Bimetal organic framework material catalyst as well as preparation method and application thereof
By introducing -COOH groups into metal organic framework materials and preparing bimetallic organic framework materials by solvothermal method, the problem of unsatisfactory ozone degradation effect in the prior art is solved, efficient removal of phenyleuro compounds is achieved, and the benefits of the water treatment process are improved.
Patent Information
- Application Number
- CN202510330466.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-20
- Publication Date
- 2025-06-20
AI Technical Summary
When the prior art uses ozone catalytic oxidation technology, it is difficult to effectively degrade pollutants such as Dicaolon in water bodies, and metal organic framework materials are rarely used in the research on catalytic ozonation degradation, and the catalytic effect is not ideal.
A bimetallic organic framework material is used to modify a catalyst. By introducing a -COOH group, the catalyst improves the reactivity of the material to ozone and the adsorption of the phenyladium compounds, and is prepared in combination with the solvothermal method, and overcomes the problems of incomplete catalyst coating and carbonization.
The degradation rate of the ozone-based compounds of the ozone system is significantly improved, and the modification catalyst can be efficiently removed in a shorter time, which improves the benefits of the ozone oxidation process of water treatment.
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Figure CN120169438A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of water treatment, and particularly relates to a bimetallic organic framework material catalyst, a preparation method thereof, and an application thereof. Background Art
[0003] As a kind of advanced oxidation technology, the ozone catalytic oxidation technology can effectively degrade the refractory pollutants in water, and it will not produce secondary pollution itself. And the ozone and the ozone-based combined process are common advanced treatment processes in water plants and are also widely used in the treatment of new pesticides. Experiments show that the degradation rate of diuron by ozone alone is 5.5%, and the degradation effect of oxidation alone is not ideal.
[0004] Metal-organic framework materials, namely MOFs, are mainly new materials with a porous network structure framework formed by self-assembly of organic ligands containing oxygen and nitrogen elements and metal ions, and they belong to microporous or mesoporous materials. In recent years, the use of MOFs and their composites for the degradation of organic compounds has been deeply studied, but there are few research reports on the catalytic ozonation degradation of diuron, and it is not clear how to introduce new groups to modify the materials to achieve better catalytic effects. Summary of the Invention
[0005] The purpose of the present invention is to provide a bimetallic organic framework material catalyst, a preparation method thereof, and an application thereof, which have good catalytic effects on the degradation of phenylurea compounds in the ozonation system.
[0006] The technical solution of the present invention is as follows:
[0007] A preparation method of a modified catalyst of bimetallic organic framework material, comprising the following steps:
[0008] Add zero-valent iron, manganese nitrate solution, trimesic acid, hydrofluoric acid, and acetic acid into a reaction kettle with a polytetrafluoroethylene lining, mix evenly, then calcine at 100-150 °C for 2-4 h, then calcine at 150-200 °C for 2-6 h, and finally separate to obtain a solid, that's it; wherein, the molar ratio of iron element to manganese element is 1:0.5-2, the molar ratio of iron element to trimesic acid is 1:1-2, and the volume ratio of hydrofluoric acid to acetic acid is 1:100-150.
[0009] In some preferred embodiments, the preparation method further includes washing and drying the product in sequence after preparation.
[0010] In some preferred embodiments, the specific operation of washing is: stir and soak the obtained solid in absolute ethanol for 24 h, and then wash it with absolute ethanol.
[0011] In some preferred embodiments, the drying temperature is 40 - 80 °C and the drying time is 12 - 48 h.
[0012] In some preferred embodiments, the way of mixing evenly is stirring or ultrasonic oscillation.
[0013] A bimetallic organic framework material catalyst is prepared by the above preparation method.
[0014] The application of the above bimetallic organic framework material catalyst in the catalytic ozonation system for degrading phenylurea compounds.
[0015] In some preferred embodiments, the phenylurea compound is diuron.
[0016] A method for degrading phenylurea compounds in a catalytic ozonation system uses the above bimetallic organic framework material catalyst as the catalyst and ozone as the oxidant.
[0017] In some preferred embodiments, the phenylurea compound is diuron, the mass ratio of the catalyst to the phenylurea compound is 50:1, and the mass ratio of ozone to the phenylurea compound is 5:1.
[0018] In some preferred embodiments, the pH of the reaction system is not greater than 8.
