Application of porous material loaded metal oxide nanoparticle composite material based on microwave-assisted method in catalytic ozonolysis
The preparation of porous material-loaded metal oxide nanoparticle composite materials through microwave-assisted method solves the problems of high cost of nanoparticle synthesis and high energy consumption, achieves efficient and stable ozone degradation effects, and improves the activity and mass transfer efficiency of the catalyst.
Patent Information
- Application Number
- CN202510588081.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-08-05
AI Technical Summary
The prior art lacks universal microwave-assisted synthesis methods, resulting in high cost of nanoparticle synthesis, high energy consumption and uneven particle size distribution, making it difficult to achieve efficient and stable preparation of porous material-loaded metal oxide nanoparticle composite materials, which in turn affects the catalytic ozone decomposition efficiency.
Using microwave-assisted method, porous material-loaded metal oxide nanoparticle composite materials are prepared by low-temperature storage of metal precursors, building a hydrophobic carrier system, low-temperature in-situ packaging reaction and microwave-assisted rapid nucleation, so as to achieve uniform dispersion and efficient coating of nanoparticles within the porous material.
It significantly improves the ozone degradation efficiency, reduces energy consumption and reaction temperature, and builds a composite material with high dispersion and high active sites, which improves the performance of catalytic ozone decomposition.
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Figure CN120421044A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of nanocomposite materials, and in particular relates to an application of a porous material-loaded metal oxide nanoparticle composite material in catalytic ozone decomposition based on a microwave-assisted method. Background Art
[0002] The field of nanocatalysis has ushered in a revolutionary breakthrough, with ultrafine metal oxide nanoparticles (UMONPs) with a particle size of less than 3 nanometers emerging with their unique quantum properties. Their unique electronic properties at the quantum scale, such as the shift of the d-band center and the precise control of the Fermi level, can greatly improve the utilization efficiency of catalytically active atoms. In environmental catalytic applications, experimental data show that UMONPs can achieve a carbon monoxide (CO) conversion rate exceeding 99% at a low temperature of 150°C during the purification of automobile exhaust. Compared with the activation temperature of traditional catalysts, this is significantly reduced by about 100°C, and does not rely on precious metal carriers, demonstrating strong disruptive technological potential.
[0003] Looking back at traditional chemical synthesis pathways, the sol-gel method is limited by differences in the kinetics of hydrolysis and condensation reactions, resulting in a high degree of discreteness in the particle size distribution; while the precipitation method causes grain coarsening problems due to the Ostwald ripening effect. In contrast, microwave-assisted synthesis technology, by virtue of the uniform nucleation mechanism mediated by electromagnetic fields, can precisely control the particle size distribution of UMONPs such as ferroferric oxide (Fe3O4). To address the problem of secondary aggregation driven by the surface energy of nanoparticles, although traditional surfactant coating (such as polyvinylpyrrolidone PVP) can stabilize the colloid in the short term, the thermal decomposition residues of organic matter easily cover the active sites, weakening the catalytic efficiency. The microwave method, by directionally controlling the hydroxyl density on the particle surface and combining it with a pulse energy input strategy, enables UMONPs such as zinc oxide (ZnO) to maintain monodisperse stability for up to 180 days without the use of surface modifiers.
[0004] From the perspective of industrial cost-benefit analysis, the investment cost of a single device for physical vapor deposition (PVD) technology exceeds US$500,000, and the unit energy consumption is as high as 8-10 kWh / g. The microwave synthesis system, based on the principle of dielectric heating, reduces the unit energy consumption to 1.2-1.5 kWh / g, and the reaction cycle is shortened to one-tenth of the traditional hydrothermal method. It is particularly noteworthy that the microwave method has achieved a breakthrough in low-temperature and high-efficiency synthesis process. For example, the synthesis temperature of UMONPs such as copper oxide (CuO) can be as low as 120°C, which saves more than 72% energy compared to the traditional calcination method (which needs to be above 800°C), providing solid technical support for large-scale industrial production. Therefore, microwave-assisted synthesis technology is recognized as an efficient and feasible path for the preparation of UMONPs. However, there is currently a lack of universal microwave-assisted synthesis methods. Summary of the Invention
[0005] This invention aims to address related issues in the prior art and provides a microwave-assisted method for preparing a porous material-loaded metal oxide nanoparticle composite material and its application in catalytic ozone decomposition. This method, through innovative process steps, achieves efficient, stable, and economical preparation of the composite material. This composite material can serve as a high-quality ozone decomposition catalyst, significantly improving ozone reaction efficiency and achieving highly effective ozone pollution control.
