Method for preparing metal particle confined porous oxide and application thereof

Abstract

The application discloses a preparation method and application of metal particle confined porous oxide, relates to the technical field of thermal catalytic material preparation, and aims to solve the problems of low propylene selectivity of a platinum catalyst in the existing propane dehydrogenation technology and catalyst deactivation caused by high-temperature sintering and coke formation. The preparation method of the metal particle confined porous oxide comprises the following steps: obtaining a metal target material; placing the metal target material in an organic solvent, and bombarding the metal target material with a laser beam under ultrasonic conditions to obtain a colloidal solution containing metal particles; adding aldehyde and amine into the colloidal solution, washing and drying the precipitate after reaction to obtain a first powder; dispersing the first powder in an ethanol solution of a metal salt, uniformly mixing, and then concentrating and drying to obtain a second powder; and calcining the second powder to obtain the metal particle confined porous oxide. The technical scheme is used for providing the preparation method and application of the metal particle confined porous oxide.

Description

Technical Field

[0001] This invention relates to the field of thermocatalytic material preparation technology. More specifically, it relates to a method for preparing and applying a metal particle-confined porous oxide. Background Technology

[0002] With the rapid development of the global chemical industry, the demand for propylene, as an important basic chemical raw material, continues to grow. Propylene is widely used in the production of various chemicals such as polypropylene, acrylonitrile, propylene oxide, acrylic acid and its esters, playing an indispensable role in many industries including plastics, textiles, pharmaceuticals, and coatings. However, traditional propylene production methods, such as steam cracking and fluid catalytic cracking, while technologically mature, are limited by raw material sources and production costs, making it difficult to meet the ever-increasing market demand for propylene.

[0003] In recent years, propane dehydrogenation (PDH) technology has gradually become a major method for propylene production due to its ability to efficiently utilize abundant shale gas resources and its high selectivity. Shale gas, as an unconventional natural gas resource, has huge reserves and is widely distributed. Its abundant propane content provides a stable feedstock for propane dehydrogenation to propylene production. Furthermore, propane dehydrogenation technology has high conversion rates and selectivity, directly converting propane into propylene, reducing intermediate steps and byproduct generation, thereby improving the production efficiency and economics of propylene.

[0004] However, in the application of propane dehydrogenation technology, the selection and performance of catalysts have become key factors restricting its development. Platinum metal, due to its excellent catalytic activity, occupies an important position among propane dehydrogenation catalysts. However, under high-temperature propane dehydrogenation reaction conditions, platinum catalysts face technical problems such as reduced propylene selectivity and catalyst deactivation caused by high-temperature sintering and coke formation. This not only affects the yield and purity of propylene but also increases the frequency of catalyst replacement and production costs. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing and applying a metal particle-confined porous oxide, which addresses the technical problems of low propylene selectivity of platinum catalysts and catalyst deactivation due to high-temperature sintering and coke formation in existing propane dehydrogenation technologies. In view of this, the present invention provides the following technical solution.

[0006] In a first aspect, the present invention provides a method for preparing a metal particle-confined porous oxide, comprising:

[0007] Obtaining metal targets;

[0008] The metal target is placed in an organic solvent, and under ultrasonic conditions, it is bombarded with a laser beam to obtain a colloidal solution containing metal particles; the temperature of the organic solvent is -20~0℃.

[0009] Aldehydes and amines are added to the colloidal solution and stirred until the reaction is complete. The precipitate is then washed and dried to obtain a first powder, which is a metal particle-confined porous organic framework.

[0010] The first powder is dispersed in an ethanol solution of a metal salt, mixed evenly, concentrated and dried to obtain the second powder;

[0011] The second powder is calcined to obtain a metal particle-confined porous oxide; wherein the calcination temperature is 300~650℃ and the time is 4~7 hours.

[0012] Compared with existing technologies, the method for preparing metal particle-confined porous oxides of the present invention involves bombarding a metal target with a laser beam to obtain a colloidal solution containing metal particles. During this process, by controlling the temperature of the organic solvent to -20 to 0°C and conducting the process under ultrasonic conditions, the aggregation or agglomeration of the metal particles obtained from the laser beam bombardment of the metal target in the organic solvent can be avoided. Aldehydes and amines are added to the colloidal solution, and the aldehydes and amines react in the colloidal solution. The precipitate is then washed and dried to obtain a metal particle-confined porous organic framework, in which the loading of metal particles can reach up to 15 wt%. Further, using this porous organic framework as a template, the porous organic framework (first powder) is dispersed in an ethanol solution of a metal salt. The metal salt permeates into the porous organic framework, thereby obtaining a second powder. Further, the second powder is calcined to remove the porous organic framework, thus obtaining the metal particle-confined porous oxide. In the above process, for example, the temperature of the organic solvent can be -20℃, -10℃, or 0℃, the calcination temperature can be 300℃, 400℃, 550℃, or 650℃, and the calcination time can be 4 hours, 5 hours, 6 hours, or 7 hours. The metal particle-confined porous oxide prepared by this invention provides a large number of active sites for the catalytic process. When used in the propane dehydrogenation to propylene reaction, it exhibits high propane conversion and propylene selectivity, and does not sinter or form coke under high-temperature conditions. The technical solution of this invention solves the technical problems of low propylene selectivity of platinum catalysts and catalyst deactivation due to high-temperature sintering and coke formation in existing propane dehydrogenation technologies.

