Catalytic converter, manufacturing method thereof, tail gas treatment system and vehicle

Abstract

The invention discloses a catalyst, a manufacturing method thereof, a tail gas treatment system and a vehicle. The catalyst comprises a molecular sieve catalyst and a microwave receptor, and the microwave receptor is suitable for absorbing microwave radiation energy to rise temperature. The catalyst provided by the invention can solve the problems of high cost and low catalytic efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of exhaust gas treatment, and in particular to a catalyst and a manufacturing method thereof, an exhaust gas treatment system and a vehicle. Background Art

[0002] At present, in order to improve the thermal efficiency and economy of fuel, many car companies have chosen the lean-burn mode for fuel vehicle engines. In the lean-burn state, the air / fuel ratio inhaled by the car engine is higher, and the oxygen content in the cylinder is high, so the fuel can be fully burned, and the CO and hydrocarbon emissions in the exhaust are reduced. However, due to the increase in the intake of oxygen, the conventional three-way catalytic converter will be oxygen poisoned, which will increase the NO x The catalytic treatment efficiency of the gas decreases, causing NO x The gas content further increased. Therefore, it is urgent to x New solutions are proposed for gas processing to adapt to the promotion and application of lean-burn engines. Summary of the invention

[0003] The purpose of the present invention is to provide a catalyst and a manufacturing method thereof, an exhaust gas treatment system and a vehicle, so as to solve the problems of high catalyst cost and low catalytic efficiency.

[0004] To achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides a catalyst, comprising a molecular sieve catalyst and a microwave receptor, wherein the microwave receptor is suitable for absorbing microwave radiation energy and raising its temperature.

[0006] In one embodiment, the molecular sieve catalyst includes a zeolite molecular sieve and metal ions bound to the zeolite molecular sieve.

[0007] In one embodiment, the molecular sieve catalyst further includes silicon and aluminum, and the molar ratio of silicon to aluminum is (30-70):1.

[0008] In one embodiment, the microwave receptor comprises a first metal oxide.

[0009] In one embodiment, the first metal oxide includes one or more of NiO2, MnO2 and CoO.

[0010] In one embodiment, the mass ratio of the molecular sieve catalyst to the microwave receptor is 10:(1-7).

[0011] In one embodiment, the catalyst further comprises a carrier, and the molecular sieve catalyst and the microwave receptor are both loaded on the surface of the carrier.

[0012] In one embodiment, the material of the carrier includes one or more of cordierite, silicon carbide, and metal.

[0013] In one embodiment, the catalyst further comprises one or more of a coating substrate, a thermal stabilizer, and an oxygen storage material, and the coating substrate, the thermal stabilizer, and the oxygen storage material are loaded on the surface of the carrier.

[0014] In one embodiment, the coating substrate includes a second metal oxide, the thermal stabilizer includes a third metal oxide, and the oxygen storage material includes a fourth metal oxide; the first metal oxide, the second metal oxide, the third metal oxide, and the fourth metal oxide are not all the same.

[0015] In one embodiment, the second metal oxide comprises γ-Al2O3.

[0016] In one embodiment, the third metal oxide includes La2O3 and / or Y2O3.

[0017] In one embodiment, the fourth metal oxide includes CeO2 and / or ZrO2.

[0018] In one embodiment, when the catalyst further includes the coating substrate, the heat stabilizer, and the oxygen storage material, the mass ratio of the coating substrate, the heat stabilizer, and the oxygen storage material is 100:(0.05-5):(0.05-5).

[0019] In one embodiment, the catalyst includes a first coating and a second coating, the first coating is arranged on the surface of the carrier, and the second coating is arranged on the side of the first coating facing away from the carrier, the first coating includes one or more of the coating substrate, the thermal stabilizer, and the oxygen storage material, and the second coating includes the molecular sieve catalyst and the microwave receptor.

[0020] In a second aspect, the present invention provides a method for manufacturing a catalyst, comprising: preparing an active slurry from a molecular sieve catalyst and a precursor of a microwave receptor; obtaining the catalyst after drying the active slurry; wherein the precursor of the microwave receptor is converted into a microwave receptor, and the microwave receptor is suitable for absorbing microwave radiation energy and raising its temperature.

[0021] In one embodiment, after the precursors of the molecular sieve catalyst and the microwave receptor are made into active slurry, the method further comprises: placing a carrier into the active slurry so that the precursors of the molecular sieve catalyst and the microwave receptor are loaded on the surface of the carrier.

[0022] In one embodiment, before placing the carrier into the active slurry, it also includes: making one or more of the coating substrate, the heat stabilizer, and the oxygen storage material into a coating slurry; placing the carrier into the coating slurry, and obtaining a composite carrier after drying and roasting; wherein the composite carrier is loaded with one or more of the coating substrate, the heat stabilizer, and the oxygen storage material.