[0019] The present invention has at least the following beneficial effects:
[0020] (1) The present invention discloses a modified catalyst of bimetallic organic framework material. Introducing -COOH (carboxyl) groups onto the bimetallic organic framework material enables the material to have good catalytic effect on the reaction of ozone degrading phenylurea compounds.
[0021] (2) Compared with the prior art, the present invention improves the adsorption performance of the material, provides more adsorption sites, improves the adsorption of the material to phenylurea compounds, and enables phenylurea compounds to react better with the oxidant ozone on the material surface.
[0022] (3) The present invention uses the solvothermal method for preparation, overcomes the technical problems of incomplete catalyst coating, leakage of metal ions, and uneven distribution caused by the immiscibility of metal ions and organic ligands in the hydrothermal method. Adding acetic acid greatly shortens the preparation time of the precursor drug mutual solubility and the long calcination time and the carbonization problem of the catalyst caused by calcination.
[0023] (4) The preparation method uses inexpensive and readily available raw materials, such as common metal ions like iron and manganese that are easily obtainable. The improved synthesis method greatly enhances the mutual solubility effect between metal ions and ligands, shortens the preparation time, enables the crystals to form better, further increases the yield of the modified catalyst, and reduces the preparation cost. The activation step is omitted to remove the cumbersome preparation process to reduce the preparation cost.
[0024] (5) The present invention also provides an application of the above material in the catalytic ozonation degradation of phenylurea compounds (especially diuron), which can effectively remove phenylurea compounds and improve the efficiency of the water treatment ozonation oxidation process. Description of the Drawings
[0025] Figure 1 FT-IR diagrams of the modified catalyst and the comparative catalyst;
[0026] Figure 2 XPS diagrams of the modified catalyst and the comparative catalyst;
[0027] Figure 3 Comparison of the catalytic effects of the catalyst-free, comparative catalyst, and modified catalyst;
[0028] Figure 4 Effect of the dosage of different modified catalysts on the degradation effect of diuron by catalytic ozonation;
[0029] Figure 5 Effect of different ozone concentrations on the degradation effect of diuron by catalytic ozonation;
[0030] Figure 6 Effect of the bimetallic organic framework material on the degradation effect of diuron by catalytic ozonation at different pH values;
[0031] Figure 7 Effect of different coexisting ions on the degradation effect of diuron. Detailed Embodiments
[0032] The technical solutions of the present invention are further described and illustrated below through specific embodiments.
[0033] In the following examples, the water used can be one or more of distilled water, purified water, and drinking water; unless otherwise specified, the detection methods in the following examples are all conventional detection methods; unless otherwise specified, the reagents in the following examples are all purchased from commercial channels.
[0034] Example 1
[0035] (1) Synthesis: 0.335 g of zero-valent iron, 2.147 g of Mn(NO3)2 solution (50 wt%), 2.522 g of H3BTC, 600 μL of hydrofluoric acid (100%), and 75 ml of analytical pure acetic acid were placed in a 100 mL autoclave with a polytetrafluoroethylene liner. They were stirred and mixed evenly with a polytetrafluoroethylene stir bar. After calcination at 120 °C for 2 h, the temperature was programmed to rise to 150 °C and continue to calcine for 4 h. In the above reaction, the molar ratio of iron to manganese metals was 1:1.
[0036] (2) Washing: The product was taken out and filtered by suction filtration. The obtained product was soaked in absolute ethanol for 24 h and then washed 2 times with fresh absolute ethanol.
[0037] (3) Drying: The orange powder product was obtained by suction filtration and separation, and dried at a constant temperature of 50 °C for 12 h to obtain a bimetallic organic framework material modified catalyst (or modified catalyst).
[0038] Comparative Example 1
[0039] It was prepared according to the method described in Patent CN112958157B, denoted as the comparative catalyst.
[0040] Performance Test
[0041] (1) Perform performance characterization on the bimetallic organic framework material modified catalyst
[0042] FT-IR (Fourier Transform Infrared Spectroscopy) mainly characterizes the surface functional groups and compound structure information of the catalyst material. The results are as Figure 1 shown. By comparing the peak patterns of the original catalyst, it can be seen that in the X-H stretching vibration range of 3300 - 2500 cm -1 there is a large broad peak, and a special peak appears near 1710 cm -1 in the double bond stretching vibration region, indicating the presence of a C=O bond; a peak appears near 940 cm -1 in the fingerprint region, indicating the presence of -OH. In summary, the modified catalyst has a characteristic functional group carboxyl, and the -COOH group is loaded on the modified catalyst.