[0013] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, the content of metal particles in the colloidal solution is 0.0001~0.0015 g / ml; and / or,

[0014] The laser beam is a nanosecond pulsed laser beam with a laser flux of 600-2000 mJ / pulse. -1 cm -1The bombardment time for the metal target is 2 to 15 minutes.

[0015] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, the metal includes one or any two of platinum, silver, palladium, gold, gallium, cobalt, nickel, copper, iron, zinc and tin.

[0016] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, the organic solvent includes n-butanol, methanol, ethanol, dimethyl sulfoxide, dioxane, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0017] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, the aldehyde includes terephthalaldehyde, substituted terephthalaldehyde, isophenyltricarbonaldehyde, biphenyl dicarbonaldehyde, substituted biphenyl dicarbonaldehyde, terphenyl dicarbonaldehyde, substituted terphenyl dicarbonaldehyde, and trialdehyde-based phloroglucinol; and / or,

[0018] The amines include p-phenylenediamine, substituted p-phenylenediamine, benzidine, substituted benzidine, terphenylenediamine, substituted terphenylenediamine, and 1,3,5-triaminobenzene.

[0019] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, the addition of aldehyde and amine to the colloidal solution includes:

[0020] Add 0.01 mol of aldehyde and 0.01 mol of amine to every 200 ml of the colloidal solution.

[0021] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, during the process of adding aldehyde and amine to the colloidal solution and stirring until the reaction is completed, the reaction temperature is 60~80℃ and the time is 12~72 hours.

[0022] Furthermore, in the method for preparing the metal particle-confined porous oxide of the present invention, the metal salt includes aluminum nitrate, aluminum chloride, cerium nitrate, cerium ammonium nitrate, cerium chloride, zirconium nitrate, and zirconium acetate; and / or,

[0023] In the ethanol solution of the metal salt, the mass ratio of the metal salt to ethanol is 1:(35~50).

[0024] Secondly, the present invention provides a metal particle-confined porous oxide, which is prepared using the above-described method for preparing metal particle-confined porous oxides.

[0025] Compared with the prior art, the beneficial effects of the metal particle-confined porous oxide of the present invention are the same as the beneficial effects of the preparation method of the metal particle-confined porous oxide described in the above technical solution, and will not be repeated here.

[0026] Thirdly, the present invention provides the application of the above-mentioned metal particle-confined porous oxide in the dehydrogenation of propane to propylene. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 This is an X-ray diffraction pattern of the Pt metal particle-confined porous organic framework powder in Example 1 of the present invention;

[0029] Figure 2 This is an X-ray diffraction pattern of Pt metal particles confined within porous alumina in Embodiment 1 of the present invention;

[0030] Figure 3 This is the X-ray diffraction pattern of Pt metal particles confined to porous cerium oxide in Example 2 of the present invention;

[0031] Figure 4 The X-ray photoelectron spectrum of the Pt metal particle-confined porous organic framework powder in Example 1 of this invention is shown.

[0032] Figure 5 This is the X-ray photoelectron spectrum of Pt metal particles confined to porous alumina in Example 1 of the present invention;

[0033] Figure 6 This is the X-ray photoelectron spectrum of Pt metal particles confined to porous cerium oxide in Example 2 of the present invention;

[0034] Figure 7 This is a high-angle annular dark-field scanning transmission electron microscope image of the Pt metal particle-confined porous organic framework in Embodiment 1 of the present invention, with spherical aberration correction.

[0035] Figure 8 This is a high-angle annular dark-field scanning transmission electron microscope image of Pt metal particles confined in porous alumina in Embodiment 1 of the present invention.

[0036] Figure 9 This is a high-angle annular dark-field scanning transmission electron microscope image of Pt metal particles confined to porous cerium oxide in Embodiment 2 of the present invention.

[0037] Figure 10 The diagram shows the propane direct dehydrogenation performance of the Pt metal particle-confined porous alumina composite catalyst in Example 1 of this invention.

[0038] Figure 11This is a graph showing the CO2-assisted propane oxidative dehydrogenation performance of the Pt metal particle-confined porous cerium oxide composite catalyst material in Example 2 of the present invention. Detailed Implementation

[0039] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0040] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0042] In recent years, propane dehydrogenation (PDH) technology has gradually become a major method for propylene production due to its efficient utilization of abundant shale gas resources and its high selectivity. Shale gas, as an unconventional natural gas resource, boasts vast reserves and wide distribution, and its abundant propane content provides a stable feedstock for propylene production via PDH. Furthermore, PDH technology exhibits high conversion rates and selectivity, directly converting propane into propylene, reducing intermediate steps and byproduct generation, thereby improving propylene production efficiency and economics. However, in the application of PDH technology, catalyst selection and performance have become key factors restricting its development. Platinum metal, due to its excellent catalytic activity, occupies an important position among PDH catalysts. However, under high-temperature PDH reaction conditions, platinum catalysts face technical challenges such as reduced propylene selectivity and catalyst deactivation due to high-temperature sintering and coke formation. This not only affects propylene yield and purity but also increases catalyst replacement frequency and production costs.

