Catalyst, engine, and vehicle

Abstract

A catalyst, an engine, and a vehicle. The catalyst comprises: copper. The copper includes: isolated copper ions and copper ions present in copper oxide, wherein the number of atoms of the isolated copper ions is greater than the number of atoms of the copper ions in the copper oxide.

Description

Catalysts, engines and vehicles

[0001] This application claims priority to Chinese patent application No. 202510570780.1, filed on April 30, 2025, and Chinese patent application No. 202411998500.9, filed on December 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of catalysis technology, and more particularly to a catalyst, an engine, and a vehicle. Background Technology

[0003] Nitrogen oxides (NOx) are a common air pollutant, widely originating from both nature and human activities. The primary source of anthropogenic NOx emissions is from transportation engines. Selective catalytic reduction (SCR) systems, through the action of a catalyst, can selectively reduce NOx gases into nitrogen and water, effectively reducing NOx emissions from vehicle exhaust. Summary of the Invention

[0004] This disclosure provides a catalyst, an engine, and a vehicle, aimed at solving the problem of low catalytic activity of the catalyst in a temperature window range of 550°C to 650°C.

[0005] In a first aspect, a catalyst is provided for catalyzing the reduction reaction of nitrogen oxide gas. The catalyst comprises copper. The copper element includes isolated copper ions and copper ions present in copper oxide, wherein the number of atoms of the isolated copper ions is greater than the number of atoms of the copper ions in the copper oxide.

[0006] The catalyst provided in this disclosure uses copper as an active component that catalyzes the reduction reaction of nitrogen oxides. The active sites in copper promote the reaction between nitrogen oxides and the reducing agent. Copper exists primarily in the form of isolated copper ions and copper ions present in copper oxide, including isolated Cu. 2+ CuO and Cu + Isolated Cu 2+ As the active site for the reduction reaction of nitrogen oxides, it can more easily come into contact with and interact with nitrogen oxides. The isolated copper ions react with nitrogen oxides through two reduction steps to finally reduce to Cu(Cu). 2+ →Cu + Cu + →Cu): At temperatures below 800℃, Cu 2+ Reduced to Cu + At temperatures above 800℃, Cu+ The isolated copper ions are reduced to Cu, thereby promoting the progress of the catalytic reaction; and the isolated copper ions are more inclined to directly participate in the reduction reaction of the nitrogen oxide, thereby promoting the decomposition and reduction of the nitrogen oxide through processes such as electron transfer. Through the setting that the atomic number of the isolated copper ions is greater than the atomic number of the copper ions in the copper oxide, even if a small part of the isolated copper ions are aggregated at a relatively high temperature of 550°C to 650°C, there are still sufficient isolated copper ions present, and a large amount of copper oxide particles are not formed, the influence of the ammonia gas oxidation is weakened, thereby reducing the consumption of the reducing agent, enabling more reducing agent to be used for the reduction reaction of the nitrogen oxide, and thereby improving the conversion rate of the nitrogen oxide gas in the reduction reaction of the nitrogen oxide gas in the temperature window range of 550°C to 650°C.

[0007] Therefore, in the copper element, the more the atomic number of the isolated copper ions, the more the active sites, and the better the performance of the catalyst, and increasing the atomic number will help to improve the catalytic activity of the entire catalyst, promote the progress of the reduction reaction of the nitrogen oxide, and can improve the conversion rate of the reduction reaction of the nitrogen oxide gas in the temperature window range of 550°C to 650°C.

[0008] In some embodiments, the catalyst further comprises: a molecular sieve.

[0009] The ratio of the mass of the copper element to the sum of the mass of the molecular sieve and the mass of the copper element ranges from 0.01 to 0.04.

[0010] In some embodiments, the catalyst further comprises a first catalyst and a second catalyst, and the second catalyst is different from the first catalyst.

[0011] In some embodiments, the conversion rate of the first catalyst for the reduction reaction of the nitrogen oxide gas is greater than the conversion rate of the second catalyst for the reduction reaction of the nitrogen oxide gas in the temperature range of 550°C to 650°C.

[0012] In some embodiments, the first catalyst comprises: at least one of an AEI type molecular sieve and a CHA type molecular sieve.

[0013] In some embodiments, the first catalyst comprises: Cu-SSZ-39.

[0014] In some embodiments, the ratio of the mass of the copper element in the Cu-SSZ-39 to the mass of the Cu-SSZ-39 ranges from 0.01 to 0.04.

[0015] In some embodiments, the ratio of the mass of the copper element in the Cu-SSZ-39 and the mass of the Cu-SSZ-39 ranges from 0.01 to 0.

[0016] In some embodiments, the second catalyst comprises: at least one of a BEA type molecular sieve, an MFI type molecular sieve, and a CHA type molecular sieve.

[0017] In some embodiments, the second catalyst comprises: Cu-SSZ-13.

[0018] In some embodiments, a ratio of a mass of the copper element in the Cu-SSZ-13 to a mass of the Cu-SSZ-13 ranges from 0.01 to 0.04.

[0019] In some embodiments, a ratio of a mass of the copper element in the Cu-SSZ-13 to a mass of the Cu-SSZ-13 ranges from 0.01 to 0.03.

[0020] In some embodiments, the catalyst further comprises: a carrier. The catalyst is disposed on the carrier.

[0021] In some embodiments, the carrier comprises a porous ceramic material.

[0022] In some embodiments, the carrier comprises: a first carrier and a second carrier. The first catalyst is disposed on the first carrier. The second catalyst is disposed on the second carrier.

[0023] In some embodiments, the first carrier has a pore structure. The first catalyst is at least partially disposed on a pore wall of the first carrier. A thickness of the first catalyst on the pore wall of the first carrier ranges from 50 μm to 100 μm.

[0024] In some embodiments, the second carrier has a pore structure. The second catalyst is at least partially disposed on a pore wall of the second carrier. A thickness of the second catalyst on the pore wall of the second carrier ranges from 50 μm to 100 μm.

[0025] In some embodiments, the thickness of the first catalyst on the pore wall of the first carrier ranges from 70 μm to 80 μm.

[0026] In some embodiments, the thickness of the second catalyst on the pore wall of the second carrier ranges from 70 μm to 80 μm.

[0027] In some embodiments, the catalyst comprises a first catalytic region and a second catalytic region arranged along a first direction. The first direction is a flow direction of the nitrogen oxide gas. The first catalytic region is provided with: a first carrier and a first catalyst. The second catalytic region is provided with: a second carrier and a second catalyst.

[0028] In some embodiments, a ratio between a length of the first catalytic region and a length of the second catalytic region ranges from 0.2 to 5. The length direction is the flow direction of the nitrogen oxide gas.

[0029] In some embodiments, a ratio between a mass of the first catalyst and a mass of the second catalyst ranges from 0.2 to 5.