[0006] The technical solution adopted in the present invention is:
[0007] Application of a porous material loaded metal oxide nanoparticle composite material in catalytic ozone decomposition based on microwave assisted method.
[0008] Furthermore, the above application is carried out as follows: 10-100 mg of a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method is evenly mixed with 9 times the mass of quartz sand, and added to a double-pass quartz tube with a diameter of 6 mm, ozone is introduced at an inlet air flow rate of 0.1-1 L / min, and ozone is catalytically decomposed at a relative humidity of 10-90% and a temperature of 10-40°C.
[0009] Furthermore, in the above application, the method for preparing the porous material-loaded metal oxide nanoparticle composite material based on the microwave-assisted method comprises the following steps:
[0010] 1) Low-temperature storage of metal precursors: Dissolve the metal source and precipitant in ultrapure water, mix and dissolve thoroughly to form a homogeneous metal precursor solution, and store it at a low temperature of 0 to 20°C to prevent hydrolysis and precipitation of metal ions;
[0011] 2) Constructing a hydrophobic carrier system: The porous material powder is dispersed in a hydrophobic solvent, and then subjected to ultrasonic dispersion and vigorous stirring for 15 to 20 minutes to prepare a uniform and stable porous material suspension;
[0012] 3) Low-temperature in-situ encapsulation reaction: Add the metal precursor solution dropwise to the porous material suspension under continuous vigorous stirring at a temperature of 0 to 20°C for 2 to 3 hours;
[0013] 4) Microwave-assisted rapid nucleation: After filtering and removing the hydrophobic solvent, the metal precursor is treated with microwave radiation for 5 to 30 minutes to promote rapid nucleation of the metal precursor inside the porous support and in situ growth of metal oxide nanoparticles. After washing and drying, a porous material-loaded metal oxide nanoparticle composite material with a core-shell channel structure is obtained.
[0014] Preferably, in the above-mentioned method for preparing a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method, in step 1), the mass ratio of the metal source and the precipitant is controlled in the range of 5:10 to 5:30 to ensure uniform precipitation of metal ions and regular growth of nanoparticles.
[0015] Preferably, in the above-mentioned method for preparing porous material-loaded metal oxide nanoparticle composite materials based on microwave-assisted method, in step 1), the metal source is a single component of metal inorganic salt and metal organic complex or a composite system of two or more, which broadens the raw material adaptability of the precursor.
[0016] More preferably, the metal source is a single component of metal sulfate, metal nitrate, metal halide, or metal acetate, or a composite system of two or more.
[0017] Preferably, in the above-mentioned microwave-assisted method for preparing a porous material-loaded metal oxide nanoparticle composite material, in step 1), the precipitant is an organic base compound, which utilizes the effect of generating hydroxide particles upon heating to induce metal ion precipitation.
[0018] More preferably, the precipitant is an alkaline organic substrate such as urea or hydrazine hydrate, which can achieve controllable temperature precipitation of metal ions at low temperatures.
[0019] Preferably, in the above-mentioned method for preparing a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method, in step 2), the porous material is a metal organic framework, a covalent organic framework, a zeolite or a porous carbon material.
[0020] Preferably, in the above-mentioned method for preparing a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method, in step 2), the hydrophobic solvent is a single component or a composite system of two or more of n-hexane, cyclohexane, ethyl acetoacetate, ethyl acetate, polar esters or their complex systems, and the growth environment of the nanoparticles is regulated by the solvent effect.
[0021] Preferably, in the above-mentioned microwave-assisted method for preparing porous material-loaded metal oxide nanoparticle composite materials, in step 3), the droplet acceleration rate of the metal precursor solution is an ultra-low flow rate of 0.005 to 0.01 ml per minute to ensure that the precursor can smoothly enter the pores.
[0022] Preferably, in the above-mentioned method for preparing a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method, in step 3), the added volume of the metal precursor solution is precisely controlled within a trace range of 0.01 to 1 ml, and a dropwise addition process is used to achieve uniform dispersion of the nanoparticles in the pores of the carrier.
[0023] Preferably, in the above-mentioned method for preparing a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method, in step 4), the microwave power is regulated in a wide power range of 300 to 800 W, which can not only ensure the rapid thermal decomposition of the metal precursor, but also avoid the agglomeration of nanoparticles caused by overheating.