[0043] To address the aforementioned technical problems, in a first aspect, the present invention provides a method for preparing a metal particle-confined porous oxide, comprising:

[0044] Obtaining metal targets;

[0045] The metal target is placed in an organic solvent, and under ultrasonic conditions, it is bombarded with a laser beam to obtain a colloidal solution containing metal particles; the temperature of the organic solvent is -20~0℃.

[0046] Aldehydes and amines are added to the colloidal solution and stirred until the reaction is complete. The precipitate is then washed and dried to obtain a first powder, which is a metal particle-confined porous organic framework.

[0047] The first powder is dispersed in an ethanol solution of a metal salt, mixed evenly, concentrated and dried to obtain the second powder;

[0048] The second powder is calcined to obtain a metal particle-confined porous oxide; wherein the calcination temperature is 300~650℃ and the time is 4~7 hours.

[0049] Compared with the prior art, the method for preparing metal particle-confined porous oxide of the present invention, by bombarding a metal target with a laser beam, yields a colloidal solution containing metal particles. During this process, by controlling the temperature of the organic solvent to -20~0℃ and conducting the process under ultrasonic conditions, the aggregation or agglomeration of metal particles obtained from the laser beam bombardment of the metal target in the organic solvent can be avoided. Aldehydes and amines are added to the colloidal solution, and the aldehydes and amines react in the colloidal solution. The precipitate is then washed and dried to obtain a metal particle-confined porous organic framework, in which the loading of metal particles can reach up to 15 wt%. Further, using this porous organic framework as a template, the porous organic framework (first powder) is dispersed in an ethanol solution of a metal salt. The metal salt permeates into the porous organic framework, thereby obtaining a second powder. Further, the second powder is calcined to remove the porous organic framework, thus obtaining the metal particle-confined porous oxide. In the above process, for example, the temperature of the organic solvent can be -20℃, -10℃, or 0℃, the calcination temperature can be 300℃, 400℃, 550℃, or 650℃, and the calcination time can be 4 hours, 5 hours, 6 hours, or 7 hours. The metal particle-confined porous oxide prepared by this invention provides a large number of active sites for the catalytic process. When used in the propane dehydrogenation to propylene reaction, it exhibits high propane conversion and propylene selectivity, and does not sinter or form coke under high-temperature conditions. The technical solution of this invention solves the technical problems of low propylene selectivity of platinum catalysts and catalyst deactivation due to high-temperature sintering and coke formation in existing propane dehydrogenation technologies.

[0050] It should be understood that in the method for preparing the metal particle-confined porous oxide of the present invention, the content of metal particles in the colloidal solution can be controlled by controlling the laser flux of the laser beam and the bombardment time of the metal target. For example, the laser beam can be a nanosecond pulsed laser beam with a laser flux of 600-2000 mJ / pulse. -1 cm -1 The bombardment time of the metal target is 2 to 15 minutes. As another example, the laser flux of the nanosecond pulsed laser beam is 600 mJ / pulse. - 1 cm -1 1000mJpulse -1 cm -1 15000mJpulse -1 cm -1 Or 2000mJpulse -1 cm -1 For example, the content of metal particles in the colloidal solution can be 0.0001~0.0015 g / ml.

[0051] It should also be understood that in the preparation method of the metal particle-confined porous oxide of the present invention, the prepared metal particle-confined porous oxide is used in the propane dehydrogenation to propylene reaction. In order to further improve the propane conversion rate and propylene selectivity, it is necessary to control the types of metal and organic solvent. For example, the metal includes one or any two of platinum, silver, palladium, gold, gallium, cobalt, nickel, copper, iron, zinc and tin. For another example, the metal can be platinum, silver, palladium, gold, gallium, cobalt, nickel, copper, iron, zinc or tin, or platinum and silver, platinum and tin, platinum and gallium, cobalt and nickel, or gallium and zinc. For example, the organic solvent includes n-butanol, methanol, ethanol, dimethyl sulfoxide, dioxane, N,N-dimethylformamide and N,N-dimethylacetamide. For yet another example, the organic solvent can be n-butanol, methanol, ethanol, dimethyl sulfoxide, dioxane, N,N-dimethylformamide or N,N-dimethylacetamide.

