Composite catalytic material, preparation method and application thereof

Abstract

The present application relates to a kind of composite catalytic materials and its preparation method and application, the composite catalytic material has the structure of hollow multistage hole ZSM-5 nanocrystalline material encapsulation reinforcing heating material;Wherein, the hollow multistage hole ZSM-5 nanocrystalline material has closed hollow structure, average grain size is 0.4-3.0 μm, the ratio of the molar ratio of surface silicon aluminum and the molar ratio of body phase silicon aluminum is 1.0-1.2, total specific surface area is 340-400 m 2 / g, mesoporous specific surface area is 40-150 m 2 / g, N2 adsorption-desorption curve presents H4 type hysteresis loop;The reinforcing heating material includes perovskite type heating material and sodium tungstate, the perovskite type heating material contains copper-doped perovskite, the molecular general formula of the copper-doped perovskite is ABO3, wherein copper is B site doping and has reduced valence.The composite catalytic material of the present application has good catalytic activity and more optimal exothermic performance, and when it is used in catalytic cracking reaction of raw oil, the yield of low carbon olefin can be significantly improved.

Description

Technical Field

[0001] This application relates to a composite catalytic material, its preparation method, and its application. Background Technology

[0002] Catalytic cracking is the core of secondary processing in oil refineries. It converts distillate or residue oil obtained from atmospheric and vacuum distillation into fuels such as liquefied petroleum gas (LPG), gasoline, and diesel, or chemical feedstocks such as ethylene, propylene, butene, and BTX, under the action of catalysts and high temperatures. The catalyst is not only the reactive center of the catalytic cracking reaction but also the heat and mass transfer carrier in the catalytic cracking regeneration system. The catalyst enters the reactor from the high-temperature regenerator, bringing in a large amount of heat to promote the catalytic cracking reaction. The coke produced in the reaction is loaded on the catalyst surface and then regenerated by combustion with oxygen in the air, generating a large amount of heat.

[0003] With the increasing weight and quality of raw materials and the transformation of oil refining units into chemical-oriented systems, reaction conditions have become more stringent, requiring catalysts to provide more heat. However, the heat capacity of catalysts is limited, resulting in limited heat supplied to the reaction section, making it difficult to further increase the reaction temperature. In order to transfer more heat, the catalyst-to-oil ratio is increased, which often leads to more side reactions.

[0004] The heat released by the continuous oxidation-reduction reaction of metals and their oxides through heating materials can provide heat for hydrocarbon conversion. However, the direct contact between the heating material and heavy oil hydrocarbon molecules makes it prone to acting as a dehydrogenation center, leading to a significant increase in coking. Therefore, ensuring heating efficiency while avoiding or reducing the impact of the heating material on its reactivity is crucial for the industrial application of heating materials.

[0005] Hollow materials possess unique internal microenvironments and spatial confinement effects, exhibiting superior performance in heterogeneous catalysis, biomedicine, adsorption separation, and energy storage. Hollow ZSM-5 molecular sieves, with their nanoscale hierarchical porous outer shell and relatively closed internal structure, possess advantages such as strong acidity, excellent diffusion properties, and outstanding encapsulation capabilities, making them a highly valuable and promising material for industrial catalysis and adsorption separation.

[0006] CN106082263B developed a porous hollow ZSM-5 molecular sieve. The method involves mixing tetraethyl orthosilicate, tetrapropylammonium hydroxide, aluminum nitrate, sodium hydroxide, and deionized water as raw materials. The solution is then aged, crystallized, centrifuged, washed, dried, and calcined to obtain the nano-ZSM-5 molecular sieve. The nano-ZSM-5 molecular sieve is then added to an inorganic alkaline aqueous solution, stirred for 10–50 h, separated, washed, and dried to obtain nano-ZSM-5 with a hollow structure. However, the raw materials used in this preparation method are relatively limited, and the resulting product has a size of 50–100 nm, with excessively large mesopores. Further improvements are needed in its hydrothermal stability and mechanical strength. Summary of the Invention

[0007] The purpose of this invention is to provide a composite catalytic material, its preparation method, and its application. The composite catalytic material of this invention can improve the yield of low-carbon olefins, reduce the yield of by-products, and has optimized exothermic performance.

[0008] To achieve the above objectives, the first aspect of the present invention provides a composite catalytic material having a structure in which a hollow hierarchical porous ZSM-5 nanocrystalline material encapsulates and strengthens a heat-generating material.

[0009] The enhanced heating material includes a perovskite heating material and sodium tungstate. The perovskite heating material contains copper-doped perovskite with the general molecular formula ABO3, wherein copper is a B-site dopant and has a reduced valence state. The average grain size of the copper-doped perovskite is less than 0.1 μm.

