containing samples, the magnesium / zeolite ratio was 0.13 mmol / g (L31), 0.25 mmol / g (L32), or 0.48 mmol / g (L33), as shown in Table 5. For the zinc-containing samples, the zinc / zeolite ratio was 0.12 mmol / g (L34) or 0.23 mmol / g (L35), as shown in Table 5. After impregnation, the wet powder was immersed in a sealed jar at 25°C for 24 hours, then dried and calcined at 550°C. The obtained zeolite powder was suspended in DI water, and D 90 The particles were milled to a particle size of <9 μm. The resulting slurry was processed with a channel density of 400 / inch. 2 The coating was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and then fired at 550°C for 1 hour. Each sample was degreened in still air at 650°C for 2 hours, or aged in 10% H2O / air at 650°C for 50 hours. The degreened and aged samples were evaluated for SCR activity using a standard SCR protocol, i.e., 500 ppm NH3, 500 ppm NO, 8% CO2, 7% H2O, 10% O2, the remainder N2, and SV = 80,000 / hour.

[0134] Figure 12 shows NO at 200°C for a series of aged catalyst formulations (in 10% H2O / air, at 650°C for 50 hours) with copper loading = 0.44 mmol / g and different loading amounts of magnesium or zinc as shown. x This shows the conversion rate. The data shows the NO after aging by adding additional metal species until the total metal load = 0.69 mmol / g. xThis demonstrates that it is possible to increase the conversion rate. Figure 12 also shows how N2O formation can be reduced by adding additional metal ions. The degree of improvement is smaller than that seen for formulations containing copper at loading amounts of 0.25 mmol / g or 0.12 mmol / g. This is because as the copper loading increases in zeolites with immobilized SAR, site T (2~4) This is due to the fact that the amount of uncompensated ion exchange capacity in decreases. As a result, residual T (2~4) The amount of additional metal that can be stored at the site will decrease.

[0135] Example 14: Preparation of a monolith sample having a zeolite copper loading of 0.63 mmol / g. A CHA zeolite with SAR=16 is suspended in DI water, and D 90 The material was milled to a particle size <9 μm. CuO powder was added at a copper / zeolite ratio of 0.63 mmol / g. The resulting slurry was stirred for 24 hours, and then the channel density was adjusted to 400 / inch. 2 The material was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and the sample J30 was fired at 550°C for 1 hour (Table 5). Each sample was degreened in still air at 650°C for 2 hours, or aged in 10% H2O / air at 650°C for 50 hours.

[0136] Example 15: Preparation of monolithic samples having a zeolite copper loading of 0.63 mmol / g and different loading amounts of magnesium or zinc. CHA zeolite with SAR=16 was pre-calcined at 550°C to generate a protonate form. The calcined zeolite powder was impregnated with a solution containing copper acetate and either magnesium acetate or zinc acetate. The copper / zeolite ratio was fixed at 0.63 mmol / g. For the magnesium-containing sample, the magnesium / zeolite ratio was 0.074 mmol / g (J32), as shown in Table 5. For the zinc-containing sample, the zinc / zeolite ratio was 0.061 mmol / g (J35), as shown in Table 5. After impregnation, the wet powder was immersed in a sealed jar at 25°C for 24 hours, then dried and calcined at 550°C. The obtained zeolite powder was suspended in DI water, and D 90 The particles were milled to a particle size of <9 μm. The resulting slurry was processed with a channel density of 400 / inch. 2 The material was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and then fired at 550°C for 1 hour. Each sample of the formulation was degreened in still air at 650°C for 2 hours, or aged in 10% H2O / air at 650°C for 50 hours.

[0137] Example 16: Preparation of a monolith sample having a zeolite copper loading of 0.50 mmol / g. A CHA zeolite with SAR=16 is suspended in DI water, and D 90 The material was milled to a particle size <9 μm. CuO powder was added at a copper / zeolite ratio of 0.50 mmol / g. The resulting slurry was stirred for 24 hours, and then the channel density was adjusted to 400 / inch. 2 The material was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and the sample K30 was fired at 550°C for 1 hour (Table 5). Each sample was degreened in still air at 650°C for 2 hours, or aged in 10% H2O / air at 650°C for 50 hours.