[0023] In a third aspect, the present invention provides an exhaust gas treatment system, the exhaust gas treatment system comprising the catalyst as described in the first aspect, or the exhaust gas treatment system comprising the catalyst manufactured by the manufacturing method as described in the second aspect.

[0024] In a fourth aspect, the present invention provides a vehicle, comprising the exhaust gas treatment system as described in the third aspect.

[0025] The catalyst provided by the present invention comprises a carrier, a molecular sieve catalyst and a microwave receptor loaded on the carrier, and has the following advantages: the microwave receptor is mixed with the molecular sieve catalyst, and the catalyst can be quickly heated under microwave radiation to achieve a more uniform catalyst bed temperature, thereby increasing NO x Catalytic degradation efficiency of gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a schematic cross-sectional view of a carrier, a first coating layer, and a second coating layer on a catalyst according to an embodiment;

[0028] Figure 2 The present invention is a process for preparing a molecular sieve catalyst and a microwave receptor on a catalyst in an embodiment;

[0029] Figure 3 A preparation process of a coating substrate, a thermal stabilizer, and an oxygen storage material on a catalyst in an implementation manner;

[0030] Figure 4 It is the electron microscope picture of the catalyst at different steps in Example 1. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there can be a central component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there can be a central component at the same time.

[0033] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0034] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0035] The present invention provides a catalyst for catalytically decomposing harmful exhaust gas, which can be specifically applied to vehicles to catalytically decompose nitrogen oxides (NO x ) gas. Optionally, the catalyst provided by the present invention can solve the problem of (NO x )The problem of difficulty in gas removal.

[0036] In one embodiment, the catalyst includes a carrier, a molecular sieve catalyst and a microwave receptor. The molecular sieve catalyst and the microwave receptor are both loaded on the surface of the carrier. The microwave receptor is suitable for absorbing microwave radiation energy and raising its temperature. The microwave receptor includes a first metal oxide.

[0037] Specifically, the carrier is the main substrate for loading molecular sieve catalysts and microwave receptors; the molecular sieve catalyst is used to catalyze NO x gas decomposition, and the molecular sieve catalyst has a high xThe efficiency of direct catalytic decomposition of the gas; the microwave receptor can absorb microwave radiation energy and rapidly increase the temperature, thereby further improving the catalytic efficiency of the molecular sieve catalyst, wherein "rapid temperature increase" means that the temperature increase rate is faster than that without absorbing microwave radiation energy. Microwave refers to electromagnetic waves of 300MHz-300GHz, and the microwave used in the present invention is 2000MHz-5000MHz, preferably 2450MHz.

[0038] Some studies have suggested that wastewater or contaminated soil can effectively degrade and remove organic pollutants under microwave radiation. However, as an inorganic ceramic, molecular sieve catalysts do not absorb microwave radiation. Therefore, if you want to improve their catalytic efficiency under microwave radiation, you must first enhance their microwave absorption capacity. Therefore, by loading molecular sieve catalysts and microwave receptors on the carrier at the same time, the microwave receptors can absorb microwaves to improve the catalytic efficiency of molecular sieve catalysts.

[0039] Optionally, the molecular sieve catalyst and the microwave receptor may be prepared as a homogeneous mixture and then loaded onto the surface of the carrier together. Alternatively, in other embodiments, the molecular sieve catalyst may be loaded onto the surface of the carrier first and then the microwave receptor may be loaded onto the molecular sieve catalyst.

[0040] The catalyst provided by the present invention includes a carrier, a molecular sieve catalyst loaded on the carrier, and a microwave receptor, and has the following advantages: 1) the catalyst does not involve the use of precious metals (precious metals include Pt, Pd, Rh, etc.), which can reduce the catalytic decomposition of NO x 1) The microwave receptor and the molecular sieve catalyst are mixed and loaded on the carrier. Under microwave radiation, the catalyst can be heated up quickly to achieve a more uniform catalyst bed temperature, thereby increasing NO x The catalytic degradation efficiency of the gas; 3) Using a carrier to carry the molecular sieve catalyst and the microwave receptor can improve the thermal stability and mechanical properties of the catalyst and make it more resistant to vibration.

[0041] In one embodiment, the carrier may be a honeycomb porous structure, so that the carrier may have a high specific surface area, so that as much molecular sieve catalyst and microwave receptor as possible can be loaded, and a large specific surface area is also conducive to the carrier and NO x Gas contact, thereby improving the catalytic efficiency of the molecular sieve catalyst.

[0042] In one embodiment, the material of the carrier includes one or more of cordierite, silicon carbide, molecular sieve carrier, and honeycomb metal. It is understandable that the above materials all have high thermal stability and mechanical vibration resistance. Using the above materials as carriers can improve the stability of the catalyst used in the vehicle and prevent the catalyst from being cracked by heat or damaged by external force.