[0030] In some embodiments, the catalyst is applied to a nitrogen oxide gas treatment system. The treatment system comprises: a gas inlet end arranged in a first direction, the catalyst described above, and a gas outlet end.

[0031] In some embodiments, when the catalyst comprises a first catalytic region and a second catalytic region arranged in the first direction, the first catalytic region is closer to the gas inlet end than the second catalytic region.

[0032] In a second aspect, an engine is provided, comprising a catalyst device, the catalyst device comprising a housing, the housing comprising a receiving cavity, the receiving cavity comprising the catalyst described above.

[0033] In some embodiments, the engine further comprises an engine body and a plurality of exhaust pipes, the plurality of exhaust pipes being connected in series and connected to the engine body, and the catalyst device being arranged between the plurality of exhaust pipes to treat nitrogen oxide emitted by the engine.

[0034] In some embodiments, an ammonia generating component is further arranged between the plurality of exhaust pipes, the ammonia generating component being arranged upstream of the catalyst device in a flow direction of the nitrogen oxide gas, the ammonia generating component being configured to generate ammonia, and the catalyst device being configured to accelerate a reaction between the nitrogen oxide and the ammonia.

[0035] In some embodiments, the ammonia generating component comprises an ammonia generation catalyst assembly, the ammonia generation catalyst assembly being configured to catalytically convert the nitrogen oxide into ammonia.

[0036] In some embodiments, the ammonia generating component comprises a urea injection device, the urea injection device being configured to provide a urea aqueous solution to generate the ammonia.

[0037] In a third aspect, a vehicle is provided. The vehicle comprises one of: the nitrogen oxide gas treatment system comprising the catalyst described above; or the engine described above. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art without any creative effort based on these drawings.

[0039] FIG. 1 is a schematic diagram of a nitrogen oxide gas treatment system according to some embodiments;

[0040] FIG. 2 is a schematic diagram of a cross section of a catalyst according to some embodiments;

[0041] FIG. 3 is a schematic diagram of a cross section of another catalyst according to some embodiments;

[0042] FIG. 4 is a graph of conversion of nitrogen oxides for a fresh sample of catalyst according to some embodiments;

[0043] FIG. 5 is a graph of conversion of nitrogen oxides for an aged sample of catalyst according to some embodiments;

[0044] FIG. 6 is a graph of H2-temperature programmed reduction profile of Cu-SSZ-13 according to some embodiments;

[0045] FIG. 7 is a graph of H2-temperature programmed reduction profile of Cu-SSZ-39 according to some embodiments;

[0046] FIG. 8 is a schematic diagram of a structure of a catalyst device according to some embodiments;

[0047] FIG. 9 is a schematic diagram of a structure of an engine according to some embodiments;

[0048] FIG. 10 is a schematic diagram of a structure of another engine according to some embodiments;

[0049] FIG. 11 is a block diagram of a vehicle according to some embodiments;

[0050] FIG. 12 is a block diagram of another vehicle according to some embodiments;

[0051] FIG. 13 is a block diagram of yet another vehicle according to some embodiments.

[0052] Reference signs: C1 - first catalytic region, C2 - second catalytic region, 10 - catalyst, 11 - first carrier, 12 - first catalyst, 13 - second carrier, 14 - second catalyst; 20 - catalyst device, housing - 21, accommodation cavity - 22; 30 - engine; 31 - engine main body; 32 - exhaust pipe; 33 - ammonia generation catalyst assembly (ammonia generation component); 34 - urea injection device (ammonia generation component); urea tank - 35; 1000 - vehicle; 100 - nitrogen oxide gas treatment system. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present disclosure.

[0054] In the description of the disclosure, it needs to be understood that the terms "upper", "lower", "left", "right", "front", "back", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or relative position relationship shown in the drawings, and are only for the convenience of describing the disclosure and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the disclosure. Unless otherwise specified, the above orientation description can be flexibly arranged in the actual application process under the condition of meeting the relative position relationship shown in the drawings.

[0055] The terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implying a specific number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the disclosure, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0056] In the description of the disclosure, it needs to be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "communicating" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected. It can be directly connected, or indirectly connected through an intermediate medium, or the communication between the two elements inside. For those skilled in the art, the specific meaning of the above terms in the disclosure can be understood according to the specific circumstances.

[0057] In the embodiments of the disclosure, the terms "comprising", "containing" or any other variants thereof are intended to cover non-exclusive containing, so that the process, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, article or device. Without more limitation, the element defined by the sentence "including a…" does not exclude the existence of other identical elements in the process, article or device including the element.

[0058] In the embodiments of the disclosure, the words "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design presented as "exemplary" or "for example" in the embodiments of the disclosure should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present concepts in a concrete manner. The embodiments of the disclosure are described in the description of the disclosure.

[0059] In the description of the specification, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0060] Vehicles are indispensable means of transportation, however, nitrogen oxides in vehicle exhaust emissions are one of the main air pollutants, which will cause serious impact on the atmospheric environment and human health.

[0061] Some embodiments of the present disclosure provide a vehicle 1000.

[0062] As shown in FIG. 11, in some embodiments, the vehicle 1000 comprises a nitrogen oxide gas treatment system 100.

[0063] The nitrogen oxide gas treatment system 100 is a kind of exhaust purification technology. Through the action of the catalyst, the nitrogen oxide gas in the exhaust reacts with the reducing agent (such as ammonia) to generate harmless nitrogen and water, achieving effective purification of nitrogen oxides in vehicle exhaust, and is widely used in the field of vehicles.

[0064] As shown in FIG. 1, the nitrogen oxide gas treatment system 100 of some embodiments of the present disclosure comprises an inlet end I, a catalyst 10 and an outlet end E arranged along a first direction X.

[0065] It can be understood that the inlet end I is the starting part of the nitrogen oxide gas treatment system 100, which is responsible for receiving exhaust gas from the vehicle nitrogen oxide emission source. The outlet end E is the end of the nitrogen oxide gas treatment system 100, which can discharge the treated exhaust gas into the atmosphere.

[0066] The catalyst 10 is the core part of the nitrogen oxide gas treatment system 100, which can promote the chemical reaction between the nitrogen oxide gas and the reducing agent, accelerate the reaction between the reducing agent and the nitrogen oxide gas, and generate harmless nitrogen and water.

[0067] As shown in FIG. 12, in some embodiments, the vehicle 1000 comprises a catalyst device 20.

[0068] As shown in FIG. 8, some embodiments of the present disclosure provide a catalyst device 20, which is the core part of the engine. The catalyst device 20 comprises a shell 21, and the shell 21 is provided with a containing cavity 22, and the containing cavity 22 is provided with the catalyst 10.

[0069] As shown in FIG. 13, in some embodiments, the vehicle 1000 comprises an engine 30.