[0138] Example 17: Preparation of monolithic samples having a zeolite copper loading of 0.50 mmol / g and different loading amounts of magnesium or zinc. CHA zeolite with SAR=16 was pre-calcined at 550°C to generate a protonate form. The calcined zeolite powder was impregnated with a solution containing copper acetate and either magnesium acetate or zinc acetate. The copper / zeolite ratio was fixed at 0.50 mmol / g. For the magnesium-containing sample, the magnesium / zeolite ratio was 0.19 mmol / g (K32), as shown in Table 5. For the zinc-containing sample, the zinc / zeolite ratio was 0.19 mmol / g (K35), as shown in Table 5. After impregnation, the wet powder was immersed in a sealed jar at 25°C for 24 hours, then dried and calcined at 550°C. The obtained zeolite powder was suspended in DI water, and D 90 The particles were milled to a particle size of <9 μm. The resulting slurry was processed with a channel density of 400 / inch. 2 The material was applied to a 1"OD×3"L ceramic monolith, the coated monolith was dried, and then fired at 550°C for 1 hour. Each sample of the formulation was degreened in still air at 650°C for 2 hours, or aged in 10% H2O / air at 650°C for 50 hours.

[0139] Example 18: Evaluation of monolithic samples degreened and aged with different copper loads. Degreened and aged samples were evaluated for SCR activity using a standard SCR protocol, i.e., 500 ppm NH3, 500 ppm NO, 8% CO2, 7% H2O, 10% O2, the remainder N2, and SV = 80,000 / hour. The upper chart of Figure 13 shows the NO activity at T = 200°C for a given catalyst formulation in the degreened and aged states. x Absolute difference between conversion rates (ΔdeNO xThe chart below shows the N2O selectivity at T=300°C for the same series of catalyst samples. Data is shown for catalyst formulations with copper loadings of 0.25, 0.44, 0.50, and 0.63 mmol / g. The black bars in Figure 13 show the ΔdeNOx and N2O selectivity for formulations that do not contain any additional magnesium or zinc (i.e., copper-only formulations). Reducing the copper loading to 0.25 mmol / g significantly reduces the selectivity for forming N2O from NO and NH3, but ΔDeNOx x The value of NO during aging is also 26%. x This shows a significant decrease in conversion activity. This demonstrates how N2O formation by copper zeolite catalysts can be reduced by decreasing the copper load, but the trade-off is lower catalyst stability. Adding 0.44 mmol / g of magnesium or zinc to a formulation containing 0.25 mmol / g of copper further reduces N2O formation. Furthermore, the addition of magnesium or zinc reduces NO between the degreened and aged catalysts. x Eliminate the conversion rate gap. In fact, samples containing additional magnesium or zinc show NO after aging. x It showed a slight increase in conversion activity, which is less than zero ΔdeNO x The values ​​indicate the following: A formulation containing 0.44 mmol / g of copper shows a similar response in N2O selectivity and improved catalyst stability when 0.25 mmol of magnesium or zinc is added. A formulation containing 0.50 mmol / g of copper shows increased catalyst stability when 0.19 mmol / g of magnesium or zinc is added, but shows only a small response in N2O selectivity. At 0.63 mmol / g of copper, the tetrahedral site T (2~4)The residual ion exchange capacity in this sample is only 0.06 mmol / g, which limits the amount of additional magnesium or zinc that can be added before copper is replaced at these sites. In this case, the amount of copper alone is sufficient to ensure high catalytic stability. The addition of 0.06 mmol / g of magnesium or zinc does not result in any reduction in N2O formation, and N2O formation in a sample containing 0.63 mmol / g of copper is further increased by the addition of magnesium or zinc. This data is relevant when the copper load is not high enough to compensate for all high-density ion exchange sites (i.e., T (2~4) This shows how the addition of divalent metal species such as magnesium or zinc to the residual ion exchange sites of copper zeolite can be used to improve the performance and selectivity of catalysts for selective catalytic reduction. (2~4) As the ion exchange capacity at the site approaches its limit, the ability to improve performance by adding additional metal ions decreases.