[0024] The beneficial effects of the present invention are:
[0025] 1. Through the hydrophobic force of the solvent, UMONPs are coated on PM, overcoming the surface agglomeration and pore blockage problems of the traditional impregnation method.
[0026] 2. Construct a microwave-assisted in-situ synthesis system to achieve targeted nucleation of nanoparticles in pores at lower temperatures, significantly reducing energy consumption and reaction temperature.
[0027] 3. The formation of a three-level structure of "nanoparticles-porous carrier-three-dimensional channels" significantly enhances the high dispersibility and accessibility of UMONPs in this structure, significantly improving their performance in ozone degradation. During ozone degradation, the material's high specific surface area fully exposes active sites, allowing for the efficient generation of reactive oxygen species and accelerating the degradation rate. Simultaneously, the three-dimensional mass transfer channels significantly enhance the mass transfer and diffusion efficiency of ozone, thereby increasing the reaction rate and efficiency. This technology overcomes the challenge of synergistically improving the activity, stability, and mass transfer efficiency of nanocomposites, providing a new approach for the development of high-performance environmental catalytic materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 2 is the PXRD pattern of Co3O4@MOF-235 prepared in Example 1 and the original MOF-235.
[0029] Figure 2 This is an ozone degradation performance curve of Co3O4@MOF-235 prepared in Example 1 with different masses at 10% RH (Examples 2-4).
[0030] Figure 3 This is a graph showing the ozone degradation performance of 10 mg of Co3O4@MOF-235 prepared in Example 1 at 10-90% RH (Examples 2, 5, and 6). DETAILED DESCRIPTION
[0031] To clarify the purpose, technical solutions and advantages of the present invention, the following will describe the technical solutions in the embodiments of the present invention in more detail in conjunction with the preferred embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of them.
[0032] Example 1
[0033] A method for preparing a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method, the specific steps are as follows:
[0034] 1) Prepare a metal precursor solution: Dissolve cobalt nitrate hexahydrate and urea in ultrapure water at a mass ratio of 5:10. Stir thoroughly until completely dissolved and mixed to form a clear metal precursor solution. Store the solution at 10°C to prevent premature hydrolysis and precipitation of the metal ions.
[0035] 2) Preparation of a porous material suspension: MOF-235 powder was added to n-hexane, and the MOF-235 powder was uniformly dispersed in the n-hexane by ultrasonic treatment and vigorous stirring for 15 minutes to form a stable porous material suspension.
[0036] 3) Addition and Reaction of Metal Precursor Solution: Slowly add 0.1 mL of the metal precursor solution to the porous material suspension at a rate of 0.005 mL / min while maintaining a controlled temperature of 0-20°C. Maintain vigorous stirring during the addition process to ensure sufficient contact between the metal precursor solution and the porous material. After the addition is complete, continue stirring for 2 hours to ensure uniform distribution of the metal precursor within the pores of the porous material and to allow for a preliminary reaction.
[0037] 4) Microwave-assisted rapid nucleation: The reaction mixture was filtered to remove the hydrophobic solvent, n-hexane. The filter cake was then subjected to a 600W microwave for 15 minutes, prompting the metal precursor to rapidly nucleate and in situ grow into metal oxide nanoparticles within the porous support. After washing and drying, the resulting powder was collected to form the Co3O4@MOF-235 composite material.
[0038] like Figure 1 As shown, the PXRD pattern of MOF-235(Fe) after encapsulation of Co3O4 still maintains characteristic peaks that are highly consistent with those of the original MOF-235(Fe), indicating that the encapsulation process did not destroy the structure of MOF-235. Furthermore, the absence of characteristic peaks of Co3O4 indicates that the Co3O4 nanoparticles are highly dispersed and lack strong diffraction. This preparation strategy cleverly combines sophisticated methods such as microwave irradiation, precise droplet rate regulation, and strict control of reaction time to achieve near-ideal uniform dispersion and efficient encapsulation of metal oxide nanoparticles within the porous matrix, thereby successfully constructing a composite material system with excellent overall performance.