[0070] As shown in Figures 9 and 10, some embodiments of this disclosure provide an engine 30, which includes the catalyst device 20 described above. The engine 30 also includes an engine body 31 and multiple exhaust pipes 32. The engine body 31 can be a gasoline engine body or a diesel engine body. A gasoline engine body is a device that uses gasoline as fuel and ignites the air-fuel mixture with a spark plug to perform work. Its basic structure includes components such as a cylinder block, piston, connecting rod, crankshaft, intake valve, and exhaust valve. Taking a common four-stroke gasoline engine as an example, during the intake stroke, the piston moves downward from top dead center, the intake valve opens, and the combustible mixture (a mixture of gasoline and air) is drawn into the cylinder. During the compression stroke, the piston moves upward, and the top of the piston compresses the combustible mixture to a certain pressure and temperature. When the compression reaches near top dead center, the spark plug generates an electric spark to ignite the mixture. The combustion of the mixture produces high-temperature, high-pressure gas, which pushes the piston downward to perform work; this is the power stroke. During the exhaust stroke, the piston moves upward, the exhaust valve opens, and the combustible gas is discharged from the cylinder.

[0071] A diesel engine is also mainly composed of basic components such as a cylinder block, piston, connecting rod, and crankshaft. However, the working principle of a diesel engine differs from that of a gasoline engine. It relies on compressed air to ignite diesel fuel. During the intake stroke, only air is drawn into the cylinder. The piston moves upward during the compression stroke, compressing the air to very high pressure and temperature, typically reaching 500-1000℃. When the pressure approaches top dead center, the injector injects diesel fuel into the cylinder. The diesel fuel spontaneously combusts in the high-temperature, high-pressure air, generating a large amount of heat that pushes the piston downward to do work.

[0072] The exhaust pipe 32 is an important passage for the exhaust gases emitted by the engine 30. Multiple exhaust pipes 32 can be better integrated with exhaust gas treatment devices. Multiple exhaust gas purification devices can be installed on the exhaust pipe 32. The design of multiple exhaust pipes 32 facilitates the placement of these purification devices in appropriate locations to achieve better exhaust gas treatment effects and meet increasingly stringent environmental emission standards.

[0073] In some embodiments, as shown in Figures 9 and 10, the design of multiple exhaust pipes 32 connected end-to-end and connected to the engine body facilitates better collection and treatment of exhaust gas emitted from the engine 30. This allows the exhaust gas to flow along the direction in which the multiple exhaust pipes 32 are connected sequentially, passing through each exhaust pipe 32 in turn. A catalyst device 20 can be installed at the connection points of the different exhaust pipes 32. The catalyst device 20 includes an inlet and an outlet. The inlet is connected to the exhaust pipe 32 upstream in the direction of nitrogen oxide gas flow, and the outlet is connected to the exhaust pipe 32 downstream in the direction of nitrogen oxide gas flow. The exhaust gas emitted from the engine 30 flows through the catalyst device 20, allowing the catalyst device 20 to treat the nitrogen oxides in the exhaust gas.

[0074] In some embodiments, as shown in Figures 9 and 10, an ammonia generating component is also provided between the plurality of exhaust pipes 32. The main function of this component is to generate ammonia. Ammonia can act as a reducing agent during the treatment of nitrogen oxides. The ammonia generating component typically introduces ammonia into the exhaust pipes 32 at appropriate locations to provide sufficient ammonia for subsequent nitrogen oxide reduction reactions.

[0075] In the direction of nitrogen oxide gas flow, the ammonia generating component is positioned upstream of the catalyst unit 20. This design ensures that the ammonia gas can fully contact the catalyst and nitrogen oxides within the catalyst unit 20. When exhaust gas containing nitrogen oxides flows from the exhaust pipe 32 to the catalyst unit 20, it first enters the area where the ammonia generating component is located, and then the ammonia-carrying exhaust gas continues to flow into the catalyst unit 20. Inside the catalyst unit 20, the ammonia gas undergoes a chemical reaction with the nitrogen oxides under the action of the catalyst, such as a selective catalytic reduction (SCR) reaction. This reaction effectively converts nitrogen oxides into nitrogen and water, thereby reducing the amount of nitrogen oxides emitted in the exhaust gas of the engine 30.

[0076] In some embodiments, as shown in Figure 9, the ammonia generating component includes an ammonia generating catalyst assembly 33. When the engine body 31 operates under rich combustion conditions, the nitrogen oxides in the exhaust gas are mainly nitric oxide and nitrogen dioxide. Rich combustion refers to a combustion mode where the air-fuel ratio is less than the stoichiometric air-fuel ratio when the engine body 31 is a gasoline engine. In this state, the concentration of the mixture exceeds the theoretical ratio required for complete combustion, and the fuel cannot be completely burned. When the gasoline engine body is in rich combustion conditions, it has good power performance but poor fuel economy and higher exhaust emissions. The air-fuel ratio refers to the mass ratio of air to fuel in the gasoline engine body. Lean combustion refers to a gasoline engine operating with an air-fuel ratio greater than the stoichiometric air-fuel ratio. When the gasoline engine body is in lean combustion conditions, it has advantages such as improved fuel economy, improved thermal efficiency, and reduced knocking tendency. The stoichiometric air-fuel ratio is the ratio of the mass of air to the mass of fuel theoretically required for complete combustion of 1 gram of fuel.

[0077] In the direction of nitrogen oxide gas flow, the ammonia generating catalyst assembly 33 is positioned upstream of the catalyst device 20. During operation, the gasoline engine switches between rich and lean combustion conditions. When the gasoline engine is in rich combustion mode, the ammonia generating catalyst assembly 33 converts nitrogen oxides into ammonia under catalytic action. The generated ammonia flows along the gas flow direction into the catalyst device 20 and is stored there. When the gasoline engine is in lean combustion mode, the catalyst device 20 catalyzes the reaction of nitrogen oxides and ammonia in the exhaust gas of the gasoline engine into nitrogen and water, thereby reducing the amount of nitrogen oxides emitted in the exhaust gas of the gasoline engine.

[0078] In some embodiments, as shown in FIG10, the ammonia generating component includes a urea injection device 34, which injects urea solution stored in a urea tank 35 into an exhaust pipe 32. The urea solution decomposes under certain conditions to generate ammonia. In the direction of nitrogen oxide gas flow, the urea injection device 34 is positioned upstream of the catalyst device 20 to provide sufficient ammonia for the nitrogen oxide reduction reaction in the catalyst device 20.

[0079] In some implementations, the catalyst 10 exhibits low reactivity over a wide reaction temperature range (e.g., 200–700 °C), particularly within a temperature window of 550 °C–650 °C. This results in a low conversion rate for the reduction reaction of nitrogen oxides, affecting the efficiency of the nitrogen oxide gas treatment system 100 and the catalyst device 20.