[0140] [Table 1]

[0141] [Table 2]

[0142] [Table 3]

[0143] [Table 4]

[0144] [Table 5]

[0145] This disclosure is not limited to the specific systems, devices, and methods described, as they may vary. The terms used in this description are intended solely to describe specific variations or embodiments and are not intended to limit their scope.

[0146] As used herein, the singular forms “a,” “an,” and “the” include multiple references unless the context explicitly indicates otherwise. Unless otherwise defined, all technical and scientific terms as used herein have the same meaning as commonly understood by those skilled in the art. Nothing in this disclosure should be construed as acknowledging that the embodiments described herein do not have prior rights to such disclosures by prior art. As used herein, the term “comprising” means “including, but not limited to.”

[0147] Where used herein, the term "about" means plus or minus 10% of the number in which it is used. For example, "about 50%" means within the range of 45 to 55%.

[0148] The detailed description above refers to the accompanying drawings, which form part of this specification. In the drawings, unless the context indicates otherwise, similar symbols typically identify similar components. The exemplary embodiments described in the detailed description, drawings, and claims are not intended to limit. Other embodiments may be used and other modifications may be made without departing from the spirit or scope of the subject matter presented herein. It will be readily apparent that the aspects of this disclosure described herein and shown in the drawings can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are expressly intended herein.

[0149] This disclosure should not be limited to the specific embodiments described in this application, which are intended as examples of various aspects. As will be apparent to those skilled in the art, many modifications and changes can be made without departing from its spirit and scope. In addition to those enumerated herein, functionally equivalent methods and apparatus within the scope of this disclosure will be apparent to those skilled in the art from the foregoing description. Such modifications and changes are intended to fall within the scope of the appended claims. This disclosure should be limited only by the terminology of the appended claims and the entire scope of equivalents to which such claims are granted. It should be understood that this disclosure is not limited to any particular method, reagent, compound, composition or biological system, and may vary accordingly. It should also be understood that the terminology used herein is for the purpose of describing a particular embodiment and is not intended to limit it.

[0150] With regard to the use of substantially any plural and / or singular terms herein, those skilled in the art can substitute plurals for singulars and / or singulars for plurals as appropriate to the context and / or use. Various singular / plural substitutions may be explicitly stated herein for clarity.

[0151] In general, the terms used herein, particularly in the appended claims (e.g., the text of the appended claims), are intended to be "open" terms (for example, the term "includes" should be interpreted as "includes, but not limited to," the term "have" should be interpreted as "have at least," and the term "includes" should be interpreted as "includes, but not limited to," etc.), as will be understood by those skilled in the art. Various compositions, methods, and devices are described using the term "includes" (to be interpreted as "includes, but not limited to") various components or steps, but compositions, methods, and devices may also "essentially consist of" or "consist of" various components and steps, and such terms should be interpreted as defining an essentially closed set of elements. It will further be understood by those skilled in the art that where a certain number of introduced claims are intended, such intention is explicitly stated in the claims, and where there is no such statement, such intention does not exist.

[0152] For example, to aid understanding, the attached claims below may include the use of the introductory phrases “at least one” and “one or more” to introduce the description of a claim. However, the use of such phrases should not be interpreted as meaning that the introduction of the description of a claim by the indefinite article “a” or “an” means that any particular claim containing such introduced description is limited to embodiments containing only one such description (for example, “a” and / or “an” should be interpreted as meaning “at least one” or “one or more”). The same applies to the use of the definite article used to introduce the description of a claim.