[0010] The hollow hierarchical porous ZSM-5 nanocrystalline material has a closed hollow structure, an average grain size of 0.4-3.0 μm, a bulk silicon-aluminum molar ratio to surface silicon-aluminum molar ratio of 1.0-1.2, and a total specific surface area of ​​340-400 m². 2 / g, mesoporous specific surface area is 40-150m² 2 / g, the N2 adsorption-desorption curves show an H4-type hysteresis loop.

[0011] Optionally, in the copper-doped perovskite, A is a rare earth element and / or an alkaline earth metal element, preferably one or more of calcium, strontium, barium, and lanthanum; B is copper and optionally a variable valence metal element, wherein the variable valence metal element is selected from one or more of titanium, iron, cobalt, nickel, and manganese.

[0012] Optionally, the composite catalytic material contains hollow hierarchical porous ZSM-5 nanocrystalline material, perovskite-type heating material and sodium tungstate in a molar ratio of 1:(0.01-0.1):(0.005-0.01), wherein the hollow hierarchical porous ZSM-5 nanocrystalline material is calculated as SiO2 and the perovskite-type heating material is calculated as CuO.

[0013] Optionally, the hollow hierarchical porous ZSM-5 nanocrystalline material has an average grain size of 0.4-2.5 μm, a bulk silicon-aluminum molar ratio to a surface silicon-aluminum molar ratio of 1.0-1.1, and a total specific surface area of ​​360-400 m². 2 / g, mesoporous specific surface area is 50-140m² 2 / g.

[0014] A second aspect of the present invention provides a method for preparing the composite catalytic material provided in the first aspect of the present invention, the method comprising:

[0015] S1. The silicon source, copper-doped perovskite, sodium tungstate and the first solvent are mixed and reacted at 30-50℃ for 0.5-5 hours, and then the temperature is raised to 70-100℃ and stirred for 2-10 hours. The resulting mixed liquid is mixed with the template agent at 20-30℃ for 0.5-3.0 hours to obtain the first mixed product.

[0016] S2. Mix alkali metal hydroxide (calculated as alkali metal oxide), second solvent, and aluminum source (calculated as Al2O3) in a molar ratio of (1.5-5):(60-350):1 at 20-80℃ for 0.5-2 hours to obtain a second mixed product.

[0017] S3. The first mixed product and the second mixed product are mixed and then dynamically crystallized. The resulting solid is taken out and subjected to a first calcination to obtain the first solid product.

[0018] S4. The first solid product is mixed with an alkaline solution, and the temperature is increased to the reaction temperature at a rate of 1-5℃ / min. The mixture is then reacted at the reaction temperature for 10-90 min to obtain the second solid product. The reaction temperature is 60-90℃, and the alkaline content in the alkaline solution is 0.45-2 mol / L.

[0019] S5. The second solid product is subjected to ammonium exchange, and the solid product obtained by ammonium exchange is subjected to a second calcination to obtain a composite catalyst material.

[0020] Optionally, the molar ratio of the total amount of the copper-doped perovskite, the sodium tungstate, the template agent, the first solvent and the second solvent, the alkali metal hydroxide and the silicon source is (0.01-0.1):(0.005-0.01):(0.06-0.55):(10-100):(0.02-1.5):1, and the molar ratio of the silicon source to the aluminum source is (20-500):1; wherein the copper-doped perovskite is calculated as CuO, the silicon source is calculated as SiO2, the alkali metal hydroxide is calculated as alkali metal oxide, and the aluminum source is calculated as Al2O3.

[0021] Optionally, in step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (1.5-5):(60-500):1, preferably (2-4.5):(80-350):1.

[0022] Optionally, in step S4, the molar ratio of the first solid product to the amount of the alkaline solution is 1:(2-10), preferably 1:(4-8, and the first solid product is calculated as SiO2;

[0023] The ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the first solid product is 1.2-5.0;

[0024] The conditions for dynamic crystallization include: a temperature of 160-180℃ and a time of 12-60 hours;

[0025] The conditions for the first and second roastings are each independent of each other: a temperature of 400-600℃ and a time of 2-6 hours.

[0026] Optionally, in step S5, the ammonium exchange of the second solid product includes: mixing the second solid product, the ammonium source, and the third solvent in a weight ratio of 1:(0.5-1.0):(8-10), and then reacting the resulting mixture at 70-90°C for 0.5-2 hours; wherein the ammonium source is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0027] Optionally, the template agent is selected from one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, n-butylamine, and hexamethylenediamine;

[0028] The silicon source is methyl orthosilicate and / or ethyl orthosilicate;

[0029] The aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum isopropoxide, and aluminum sol;

[0030] The alkali metal hydroxide is selected from one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide;

[0031] The first solvent and the second solvent are each independently water.