[0080] Based on this, some embodiments of this disclosure provide a catalyst 10 for catalyzing the reduction reaction of nitrogen oxide gas. The catalyst 10 comprises copper. The copper element includes isolated copper ions and copper ions present in copper oxide. The number of atoms of the isolated copper ions is greater than the number of atoms of the copper ions in copper oxide.

[0081] Copper is an active component that catalyzes the reduction reaction of nitrogen oxides. The active sites in copper can promote the reaction between nitrogen oxides and reducing agents, thereby increasing the conversion rate of nitrogen oxides.

[0082] The copper element in catalyst 10 exists mainly in the forms of isolated copper ions and copper ions present in copper oxide, including isolated Cu. 2+ CuO and Cu + In copper oxide, the copper ion forms a polar covalent bond with oxygen. Isolated copper ions are bonded to other elements through ionic bonds or other non-covalent bonds. Isolated Cu 2+ As an active site for the reduction reaction of nitrogen oxides, it can more easily come into contact with and interact with nitrogen oxides. The isolated copper ions react with nitrogen oxides through two reduction steps to finally reduce to Cu. 0 (Cu 2+ →Cu + Cu + →Cu 0 ): At temperatures below 800℃, Cu 2+ Reduced to Cu + At temperatures above 800℃, Cu + Reduced to Cu 0 This promotes the catalytic reaction; moreover, isolated copper ions tend to directly participate in the reduction reaction of nitrogen oxides, promoting the decomposition and reduction of nitrogen oxides through processes such as electron transfer.

[0083] However, at temperatures between 550℃ and 650℃, a small number of metal atoms coordinated with isolated copper ions will be removed, causing the isolated copper ions to aggregate and form copper oxide particles. These copper oxide particles promote the oxidation reaction of ammonia and consume the reducing agent in the reduction reaction of nitrogen oxides. Therefore, by setting the number of isolated copper ions to be greater than the number of copper ions in copper oxide, even if a small number of isolated copper ions aggregate at the higher temperatures of 550℃ to 650℃, there will still be enough isolated copper ions to form a large number of copper oxide particles. This will have a weaker impact on the oxidation of ammonia, thereby reducing the consumption of reducing agent and allowing more reducing agent to be used in the reduction reaction of nitrogen oxides, thus improving the conversion rate of nitrogen oxides.

[0084] Therefore, the more isolated copper ions there are in copper, the more active sites there are, and the better the performance of catalyst 10. Increasing the number of atoms will help improve the overall catalytic activity of catalyst 10 and promote the reduction reaction of nitrogen oxides. It can also improve the conversion rate of nitrogen oxide gas reduction reaction of catalyst 10 in the temperature window range of 550℃~650℃.

[0085] In some embodiments of this disclosure, the copper elements in catalyst 10 can be characterized by H2-temperature programmed reduction (H2-TPR) spectra. Isolated copper ions located near the octagonal ring window are more easily reduced by the reducing agent (H2), thus corresponding to a reduction peak at a lower temperature (200℃~300℃) in H2-TPR. Isolated copper ions located at the center of the hexagonal prism are coordinated with two tetragonal Al crystals, making the isolated copper ions more stable, thus requiring a higher temperature for reduction, corresponding to a reduction peak at a higher temperature (400℃~700℃) in H2-TPR. The reduction peaks in copper oxide, where copper ions are reduced at moderate temperatures (300℃~400℃), correspond to reduction peaks in the H2-TPR temperature range of 300℃~400℃. Furthermore, the number of copper atoms can be obtained from the integrated area of ​​the reduction peaks. In other words, the number of isolated copper atoms can be obtained by summing the integrated area of ​​the reduction peaks at 200℃~300℃ and 400℃~700℃. The number of copper ions in copper oxide can be obtained from the integrated area of ​​the reduction peaks at 300℃~400℃.

[0086] In some embodiments, catalyst 10 further includes a molecular sieve.

[0087] The ratio of the mass of copper to the sum of the mass of the molecular sieve and the mass of copper ranges from 0.01 to 0.04.

[0088] For example, the ratio of the mass of copper to the sum of the mass of the molecular sieve and the mass of copper can be 0.01, 0.02, 0.027, 0.03, or 0.04, etc., and there is no limit here.

[0089] It is understandable that molecular sieves are inorganic crystalline materials with regular pore structures formed by connecting tetrahedrons with common vertices. They have abundant acidic sites and ion exchange sites, exhibit excellent catalytic activity against nitrogen oxides, nitrogen selectivity, hydrothermal stability, and a wide temperature window. Furthermore, they can efficiently remove nitrogen oxides under high space velocity conditions.

[0090] By setting the ratio of the mass of copper to the sum of the mass of the molecular sieve and the mass of copper within the range of 0.01 to 0.04, the distribution of active sites in catalyst 10 can be optimized, allowing copper to achieve the best dispersion state on the surface of catalyst 10, thereby improving the catalytic effect of catalyst 10 on nitrogen oxides. It can also prevent the problem of insufficient catalyst activity due to too low copper content, and the problem of copper agglomeration or migration due to too high copper content, effectively preventing the deactivation or performance degradation of catalyst 10, so that copper can exist stably in the channels of copper-based molecular sieve, and is not prone to migration or agglomeration, thereby maintaining the stability of catalyst 10.

[0091] In some embodiments, as shown in Figures 2 and 3, catalyst 10 includes a first catalyst 12 and a second catalyst 14, wherein the second catalyst 14 is different from the first catalyst 12.

[0092] It is understandable that different catalysts 10 (first catalyst 12 and second catalyst 14) have different catalytic activities, providing more active sites and increasing the reduction rate of nitrogen oxides. Furthermore, different catalysts 10 have different reaction temperature ranges, allowing them to maintain high activity over a wider temperature range. Therefore, first catalyst 12 and second catalyst 14 can optimize the diffusion process of nitrogen oxides on the surface of catalyst 10, improving reaction efficiency. Moreover, the second catalyst 14 differs from the first catalyst 12; that is, the structural difference between the second catalyst 14 and the first catalyst 12 allows them to exhibit different catalytic activities in the catalytic reaction. This makes catalyst 10 suitable for catalytic activity within the overall temperature window (200℃~700℃), thereby further improving the catalytic conversion of catalyst 10 within the overall temperature window.

[0093] In some embodiments, within a temperature range of 550°C to 650°C, the conversion rate of the first catalyst 12 for the reduction reaction of nitrogen oxides is greater than that of the second catalyst 14 for the reduction reaction of nitrogen oxides.

[0094] Understandably, within the temperature range of 550℃ to 650℃, the first catalyst 12 can effectively promote the chemical reaction between nitrogen oxide gas and the reducing agent, generating harmless nitrogen gas and water vapor. The first catalyst 12 is more effective at temperatures between 550℃ and 650℃, which solves the problem of the second catalyst 14 having a low conversion rate at higher temperatures. Thus, the first catalyst 12 and the second catalyst 14 can work synergistically, enabling the catalyst 10 to achieve a good conversion rate within the overall temperature window (200℃ to 700℃) of the nitrogen oxide gas treatment system 100 or the catalyst device 20, thereby providing a higher overall catalytic efficiency.