[0043] In one embodiment, the molecular sieve catalyst includes ZSM-5 zeolite molecular sieve, and metal ions bound to the ZSM-5 zeolite molecular sieve.

[0044] Specifically, ZSM-5 is a kind of catalyst that directly decomposes NO at low temperature. x The catalyst with the best gas activity has a uniform pore size in the molecular sieve structure and NO x The aerodynamic diameters are similar, which is favorable for NO x Adsorption and desorption of gases.

[0045] However, NO is NO in vehicle exhaust. x The main component of the gas, accounting for 90-95%. At present, the catalytic degradation efficiency of ZSM-5 for NO is still not enough to meet the national standards for exhaust emissions, and the thermal stability of the molecular sieve also has certain problems under the high temperature of the exhaust gas.

[0046] Therefore, metal ions can be bound to ZSM-5, and such metal ions can be non-noble metal ions.

[0047] Optionally, a static seed cultivation method and a method for controlling the ratio of silicon source to aluminum source are used to prepare a molecular sieve ZSM-5 with a suitable silicon-aluminum ratio, and ion exchange is carried out between the molecular sieve ZSM-5 and a transition metal ion nitrate with a variable valence to obtain M-ZSM-5 with a metal ion exchange degree higher than a certain level.

[0048] Optionally, the molecular sieve catalyst may be one or both of Fe-ZSM-5 and Cu-ZSM-5; therefore, the metal ions bound to the ZSM-5 zeolite molecular sieve may be iron ions or copper ions. The metal ions bound to the zeolite molecular sieve may increase the catalytic activity of the molecular sieve catalyst, so that the molecular sieve catalyst has a higher catalytic activity.

[0049] In one embodiment, the molecular sieve catalyst also includes silicon and aluminum, and the molar ratio of silicon to aluminum is (30-70):1. Specifically, the loading amount of metal ions in the molecular sieve catalyst is 1%-5%. Optionally, the silicon-aluminum molar ratio in the molecular sieve catalyst can be 30:1, 40:1, 50:1, 60:1, 70:1. The loading amount of metal ions in the molecular sieve catalyst can be 1%, 2%, 3%, 4%, 5%. Meeting the above molar ratios can regulate the metal loading amount in the molecular sieve catalyst.

[0050] In one embodiment, the first metal oxide includes one or more of NiO2, MnO2 and CoO.

[0051] Specifically, the first metal oxide has a high microwave absorption capacity, and nickel oxide, manganese oxide or cobalt oxide is used as a microwave receptor to absorb microwave radiation to cause a "hot spot effect", which quickly increases the bed temperature of the molecular sieve catalyst and increases NO x degradation reaction efficiency.

[0052] Optionally, in order to ensure that the molecular sieve catalyst has good microwave receiving ability, one or more first metal oxides can be mixed and sintered with M-ZSM-5 to obtain KM-ZSM-5 (K is the first metal oxide in the above, and M is the metal ion in the above). The temperature can be increased to 550° C. under a microwave radiation power of 300 W, and after long-term hydrothermal aging, the molecular sieve catalyst does not undergo obvious aggregation.

[0053] In one embodiment, the mass ratio of the molecular sieve catalyst to the microwave receptor is 10:(1-7). Optionally, the mass ratio of the molecular sieve catalyst to the microwave receptor may be 10:1, 10:2, 10:3, 10:4, 10:5, 10:6, 10:7. The mass ratio of the molecular sieve catalyst to the microwave receptor is met, so that the mass proportion of the microwave receptor remains high, and rapid heating can be achieved.

[0054] In one embodiment, the catalyst further includes one or more of a coating substrate, a heat stabilizer, and an oxygen storage material, and the coating substrate, the heat stabilizer, and the oxygen storage material are loaded on the surface of the carrier; the coating substrate includes a second metal oxide, the heat stabilizer includes a third metal oxide, and the oxygen storage material includes a fourth metal oxide; the first metal oxide, the second metal oxide, the third metal oxide, and the fourth metal oxide are not all the same.

[0055] Specifically, the microwave receptor, coating substrate, thermal stabilizer, and oxygen storage material provided in the present invention are all metal oxides, and the four metal oxides are of different types and have different functions.

[0056] In one embodiment, the second metal oxide includes γ-Al2O3. The coating substrate can be used as a substrate coating for a catalyst, the coating substrate can be directly connected to a carrier, and the coating substrate thermal stabilizer, oxygen storage material, molecular sieve catalyst and microwave receptor can all be combined on the coating substrate, so the coating substrate has the characteristics of high specific surface area, high temperature resistance and strong connectivity.