[0153] Furthermore, even if a specific number of introduced claims is explicitly stated, a person skilled in the art will recognize that such a statement should be interpreted as meaning at least the number stated (for example, the mere statement “two claims” without other modifiers means at least two claims, or two or more claims). Furthermore, when conventional expressions similar to “at least one of A, B, and C, etc.” are used, such constructions are generally intended to mean that a person skilled in the art will understand the conventional expression (for example, “a system having at least one of A, B, and C” includes, but is not limited to, a system having only A, only B, only C, A and B together, A and C together, B and C together, and / or a system having A, B, and C together). Where conventional expressions similar to “at least one of A, B, or C” are used, such expressions are generally intended to be understood by those skilled in the art (for example, “a system having at least one of A, B, or C” includes, but is not limited to, A only, B only, C only, A and B together, A and C together, B and C together, and / or a system having A, B, and C together). Furthermore, substantially any disjunct words and / or disjunct phrases that present two or more alternative terms should be understood by those skilled in the art to be intended to include the possibility of including one of the terms, either of the terms, or both of the terms, whether in the specification, claims, or drawings. For example, the phrase “A or B” will be understood to include the possibility of “A” or “B” or “A and B”.

[0154] Furthermore, where any feature or aspect of the present disclosure is described in relation to the Markush Group, a person skilled in the art will recognize that the present disclosure also describes any individual element or subgroup of elements of the Markush Group.

[0155] As will be understood by those skilled in the art, for all purposes, including providing written explanations, all scopes disclosed herein also encompass all possible sub-scopes and combinations thereof. Any enumerated scope can be readily recognized as fully explaining and enabling that the same scope may be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each scope discussed herein can readily be divided into a lower third, a middle third, an upper third, etc. Also, as will be understood by those skilled in the art, all language such as “up to,” “at least,” etc., includes the enumerated number and refers to a scope that can subsequently be divided into sub-scopes as discussed above. Finally, as will be understood by those skilled in the art, a scope includes its individual components. Thus, for example, the group having 1 to 3 compounds refers to the group having 1, 2, or 3 compounds. Similarly, the group having 1 to 5 cells refers to the group having 1, 2, 3, 4, or 5 compounds, and so on.

[0156] Various features and functions disclosed above, as well as other features and functions, or their substitutes, can be combined into many other different systems or applications. Various alternatives, modifications, variations, or improvements not currently anticipated or expected may subsequently be made by those skilled in the art, each of which is also intended to be incorporated by the disclosed embodiments.

Claims

1. A catalyst composition, Contains zeolite, The aforementioned zeolite has a site T of approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. （ｎ） (n≧2) The total amount of aluminum, the silica-to-alumina ratio (SAR) of about 5 to about 120, copper, and at least one additional metal other than copper, The additional metal has a charge-to-radius ratio (Z / r) of approximately 1.2 to approximately 3.0, and the metal is not sodium or potassium. The zeolite is Cu ２＋ It has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g according to the standard. Cu ２＋ The amount of copper loaded in milliequivalents / g at the standard is site T （ｎ） The total amount of aluminum equivalents in (n≧2) is less than the amount of the additional metal supported at site T （ｎ） A catalyst composition selected such that the total amount of aluminum equivalents for n≧1 is less than or equal to the total amount of aluminum equivalents for n≧1.

2. The amount of the additional metal supported is, the total amount of metal supported in milliequivalents / g is, site T （ｎ） The catalyst composition according to claim 1, wherein the total amount of aluminum equivalents for n≧2 is selected to be less than or equal to the total amount of aluminum equivalents.

3. The amount of the additional metal supported is the total amount of metal supported in milliequivalents / g at site T （ｎ） The catalyst composition according to claim 1, selected to be substantially equal to the total amount of aluminum equivalents for n≧2.

4. The catalyst composition according to claim 1, wherein the copper and at least one additional metal ion are added to the zeolite by an ion exchange process.