[0095] In some embodiments, the first catalyst 12 comprises at least one of AEI-type molecular sieve and CHA-type molecular sieve.

[0096] AEI-type molecular sieves are composed of tetrahedral units of silicon, aluminum, and phosphorus interconnected through shared oxygen atoms, forming a stable framework structure. The framework contains nanocages, which facilitate effective contact and reaction between nitrogen oxide gases and reducing agents, resulting in excellent thermal stability and catalytic activity. CHA-type molecular sieves are silicon-aluminum molecular sieves with an eight-membered ring crystal structure. Their small pore size allows them to form unique nanocages; and their cation exchangeability makes them highly efficient catalyst supports for the reduction of nitrogen oxide gases, exhibiting excellent thermal stability and catalytic performance.

[0097] In catalyst 10, isolated copper ions act as active centers for the reduction reaction of nitrogen oxides, promoting the catalytic reduction of nitrogen oxides. The nanocages in the AEI-type and CHA-type molecular sieve structures confine the isolated copper ions, separating them and preventing their aggregation.

[0098] Therefore, the nanocages in the structures of AEI-type and CHA-type molecular sieves confine isolated copper ions, resulting in better dispersion of isolated copper ions and a larger contact area between nitrogen oxides and isolated copper ions, which is more conducive to the reduction reaction of nitrogen oxides.

[0099] When the number of isolated copper ions is the same, and the isolated copper ions are dispersed in nanocages at the atomic level, the isolated copper ions can fully contact nitrogen oxides. Compared to the case where isolated copper ions are directly contacted with nitrogen oxides, i.e., the isolated copper ions may aggregate to form spheres, and the contact area between nitrogen oxides and isolated copper ions is only the outer surface of the spheres, the contact area between isolated copper ions and nitrogen oxides in the AEI-type molecular sieve and CHA-type molecular sieve structures is larger, which is conducive to the reduction reaction of nitrogen oxide gas and the conversion of nitrogen oxides.

[0100] In some embodiments, the first catalyst 12 comprises Cu-SSZ-39.

[0101] Cu-SSZ-39 belongs to the AEI type molecular sieve structure. Its aluminum-rich characteristics and relatively tortuous pore structure enable it to inhibit the migration and accumulation of copper species and the extraction of skeletal aluminum during hydrothermal aging. This makes it less prone to the migration, accumulation, or transformation of copper species in Cu-SSZ-39, thus maintaining excellent catalytic performance even after severe hydrothermal aging at relatively high temperatures (550℃~600℃). Therefore, using Cu-SSZ-39 as the first catalyst 12 can improve the conversion rate of catalyst 10. Moreover, Cu-SSZ-39 is relatively inexpensive, effectively reducing the cost of catalyst 10 while ensuring its catalytic effect. Further details regarding the excellent catalytic performance of Cu-SSZ-39 after hydrothermal aging will be provided later.

[0102] Figure 7 shows the H2-TPR spectrum of Cu-SSZ-39 in Preparation Example 2. Based on the corresponding temperature ranges of isolated copper ions and copper ions in copper oxide in the H2-TPR spectrum, the reduction peaks at 200℃~300℃ and 400℃~700℃ are attributed to isolated Cu. 2+ The reduction peak at 300℃~400℃ belongs to CuO. As shown in Figure 7, the sum of the integrated area of ​​the reduction peak at 200℃~300℃ and the integrated area of ​​the reduction peak at 400℃~700℃ is much larger than the integrated area of ​​the reduction peak at 300℃~400℃. This means that the number of isolated copper ions is much greater than the number of copper ions in copper oxide. Copper ions in copper oxide only account for a small portion of all copper; most copper exists in the form of isolated copper ions. 2+ The more active sites there are, the better the catalytic activity of Cu-SSZ-39.

[0103] In some embodiments, the ratio of the mass of copper in Cu-SSZ-39 to the mass of Cu-SSZ-39 ranges from 0.01 to 0.04.

[0104] For example, the ratio of the mass of copper in Cu-SSZ-39 to the mass of Cu-SSZ-39 can be 0.01, 0.02, 0.03 or 0.04, etc., and there is no limit here.

[0105] In some embodiments, the ratio of the mass of copper in Cu-SSZ-39 to the mass of Cu-SSZ-39 ranges from 0.01 to 0.03.

[0106] For example, the ratio of the mass of copper in Cu-SSZ-39 to the mass of Cu-SSZ-39 can be 0.01, 0.015, 0.02, 0.025 or 0.03, etc., and there is no limit here.

[0107] By further setting the ratio of the mass of copper to the mass of Cu-SSZ-39 within the range of 0.01 to 0.03, the catalytic effect of the first catalyst 12 on nitrogen oxide gas and the stability of the first catalyst 12 can be further improved.

[0108] In some embodiments, the second catalyst 14 includes at least one of BEA-type molecular sieve, MFI-type molecular sieve, and CHA-type molecular sieve.

[0109] The structure of CHA-type molecular sieves has been described above and will not be repeated here. BEA-type molecular sieves possess a three-dimensional twelve-membered ring pore structure. These intersecting channels form a complex network, giving them a large specific surface area and adsorption capacity. This allows them to adsorb and enrich reactant molecules, promoting catalytic reactions and resulting in high activity and selectivity in catalytic reactions. MFI-type molecular sieves are composed of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra connected by shared oxygen atoms, forming a three-dimensional intersecting pore system. The alternation of straight and sinusoidal channels provides excellent diffusion channels for reactant molecules, enabling MFI-type molecular sieves to exhibit high activity and selectivity in catalytic reactions. Both BEA-type and MFI-type molecular sieves have abundant pore and cavity structures. These cavities function similarly to nanocages, increasing the contact area between isolated copper ions and nitrogen oxides, which is beneficial for the reduction and conversion of nitrogen oxides.

[0110] At least one of the above-mentioned BEA-type molecular sieves, MFI-type molecular sieves, and CHA-type molecular sieves can be used as the second catalyst 14 to improve the conversion rate of the reduction reaction of nitrogen oxide gas by the second catalyst 14, while maintaining good stability and selectivity.

[0111] In some embodiments, the second catalyst 14 comprises Cu-SSZ-13.

[0112] Cu-SSZ-13 belongs to the CHA-type molecular sieve structure. At higher temperatures (e.g., above 550℃), it may experience stability issues such as copper species aggregation and dealumination of the molecular sieve framework. However, at lower temperatures (e.g., below 550℃), it exhibits good structural stability and is not prone to collapse or deformation. This results in Cu-SSZ-13 displaying good catalytic activity and high-temperature hydrothermal stability between 200℃ and 550℃, thus ensuring the continuous progress of the catalytic reaction. Moreover, Cu-SSZ-13 is relatively inexpensive, effectively reducing the cost of catalyst 10 while maintaining its catalytic effect.