[0057] In one embodiment, the third metal oxide includes La2O3 and / or Y2O3. The heat stabilizer is used to improve the stability of the catalyst in the high-temperature exhaust environment of the vehicle, so the heat stabilizer needs to have good compatibility with the molecular sieve catalyst and high-temperature stability, so that the catalyst can be applied to the high-temperature environment of the vehicle exhaust. At the same time, the above third metal oxide is also conducive to inhibiting the growth of grain size, maintaining the morphological stability and good dispersion of other materials, and preventing aggregation.

[0058] In one embodiment, the fourth metal oxide includes CeO2 and / or ZrO2. The oxygen storage material is used to convert part of the oxygen into lattice oxygen. The oxygen storage material increases the operating window of the catalyst in the oxygen-rich state and improves the NOx reduction in the lean combustion state. x The efficiency of gas removal catalysis. Optionally, the oxygen storage material can be uniformly mixed with a thermal stabilizer, so as to stabilize the structure of the oxygen storage material with the thermal stabilizer and improve the thermal stability of the oxygen storage material. Optionally, the oxygen storage material uses CeO2 and ZrO2, and CeO2 and ZrO2 are coated on the outer surface of the carrier by a co-precipitation method.

[0059] In one embodiment, when the catalyst further comprises a coating substrate, a heat stabilizer, and an oxygen storage material, the mass ratio of the coating substrate, the heat stabilizer, and the oxygen storage material is 100:(0.05-5):(0.05-5). Optionally, the mass ratio of the above materials can be 100:(0.05-5):0.05, 100:(0.05-5):0.1, 100:(0.05-5):0.5, 100:(0.05-5):1, 100:(0.05-5):5, 100:0.05:(0.05-5), 100:0.1:(0.05-5), 100:0.5:(0.05-5), 100:1:(0.05-5), 100:5:(0.05-5). The above mass ratio of heat stabilizer and oxygen storage material is met. The heat stabilizer can prevent the coating substrate from being damaged during overheating during microwave heating, thereby improving its thermal stability and morphological stability.

[0060] In one implementation, please refer to Figure 1 The catalyst includes a first coating 20 and a second coating 30. The first coating 20 is arranged on the surface of the carrier 10, and the second coating 30 is arranged on the side of the first coating 20 facing away from the carrier 10. The first coating 20 includes one or more of a coating substrate, a thermal stabilizer, and an oxygen storage material, and the second coating 30 includes a molecular sieve catalyst and a microwave receptor.

[0061] Specifically, based on the above embodiment, the surface of the carrier 10 can have a two-layer structure, wherein the first coating 20 is composed of a coating substrate, a thermal stabilizer, and an oxygen storage material, and the above three materials can be mixed and first made on the surface of the carrier 10; the second coating 30 is composed of a catalyst carrier 10 and a microwave receptor, and the above two materials can be mixed and then made on the surface of the first coating 20.

[0062] Of course, in other embodiments, a thermal stabilizer may also be added to the second coating layer 30 , that is, the second coating layer 30 includes a catalyst carrier 10 , a microwave receptor and a thermal stabilizer.

[0063] Optionally, in order to ensure that the molecular sieve catalyst and microwave receptor (KM-ZSM-5) in the second coating 30 can have high thermal stability to adapt to the high temperature environment of vehicle exhaust, one or more thermal stabilizers (La2O3, Y2O3) in the above embodiment can be mixed and sintered with the oxygen storage material to obtain the first coating 20 on the surface of the carrier 10 in advance, so as to improve thermal stability. In addition, the metal in the above thermal stabilizer is a trivalent rare earth metal ion, which can improve the oxygen vacancy density and oxygen species diffusion rate of the oxygen storage material.

[0064] In one embodiment, the present invention also provides a method for making a catalyst, please refer to Figure 2 , including the following steps:

[0065] Step S10, preparing the precursors of the molecular sieve catalyst and the microwave receptor into an active slurry.

[0066] Step S20, the active slurry is dried to obtain a catalyst.

[0067] The precursor of the microwave receptor is converted into the microwave receptor, and the microwave receptor is suitable for absorbing microwave radiation energy and raising its temperature.

[0068] Optionally, in step S10, the precursors of the molecular sieve catalyst and the microwave receptor are made into an active slurry, specifically comprising:

[0069] Preparation of H-ZSM-5 (zeolite molecular sieve): Stir the aluminum source (sodium aluminate) and the template (N,N,N-trimethyl-1-adamantyl ammonium hydroxide) in deionized water until completely dissolved, then quickly add the silicon source (tetraethyl orthosilicate) under rapid stirring, and stir for 5h to 8h to completely dissolve the silicon source. Then move the mixture into a homogeneous reactor at 170°C for static crystal cultivation for 48h to 96h. The obtained product is washed with deionized water, dried and baked at 550°C for 5h to 8h in a nitrogen atmosphere to obtain H-ZSM-5.