5. The catalyst composition according to claim 1, wherein the copper and at least one additional metal ion are added to the zeolite by a co-exchange process.

6. The catalyst composition according to claim 1, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 2.0 to 2.

5.

7. The catalyst composition according to claim 1, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 2.2 to about 2.

4.

8. The catalyst composition according to claim 6, wherein the additional metal comprises magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or a combination thereof.

9. The catalyst composition according to claim 1, wherein the zeolite has about 10 to about 50 SARs.

10. The catalyst composition according to claim 1, wherein the zeolite has about 15 to about 40 SARs.

11. The catalyst composition according to claim 1, wherein the zeolite is a small-pore zeolite, a medium-pore zeolite, or a large-pore zeolite.

12. The catalyst composition according to claim 1, wherein the zeolite is an 8-membered ring zeolite, a 10-membered ring zeolite, or a 12-membered ring zeolite.

13. The catalyst composition according to claim 1, wherein the zeolite has a skeletal structure selected from AEI, AFT, CHA, LTA, AFX, ERI, UFI, KFI, AFV, AVL, SFW, SWY, or a mixture and / or intercrystal containing one or more of these.

14. The catalyst composition according to claim 1, wherein the zeolite has a skeletal structure selected from MFI, MWW, FER, MSE, YFI, or a mixture containing one or more of these and / or intercrystals.

15. The catalyst composition according to claim 1, wherein the zeolite has a skeletal structure selected from FAU, BEA, or a mixture containing one or more of these, and / or intercrystals.

16. The catalyst composition according to claim 1, wherein the zeolite is CHA.

17. The catalyst composition according to any one of claims 1 to 16, wherein the catalyst composition is coated on a monolithic substrate in a wash coat layer, and the substrate is a metal, cordierite, or silicon carbide (SiC) substrate.

18. The catalyst composition according to claim 17, wherein the substrate is a flow-through substrate or a wall-flow substrate.

19. The amount of the catalyst composition in the washcoat layer is about 0.1 g / in ３ to about 5.0 g / in ３ based on the bulk volume of the substrate. The catalyst composition according to claim 17 or 18

20. The catalyst composition, after aging at a temperature of 550°C or higher, is subjected to 60,000 h －１ At the space velocity and temperatures above 250°C, at least 80% NO ｘ It provides a conversion rate, and when the catalyst composition is used for selective catalytic reduction, it provides less than 1.0% NO to N at temperatures below 400°C. ２ A catalyst composition according to any one of claims 1 to 19, which provides a conversion rate to O.

21. NO ｘ NO in a gas stream containing NO ｘ A method for reducing the amount, This includes bringing the gas flow into contact with the catalyst composition, The catalyst composition comprises a zeolite, The aforementioned zeolite has a site T of approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. （ｎ） (n≧2) The total amount of aluminum, the silica-to-alumina ratio (SAR) of about 5 to about 120, copper, and at least one additional metal other than copper, The additional metal has a charge-to-radius ratio (Z / r) of approximately 1.2 to approximately 3.0, and the metal is not sodium or potassium. The zeolite is Cu ２＋ It has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g according to the standard. Cu ２＋ The amount of copper loaded in milliequivalents / g at the standard is site T （ｎ） The total amount of aluminum equivalents in (n≧2) is less than the amount of the additional metal supported at site T （ｎ） A method selected such that the total amount of aluminum equivalents for n≧1 is less than or equal to the total amount of aluminum equivalents.

22. The amount of the additional metal supported is, the total amount of metal supported in milliequivalents / g is, site T （ｎ） The method according to claim 21, wherein the amount is selected to be less than or equal to the total amount of aluminum equivalents for n≧2.

23. The amount of the additional metal supported is, the total amount of metal supported in milliequivalents / g is, site T （ｎ） The method according to claim 21, wherein the amount is selected to be substantially equal to the total amount of aluminum equivalents for n≧2.