[0052] It should also be understood that in the preparation method of the metal particle-confined porous oxide of the present invention, different aldehydes and amines have different chemical structures and reactivity. By selecting specific aldehydes and amines, the reaction conditions can be optimized, and the yield and purity of the target product can be improved. Furthermore, the types of aldehydes and amines directly affect the pore structure of the porous organic framework, thereby affecting the structure and performance of the subsequent porous oxide. The confinement effect of metal particles in the porous organic framework is also affected by the specific types of aldehydes and amines. Therefore, in order to obtain a porous organic framework with a better structure, the types of aldehydes and amines in the present invention also need to be controlled. For example, the aldehydes include terephthalaldehyde, substituted terephthalaldehyde, m-phenylenedialdehyde, biphenylenedialdehyde, substituted biphenylenedialdehyde, terphenylenedialdehyde, substituted terphenylenedialdehyde, and trialdehyde-resorcinol; the amines include p-phenylenediamine, substituted p-phenylenediamine, biphenylenediamine, substituted biphenylenediamine, terphenylenediamine, substituted terphenylenediamine, and 1,3,5-triaminobenzene. In another example, the aldehyde may be terephthalaldehyde, substituted terephthalaldehyde, isophenyltricarbonaldehyde, biphenyl dicarbonaldehyde, substituted biphenyl dicarbonaldehyde, terphenyl dicarbonaldehyde, substituted terphenyl dicarbonaldehyde, or trialdehyde-based phloroglucinol; the amine may be p-phenylenediamine, substituted p-phenylenediamine, biphenylenediamine, substituted biphenylenediamine, terphenylenediamine, substituted terphenylenediamine, or 1,3,5-triaminobenzene.

[0053] It should also be understood that in the preparation method of the metal particle confined porous oxide of the present invention, in order to improve the formation rate and purity of the target product (i.e., porous organic framework), the mixing ratio of the colloidal solution with the aldehyde and amine in the colloidal solution should be controlled within a reasonable range during the process of adding aldehyde and amine to the colloidal solution; for example, 0.01 mol of aldehyde and 0.01 mol of amine can be added to 200 ml of the colloidal solution.

[0054] It should also be understood that in the method for preparing the metal particle-confined porous oxide of the present invention, in order to ensure the complete reaction of the aldehyde and amine after adding aldehyde and amine to the colloidal solution and to obtain a porous organic framework with a better structure, it is necessary to control the reaction temperature and reaction time within a reasonable range; for example, the reaction temperature can be 60~80°C and the reaction time can be 12~72 hours; in another example, the reaction temperature can be 60°C, 70°C or 80°C and the reaction time can be 12 hours, 24 hours, 48 ​​hours or 72 hours.

[0055] It should also be understood that in the method for preparing the metal particle-confined porous oxide of the present invention, the prepared metal particle-confined porous oxide is used in the propane dehydrogenation to propylene reaction. In order to further improve the propane conversion rate and propylene selectivity, the type of metal salt should be controlled. For example, the metal salt includes aluminum nitrate, aluminum chloride, cerium nitrate, cerium ammonium nitrate, cerium chloride, zirconium nitrate and zirconium acetate; in another example, the metal salt can be aluminum nitrate, aluminum chloride, cerium nitrate, cerium ammonium nitrate, cerium chloride, zirconium nitrate or zirconium acetate.

[0056] It should also be understood that in the preparation method of the metal particle confined porous oxide of the present invention, the first powder is dispersed in an ethanol solution of a metal salt, mixed evenly, concentrated and dried to obtain the second powder. In order to uniformly disperse the first powder in the ethanol solution of the metal salt and prepare a porous oxide with higher propylene selectivity, it is also necessary to control the mass ratio of metal salt to ethanol within a reasonable range. For example, the mass ratio of metal salt to ethanol is 1:(35~50); in another example, the mass ratio of metal salt to ethanol can be 1:35, 1:40 or 1:50.

[0057] Secondly, the present invention also provides a metal particle-confined porous oxide, which is prepared by the metal particle-confined porous oxide preparation method described in the above technical solution.

[0058] Using the above technical solution, the metal particle-confined porous oxide of the present invention is prepared by the preparation method of the metal particle-confined porous oxide described in the above technical solution. In this preparation method, a colloidal solution containing metal particles is obtained by bombarding a metal target with a laser beam. During this process, by controlling the temperature of the organic solvent to -20~0℃ and carrying out the process under ultrasonic conditions, the metal particles obtained by bombarding the metal target with the laser beam can be prevented from agglomerating or accumulating in the organic solvent. Aldehydes and amines are added to the colloidal solution, and the aldehydes and amines react in the colloidal solution. The precipitate is washed and dried to obtain a metal particle-confined porous organic framework. The loading of metal particles in the porous organic framework can be as high as 15 wt%. Further, using the porous organic framework as a template, the porous organic framework (first powder) is dispersed in an ethanol solution of a metal salt. The metal salt will penetrate into the porous organic framework to obtain a second powder. Further, the second powder is calcined to remove the porous organic framework, thereby obtaining the metal particle-confined porous oxide. The metal particle-confined porous oxide prepared by this invention can provide a large number of active sites for the catalytic process. When used in the propane dehydrogenation to propylene reaction, it has a high propane conversion rate and propylene selectivity, and reduces the formation of sintering or coke under high temperature conditions.

[0059] Thirdly, the present invention provides the application of the above-mentioned metal particle-confined porous oxide in the dehydrogenation of propane to propylene.