[0070] Preparation of M-ZSM-5: H-ZSM-5 is subjected to ion exchange in 0.01mol / L to 0.1mol / L ammonium nitrate solution for 24h to 72h, then washed with deionized water and dried, and the obtained NH4-ZSM-5 is added to 0.05mol / L to 0.1mol / L nitrate solution (which can be copper nitrate or iron nitrate), stirred at 40℃ to 60℃ for ion exchange for 24h, and finally filtered, washed and dried, and calcined at 550℃ for 6h to 8h to obtain M-ZSM-5. The copper ion concentration in M-ZSM-5 can be adjusted by adjusting the molar concentration of nitrate and the time of ion exchange.

[0071] Optionally, the template agent may also be ammonium salts such as n-butylamine, isopropylamine, ethylenediamine, ethanolamine, tetraethylammonium salt, tetramethylethyldiamine, diisopropylamine, etc.

[0072] Optionally, the nitrate may also be nickel nitrate, manganese nitrate, cobalt nitrate, etc.

[0073] Optionally, the molar concentration of nitrate is increased to 0.08 mol / L and the ion exchange time is extended to 36 h, so that the copper ion exchange degree of the prepared M-ZSM-5 is 90%.

[0074] Preparation of active slurry of screening catalyst and precursor of microwave receptor: M-ZSM-5, nitrates corresponding to different metal ions (precursor of microwave receptor) and a small amount of glacial acetic acid are mixed in a proper amount of deionized water and dissolved to prepare active slurry.

[0075] Optionally, the mass ratio of M-ZSM-5 to the precursor of the microwave receptor may be 10:(1-7), and the solid content of the active slurry may be 20%-40%.

[0076] Optionally, in step S20, after the precursors of the molecular sieve catalyst and the microwave receptor are made into active slurry, the process further includes: placing a carrier into the active slurry so that the precursors of the molecular sieve catalyst and the microwave receptor are loaded on the surface of the carrier.

[0077] The carrier is inserted into the active slurry in a vertical manner through the channels, and after being evenly coated, it is taken out, placed at room temperature for 2h to 3h, and then placed in a 95°C oven to dry overnight, and then calcined at 550°C for 4h to 5h to obtain a catalyst.

[0078] In one embodiment, before placing the carrier into the active slurry, refer to Figure 3 , including the following steps:

[0079] Step S01, preparing a coating slurry from one or more of a coating substrate, a heat stabilizer, and an oxygen storage material.

[0080] Step S02, placing the carrier into the coating slurry, drying and calcining to obtain a composite carrier.

[0081] The composite carrier is loaded with one or more of a coating substrate, a thermal stabilizer, and an oxygen storage material.

[0082] Optionally, in step S01, one or more of the coating substrate, the heat stabilizer, and the oxygen storage material are made into a coating slurry, specifically comprising:

[0083] Preparation of coating substrate: dissolve a certain amount of pseudo-boehmite with 1 mol / L HNO3 at 85°C, slowly add HNO3 until it becomes a translucent sol, and control the amount of pseudo-boehmite and nitric acid solution added until the aluminum oxide content is 5%.

[0084] Preparation of a mixture of a heat stabilizer and an oxygen storage material: Take an appropriate amount of cerium nitrate, zirconium nitrate and a trace amount of lanthanum nitrate, mix them with citric acid to form a solution of a certain concentration, control the amount of citric acid added until it is completely dissolved, continue stirring at 80°C to form a gel, and then dry. Then place the gel solution in a muffle furnace and roast it at 500°C for 5h to 6h to obtain a mixed powder of a heat stabilizer and an oxygen storage material (CeO2-ZrO2-La2O3).

[0085] Optionally, the molar ratio of cerium nitrate: zirconium nitrate: lanthanum nitrate can be (3-7): (1-3): (0.03-0.05), preferably 7: 3: 0.05. When the molar ratio of cerium nitrate, zirconium nitrate and lanthanum nitrate is within the above range, the catalyst can be ensured to have relatively excellent thermal stability.

[0086] Prepare coating slurry of coating substrate, heat stabilizer and oxygen storage material: mix a certain amount of aluminum sol (alumina content is 5%), a small amount of glacial acetic acid (50%, 10ml) and ground mixed powder (CeO2-ZrO2-La2O3) evenly, wherein; the mass of aluminum sol is 1000g, the mixed powder (CeO2-ZrO2-La2O3) is 5g, and then add appropriate amount of deionized water 200ml; then stir evenly in a high-speed stirrer to obtain a sol-like coating slurry.