[0032] The third aspect of this invention provides the application of the composite catalytic material provided in the first aspect of this invention in the catalytic cracking reaction of heavy hydrocarbon oil.

[0033] The hollow hierarchical porous ZSM-5 nanocrystals described above have suitable grain size and a complete hollow structure. They can be matched with suitable mesoporous structures for reactants with different molecular structures. Their shell is mainly composed of microporous structures, while also being rich in mesoporous and macroporous structures. They have a large external surface area and can provide multi-directional diffusion paths, expand the confined space, improve the diffusion performance of molecular sieves, and increase the accessibility of active centers. They have the potential to catalyze the cracking of macromolecular hydrocarbons and can be applied in high-efficiency heavy oil feedstock catalytic cracking / cracking catalysts.

[0034] Through the above technical solution, the composite catalytic material of the present invention contains a heat-enhancing material, which includes a perovskite-type heat-enhancing material and sodium tungstate. The perovskite-type heat-enhancing material has good structural stability and exothermic performance; while sodium tungstate has a heat-enhancing effect because it can promote the redox reaction of copper. It can reduce the content of perovskite-type heat-enhancing material in the composite catalytic material while still making the catalytic material have a good heat-enhancing effect, and make the composite catalytic material maintain better catalytic activity and lower coke yield.

[0035] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0036] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0037] The first aspect of this invention provides a composite catalytic material having a structure in which a hollow hierarchical porous ZSM-5 nanocrystalline material encapsulates and strengthens a heating material;

[0038] The enhanced heating material includes a perovskite heating material and sodium tungstate. The perovskite heating material contains copper-doped perovskite with the general molecular formula ABO3, wherein copper is a B-site dopant and has a reduced valence state. The average grain size of the copper-doped perovskite is less than 0.1 μm.

[0039] The hollow hierarchical porous ZSM-5 nanocrystalline material has a closed hollow structure, an average grain size of 0.4-3.0 μm, a bulk silicon-aluminum molar ratio to surface silicon-aluminum molar ratio of 1.0-1.2, and a total specific surface area of ​​340-400 m². 2 / g, mesoporous specific surface area is 40-150m² 2 / g, the N2 adsorption-desorption curves show an H4-type hysteresis loop.

[0040] In this invention, "hollow hierarchical porous ZSM-5 nanocrystalline material encapsulating enhanced heating material" refers to a hollow structure within the ZSM-5 nanocrystalline material containing enhanced heating material. The outer surface of the enhanced heating material can be connected to or not connected to the inner surface of the ZSM-5 nanocrystalline material. When connected, the composite catalytic material can also be described as having a core-shell structure. The composite catalytic material of this invention uses the hollow hierarchical porous ZSM-5 nanocrystalline material to screen hydrocarbon molecules entering the hollow interior, avoiding direct contact between the perovskite-type heating material as a dehydrogenation center and heavy oil hydrocarbon molecules, which would lead to increased coking. Furthermore, copper is incorporated into the perovskite structure as a dopant, giving the copper-doped perovskite better structural stability and further reducing the impact of the perovskite-type heating material on the catalytic cracking catalyst's reaction performance. The contained sodium tungstate further enhances its heating effect, enabling the composite catalytic material of this invention to achieve both superior heating effect and good catalytic activity, further improving feedstock conversion rate and low-carbon olefin yield while reducing coke yield.

[0041] In one specific embodiment of the present invention, the perovskite-type exothermic material exhibits diffraction peaks at diffraction angles of 23±2°, 33±2°, 47±2°, and 58±2° in its XRD pattern. The perovskite exothermic material possesses structural stability, high-temperature resistance, and abundant oxygen vacancies, enabling the composite catalytic material of the present invention to exhibit excellent exothermic effect and catalytic activity, further improving the yield of low-carbon olefins.

[0042] In one specific embodiment of the present invention, A is a rare earth element or an alkaline earth metal element, preferably one or more of calcium, strontium, barium and lanthanum; B is copper and optionally a variable valence metal element, wherein the variable valence metal element is selected from one or more of titanium, manganese, cobalt, nickel and iron.

[0043] In one specific embodiment of the present invention, the composite catalytic material contains a hollow hierarchical porous ZSM-5 nanocrystalline material, a perovskite-type heating material, and sodium tungstate in a molar ratio of 1:(0.01-0.1):(0.005-0.01), preferably 1:(0.01-0.09):(0.005-0.01), wherein the hollow hierarchical porous ZSM-5 nanocrystalline material is calculated as SiO2, and the perovskite-type heating material is calculated as CuO.