24. The method according to claim 21, wherein the copper and at least one additional metal ion are added to the zeolite by an ion exchange process.

25. The method according to claim 21, wherein the copper and at least 21 additional metal ions are added to the zeolite by a co-exchange process.

26. The method according to claim 21, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 2.0 to 2.

5.

27. The method according to claim 21, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 2.2 to about 2.

4.

28. The method according to claim 26, wherein the additional metal includes magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or a combination thereof.

29. The method according to claim 21, wherein the zeolite has about 10 to about 50 SARs.

30. The method according to claim 21, wherein the zeolite has about 15 to about 40 SARs.

31. The method according to claim 21, wherein the zeolite is a small-pore zeolite, a medium-pore zeolite, or a large-pore zeolite.

32. The catalyst composition according to claim 21, wherein the zeolite is an 8-membered ring zeolite, a 10-membered ring zeolite, or a 12-membered ring zeolite.

33. The method according to claim 21, wherein the zeolite has a skeletal structure selected from AEI, AFT, CHA, LTA, AFX, ERI, UFI, KFI, AFV, AVL, SFW, SWY, or a mixture and / or intercrystal containing one or more of these.

34. The method according to claim 21, wherein the zeolite has a skeletal structure selected from MFI, MWW, FER, MSE, YFI, or a mixture and / or intercrystal containing one or more of these.

35. The method according to claim 21, wherein the zeolite has a skeletal structure selected from FAU, BEA, or a mixture containing one or more of these, and / or intercrystals.

36. The method according to claim 21, wherein the zeolite is CHA.

37. The method according to any one of claims 21 to 36, wherein a wash coat layer is coated on a monolithic substrate, the substrate being a metal, cordierite, or silicon carbide (SiC) substrate.

38. The method according to claim 37, wherein the substrate is a flow-through substrate or a wall-flow substrate.

39. The amount of the catalyst composition in the wash coat layer is approximately 0.1 g / in based on the bulk volume of the substrate. ３ ~Approximately 5.0 g / in ３ The method according to claim 37 or 38.

40. The catalyst composition, after aging at a temperature of 550°C or higher, is subjected to 60,000 h －１ At the space velocity and temperatures above 250°C, at least 80% NO ｘ It gives a conversion rate, and when the catalyst composition is used for selective catalytic reduction, it gives less than 1.0% NO to N at temperatures below 400°C. ２ The method according to any one of claims 21 to 39, which results in a conversion rate to O.

41. An exhaust gas treatment system, NO ｘ A NOx generator that produces an exhaust gas flow containing, A catalyst composition containing zeolite, The aforementioned zeolite has a site T of approximately 0.05 milliequivalents / g to approximately 5 milliequivalents / g. （ｎ） (n≧2) The total amount of aluminum, the silica-to-alumina ratio (SAR) of about 5 to about 120, copper, and at least one additional metal other than copper, The additional metal has a charge-to-radius ratio (Z / r) of approximately 1.2 to approximately 3.0, and the metal is not sodium or potassium. The zeolite is Cu ２＋ It has a copper content of approximately 0.05 milliequivalents / g to approximately 5.0 milliequivalents / g according to the standard. Cu ２＋ The amount of copper loaded in milliequivalents / g at the standard is site T （ｎ） The total amount of aluminum equivalents in (n≧2) is less than the amount of the additional metal supported at site T （ｎ） A catalyst composition selected such that the total amount of aluminum equivalents in (n≧1) is less than or equal to the total amount of aluminum equivalents, The injector is configured to inject a reducing agent into the exhaust gas flow, The catalyst composition is in fluid communication with the exhaust gas flow, The reducing agent and the catalyst composition are NO ｘ N ２ and promotes conversion to compositions containing water, The catalyst composition, after aging at a temperature of 550°C or higher, is subjected to 60,000 h －１ At the space velocity and temperatures above 250°C, at least 80% NO ｘ It provides a conversion rate, and when the catalyst composition is used for selective catalytic reduction, it provides less than 1.0% NO to N at temperatures below 400°C. ２ An exhaust gas treatment system that increases the conversion rate to oxygen.