[0087] Optionally, the mass ratio of the coating substrate to the mixed powder (CeO2-ZrO2-La2O3) is 10:(1-2). When the mass ratio of the coating substrate to the mixed powder is within the above range, the catalyst can be ensured to have relatively excellent thermal stability.

[0088] Optionally, in step S02, the carrier is placed in the coating slurry, and dried and calcined to obtain a composite carrier, which specifically includes:

[0089] The carrier is inserted into the coating slurry in a vertical manner through the hole, and after being evenly coated, it is taken out, placed at room temperature for 2h to 3h, and then placed in a 95°C oven for overnight drying, and then calcined at 550°C for 4h to 5h to obtain a composite carrier with a first coating. The first coating includes a coating substrate, a heat stabilizer, and an oxygen storage material.

[0090] In one embodiment, the method for manufacturing a catalyst further includes treating a carrier, and the specific steps are as follows:

[0091] The carrier is prepared into a cylinder with a diameter slightly smaller than that of the direct-current ceramic tube, and then immersed in 0.01mol / L to 0.1mol / L nitric acid for 8h to 10h to remove surface stains, and then immersed in deionized water for 8h to 10h, and then dried at 95°C or vacuum dried at 65°C.

[0092] In one embodiment, the present invention further provides an exhaust gas treatment system, the exhaust gas treatment system includes the catalyst provided above, or the exhaust gas treatment system includes the catalyst manufactured by the manufacturing method provided above.

[0093] In one embodiment, the present invention further provides a vehicle, which includes the above-mentioned exhaust gas treatment system.

[0094] The technical solution of the present invention is described in detail below through specific embodiments.

[0095] Example 1

[0096] This embodiment 1 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2-Cu-ZSM-5).

[0097] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10: 1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to NiO2 is 6:4.

[0098] The production method of the catalyst is as follows, please refer to Figure 4 :

[0099] 1) Commercially available cordierite (600 cell / inch) was prepared into a cylinder with a diameter slightly smaller than that of the direct current ceramic tube, and then immersed in 0.5 mol / L nitric acid for 9 h to remove surface stains, and then immersed in deionized water for 9 h, and then dried at 95°C.

[0100] 2) Dissolve the pseudo-boehmite with 1 mol / L HNO3 at 85°C, slowly add HNO3 until it becomes a translucent sol, and control the amount of pseudo-boehmite and nitric acid solution added until the alumina content is 5%.

[0101] 3) Take cerium nitrate, zirconium nitrate and lanthanum nitrate (molar ratio of 7:3:0.05), mix with citric acid to form a solution, control the amount of citric acid added until it is completely dissolved, continue to stir at 80°C to form a gel, and then dry. Then place the gel solution in a muffle furnace and calcine at 500°C for 5h to obtain a mixed powder of heat stabilizer and oxygen storage material (CeO2-ZrO2-La2O3).

[0102] 4) Mix the aluminum sol (aluminum oxide content is 5%) in step 2), glacial acetic acid (50%, 10ml) and the ground mixed powder (CeO2-ZrO2-La2O3) evenly, wherein; the mass of aluminum sol is 1000g, the mixed powder (CeO2-ZrO2-La2O3) is 5g, and then add appropriate amount of deionized water 200ml; then stir evenly in a high-speed stirrer to obtain a sol-like coating slurry.

[0103] 5) The treated cordierite is inserted into the coating slurry in a vertical manner through the hole, and after being evenly coated, it is taken out, placed at room temperature for 3 hours, and then placed in a 95°C oven to dry overnight, and then calcined at 550°C for 5 hours to obtain the cordierite with the first coating.

[0104] 6) Sodium aluminate and N,N,N-trimethyl-1-adamantyl ammonium hydroxide were stirred in deionized water until completely dissolved, and the silicon source tetraethyl orthosilicate was quickly added under rapid stirring, and stirred for 6 hours to completely dissolve the silicon source. The mixture was then transferred to a homogeneous reactor at 170°C for static crystal cultivation for 72 hours, and the obtained product was washed with deionized water, dried and baked at 550°C for 4 hours in a nitrogen atmosphere to obtain H-ZSM-5.

[0105] 7) The H-ZSM-5 was subjected to ion exchange in a 0.05 mol / L ammonium nitrate solution for 36 h, then washed with deionized water and dried, and the obtained NH4-ZSM-5 was added to a 0.05 mol / L copper nitrate solution, stirred at 50°C for ion exchange for 36 h, and finally filtered, washed, dried, and calcined at 550°C for 7 h to obtain Cu-ZSM-5 (Cu 2+ The exchange rate is 40%).

[0106] 8) Cu-ZSM-5 and nickel nitrate are mixed and dissolved to prepare an active slurry.

[0107] 9) The cordierite obtained in step 5) is impregnated into the active slurry, and after drying, it is impregnated multiple times, and then calcined at 550° C. to obtain a catalyst.