[0044] In one specific embodiment of the present invention, the average grain size of the hollow hierarchical porous ZSM-5 nanocrystalline material is 0.4-2.5 μm. In the present invention, grain size refers to the size of the widest part of the grain, which can be obtained by measuring the size of the widest part of the grain projection plane in the SEM or TEM image of the sample. The average grain size is obtained by selecting any 10 molecular sieves in the SEM or TEM image and calculating their average value.

[0045] In one specific embodiment of the present invention, the ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the hollow hierarchical porous ZSM-5 nanocrystalline material is 1.0-1.1, and the total specific surface area is 360-400 m². 2 / g, mesoporous specific surface area is 50-140m² 2 / g. The bulk silicon-aluminum molar ratio refers to the overall silicon-aluminum molar ratio of the hollow hierarchical porous ZSM-5 nanocrystalline material. The bulk silicon-aluminum molar ratio was determined by XRF, and the surface silicon-aluminum molar ratio was determined by XPS. The specific testing methods are well known to those skilled in the art and will not be elaborated here. In this invention, the total specific surface area and mesoporous specific surface area were obtained using BET analysis.

[0046] In one specific embodiment of the present invention, the relative crystallinity of the hollow hierarchical porous ZSM-5 nanocrystalline material is 75-95%. In the present invention, the relative crystallinity of the molecular sieve is based on the XRD standard ZSM-5 molecular sieve standard sample of Sinopec Petrochemical Research Institute Co., Ltd., and the crystallinity of the standard sample is regarded as 100%.

[0047] A second aspect of the present invention provides a method for preparing the composite catalytic material provided in the first aspect of the present invention, the method comprising:

[0048] S1. The silicon source, copper-doped perovskite, sodium tungstate and the first solvent are mixed and reacted at 30-50℃ for 0.5-5 hours, and then the temperature is raised to 70-100℃ and stirred for 2-10 hours. The resulting mixed liquid is mixed with the template agent at 20-30℃ for 0.5-3.0 hours to obtain the first mixed product.

[0049] S2. Mix alkali metal hydroxide (calculated as alkali metal oxide), second solvent, and aluminum source (calculated as Al2O3) in a molar ratio of (1.5-5):(60-350):1 at 20-80℃ for 0.5-2 hours to obtain a second mixed product.

[0050] S3. The first mixed product and the second mixed product are mixed and then dynamically crystallized. The resulting solid is taken out and subjected to a first calcination to obtain the first solid product.

[0051] S4. The first solid product is mixed with an alkaline solution, and the temperature is increased to the reaction temperature at a rate of 1-5℃ / min. The mixture is then reacted at the reaction temperature for 10-90 min to obtain the second solid product. The reaction temperature is 60-90℃, and the alkaline content in the alkaline solution is 0.45-2 mol / L.

[0052] S5. The second solid product is subjected to ammonium exchange, and the solid product obtained by ammonium exchange is subjected to a second calcination to obtain a composite catalyst material.

[0053] According to the present invention, the molar ratio of the copper-doped perovskite, the sodium tungstate, the template agent, the total amount of the first solvent and the second solvent, the alkali metal hydroxide, and the amount of the silicon source is (0.01-0.1):(0.005-0.01):(0.06-0.55):(10-100):(0.02-1.5):1, and the molar ratio of the silicon source to the aluminum source is (20-500):1, wherein the copper-doped perovskite is calculated as CuO, the silicon source is calculated as SiO2, the alkali metal hydroxide is calculated as alkali metal oxide, and the aluminum source is calculated as Al2O3.

[0054] According to the present invention, in step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (1.5-5):(60-500):1, preferably (2-4.5):(80-350):1.

[0055] In one specific embodiment of the present invention, in step S3, dynamic crystallization is well known to those skilled in the art, and the conditions for dynamic crystallization include: a temperature of 160-180°C and a time of 12-60 hours.

[0056] In one specific embodiment of the present invention, in step S4, the molar ratio of the first solid product to the amount of the alkali-containing solution is 1:(2-10), preferably 1:(4-8), the first solid product is calculated as SiO2, and the ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the first solid product is 1.2-5.0.

[0057] In one specific embodiment of the present invention, step S5, wherein the ammonium exchange of the second solid product comprises: mixing the second solid product, an ammonium source, and a third solvent in a weight ratio of 1:(0.5-1.0):(8-10), and reacting the resulting mixture at 70-90°C for 0.5-2 hours; wherein the ammonium source is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

[0058] In one embodiment, the first solvent, the second solvent, and the third solvent may each be water independently.