[0043] Figure 2 The surface chemical information of MIL-100(Fe-Mn) before and after modification, that is, the comparative catalyst and the modified catalyst, was further explored by X-ray photoelectron spectroscopy (XPS). The wide-scan XPS spectra shown in the figure indicate that the synthesized sample is composed of C, O, N, Fe, and Mn elements. The main peak positions in the figure are Fe2p, Mn2p, O1s, and C1s respectively. Characteristic peaks appear at a binding energy of 531.8 eV, which can be attributed to the presence of lattice oxygen O on the sample surface 2-Therefore, the oxygen in the sample mainly exists in the framework in the form of bound oxygen, corresponding to the O=C group belonging to BTC, which also indicates the existence of oxygen vacancies in the catalyst, playing a major role in the activity of the catalyst.
[0044] (2) Influence of the catalysts in Example 1 and Comparative Example 1 on the degradation rate of diuron
[0045] Blank group: The sample of 2 mg / L diuron was oxidized under the condition of an ozone dosage of 4 mg / L, and then quenched with 1 ml of 80 g / L sodium thiosulfate solution to terminate the reaction.
[0046] Control group: 40 mg / L of the above-mentioned comparative catalyst was added to the sample containing 2 mg / L diuron, and catalytic oxidation was carried out under the conditions of not adjusting the pH and an ozone dosage of 4 mg / L, and then quenched with 1 ml of 80 g / L sodium thiosulfate solution to terminate the reaction.
[0047] Experimental group: 40 mg / L of the above-mentioned modified catalyst was added to the sample containing 2 mg / L diuron, and catalytic oxidation was carried out under the conditions of not adjusting the pH and an ozone dosage of 4 mg / L, and then quenched with 1 ml of 80 g / L sodium thiosulfate solution to terminate the reaction.
[0048] The remaining diuron content in the reactions of the above groups was detected by high-performance liquid chromatography respectively, and the results are as Figure 3 . Among them, the degradation rate of diuron in the blank group was 20.64%, the degradation rate was 24.04% after adding the comparative catalyst, and the degradation rate was 45.72% after adding the modified catalyst. It can be seen that the comparative catalyst has a poor catalytic effect on the reaction of ozone degrading diuron, while the modified catalyst can more than double the degradation rate.
[0049] (3) Influence of the catalyst concentration on the degradation rate of diuron
[0050] 0, 20, 40, 60, 80 and 100 mg / L of the modified catalyst were respectively added to a series of diuron samples of 2 mg / L, and catalytic oxidation was carried out under the conditions of not adjusting the pH and an ozone dosage of 8 mg / L, and then quenched with 1 ml of 80 g / L sodium thiosulfate solution to terminate the reaction.
[0051] The remaining diuron content in the reactions of the above groups was detected by high-performance liquid chromatography respectively, and the results are as Figure 4 . It can be seen that when the concentration of the modified catalyst reaches 20 mg / L, the degradation rate of diuron is greater than 75%. As the catalyst concentration increases, the degradation rate of diuron gradually increases. When the concentration of the modified catalyst reaches 80 mg / L, the degradation rate exceeds 90%. It shows that the improved catalyst has an excellent catalytic effect on the reaction of ozone degrading diuron.
[0052] (4) Influence of ozone concentration on the degradation rate of diuron
[0053] Ozone with concentrations of 2, 4, 6, 8, and 10 mg / L was added to a series of diuron samples with a concentration of 2 mg / L, and catalytic oxidation was carried out without adjusting the pH and with a modified catalyst dosage of 100 mg / L or without adding the modified catalyst. The reaction was quenched with a 80 g / L sodium thiosulfate solution to terminate the reaction, and the remaining amount of diuron was detected respectively to obtain the degradation rate.
[0054] The results are as Figure 5 . It can be seen that without adding the modified catalyst, the ozone concentration has no significant effect on the degradation rate of diuron. In each experimental group with 100 mg / L of the modified catalyst added, the degradation rate of diuron is positively correlated with the ozone concentration. When the ozone concentration is greater than or equal to 4 mg / L, the modified catalyst can significantly improve the degradation rate of diuron. When the ozone dosage is 10 mg / L, diuron is completely removed.