[0108] Example 2

[0109] This embodiment 2 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (MnO2-Cu-ZSM-5).

[0110] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10: 1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to MnO2 is 6:4.

[0111] The difference between the manufacturing method of the catalyst of Example 2 and Example 1 is that: Step 8) Cu-ZSM-5 and manganese nitrate are mixed and dissolved to form an active slurry.

[0112] Example 3

[0113] This embodiment 3 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2-Cu-ZSM-5).

[0114] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10: 1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to NiO2 is 6:4.

[0115] The difference between the preparation method of the catalyst of Example 3 and Example 1 is that: Step 7) H-ZSM-5 is subjected to ion exchange in 0.1 mol / L ammonium nitrate solution for 36 h, then washed with deionized water and dried, the obtained NH4-ZSM-5 is added to 0.05 mol / L copper nitrate solution, stirred at 50°C for ion exchange for 36 h, finally filtered, washed and dried, and calcined at 550°C for 7 h to obtain Cu-ZSM-5 (Cu 2+ The exchange degree is 90%).

[0116] Example 4

[0117] This embodiment 4 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (MnO2-Cu-ZSM-5).

[0118] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10: 1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to MnO2 is 6:4.

[0119] The difference between the preparation method of the catalyst of Example 4 and Example 3 is that: Step 7) H-ZSM-5 is subjected to ion exchange in 0.1 mol / L ammonium nitrate solution for 36 h, then washed with deionized water and dried, the obtained NH4-ZSM-5 is added to 0.05 mol / L copper nitrate solution, stirred at 50°C for ion exchange for 36 h, finally filtered, washed and dried, and calcined at 550°C for 7 h to obtain Cu-ZSM-5 (Cu 2+ The exchange degree is 90%).

[0120] Example 5

[0121] This embodiment 5 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2 / La2O3-Cu-ZSM-5).

[0122] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10:1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5, NiO2, and La2O3 is 6:4:0.02.

[0123] The difference between the manufacturing method of the catalyst of Example 5 and Example 1 is that: Step 8) Cu-ZSM-5, nickel nitrate and a trace amount of lanthanum nitrate are mixed and dissolved to form an active slurry.

[0124] Example 6

[0125] This embodiment 6 provides a catalyst, including a carrier (silicon carbide), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2-Cu-ZSM-5).

[0126] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10: 1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to NiO2 is 6:4.

[0127] The difference between the manufacturing method of the catalyst of Example 6 and Example 1 is that: Step 1) prepare commercially available silicon carbide into a cylinder with a diameter slightly smaller than that of the direct-current ceramic tube, then soak it in 0.5 mol / L nitric acid for 9 hours to remove surface stains, then soak it in deionized water for 9 hours, and then dry it at 95°C.

[0128] Example 7

[0129] This embodiment 7 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2-Cu-ZSM-5).

[0130] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10:1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to NiO2 is 9:1.

[0131] The manufacturing method of the catalyst of this embodiment 7 is the same as that of embodiment 1.

[0132] Example 8

[0133] This embodiment 8 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2-Cu-ZSM-5).

[0134] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10:2. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to NiO2 is 6:4.

[0135] The manufacturing method of the catalyst of this embodiment 8 is the same as that of embodiment 1.

[0136] Example 9

[0137] This embodiment 9 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (NiO2-H-ZSM-5).

[0138] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10: 1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40; the mass ratio of Cu-ZSM-5 to NiO2 is 6:4.

[0139] The difference between the method for manufacturing the catalyst of this embodiment 9 and that of embodiment 1 is that there is no step 7).

[0140] Comparative Example 1

[0141] This comparative example 1 provides a catalyst, including a carrier (cordierite), a first coating (γ-Al2O3-CeO2 / ZrO2-La2O3), and a second coating (Cu-ZSM-5).

[0142] In the first coating, the mass ratio of γ-Al2O3 to CeO2 / ZrO2-La2O3 is 10:1. In the second coating, the silicon-aluminum ratio of ZSM-5 is 40.

[0143] The difference between the preparation method of the catalyst of this comparative example 1 and that of the embodiment 1 is that there is no step 8).

[0144] Comparative Example 2

[0145] This comparative example 2 provides a catalyst, including a carrier (cordierite) and Cu-ZSM-5.

[0146] Among them, the silicon-to-aluminum ratio of ZSM-5 is 40.

[0147] The difference between the preparation methods of the catalysts of Comparative Example 2 and Example 1 is that no first layer is prepared, and Cu-ZSM-5 is directly loaded onto cordierite.

[0148] The catalysts obtained in Examples 1-9 and Comparative Examples 1-2 were placed under 300W microwave radiation to rapidly heat the catalysts and obtain the temperature rise data in Table 1. The temperature rise test method in Table 1 includes: using a precision infrared thermometer to monitor the temperature rise process and record the temperature after stabilization.