[0059] In one specific embodiment of the present invention, roasting is a technical means conventionally used by those skilled in the art, and roasting can be carried out in a muffle furnace, tube furnace, etc. In one embodiment, the conditions for the first roasting and the second roasting each independently include: a temperature of 400-600°C and a time of 2-6 hours, preferably, a temperature of 450-580°C and a time of 3-5 hours.

[0060] In one specific embodiment of the present invention, compared with the first solid product, the composite catalytic material has a 100-500% increase in mesoporous specific surface area, a 150-600% increase in mesoporous volume, and a 50-250% increase in total acidity. In this invention, the mesoporous volume can be obtained by BET testing, and the total acidity can be detected by the NH3-TPD method.

[0061] According to the present invention, copper-doped perovskites are prepared by one or more of the following methods: co-precipitation, sol-gel, and complexation. In a preferred embodiment of the present invention, the copper-doped perovskite LaCu... x Mn1-xO3 is prepared by a method comprising the following steps:

[0062] (1) Dissolve copper source, lanthanum source and manganese source in deionized water and stir at 400-700 rpm; add citric acid monohydrate and stir at the same speed for 30-60 min at 35-55℃; add ethylene glycol to obtain the first mixture.

[0063] (2) Heat the first mixture to 80-100℃, stir until it is in a sol state, let it stand for 70-100h, and dry it overnight at 90-120℃ to obtain the second mixture;

[0064] (3) After heat-treating the second mixture at 400-500℃ for 3-6 hours, the resulting material is calcined at 750-1000℃ for 10-15 hours to obtain copper-containing perovskite LaCu. x Mn 1-x O3.

[0065] In one embodiment, the copper-doped perovskite has the molecular formula LaCu. x Mn 1-x O3, x is 0.01-0.99, for example 0.2-0.6.

[0066] In this invention, the copper source is selected from one or more of copper sulfate, copper chloride, copper nitrate and copper carbonate; the lanthanum source is selected from one or more of lanthanum nitrate hexahydrate, lanthanum chloride, lanthanum oxide and lanthanum sulfate; and the manganese source is selected from one or more of manganese nitrate, manganese chloride, manganese nitrate and manganese sulfate.

[0067] In one specific embodiment of the present invention, the average grain size of the copper-doped perovskite is preferably 0.01-0.09 μm. In this invention, the grain size of 10 copper-doped perovskites is randomly measured by SEM, and the average value is taken to obtain the average grain size.

[0068] In one specific embodiment of the present invention, the template agent is selected from one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, n-butylamine, and hexamethylenediamine; the silicon source is methyl orthosilicate and / or tetraethyl orthosilicate; the aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum isopropoxide, and aluminum sol; the alkali metal hydroxide is selected from one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide; and the first solvent and the second solvent are each independently water.

[0069] The third aspect of this invention provides the application of the composite catalytic material provided in the first aspect of this invention in the catalytic cracking and catalytic pyrolysis of feedstock oils, especially in the catalytic cracking reaction of heavy hydrocarbon oils.

[0070] The composite catalytic material of this invention, used in catalytic cracking and catalytic pyrolysis reactions, has the advantage of further increasing reaction temperature and yield of low-carbon olefins (e.g., ethylene, propylene). In one specific embodiment of this invention, the feedstock oil is contacted with the composite catalytic material to carry out the catalytic cracking or catalytic pyrolysis reaction. Preferably, the composite catalytic material is a composite catalytic material that has undergone enhanced reduction.

[0071] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0072] Unless otherwise specified, all raw materials used in the following examples and comparative examples were commercially available. The catalytic cracking equilibrium catalyst ECAT was purchased from Sinopec Catalyst Company Qilu Branch COKC-1 industrial catalyst.

[0073] In the examples and comparative examples, the crystal size of the molecular sieve was measured by SEM. Ten crystal sizes were randomly measured, and the average value was taken to obtain the average crystal size of the molecular sieve sample.

[0074] The average grain size of copper-doped perovskites was obtained by randomly measuring the grain size of 10 copper-doped perovskites using SEM and taking their average value.

[0075] The bulk silica-alumina molar ratio of the sample was determined by XRF using a ZSX Primus II (Rigaku) ​​X-ray fluorescence spectrometer. Test conditions included an excitation voltage of 50 kV, an excitation current of 50 mA, and rhodium and palladium. The elemental composition of the molecular sieve was analyzed by measuring the peak intensity of each element using a scintillation counter and a proportional counter.