[0113] Figure 6 shows the H2-TPR spectrum of Cu-SSZ-13 in Preparation Example 3. Based on the corresponding temperature ranges of isolated copper ions and copper ions in copper oxide in the H2-TPR, the reduction peaks at 200℃~300℃ and 400℃~700℃ are attributed to isolated Cu. 2+ The reduction peak at 300℃~400℃ belongs to copper ions in CuO. In Figure 6, the integrated areas of the corresponding reduction peaks of isolated copper ions and copper ions in copper oxide show that the sum of the integrated areas of the reduction peaks at 200℃~300℃ and 400℃~700℃ is much larger than the integrated area of ​​the reduction peak at 300℃~400℃. This means that the number of isolated copper ions is much greater than the number of copper ions in copper oxide. Copper ions in copper oxide only account for a small portion of all copper; most copper exists as isolated copper ions. In the Cu element, isolated Cu... 2+ The more active sites a catalyst has, the better its performance. Therefore, Cu-SSZ-13 exhibits good catalytic activity.

[0114] In some embodiments, the ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 ranges from 0.01 to 0.04.

[0115] For example, the ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 can be 0.01, 0.02, 0.03 or 0.04, etc., and there is no limit here.

[0116] In some embodiments, the ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 ranges from 0.01 to 0.03.

[0117] For example, the ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 can be 0.01, 0.015, 0.02, 0.025 or 0.03, etc., and there is no limit here.

[0118] By further setting the ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 within the range of 0.01 to 0.03, the catalytic effect of the second catalyst 14 on nitrogen oxide gas and the stability of the second catalyst 14 can be further improved.

[0119] In some embodiments, the catalyst further includes a support. The catalyst 10 is disposed on the support.

[0120] Understandably, the support is the material that supports the catalyst.

[0121] Here, the catalyst 10 disposed on the support means not only directly on the support, but also above or on the support having intermediate features or layers therein, and not only above or on the support, but also above or on the support without intermediate features or layers therein (i.e., directly on the support).

[0122] In some embodiments, the carrier comprises a porous ceramic material.

[0123] For example, porous ceramic materials can be cyanite.

[0124] In some embodiments, as shown in FIG2, the support includes a first support 11 and a second support 13. A first catalyst 12 is disposed on the first support 11. A second catalyst 14 is disposed on the second support 13.

[0125] It is understood that the first support 11 is the supporting material for the first catalyst 12. The second support 13 is the supporting material for the second catalyst 14.

[0126] Porous ceramic materials have a very high specific surface area, which can provide more surface area for loading catalyst 10 and adsorption of reactants, thereby enhancing the efficiency of catalytic reaction. The porous structure is conducive to the diffusion and transport of nitrogen oxide gas reactants inside the support, reducing mass transfer resistance and allowing reactants to reach the surface of catalyst 10 for reaction more quickly, thereby increasing the rate of catalytic reaction. In addition, porous ceramic materials have high thermal stability and mechanical strength, which can maintain stable performance under harsh conditions such as high temperature and high pressure, and extend the service life of catalyst 10.

[0127] In some embodiments, as shown in FIG2, the first support 11 has a porous structure. The first catalyst 12 is at least partially disposed on the pore walls of the first support 11. Here, the first support 11 and the second support 13 may be the same or different, and there is no limitation.

[0128] The thickness D of the first catalyst 12 on the pore wall of the first support 11 ranges from 50 μm to 100 μm.

[0129] For example, the thickness D of the first catalyst 12 on the pore wall of the first support 11 can be 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, etc., and there is no limitation here.

[0130] In some embodiments, as shown in FIG3, the second support 13 has a porous structure. The second catalyst 14 is at least partially disposed on the pore wall of the second support 13. The thickness H of the second catalyst 14 on the pore wall of the second support 13 ranges from 50 μm to 100 μm.

[0131] For example, the thickness H of the second catalyst 14 on the pore wall of the second support 13 can be 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, etc., and there is no limitation here.

[0132] By setting the thickness D of the first catalyst 12 on the pore wall of the first support 11 to be in the range of 50 μm to 100 μm, and the thickness H of the second catalyst 14 on the pore wall of the second support 13 to be in the range of 50 μm to 100 μm, the first catalyst 12 and the second catalyst 14 can provide a large surface area, which helps nitrogen oxides diffuse to the surface of the first catalyst 12 and the second catalyst 14 more quickly, forming effective contact with the active sites, thereby improving the catalytic effect of the catalytic reaction; it can also reduce mass transfer resistance, allowing reactants to reach the surface of the catalyst 10 more quickly, and reducing the decrease in reaction rate caused by mass transfer limitation; and it effectively prevents the first catalyst 12 from clogging the pores of the first support 11 and the second catalyst 14 from clogging the pores of the second support 13, thus affecting the contact between nitrogen oxide gas and the active sites.

[0133] In some embodiments, the thickness D of the first catalyst 12 on the pore wall of the first support 11 ranges from 70 μm to 80 μm.

[0134] For example, the thickness of the first catalyst 12 on the pore wall of the first support 11 can be 70μm, 72μm, 74μm, 76μm, 78μm or 80μm, etc., and there is no limitation here.

[0135] In some embodiments, the thickness H of the second catalyst 14 on the pore wall of the second support 13 ranges from 70 μm to 80 μm.

[0136] For example, the thickness H of the second catalyst 14 on the pore wall of the second support 13 can be 50 μm, 60 μm, 70 μm, 80 μm, 90 μm or 100 μm, etc., and there is no limitation here.

[0137] In some embodiments, as shown in FIG1, the catalyst 10 includes a first catalytic region C1 and a second catalytic region C2 arranged along a first direction X. The first direction X is the flow direction of the nitrogen oxide gas.

[0138] The first catalytic region C1 is configured with a first support 11 and a first catalyst 12.

[0139] The second catalytic region C2 is configured with: a second support 13 and a second catalyst 14.

[0140] The arrangement of the first catalytic region C1 and the second catalytic region C2 allows the catalyst 10 to perform multiple catalytic functions simultaneously in the reaction system. In other words, the two catalytic regions can be optimized for different stages of the reaction or different reactants, thereby improving the overall reaction efficiency of the catalyst 10. Moreover, the arrangement of the first catalytic region C1 and the second catalytic region C2 also allows for more precise control of the reaction conditions to adapt to the complex or variable reaction environment in the nitrogen oxide gas treatment system 100 or the catalyst device 20.

[0141] In some embodiments, the ratio between the length of the first catalytic region and the length of the second catalytic region ranges from 0.2 to 5. The length direction is the flow direction of the nitrogen oxide gas.