[0060] To better understand the present invention, the following specific embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0061] Unless otherwise specified, all raw materials used in the following examples are commercially available. Example 1

[0062] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0063] S100, Obtain a polished platinum (Pt) sheet with dimensions of 2cm × 2cm and a thickness of 2cm;

[0064] S200: The platinum sheet was placed in a glass bottle containing 10 ml of dimethyl sulfoxide, and the bottle was fixed in an ultrasonic machine with 0°C water circulation. Under continuous ultrasonic conditions, a laser flux of 1.0 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the platinum sheet for 15 minutes to prepare a colloidal solution of Pt metal particles; the Pt metal content in the colloidal solution was 0.0005 g / ml.

[0065] In step S300, 1.08 g of p-phenylenediamine (0.01 mol) and 1.34 g of terephthalaldehyde (0.01 mol) were dispersed in 200 ml of the Pt metal particle colloidal solution from step S200. After ultrasonic treatment for 30 min to ensure uniform dispersion, the solution was placed in an oil bath and stirred at 60 °C for 72 h to complete the reaction. The stirring speed was 700 rpm.

[0066] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 60°C (drying for 12 hours) to obtain the first powder, which is the Pt metal particle confined porous organic framework.

[0067] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 2.25g of aluminum nitrate nonahydrate, sonicate for 30min to make it evenly dispersed, and then rotary evaporate at 60℃ and dry overnight (dry for 12 hours) to obtain the second powder.

[0068] S600, the second powder from step S500 is placed in a muffle furnace, heated to 600°C in air, and calcined at 600°C for 6 hours, then cooled to room temperature to obtain a light gray powder, which is the Pt metal particle confined porous alumina composite catalytic material; wherein, the heating rate is 2°C / min. Example 2

[0069] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0070] S100, Obtain a polished platinum (Pt) sheet with dimensions of 2cm × 2cm and a thickness of 2cm;

[0071] S200: The platinum sheet was placed in a glass bottle containing 10 ml of n-butanol, and the bottle was fixed in an ultrasonic machine with water circulation at -10°C. Under continuous ultrasonic conditions, a laser flux of 1.5 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the platinum sheet for 10 minutes to prepare a colloidal solution of Pt metal particles; the Pt metal content in the colloidal solution was 0.0003 g / ml.

[0072] In step S300, 1.08 g of p-phenylenediamine (0.01 mol) and 1.34 g of terephthalaldehyde (0.01 mol) were dispersed in 200 ml of the Pt metal particle colloidal solution from step S200. After ultrasonic treatment for 30 min to ensure uniform dispersion, the solution was placed in an oil bath and stirred at 60 °C for 48 h to complete the reaction. The stirring speed was 800 rpm.

[0073] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 60°C (drying for 10 hours) to obtain the first powder, which is the Pt metal particle confined porous organic framework.

[0074] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 2g of cerium nitrate hexahydrate, sonicate for 30min to make it evenly dispersed, and then evaporate at 60℃ and dry overnight (dry for 12 hours) to obtain the second powder.

[0075] S600, the second powder from step S500 is placed in a muffle furnace, heated to 350°C in air, and calcined at 350°C for 5 hours, then cooled to room temperature to obtain a light gray powder, which is the Pt metal particle confined porous cerium oxide composite catalytic material; wherein, the heating rate is 2°C / min. Example 3

[0076] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0077] S100, Obtain a polished platinum (Pt) sheet with dimensions of 2cm × 2cm and a thickness of 2cm;

[0078] S200: The platinum sheet was placed in a glass bottle containing 10 ml of ethanol, and the bottle was fixed in an ultrasonic machine with water circulation at -20°C. Under continuous ultrasonic conditions, a laser flux of 1.2 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the platinum sheet for 5 minutes to prepare a colloidal solution of Pt metal particles; the Pt metal content in the colloidal solution was 0.001 g / ml.

[0079] In step S300, 1.08 g of p-phenylenediamine (0.01 mol) and 1.34 g of terephthalaldehyde (0.01 mol) were dispersed in 200 ml of the Pt metal particle colloidal solution from step S200. After ultrasonic treatment for 30 min to ensure uniform dispersion, the solution was placed in an oil bath and stirred at 60 °C for 72 h to complete the reaction at a stirring rate of 500 rpm.

[0080] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 60°C (drying for 10 hours) to obtain the first powder, which is the Pt metal particle confined porous organic framework.

[0081] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 1.8g of zirconium nitrate pentahydrate, sonicate for 30min to make it evenly dispersed, and then rotary evaporate at 60℃ and dry overnight (dry for 12 hours) to obtain the second powder.

[0082] S600, the second powder from step S500 is placed in a muffle furnace, heated to 350°C in air, and calcined at 350°C for 5 hours, then cooled to room temperature to obtain a light gray powder, which is the Pt metal particle confined porous zirconia composite catalyst material; wherein, the heating rate is 2°C / min. Example 4

[0083] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0084] S100, Obtain a polished sheet of tin (Sn) with dimensions of 2cm × 2cm and a thickness of 2cm;

[0085] S200: The tin sheet was placed in a glass bottle containing 10 ml of dimethyl sulfoxide, and the bottle was fixed in an ultrasonic machine with water circulation at -5°C. Under continuous ultrasonic conditions, a laser flux of 0.6 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the tin sheet for 1 minute to prepare a Sn metal particle colloidal solution; the Sn metal content in the Sn metal particle colloidal solution was 0.0015 g / ml.