[0055] (5) Influence of pH on the degradation rate of diuron
[0056] One group of a series of diuron samples with a concentration of 2 mg / L was kept at the original pH, and the others were adjusted to 5, 6, 7, 8, and 9 respectively. Oxidative degradation was carried out with an ozone dosage of 8 mg / L and a modified catalyst dosage of 100 mg / L or without adding the modified catalyst. The reaction was quenched with a 80 g / L sodium thiosulfate solution to terminate the reaction, and the remaining content of diuron after the reaction was detected respectively.
[0057] The results are as Figure 6 . Without adding the modified catalyst, there is no obvious correlation between the pH value and the degradation effect of diuron, and the degradation effect of diuron fluctuates with the increase of pH. When using the bimetallic organic framework material to catalyze ozone, the degradation effect of diuron gradually becomes worse with the increase of pH, and the effect is the best at the original pH.
[0058] (6) Influence of coexisting ions on the degradation rate of diuron
[0059] NH4-N standard solution, NO3-N standard solution, NO2-N standard solution, Br - standard solution, sodium sulfate solution, and sodium carbonate solution were added to a series of diuron samples with a concentration of 2 mg / L so that the samples contained 1 mg / L of NH4-N, NO3-N, NO2-N, Br - and 150 μmol / L of CO3 2- 、SO4 2-Oxidative degradation was carried out under the conditions of an ozone dosage of 8 mg / L and a modified catalyst dosage of 100 mg / L or without adding the modified catalyst, and quenched with an 80 g / L sodium thiosulfate solution to terminate the reaction, and the remaining situation of diuron was detected respectively.
[0060] The results are as Figure 7 , and it can be seen that under the conditions of the presence of any of the above coexisting ions, the modified catalyst can have an excellent catalytic effect on the reaction, increasing the degradation rate of diuron by about more than twice. Among them, SO4 2- has a relatively obvious inhibitory effect on the degradation, but under the condition of adding the modified catalyst, the degradation rate can still reach nearly 80%.
[0061] As described above, it is only the preferred embodiment of the present invention, so the scope of implementation of the present invention cannot be limited thereby. That is, equivalent changes and modifications made according to the scope of the present invention patent and the content of the specification should still fall within the scope covered by the present invention.
Claims
1. A method for preparing a bimetallic organic framework modified catalyst, characterized in that: The steps include: Add zero-valent iron, manganese nitrate solution, trimesic acid, hydrofluoric acid and acetic acid into a reaction kettle with a polytetrafluoroethylene liner, mix them evenly, then calcine them at 100-150° C. for 2-4 hours, then calcine them at 150-200° C. for 2-6 hours, and finally separate and obtain a solid; Among them, the molar ratio of iron element to manganese element is 1:0.5-2, the molar ratio of iron element to trimesic acid is 1:1-2, and the volume ratio of hydrofluoric acid to acetic acid is 1:100-150.
2. The preparation method according to claim 1, characterized in that The method also includes washing and drying the product in sequence after the preparation is completed.
3. The preparation method according to claim 2, characterized in that: The specific operation of washing is: stirring and soaking the obtained solid in anhydrous ethanol for 12-48 hours, and then washing with anhydrous ethanol; And / or, the drying temperature is 40-80°C, and the drying time is 12-48h; And / or, the uniform mixing method is stirring or ultrasonic vibration.
4. A bimetallic organic framework catalyst, characterized in that: The method is prepared according to any one of claims 1 to 3.
5. Use of the bimetallic organic framework catalyst according to claim 4 in catalytic ozonation system for degradation of phenylurea compounds.
6. The use according to claim 5, characterized in that The phenylurea compound is diuron.
7. A method for degrading phenylurea compounds by a catalytic ozonation system, characterized in that: The bimetallic skeleton catalyst described in claim 4 is used as a catalyst and ozone is used as an oxidant.
8. The method according to claim 7, characterized in that The phenylurea compound is diuron, the mass ratio of the catalyst to the phenylurea compound is 50:1, and the mass ratio of the ozone to the phenylurea compound is 5:
1.
9. The method according to claim 7 or 8, characterized in that The pH of the reaction system is not greater than 8.