42. The aforementioned NO ｘ The exhaust gas treatment system according to claim 41, wherein the generator is an internal combustion engine, an external combustion engine, or a chemical reactor.

43. The exhaust gas treatment system according to claim 41, wherein the catalyst composition is in a tightly bonded position.

44. The amount of the additional metal supported is the total amount of metal supported in milliequivalents / g at site T （ｎ） The exhaust gas treatment system according to claim 41, wherein the total amount of aluminum equivalents for n≧2 is selected to be less than or equal to the total amount of aluminum equivalents.

45. The amount of the additional metal supported is, the total amount of metal supported in milliequivalents / g is, site T （ｎ） The exhaust gas treatment system according to claim 41, wherein the amount is selected to be substantially equal to the total amount of aluminum equivalents for n≧2.

46. The exhaust gas treatment system according to claim 41, wherein the copper and at least one additional metal ions are added to the zeolite by an ion exchange process.

47. The exhaust gas treatment system according to claim 41, wherein the copper and at least one additional metal ion are added to the zeolite by a co-exchange process.

48. The exhaust gas treatment system according to claim 41, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 2.0 to 2.

5.

49. The exhaust gas treatment system according to claim 41, wherein the additional metal has a charge-to-radius ratio (Z / r) of about 2.2 to about 2.

4.

50. The exhaust gas treatment system according to claim 49, wherein the additional metal includes magnesium, calcium, strontium, barium, chromium, manganese, iron, cobalt, nickel, zinc, or a combination thereof.

51. The exhaust gas treatment system according to claim 41, wherein the zeolite has about 10 to about 50 SARs.

52. The exhaust gas treatment system according to claim 41, wherein the zeolite has about 15 to about 40 SARs.

53. The exhaust gas treatment system according to claim 41, wherein the zeolite is a small-pore zeolite, a medium-pore zeolite, or a large-pore zeolite.

54. The exhaust gas treatment system according to claim 41, wherein the zeolite is an 8-membered ring zeolite, a 10-membered ring zeolite, or a 12-membered ring zeolite.

55. The exhaust gas treatment system according to claim 41, wherein the zeolite has a skeletal structure selected from AEI, AFT, CHA, LTA, AFX, ERI, UFI, KFI, AFV, AVL, SFW, SWY, or a mixture and / or intercrystal containing one or more of these.

56. The exhaust gas treatment system according to claim 41, wherein the zeolite has a skeletal structure selected from MFI, MWW, FER, MSE, YFI, or a mixture containing one or more of these and / or intercrystals.

57. The exhaust gas treatment system according to claim 1, wherein the zeolite has a skeletal structure selected from FAU, BEA, or a mixture containing one or more of these, and / or intercrystals.

58. The exhaust gas treatment system according to claim 41, wherein the zeolite is CHA.

59. An exhaust gas treatment system according to any one of claims 41 to 59, wherein a wash coat layer is coated on a monolithic substrate, and the substrate is a metal, cordierite, or silicon carbide (SiC) substrate.

60. The exhaust gas treatment system according to claim 60, wherein the substrate is a flow-through substrate or a wall-flow substrate.

61. The amount of the catalyst composition in the wash coat layer is approximately 0.1 g / in based on the bulk volume of the substrate. ３ ~Approximately 5.0 g / in ３ The exhaust gas treatment system according to claim 60 or 61.

62. The catalyst composition, after aging at a temperature of 550°C or higher, is subjected to 60,000 h －１ At the space velocity and temperatures above 250°C, at least 85% NO ｘ It provides a conversion rate, and when the catalyst composition is used for selective catalytic reduction, it provides less than 1.0% NO to N at temperatures below 400°C. ２ An exhaust gas treatment system according to any one of claims 41 to 62, which provides a conversion rate to oxygen.

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