[0076] The surface silicon-to-aluminum molar ratio of the samples was determined by XPS using a Thermo Fisher ESCALab 250 X-ray photoelectron spectrometer. The testing conditions were: monochromatic Al Kα X-ray source, excitation energy 1496.6 eV, and power 150 W. The electron binding energy was corrected using the C1s peak (284.8 eV) of the contaminating carbon.

[0077] The total specific surface area and mesoporous specific surface area of ​​the samples were determined using the BET method. Instrument: Micromeritics ASAP 2420 adsorption analyzer (USA). Test conditions: The samples were degassed under vacuum at 100℃ and 300℃ for 0.5h and 6h, respectively, and then N2 adsorption-desorption tests were conducted at 77.4K. The adsorption and desorption amounts of nitrogen by the purified samples under different specific pressures were measured, and N2 adsorption-desorption isotherms were obtained. The BET specific surface area was calculated using the BET formula, the micropore area was calculated using t-plot, and the pore size distribution was calculated using the BJH method.

[0078] The molar amounts of hollow hierarchical porous ZSM-5 nanocrystalline material (calculated as SiO2), the perovskite-type heating material (calculated as CuO), and sodium tungstate in the sample were determined by XRF method.

[0079] The raw material used for ACE evaluation in the examples and comparative examples was ACE standard oil, with the following properties:

[0080]

[0081]

[0082] Example 1 below is an example of the preparation of copper-doped perovskite.

[0083] Preparation Example 1

[0084] (1) Under stirring conditions at 40℃, 3.94g (0.016mol) of copper nitrate trihydrate, 17.65g (0.041mol) of lanthanum nitrate hexahydrate, and 8.75g (0.024mol) of manganese nitrate with a mass fraction of 50% were dissolved in 664g of deionized water at a stirring speed of 500rpm; 34.3g (0.163mol) of citric acid monohydrate were added to the mixture, and the stirring conditions of 500rpm and 40℃ were maintained. After stirring for 30min, 10.11g (0.163mol) of ethylene glycol were added to obtain the first mixture.

[0085] (2) Heat the first mixture to 80°C and stir continuously until a sol is formed. After standing for 72 hours, dry it overnight at 100°C to obtain the second mixture.

[0086] (3) The second mixture was heat-treated in a muffle furnace at 450°C for 3 hours; the resulting material was then calcined at 800°C for 12 hours to obtain copper-containing perovskite LaCu. 0.4 Mn 0.6 O3.

[0087] XRD analysis revealed that the prepared copper-doped perovskite exhibited distinct diffraction peaks at diffraction angles of 23°, 33°, 47°, and 58°. The general molecular formula of the copper-doped perovskite is ABO3, where A represents lanthanum and B represents copper and manganese. The average grain size is 0.05 micrometers.

[0088] Example 1

[0089] S1. Weigh 22.44 g of the copper-doped perovskite prepared in Example 1 above, 1 g of sodium tungstate, and 91.2 g of tetraethyl orthosilicate. Add 639.14 g of deionized water and stir and heat in a water bath at 40°C for 2 h. Then raise the water bath temperature to 70°C and stir and heat for 4 h to remove the ethanol produced by the hydrolysis of the silicon source. During this process, water that evaporates along with the ethanol is intermittently added to the system. Mix the resulting liquid with 111.65 g of tetrapropylammonium hydroxide solution (tetrapropylammonium hydroxide weight fraction is 25.0 wt%) at 25°C and stir for 1 h to obtain the first mixed product.

[0090] S2. Add 3.44 g of sodium hydroxide granules to 60.80 g of deionized water to completely dissolve the sodium hydroxide, then add 8.16 g of aluminum nitrate nonahydrate and stir at room temperature for 1.0 h to obtain the second mixed product (i.e., aluminum source solution).

[0091] S3. The second mixed product is slowly added to the first mixed product and mixed evenly. The mixture is stirred at room temperature for 4.0 h. The resulting precursor liquid is transferred to a synthesis vessel and subjected to dynamic crystallization at 170 °C for 48 h. After crystallization, the resulting mixture is centrifuged, filtered, washed, and dried. It is then calcined at 550 °C for 4 h to obtain the first solid product (denoted as molecular sieve Q-M1).

[0092] S4. Mix the first solid product with a sodium hydroxide solution with a concentration of 0.65 mol / L. The weight ratio of molecular sieve to alkaline solution is 1:10. Heat the solution to 80°C at a heating rate of 2°C / min, and then heat and stir at this temperature for 30 min. Filter, wash, and dry to obtain the second solid product (denoted as molecular sieve Q-S1-Na).