[0142] For example, the ratio between the length of the first catalytic region C1 and the length of the second catalytic region C2 can be 0.2, 1, 2, 3, 4 or 5, etc., and there is no limit here.

[0143] In some embodiments, the ratio of the mass of the first catalyst 12 to the mass of the second catalyst 14 ranges from 0.2 to 5.

[0144] For example, the ratio of the mass of the first catalyst 12 to the mass of the second catalyst 14 can be 0.2, 1, 2, 3, 4 or 5, etc., and there is no limit here.

[0145] In some examples, as shown in Figure 1, the length of the first catalytic region C1 and the length of the second catalytic region C2 are equal.

[0146] By setting the above parameters, the lengths of the two catalytic regions can be adjusted to optimize the overall catalytic performance, enabling the catalyst to maintain high activity under different reaction conditions; it also allows catalyst 10 to maintain good catalytic effect under different operating conditions.

[0147] In some embodiments, when the catalyst 10 in the above embodiments is applied to the nitrogen oxide gas treatment system 100 or the catalyst device 20, the temperature of the inlet end I is relatively high, the first catalytic region C1 of the catalyst 10 is closer to the inlet end I than the second catalytic region C2 of the catalyst 10, and the first catalyst 12 in the first catalytic region C1 has better catalytic performance at higher temperatures. This allows the catalyst 10 to have excellent catalytic activity and stability throughout the entire temperature range (200°C to 700°C).

[0148] Based on the catalyst 10 described above, the following preparation examples and embodiments are provided.

[0149] Preparation Example 1

[0150] Preparation Example 1 provides a copper-based molecular sieve Cu-SSZ-39, in which the mass ratio of copper to Cu-SSZ-39 is 0.013. Cu-SSZ-39 is obtained by the following preparation method:

[0151] A copper nitrate precursor solution was mixed with CHA molecular sieves and stirred until fully dispersed. The mixture was then heated to 80°C and stirred to induce ion exchange for 12 hours. The solution was then filtered, washed, dried, and calcined sequentially. The calcination temperature was 600°C for 4 hours to obtain Cu-SSZ-39.

[0152] Preparation Example 2

[0153] Preparation Example 2 provides a copper-based molecular sieve Cu-SSZ-39, in which the mass ratio of copper to Cu-SSZ-39 is 0.027. Cu-SSZ-39 is obtained by the following preparation method:

[0154] A copper nitrate precursor solution was mixed with CHA molecular sieves and stirred until fully dispersed. The mixture was then heated to 80°C and stirred to induce ion exchange for 8 hours. The solution was then filtered, washed, dried, and calcined sequentially. The calcination temperature was 600°C for 4 hours to obtain Cu-SSZ-39.

[0155] As shown in Figure 7, the reduction peaks at 200℃~300℃ and 400℃~700℃ belong to isolated Cu. 2+ The reduction peak at 300℃~400℃ belongs to CuO. It can be seen that the sum of the integrated area of ​​the reduction peak at 200℃~300℃ and the integrated area of ​​the reduction peak at 400℃~700℃ is much larger than the integrated area of ​​the reduction peak at 300℃~400℃. This means that the number of isolated copper ions is much greater than the number of copper ions in copper oxide. Copper ions in copper oxide only account for a small portion of all copper; most copper exists in the form of isolated copper ions. 2+ The more sites there are, the more active sites there are.

[0156] Preparation Example 3

[0157] Preparation Example 3 provides a copper-based molecular sieve Cu-SSZ-13, in which the mass ratio of copper to Cu-SSZ-13 is 0.027. Cu-SSZ-13 is obtained by the following preparation method:

[0158] A copper nitrate precursor solution was mixed with AEI molecular sieves and stirred until fully dispersed. The mixture was then heated to 80°C and stirred to induce ion exchange for 6 hours. The solution was then filtered, washed, dried, and calcined sequentially. The calcination temperature was 600°C for 4 hours to obtain Cu-SSZ-13.

[0159] As shown in Figure 6, the reduction peaks at 200℃~300℃ and 400℃~700℃ are attributed to isolated Cu. 2+ The reduction peak at 300℃~400℃ belongs to copper ions in CuO. As shown in Figure 6, the sum of the integrated areas of the corresponding reduction peaks for isolated copper ions and copper ions in copper oxide reveals that the sum of the integrated areas of the reduction peaks at 200℃~300℃ and 400℃~700℃ is much larger than the integrated area of ​​the reduction peak at 300℃~400℃. This means that the number of isolated copper ions is much greater than the number of copper ions in copper oxide. Copper ions in copper oxide only constitute a small portion of all copper; most copper exists as isolated copper ions.

[0160] Example 1

[0161] Example 1 provides a catalyst 10, which is obtained by the following preparation method:

[0162] S1 forms the first catalytic region C1: The first catalyst 12, binder (silica sol) and thickener (carboxymethyl cellulose) and defoamer are made into a mixed slurry. One end of the carrier (cyanite honeycomb ceramic) is immersed in the slurry, and then taken out and dried at 100°C for 15 hours.

[0163] S2 forms the second catalytic region C2: The second catalyst 14, binder and defoamer are made into a mixed slurry, the other end of the carrier is immersed in the slurry, and then taken out and dried.

[0164] S3: The carrier impregnated with the slurry was calcined at 550°C for 4 hours to obtain catalyst 10. The thickness of the first catalyst 12 on the carrier is 70 μm, and the thickness of the second catalyst 14 on the carrier is 70 μm. The ratio between the area of ​​the first catalytic region C1 and the area of ​​the second catalytic region C2 is 1.

[0165] The first catalyst 12 is Cu-SSZ-39 prepared in Preparation Example 1. The second catalyst 14 is Cu-SSZ-13 prepared in Preparation Example 3.

[0166] Example 2

[0167] Example 2 provides a catalyst 10, which is prepared in the same way as in Example 1, except that the first catalyst 12 is Cu-SSZ-39 prepared in Preparation Example 2, and the second catalyst 14 is Cu-SSZ-13 prepared in Preparation Example 3.

[0168] Performance testing

[0169] The conversion rate of nitrogen oxides was tested using a catalyst testing platform for fresh and aged samples of catalyst 10 from the example.

[0170] (1) The test conditions were: NO content of 500 PPM and air velocity of 60,000 h⁻¹. -1 The results are shown in Figures 4 and 5.

[0171] (2) The fresh sample was aged to obtain the aged sample. The aging method was to treat the sample at 800℃, 10% water vapor, and normal pressure for 16h.

[0172] (3) The formula for calculating the conversion rate of nitrogen oxides (NOx) is:

[0173] (4) H2-Programmed Temperature Reduction (TPR) Analysis: The AutoChem II 2920 chemisorption analyzer was used. TPR is a technique that involves continuously introducing reducing gas H2 under programmed temperature conditions to cause the active components to undergo a reduction reaction, and measuring the change in the concentration of reducing gas in the outflowing gas to determine its reduction rate.