[0149] Table 1

[0150]

[0151]

[0152] From the test results of Examples 1-9 and Comparative Examples 1-2 in Table 1, it can be seen that the temperature rise values ​​of the Examples are significantly greater than those of the Comparative Examples, indicating that the catalyst provided by the present invention can quickly heat up the catalyst under microwave radiation to achieve a more uniform catalyst bed temperature, thereby accelerating the catalytic degradation of NO x This also illustrates that the solution provided by the present invention can solve the problem of high catalyst cost and low catalytic efficiency.

[0153] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship of terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" are based on the orientation or positional relationship described in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0154] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A catalyst, characterized in that: The invention comprises a molecular sieve catalyst and a microwave receptor, wherein the microwave receptor is suitable for absorbing microwave radiation energy and raising its temperature.

2. The catalyst according to claim 1, characterized in that The molecular sieve catalyst includes a zeolite molecular sieve and metal ions bound to the zeolite molecular sieve.

3. The catalyst according to claim 1, characterized in that The molecular sieve catalyst also includes silicon and aluminum, and the molar ratio of the silicon to the aluminum is (30-70):

1.

4. The catalyst according to claim 1, characterized in that The microwave receptor includes a first metal oxide.

5. The catalyst according to claim 4, characterized in that The first metal oxide includes one or more of NiO2, MnO2 and CoO.

6. The catalyst according to claim 1, characterized in that The mass ratio of the molecular sieve catalyst to the microwave receptor is 10:(1-7).

7. The catalyst according to claim 1, characterized in that The catalyst further comprises a carrier, which is a honeycomb porous structure, and the molecular sieve catalyst and the microwave receptor are both loaded on the surface of the carrier.

8. The catalyst according to claim 7, characterized in that The material of the carrier includes one or more of cordierite, silicon carbide, and metal.

9. The catalyst according to claim 7, characterized in that The catalyst further comprises one or more of a coating substrate, a thermal stabilizer, and an oxygen storage material, and the coating substrate, the thermal stabilizer, and the oxygen storage material are loaded on the surface of the carrier.

10. The catalyst according to claim 9, characterized in that The coating substrate includes a second metal oxide, the thermal stabilizer includes a third metal oxide, and the oxygen storage material includes a fourth metal oxide; the second metal oxide, the third metal oxide, and the fourth metal oxide are not all the same.

11. The catalyst according to claim 10, characterized in that The second metal oxide includes γ-Al2O3.

12. The catalyst according to claim 10, characterized in that The third metal oxide includes La2O3 and / or Y2O3.

13. The catalyst according to claim 10, characterized in that The fourth metal oxide includes CeO2 and / or ZrO2.

14. The catalyst according to claim 9, characterized in that When the catalyst further comprises the coating substrate, the heat stabilizer and the oxygen storage material, the mass ratio of the coating substrate, the heat stabilizer and the oxygen storage material is 100:(0.05-5):(0.05-5).

15. The catalyst according to claim 9, characterized in that The catalyst includes a first coating and a second coating, wherein the first coating is arranged on the surface of the carrier, and the second coating is arranged on the side of the first coating facing away from the carrier, the first coating includes one or more of the coating substrate, the thermal stabilizer, and the oxygen storage material, and the second coating includes the molecular sieve catalyst and the microwave receptor.

16. A method for manufacturing a catalyst, characterized in that: include: Precursors of molecular sieve catalyst and microwave receptor are made into active slurry; The active slurry is dried to obtain the catalyst; The precursor of the microwave receptor is converted into a microwave receptor, and the microwave receptor is suitable for absorbing microwave radiation energy and increasing in temperature.

17. The manufacturing method according to claim 16, characterized in that: After the precursors of the molecular sieve catalyst and the microwave receptor are prepared into an active slurry, the method further comprises: The carrier is placed in the active slurry so that the precursors of the molecular sieve catalyst and the microwave receptor are loaded on the surface of the carrier.

18. The manufacturing method according to claim 17, characterized in that: Before placing the carrier into the active slurry, the method further comprises: One or more of a coating substrate, a heat stabilizer, and an oxygen storage material are made into a coating slurry; Placing the carrier into the coating slurry, drying and calcining to obtain a composite carrier; The composite carrier is loaded with one or more of a coating substrate, a thermal stabilizer, and an oxygen storage material.

19. An exhaust gas treatment system, characterized in that: The exhaust gas treatment system comprises the catalyst as described in any one of claims 1-15, or the exhaust gas treatment system comprises the catalyst manufactured by the manufacturing method as described in any one of claims 16-18.

20. A vehicle, characterized in that: The vehicle includes the exhaust treatment system of claim 19.

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