[0093] S5. The second solid product, ammonium chloride, and deionized water are mixed evenly at a weight ratio of 1:1:10. The mixture is stirred and heated in an 80°C water bath for 30 minutes. After filtration, washing, and drying, the mixture is then mixed evenly again at a weight ratio of 1:0.5:10 for a second ammonium exchange. After filtration, washing, and drying, the mixture is calcined at 550°C for 2 hours to obtain the composite catalyst material (denoted as Q-S1-H). The composition of the catalyst is shown in Table 1.

[0094] Example 2

[0095] The composite catalyst Q-S2-H was prepared using the same method as in Example 1, except that in step S1, 44.88 g of the copper-doped perovskite (average grain size of 0.05 μm) prepared in Example 1, 2 g of sodium tungstate, and 91.2 g of tetraethyl orthosilicate were weighed, and then 639.14 g of deionized water was added. After stirring and heating in a water bath at 40°C for 2 h, the water bath temperature was increased to 70°C and stirred and heated for 4 h to remove the ethanol produced by the hydrolysis of the silicon source. During this process, water that evaporated along with the ethanol was intermittently added to the system. The resulting mixed liquid was mixed and stirred with 111.65 g of tetrapropylammonium hydroxide solution (tetrapropylammonium hydroxide weight fraction of 25.0 wt%) at 25°C for 1 h to obtain the first mixed product.

[0096] Comparative Example 1

[0097] Catalyst D-S1-H was prepared using the same method as in Example 1, except that copper-doped perovskite and sodium tungstate were not added in step S1.

[0098] Comparative Example 2

[0099] Catalyst D-S2-H was prepared using the same method as in Example 1, except that sodium tungstate was not added in step S1.

[0100] Comparative Example 3

[0101] Catalyst D-S3-H was prepared using the same method as in Example 1, except that copper-doped perovskite was not added in step S1.

[0102] Comparative Example 4

[0103] Kaolin carrier, aluminum sol, copper-doped perovskite (prepared in Preparation Example 1) and sodium tungstate were mixed in a weight ratio of kaolin: binder: copper-doped perovskite: sodium tungstate of 50:39:10:1 to prepare a slurry. The obtained slurry was spray-dried, and the product obtained by spray drying was calcined at 550°C for 3 hours to obtain additive G-1.

[0104] Test case

[0105] The catalysts prepared in the above examples and comparative examples were subjected to ACE evaluation at a ratio of 10 wt% (G-S1-H or G-S2-H or G-S3-H or G-S4-H or D-S1-H or G-1) + 90 wt% of catalytic cracking equilibrium catalyst (ECAT). The reaction temperature was set at 530°C, the catalyst-to-oil mass ratio was 8, and the exothermic effect was observed by recording the temperature change. The results are shown in Tables 2 and 3.

[0106] Table 1

[0107]

[0108]

[0109]

[0110]

[0111] In the composite catalytic material, CuO / SiO2 refers to the molar ratio of the perovskite-type heating material to the hollow hierarchical ZSM-5 nanocrystalline material, and Na2WO4 / SiO2 refers to the molar ratio of sodium tungstate to the hollow hierarchical ZSM-5 nanocrystalline material.

[0112] Table 2

[0113]

[0114]

[0115] Table 3

[0116]

[0117] As can be seen from the above, the composite catalytic material of the present invention has better exothermic performance and good catalytic activity, which can further improve the conversion rate of raw materials and the yield of low-carbon olefins.

[0118] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0119] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0120] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A composite catalytic material having a structure in which a hollow hierarchical porous ZSM-5 nanocrystalline material encapsulates and strengthens a heat-generating material; in, The enhanced heating material includes a perovskite-type heating material and sodium tungstate. The perovskite-type heating material is copper-doped perovskite, and the molecular formula of the copper-doped perovskite is LaCu. x Mn 1-x O3, x is 0.01-0.99; the average grain size of the copper-doped perovskite is less than 0.1 μm; The hollow hierarchical porous ZSM-5 nanocrystalline material has a closed hollow structure, an average grain size of 0.4-3.0 μm, a bulk silicon-aluminum molar ratio to a surface silicon-aluminum molar ratio of 1.0-1.2, and a total specific surface area of ​​340-400 m². 2 / g, mesoporous specific surface area is 40-150m² 2 / g, the N2 adsorption-desorption curves show an H4-type hysteresis loop.

2. The composite catalytic material according to claim 1, wherein, The composite catalytic material contains hollow hierarchical porous ZSM-5 nanocrystalline material, perovskite-type heating material and sodium tungstate in a molar ratio of 1:(0.01-0.1):(0.005-0.01), where the hollow hierarchical porous ZSM-5 nanocrystalline material is calculated as SiO2 and the perovskite-type heating material is calculated as CuO.