[0086] In step S300, 1.08 g of p-phenylenediamine (0.01 mol) and 2.1 g of trialdehyde phloroglucinol (0.01 mol) were dispersed in 200 ml of the Sn metal particle colloidal solution from step S200. After ultrasonic treatment for 30 min to ensure uniform dispersion, the solution was placed in an oil bath and stirred at 60 °C for 72 h to complete the reaction. The stirring speed was 800 rpm.

[0087] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 60°C (drying for 12 hours) to obtain the first powder, which is the Sn metal particle confined porous organic framework.

[0088] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 2.25g of aluminum nitrate nonahydrate, sonicate for 30min to make it evenly dispersed, and then rotary evaporate at 60℃ and dry overnight (dry for 12 hours) to obtain the second powder.

[0089] S600, the second powder from step S500 is placed in a muffle furnace, heated to 600°C in air, and calcined at 600°C for 6 hours, then cooled to room temperature to obtain a light gray powder, which is the Sn metal particle confined porous alumina composite catalytic material; wherein, the heating rate is 2°C / min. Example 5

[0090] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0091] S100, Obtain a polished nickel (Ni) sheet with dimensions of 2cm × 2cm and a thickness of 2cm;

[0092] S200: The nickel sheet was placed in a glass bottle containing 10 ml of n-butanol, and the bottle was fixed in an ultrasonic machine with water circulation at -10°C. Under continuous ultrasonic conditions, a laser flux of 1.2 mJ pulse was used. -1 cm -2A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the nickel sheet for 1 minute to prepare a Ni metal particle colloidal solution; the Ni metal particle colloidal solution contained 0.0008 g / ml of metallic Ni.

[0093] In step S300, 1.77 g of dichloro-p-phenylenediamine (0.01 mol) and 1.63 g of m-phenyltricarboxaldehyde (0.01 mol) were dispersed in 200 ml of the Ni metal particle colloidal solution from step S200. After ultrasonic treatment for 30 min to ensure uniform dispersion, the solution was placed in an oil bath and stirred at 60 °C for 72 h to complete the reaction at a stirring rate of 700 rpm.

[0094] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 60°C (drying for 10 hours) to obtain the first powder, which is the Ni metal particle confined porous organic framework.

[0095] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 2g of cerium nitrate hexahydrate, sonicate for 30min to make it evenly dispersed, and then evaporate at 60℃ and dry overnight (dry for 12 hours) to obtain the second powder.

[0096] S600, the second powder from step S500 is placed in a muffle furnace, heated to 600°C in air, and calcined at 600°C for 6 hours, then cooled to room temperature to obtain a light gray powder, which is the Ni metal particle confined porous cerium oxide composite catalytic material; wherein, the heating rate is 2°C / min. Example 6

[0097] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0098] S100, Obtain a polished cobalt (Co) sheet with dimensions of 2cm × 2cm and a thickness of 2cm;

[0099] S200: The cobalt sheet was placed in a glass bottle containing 10 ml of dimethyl sulfoxide, and the bottle was fixed in an ultrasonic machine with 0°C water circulation. Under continuous ultrasonic conditions, a laser flux of 1.0 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the cobalt sheet for 5 minutes to prepare a Co metal particle colloidal solution; the Co metal content in the Co metal particle colloidal solution was 0.0012 g / ml.

[0100] In step S300, 1.08 g of p-phenylenediamine (0.01 mol) and 1.34 g of terephthalaldehyde (0.01 mol) were dispersed in 200 ml of the Co metal particle colloidal solution from step S200. After ultrasonic treatment for 40 min to ensure uniform dispersion, the solution was placed in an oil bath and stirred at 60 °C for 72 h to complete the reaction. The stirring speed was 700 rpm.

[0101] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 80°C (drying for 12 hours) to obtain the first powder, which is the Co metal particle confined porous organic framework.

[0102] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 1.8g of zirconium nitrate pentahydrate, sonicate for 30min to make it evenly dispersed, and then rotary evaporate at 60℃ and dry overnight (dry for 12 hours) to obtain the second powder.

[0103] S600, the second powder from step S500 is placed in a muffle furnace, heated to 350°C in air, and calcined at 350°C for 5 hours, then cooled to room temperature to obtain a light gray powder, which is the Co metal particle confined porous zirconia composite catalyst material; wherein, the heating rate is 2°C / min. Example 7

[0104] This embodiment provides a method for preparing a metal particle-confined porous oxide, including:

[0105] S100, obtain polished platinum (Pt) and tin (Sn) sheets, both with dimensions of 2cm × 2cm and a thickness of 2cm;

[0106] S200: The platinum sheet was placed in a glass bottle containing 10 ml of dimethyl sulfoxide, and the bottle was fixed in an ultrasonic machine with 0°C water circulation. Under continuous ultrasonic conditions, a laser flux of 1.0 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the platinum sheet for 5 minutes to prepare a colloidal solution of Pt metal particles.