[0039] Example 2 Evaluation of the catalytic ozone decomposition performance of the composite material
[0040] 10 mg of the Co3O4@MOF-235 sample prepared in Example 1 was mixed evenly with 9 times the mass of quartz sand and added to a double-pass quartz tube with a diameter of 6 mm. Subsequently, the quartz tube containing the sample was placed on a self-built integrated catalytic decomposition ozone performance evaluation platform to evaluate its ozone decomposition performance. The evaluation platform integrates five functional modules: ozone preparation, flow rate detection, humidity control, ozone detection and tail gas treatment. The ozone concentration was detected using a Model 202 ozone analyzer (produced by 2B Technology). The specific test parameter ranges are as follows: catalyst dosage 10 mg, inlet air flow rate 0.1 L / min, relative humidity 10% RH, and test temperature 40 ° C. During the experiment, by precisely controlling each parameter, the ozone catalytic decomposition efficiency of the Co3O4@MOF-235 composite material under different working conditions can be systematically investigated to ensure the accuracy and repeatability of the data.
[0041] Experimental findings (such as Figure 2 and 3 ), 10 mg of the Co3O4@MOF-235 composite catalytic material prepared in Example 1 has an ozone degradation efficiency of nearly 100% at 10% RH, and the efficiency can be maintained for a long time.
[0042] Example 3 Evaluation of the catalytic ozone decomposition performance of the composite material
[0043] 50 mg of the Co3O4@MOF-235 sample prepared in Example 1 was mixed evenly with 9 times the mass of quartz sand and added to a double-pass quartz tube with a diameter of 6 mm. Subsequently, the quartz tube containing the sample was placed on a self-built integrated catalytic decomposition ozone performance evaluation platform to evaluate its ozone decomposition performance. The evaluation platform integrates five functional modules: ozone preparation, flow rate detection, humidity control, ozone detection and tail gas treatment. The ozone concentration was detected using a Model 202 ozone analyzer (produced by 2B Technology). The specific test parameter ranges are as follows: catalyst dosage 50 mg, inlet air flow rate 0.1 L / min, relative humidity 10% RH, and test temperature 40 ° C. During the experiment, by precisely controlling each parameter, the ozone catalytic decomposition efficiency of the Co3O4@MOF-235 composite material under different working conditions can be systematically investigated to ensure the accuracy and repeatability of the data.
[0044] Experimental findings (such as Figure 2 ), 50 mg of the Co3O4@MOF-235 composite catalytic material prepared in Example 1 has an ozone degradation efficiency of nearly 100% at 10% RH, and the efficiency can be maintained for a long time.
[0045] Example 4 Evaluation of the catalytic ozone decomposition performance of the composite material
[0046] 100 mg of the Co3O4@MOF-235 sample prepared in Example 1 was mixed evenly with 9 times the mass of quartz sand and added to a double-pass quartz tube with a diameter of 6 mm. Subsequently, the quartz tube containing the sample was placed on a self-built integrated catalytic decomposition ozone performance evaluation platform to evaluate its ozone decomposition performance. The evaluation platform integrates five functional modules: ozone preparation, flow rate detection, humidity control, ozone detection and tail gas treatment. The ozone concentration was detected using a Model 202 ozone analyzer (produced by 2B Technology). The specific test parameter ranges are as follows: catalyst dosage 100 mg, inlet air flow rate 0.1 L / min, relative humidity 10% RH, and test temperature 40 ° C. During the experiment, by precisely controlling each parameter, the ozone catalytic decomposition efficiency of the Co3O4@MOF-235 composite material under different working conditions can be systematically investigated to ensure the accuracy and repeatability of the data.
[0047] Experimental findings (such as Figure 2 ), 100 mg of the Co3O4@MOF-235 composite catalytic material prepared in Example 1 has an ozone degradation efficiency of nearly 100% at 10% RH, and the efficiency can be maintained for a long time.
[0048] Example 5 Evaluation of the catalytic ozone decomposition performance of the composite material
[0049] 10 mg of the Co3O4@MOF-235 sample prepared in Example 1 was mixed evenly with 9 times the mass of quartz sand and added to a double-pass quartz tube with a diameter of 6 mm. Subsequently, the quartz tube containing the sample was placed on a self-built integrated catalytic decomposition ozone performance evaluation platform to evaluate its ozone decomposition performance. The evaluation platform integrates five functional modules: ozone preparation, flow rate detection, humidity control, ozone detection and tail gas treatment. The ozone concentration was detected using a Model 202 ozone analyzer (produced by 2B Technology). The specific test parameter ranges are as follows: catalyst dosage 10 mg, inlet air flow rate 0.1 L / min, relative humidity 50% RH, and test temperature 40 ° C. During the experiment, by precisely controlling each parameter, the ozone catalytic decomposition efficiency of the Co3O4@MOF-235 composite material under different working conditions can be systematically investigated to ensure the accuracy and repeatability of the data.