[0174] As can be seen from Figure 4, the conversion rates of nitrogen oxides by catalyst 10 in Examples 1 and 2 are in the range of 65% to 99% at lower temperatures (200℃ to 400℃), 85% to 99% at medium temperatures (400℃ to 550℃), and 70% to 90% at higher temperatures (550℃ to 700℃). Therefore, the fresh samples of catalyst 10 provided in Examples 1 and 2 have good nitrogen oxide conversion rates in the range of 200℃ to 700℃.

[0175] As shown in Figure 5, the catalysts 10 of Examples 1 and 2 exhibit nitrogen oxide conversion rates ranging from 55% to 99% at lower temperatures (200℃ to 400℃), from 90% to 99% at medium temperatures (400℃ to 550℃), and from 65% to 90% at higher temperatures (550℃ to 700℃). Therefore, the aged samples of catalysts 10 provided in Examples 1 and 2 all demonstrate good nitrogen oxide conversion rates within the temperature range of 200℃ to 700℃.

[0176] Therefore, as can be seen from Figures 4 and 5, within a temperature range of 200℃ to 700℃, the catalyst 10 provided in some embodiments of this disclosure has a good conversion rate for the reduction reaction of nitrogen oxide gas.

[0177] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A catalyst for catalyzing the reduction reaction of nitrogen oxide gas, comprising: Copper element; The copper element includes: isolated copper ions and copper ions present in copper oxide; The number of atoms of the isolated copper ion is greater than the number of atoms of the copper ion in the copper oxide.

2. The catalyst according to claim 1, further comprising: Molecular sieves; The ratio of the mass of copper to the sum of the mass of the molecular sieve and the mass of copper is in the range of 0.01 to 0.

04.

3. The catalyst according to claim 1 or 2, further comprising: A first catalyst and a second catalyst; and the second catalyst is different from the first catalyst.

4. The catalyst according to claim 3, wherein, Within a temperature range of 550℃ to 600℃, the conversion rate of the first catalyst for the reduction reaction of nitrogen oxides is greater than that of the second catalyst.

5. The catalyst according to claim 3 or 4, wherein, The first catalyst includes at least one of AEI-type molecular sieve and CHA-type molecular sieve.

6. The catalyst according to any one of claims 3 to 5, wherein, The first catalyst comprises: Cu-SSZ-39.

7. The catalyst according to claim 6, wherein, The ratio of the mass of copper in Cu-SSZ-39 to the mass of Cu-SSZ-39 ranges from 0.01 to 0.

04.

8. The catalyst according to claim 7, wherein, The ratio of the mass of copper in Cu-SSZ-39 to the mass of Cu-SSZ-39 ranges from 0.01 to 0.

03.

9. The catalyst according to any one of claims 3 to 8, wherein, The second catalyst includes at least one of BEA-type molecular sieves, MFI-type molecular sieves, and CHA-type molecular sieves.

10. The catalyst according to claim 9, wherein, The second catalyst includes Cu-SSZ-13.

11. The catalyst according to claim 10, wherein, The ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 ranges from 0.01 to 0.

04.

12. The catalyst according to claim 11, wherein, The ratio of the mass of copper in Cu-SSZ-13 to the mass of Cu-SSZ-13 ranges from 0.01 to 0.

03.

13. The catalyst according to any one of claims 1 to 12, further comprising: The catalyst is disposed on the support.

14. The catalyst according to claim 13, wherein, The carrier includes: porous ceramic material.

15. The catalyst according to claim 13 or 14, wherein, The carrier includes a first carrier and a second carrier, wherein a first catalyst is disposed on the first carrier and a second catalyst is disposed on the second carrier.

16. The catalyst according to claim 15, further satisfying at least one of the following: The first support has a porous structure, and the first catalyst is at least partially disposed on the pore wall of the first support, the thickness of the first catalyst on the pore wall of the first support ranging from 50 μm to 100 μm; and The second support has a porous structure, and the second catalyst is at least partially disposed on the pore wall of the second support, with the thickness of the second catalyst on the pore wall of the second support ranging from 50 μm to 100 μm.

17. The catalyst according to claim 16, further satisfying at least one of the following: The thickness of the first catalyst on the pore walls of the first support ranges from 70 μm to 80 μm; and The thickness of the second catalyst on the pore wall of the second support ranges from 70 μm to 80 μm.

18. The catalyst according to any one of claims 15 to 17, wherein, The catalyst includes a first catalytic region and a second catalytic region arranged along a first direction; the first direction is the flow direction of the nitrogen oxide gas. The first catalytic region comprises the first support and the first catalyst; The second catalytic region has the second support and the second catalyst.

19. The catalyst according to claim 18, further satisfying at least one of the following: The ratio of the length of the first catalytic region to the length of the second catalytic region ranges from 0.2 to 5; the length direction is the flow direction of the nitrogen oxide gas; and The ratio of the mass of the first catalyst to the mass of the second catalyst is in the range of 0.2 to 5.

20. The catalyst according to any one of claims 1 to 19, wherein, The catalyst is used in a nitrogen oxide gas treatment system.

21. The catalyst according to claim 20, wherein, The catalyst includes a first catalytic region and a second catalytic region. The first catalytic region includes a first catalyst, and the second catalytic region includes a second catalyst. The first catalytic region is closer to the inlet of the nitrogen oxide gas treatment system than the second catalytic region.

22. An engine, comprising: A catalyst device, the catalyst device comprising a housing, the housing having a receiving cavity, the receiving cavity being provided with a catalyst according to any one of claims 1 to 19.

23. The engine according to claim 22 further includes an engine body and a plurality of exhaust pipes, the plurality of exhaust pipes being connected end to end and connected to the engine body, and the catalyst device being disposed between the plurality of exhaust pipes to treat nitrogen oxides emitted by the engine.

24. The engine according to claim 23, wherein, An ammonia generating component is also provided between the plurality of exhaust pipes, and the ammonia generating component is located upstream of the catalyst device in the direction of nitrogen oxide gas flow. The ammonia generating component is configured to generate ammonia, and the catalyst device is configured to accelerate the reaction of nitrogen oxides and ammonia.

25. The engine according to claim 24, wherein, The ammonia generating component includes an ammonia generating catalyst assembly configured to catalytically convert nitrogen oxides into ammonia.

26. The engine according to claim 24, wherein, The ammonia generating component includes a urea injection device configured to provide an aqueous urea solution to generate ammonia.

27. A vehicle comprising one of the following: Oxide gas treatment system, wherein the nitrogen oxide gas treatment system comprises a catalyst according to any one of claims 1 to 19; or The engine according to any one of claims 22 to 26.

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