[0107] The tin sheet was then placed in a glass bottle containing 10 ml of dimethyl sulfoxide, and the bottle was fixed in an ultrasonic machine with water circulation at -5°C. Under continuous ultrasonic conditions, a laser flux of 0.6 mJ pulse was used. -1 cm -2 A nanosecond pulsed laser beam (Nd:YAG) was used to bombard the tin sheet for 5 minutes to prepare a colloidal solution of Sn metal particles.

[0108] The Pt metal particle colloidal solution contains 0.0003 g / ml of Pt metal and the Sn metal particle colloidal solution contains 0.001 g / ml of Sn metal.

[0109] S300: Mix 100 ml of Pt metal particle colloidal solution and 100 ml of Sn metal particle colloidal solution from step S200 to obtain a mixed colloidal solution; disperse 1.08 g of p-phenylenediamine (0.01 mol) and 1.34 g of terephthalaldehyde (0.01 mol) in 200 ml of the mixed colloidal solution, sonicate for 30 min to ensure uniform dispersion, place in an oil bath, and stir at 60 °C for 72 h to complete the reaction at a stirring rate of 700 rpm;

[0110] After the reaction in step S300 is completed, a precipitate will be formed. After centrifuging the precipitate, wash it three times with N,N-dimethylformamide and ethanol respectively, and then dry it overnight in an oven at 60°C (drying for 12 hours) to obtain the first powder, which is the PtSn metal particle confined porous organic framework.

[0111] S500: Disperse 2g of the first powder obtained in step S400 in 100ml of ethanol solution containing 2.4g of aluminum nitrate hexahydrate, sonicate for 30min to make it evenly dispersed, rotary evaporate at 60℃, and dry overnight (dry for 12 hours) to obtain the second powder.

[0112] S600, the second powder from step S500 is placed in a muffle furnace, heated to 600°C in air, and calcined at 600°C for 6 hours, then cooled to room temperature to obtain a light gray powder, which is the PtSn metal particle confined porous alumina composite catalytic material; wherein, the heating rate is 2°C / min.

[0113] Through Examples 1 to 7 above, the present invention has prepared Pt metal particle-confined porous alumina composite catalysts, Pt metal particle-confined porous cerium oxide composite catalysts, Pt metal particle-confined porous zirconia composite catalysts, Sn metal particle-confined porous alumina composite catalysts, Ni metal particle-confined porous cerium oxide composite catalysts, Co metal particle-confined porous zirconia composite catalysts, and PtSn metal particle-confined porous alumina composite catalysts. The following will use Examples 1 and 2 as examples, in conjunction with the accompanying drawings. Figure 1 To be continued Figure 11 Explanation: From Figure 1As can be seen, porous organic frameworks (POFs) were successfully synthesized in Example 1. The Pt metal particle-confined porous organic framework (Pt@POF) obtained in Example 1 exhibits excellent crystallinity and ordered structure. Furthermore, the characteristic diffraction peaks of Pt (platinum) (PDF#04-0802) demonstrate that the Pt particles are highly uniformly distributed within the pores of the porous organic framework POFs. This invention provides a feasible, simple, and efficient strategy for in-situ implantation of metal-active catalysts. Figure 2 It can be seen that the Pt metal particle-confined porous alumina (Pt@Al2O3) composite catalytic material of Example 1 does not exhibit strong diffraction peaks typical of alumina, indicating that the alumina support is amorphous. A distinct Pt diffraction peak (PDF#04-0802) can be observed, proving that Pt was successfully implanted into the alumina support using a Pt particle-confined organic framework (POF) composite material as a template. Figure 3 It can be seen that the Pt metal particle-confined porous cerium oxide (Pt@CeO2) composite catalytic material of Example 2 exhibits strong diffraction peaks of cerium oxide, while the Pt diffraction peaks are not obvious, indicating that the small Pt particles were successfully and uniformly confined within the cerium oxide support. Figure 4 It can be seen that the peaks at 73.1 eV and 76.4 eV in the XPS spectrum of Pt4f are attributed to Pt in the Pt@POF composite material. 2+ This proves that Pt was successfully implanted into the POF vector. From Figure 5 It can be seen that Pt 4f 5 / 2 It overlaps with Al 2p (74.5 eV), while the peak at 71.2 eV corresponds to Pt 4f. 7 / 2 This also proves that Pt was successfully implanted into the alumina carrier. From Figure 6 It can be seen that the peaks at 73.1 eV and 76.4 eV in the XPS spectrum of Pt 4f are attributed to Pt in the Pt@CeO2 composite material. δ+ (δ < 2), proving that Pt was successfully implanted into the cerium oxide carrier. From Figure 7 It can be seen that the Pt particles are highly uniformly dispersed within the Pt metal particle-confined porous organic framework (Pt@POF). From... Figure 8 It can be seen that the Pt particles are uniformly distributed within the alumina support. From Figure 9 It can be seen that the Pt particles are uniformly distributed within the cerium oxide support.