[0050] Experimental findings (such as Figure 3 ), 10 mg of the Co3O4@MOF-235 composite catalytic material prepared in Example 1 has an ozone degradation efficiency of nearly 100% at 50% RH, and the efficiency can be maintained for a long time.
[0051] Example 6 Evaluation of the catalytic ozone decomposition performance of the composite material
[0052] 10 mg of the Co3O4@MOF-235 sample prepared in Example 1 was mixed evenly with 9 times the mass of quartz sand and added to a double-pass quartz tube with a diameter of 6 mm. Subsequently, the quartz tube containing the sample was placed on a self-built integrated catalytic decomposition ozone performance evaluation platform to evaluate its ozone decomposition performance. The evaluation platform integrates five functional modules: ozone preparation, flow rate detection, humidity control, ozone detection and tail gas treatment. The ozone concentration was detected using a Model 202 ozone analyzer (produced by 2B Technology). The specific test parameter ranges are as follows: catalyst dosage 10 mg, inlet air flow rate 0.1 L / min, relative humidity 90% RH, and test temperature 40 ° C. During the experiment, by precisely controlling each parameter, the ozone catalytic decomposition efficiency of the Co3O4@MOF-235 composite material under different working conditions can be systematically investigated to ensure the accuracy and repeatability of the data.
[0053] Experimental findings (such as Figure 3 ), 10 mg of the Co3O4@MOF-235 composite catalytic material prepared in Example 1 has an ozone degradation efficiency of nearly 100% at 90% RH, and the efficiency can be maintained for a long time.
[0054] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. Application of a porous material loaded metal oxide nanoparticle composite material based on microwave assisted method in catalytic ozone decomposition.
2. The use according to claim 1, characterized in that The method is as follows: 10-100 mg of a porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method is evenly mixed with 9 times the mass of quartz sand, and added into a double-pass quartz tube with a diameter of 6 mm, ozone is introduced at an inlet air flow rate of 0.1-1 L / min, and ozone is catalytically decomposed at a relative humidity of 10-90% and a temperature of 10-40°C.
3. The use according to claim 1 or 2, characterized in that The method for preparing the porous material-loaded metal oxide nanoparticle composite material based on a microwave-assisted method comprises the following steps: 1) Low-temperature storage of metal precursors: Dissolve the metal source and precipitant in ultrapure water, mix and dissolve thoroughly to form a homogeneous metal precursor solution, and store at a low temperature of 0 to 20°C; 2) Constructing a hydrophobic carrier system: The porous material powder is dispersed in a hydrophobic solvent, and then subjected to ultrasonic dispersion and vigorous stirring for 15 to 20 minutes to prepare a uniform and stable porous material suspension; 3) Low-temperature in-situ encapsulation reaction: 0.01 to 1 ml of the metal precursor solution was added dropwise to the porous material suspension at a rate of 0.005 to 0.01 ml per minute with continuous vigorous stirring at a temperature of 0 to 20°C for 2 to 3 hours. 4) Microwave-assisted rapid nucleation: After filtering and removing the hydrophobic solvent, the material is irradiated with microwaves at a power of 300 to 800 W for 5 to 30 minutes to promote the rapid nucleation of the metal precursor inside the porous support and the in-situ growth of metal oxide nanoparticles. After washing and drying, a porous material-loaded metal oxide nanoparticle composite material with a core-shell channel structure is obtained.
4. The use according to claim 3, characterized in that In step 1), the mass ratio of the metal source to the precipitant is controlled within the range of 5:10 to 5:
30.
5. The use according to claim 3, characterized in that In step 1), the metal source is a single component of a metal inorganic salt and a metal organic complex or a composite system of two or more.
6. The use according to claim 5, characterized in that In step 1), the metal source is a single component of metal sulfate, metal nitrate, metal halide, or metal acetate, or a composite system of two or more.
7. The use according to claim 3, characterized in that In step 1), the precipitant is an organic base compound.
8. The use according to claim 7, characterized in that In step 1), the precipitant is urea or hydrazine hydrate.
9. The use according to claim 3, characterized in that In step 2), the porous material is a metal organic framework, a covalent organic framework, a zeolite or a porous carbon material.
10. The use according to claim 3, characterized in that In step 2), the hydrophobic solvent is a single component of n-hexane, cyclohexane, ethyl acetoacetate, ethyl acetate, or a composite system of two or more.