3. The composite catalytic material according to claim 1, wherein, The hollow hierarchical porous ZSM-5 nanocrystalline material has an average grain size of 0.4-2.5 μm, a bulk silicon-aluminum molar ratio to a surface silicon-aluminum molar ratio of 1.0-1.1, and a total specific surface area of ​​360-400 m². 2 / g, mesoporous specific surface area is 50-140m² 2 / g.

4. A method for preparing the composite catalytic material according to any one of claims 1-3, the method comprising: S1. The silicon source, copper-doped perovskite, sodium tungstate and the first solvent are mixed and reacted at 30-50℃ for 0.5-5 hours, and then the temperature is raised to 70-100℃ and stirred for 2-10 hours. The resulting mixed liquid is mixed with the template agent at 20-30℃ for 0.5-3.0 hours to obtain the first mixed product. S2. Mix alkali metal hydroxide (calculated as alkali metal oxide), second solvent, and aluminum source (calculated as Al2O3) in a molar ratio of (1.5-5):(60-350):1 at 20-80℃ for 0.5-2 hours to obtain a second mixed product. S3. The first mixed product and the second mixed product are mixed and then dynamically crystallized. The resulting solid is taken out and subjected to a first calcination to obtain the first solid product. S4. The first solid product is mixed with an alkaline solution, and the temperature is increased to the reaction temperature at a rate of 1-5℃ / min. The mixture is then reacted at the reaction temperature for 10-90 min to obtain the second solid product. The reaction temperature is 60-90℃, and the alkaline content in the alkaline solution is 0.45-2 mol / L. S5. The second solid product is subjected to ammonium exchange, and the solid product obtained by ammonium exchange is subjected to a second calcination to obtain a composite catalyst material.

5. The method according to claim 4, wherein, The molar ratio of the copper-doped perovskite, the sodium tungstate, the template agent, the total amount of the first solvent and the second solvent, the alkali metal hydroxide, and the silicon source is (0.01-0.1):(0.005-0.01):(0.06-0.55):(10-100):(0.02-1.5):1, and the molar ratio of the silicon source to the aluminum source is (20-500):1; wherein the copper-doped perovskite is calculated as CuO, the silicon source is calculated as SiO2, the alkali metal hydroxide is calculated as alkali metal oxide, and the aluminum source is calculated as Al2O3.

6. The method according to claim 4, wherein, In step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (1.5-5):(60-500):

1.

7. The method according to claim 6, wherein, In step S2, the molar ratio of the alkali metal hydroxide (calculated as alkali metal oxide), the second solvent, and the aluminum source (calculated as Al2O3) is (2-4.5):(80-350):

1.

8. The method according to claim 4, wherein, In step S4, the molar ratio of the first solid product to the alkaline solution is 1:(2-10), and the first solid product is calculated as SiO2. The ratio of the bulk silicon-aluminum molar ratio to the surface silicon-aluminum molar ratio of the first solid product is 1.2-5.0; The conditions for dynamic crystallization include: a temperature of 160-180℃ and a time of 12-60 hours; The conditions for the first and second roastings are each independent of each other: a temperature of 400-600℃ and a time of 2-6 hours.

9. The method according to claim 8, wherein, In step S4, the molar ratio of the first solid product to the alkaline solution is 1:(4-8), and the first solid product is calculated as SiO2.

10. The method according to claim 4, wherein, In step S5, the ammonium exchange of the second solid product includes: mixing the second solid product, the ammonium source, and the third solvent in a weight ratio of 1:(0.5-1.0):(8-10), and then reacting the resulting mixture at 70-90°C for 0.5-2 hours; the ammonium source is selected from one or more of ammonium chloride, ammonium sulfate, and ammonium nitrate.

11. The method according to claim 4, wherein, The template agent is selected from one or more of tetrapropylammonium bromide, tetrapropylammonium hydroxide, n-butylamine, and hexamethylenediamine; The silicon source is methyl orthosilicate and / or ethyl orthosilicate; The aluminum source is selected from one or more of sodium aluminate, aluminum sulfate, aluminum nitrate, aluminum isopropoxide, and aluminum sol; The alkali metal hydroxide is selected from one or more of lithium hydroxide, sodium hydroxide, and potassium hydroxide; The first solvent and the second solvent are each independently water.

12. The application of the composite catalytic material according to any one of claims 1-3 in the catalytic cracking reaction of heavy hydrocarbon oil.

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