[0114] Taking the Pt metal particle-confined porous alumina (Pt@Al2O3) composite catalyst and the Pt metal particle-confined porous cerium oxide (Pt@CeO2) composite catalyst prepared in Examples 1 and 2 above as examples, the Pt metal particle-confined porous alumina (Pt@Al2O3) composite catalyst and the Pt metal particle-confined porous cerium oxide (Pt@CeO2) composite catalyst were respectively applied to propane dehydrogenation to propylene. For example, the Pt metal particle-confined porous alumina (Pt@Al2O3) composite catalyst of Example 1 (hereinafter referred to as the first catalyst) was applied to propane dehydrogenation to propylene: 0.3g of the first catalyst was mixed evenly with 0.7g of 40-60 mesh quartz sand, and then loaded into a fixed-bed reactor. The reactants (propane:argon = 5:15ml / min) were introduced at 600°C to carry out the direct dehydrogenation reaction of propane. Figure 10 It can be seen that the initial propane conversion and propylene selectivity of the Pt metal particle-confined porous alumina (Pt@Al2O3) composite catalytic material (the first catalyst) are 37.36% and 97.22%, respectively. After catalysis for 2160 min, the propane conversion and propylene selectivity can still be maintained at 10% and 96.7%, respectively. This proves that the Pt particle-confined porous alumina (Pt@Al2O3) composite catalytic material synthesized using a porous organic framework as a template has high selectivity and high stability, which strongly demonstrates the high efficiency and feasibility of the technical solution of this invention.

[0115] As another example, the Pt metal particle-confined porous cerium oxide (Pt@CeO2) composite catalytic material (hereinafter referred to as the second catalyst) of Example 2 was applied to propane dehydrogenation to propylene: 0.3g of the second catalyst was mixed evenly with 0.7g of 40-60 mesh quartz sand, and then loaded into a fixed-bed reactor. The reactants (propane:carbon dioxide:argon = 5:5:15ml / min) were introduced at 600°C to carry out the propane oxidative dehydrogenation reaction. Figure 11 It can be seen that the initial propane conversion, CO2 conversion and propylene selectivity of the Pt metal particle confined porous cerium oxide (Pt@CeO2) composite catalytic material (second catalyst) are 35.65%, 33.03% and 92.74%, respectively, which proves that the Pt metal particle confined porous cerium oxide (Pt@CeO2) composite catalytic material synthesized with porous organic framework as template also has high selectivity and high stability.

[0116] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0117] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a metal particle confined porous oxide, characterized by, The preparation method comprises the following steps: obtaining a metal target; the metal in the metal target comprises one or any two of platinum, silver, palladium, gold, gallium, cobalt, nickel, copper, iron, zinc and tin; The metal target is placed in an organic solvent, and the metal target is bombarded by a laser beam under ultrasonic conditions to obtain a colloidal solution containing metal particles; the temperature of the organic solvent is -20-0 ℃; the content of the metal particles in the colloidal solution is 0.0001-0.0015 g / ml, the laser beam is a nanosecond pulsed laser beam, the laser fluence of the nanosecond pulsed laser beam is 600-2000 mJpulse -1 cm -2 , and the time for bombarding the metal target is 2-15 minutes. adding aldehyde and amine into the colloidal solution, stirring until the reaction is completed, washing and drying the precipitate to obtain a first powder; the first powder is a metal particle confined porous organic framework; dispersing the first powder in an ethanol solution of a metal salt, uniformly mixing, and then concentrating and drying to obtain a second powder; the metal salt comprises aluminum nitrate, aluminum chloride, cerium nitrate, cerium ammonium nitrate, cerium chloride, zirconium nitrate or zirconium acetate; in the ethanol solution of the metal salt, the mass ratio of the metal salt to ethanol is 1: (35-50); subjecting the second powder to calcination treatment to obtain a metal particle confined porous oxide; the calcination treatment is performed at a temperature of 300-650 ℃ for 4-7 hours.

2. The method for preparing metal particle-confined porous oxides according to claim 1, characterized in that, The organic solvent comprises n-butanol, methanol, ethanol, dimethyl sulfoxide, dioxane, N,N-dimethylformamide or N,N-dimethylacetamide.

3. The method for preparing metal particle-confined porous oxides according to claim 2, characterized in that, The aldehyde comprises p-xylylformaldehyde, substituted p-xylylformaldehyde, m-triformaldehyde, biphenylformaldehyde, substituted biphenylformaldehyde, triphenylformaldehyde, substituted triphenylformaldehyde or triformaldehyde; and / or, The amine comprises p-xylylamine, substituted p-xylylamine, biphenylamine, substituted biphenylamine, triphenylamine, substituted triphenylamine or 1,3,5-triaminobenzene.

4. The method of claim 3, wherein the metal particle confined porous oxide is prepared by the steps of: The adding of the aldehyde and the amine into the colloidal solution comprises: 0.01 mol of aldehyde and 0.01 mol of amine are added into every 200 ml of the colloidal solution.

5. The method for preparing metal particle-confined porous oxide according to claim 4, characterized in that, During the process of adding the aldehyde and the amine into the colloidal solution and stirring until the reaction is completed, the reaction temperature is 60-80 ℃, and the reaction time is 12-72 hours.

6. A metal particle confined porous oxide characterized in that, The metal particle confined porous oxide is prepared by using the preparation method of any one of claims 1-5.

7. The metal particle confined porous oxide according to claim 6 is applied in the preparation of propylene from propane dehydrogenation.

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