Preparation method of ternary composite catalyst and application of ternary composite catalyst in catalytic degradation of organic pollutants

Abstract

This invention discloses a method for preparing a ternary composite catalyst and its application in the catalytic degradation of organic pollutants. The composite catalyst comprises aminated cellulose microspheres (CM), phosphomolybdate-vanadium heteropolyacid (HPMoV) supported thereon, and further composited Cu-BTC. This invention achieves efficient composite of HPMoV and Cu-BTC on a cellulose support through a stepwise loading and self-assembly method. The resulting material exhibits high catalytic activity, good stability, and recyclability. Under the synergistic effect of ozone, it can efficiently activate and generate various reactive oxygen species such as hydroxyl radicals, singlet oxygen, and superoxide radicals, demonstrating excellent catalytic degradation and mineralization performance against various PAEs (such as DEP, DBP, and DEHP) in water, and maintaining high activity and stability at low temperatures and in actual water bodies. This composite material can efficiently degrade phthalate pollutants in water and is suitable for applications such as advanced effluent treatment in wastewater treatment plants.

Description

Technical Field

[0001] This invention relates to the field of organic pollutant treatment technology, and in particular to a method for preparing a ternary composite catalyst and its application in catalytic degradation of organic pollutants. Background Technology

[0002] With industrial development and improved living standards, the removal of organic pollutants, especially persistent organic pollutants (POPs), from water has become a crucial issue in environmental governance. Traditional water treatment methods, such as adsorption and biodegradation, suffer from low efficiency and secondary pollution. Polyoxometalates (POMs) possess excellent redox catalytic capabilities and can effectively activate ozone to generate reactive oxygen species, but their water solubility and difficulty in recyclability limit their application. Ozone oxidation technology has attracted attention due to its strong oxidizing properties and lack of secondary pollution, but ozone oxidation alone suffers from poor selectivity and low mineralization rates. Therefore, the development of efficient and stable ozone catalysts has become a research hotspot.

[0003] Pom-molecules (POMs) and metal-organic frameworks (MOFs) have shown great potential in the field of catalysis due to their tunable structures, high specific surface areas, and excellent catalytic performance. However, single-component materials often suffer from poor stability and difficult recycling in practical applications. Existing composite methods often face technical challenges such as cumbersome procedures, demanding conditions, and the difficulty in simultaneously achieving stability and catalytic performance in composite materials. Summary of the Invention

[0004] This invention provides a method for preparing a ternary composite catalyst and its application in catalytic degradation of organic pollutants, in order to solve technical problems such as convenient composite of POMs and MOFs on porous supports, simple composite conditions, and balancing stability and catalytic performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The ternary composite catalyst was used to synthesize Cu-BTC in situ on the surface of HPMoV@CM using Cu(NO3)2·3H2O and 1,3,5-benzenetricarboxylic acid as precursors, resulting in a Cu-BTC / HPMoV@CM ternary composite material; among which, the phosphomolybdenum-vanadium heteropolyacid H5PMo 10 V2O 40 HPMoV is denoted as HPMoV; aminated cellulose microspheres are denoted as CM; 1,3,5-benzenetricarboxylic acid is denoted as BTC; HPMoV is loaded onto CM to obtain HPMoV@CM; The specific steps are as follows: Step 1, Preparation of HPMoV: Sodium molybdate, sodium metavanadate and disodium hydrogen phosphate were used as raw materials. The raw materials were dissolved in deionized water, and the pH value was adjusted by stirring and then reacted at high temperature. After cooling, the reaction solution was extracted and the lower layer of bright red oily substance was collected. After blowing off the ether, it was dissolved in a small amount of water and concentrated until a crystal film appeared. After crystallization, red crystals of HPMoV were obtained. Step 2, Preparation of CM: Add cellulose to this pre-cooled solvent and stir rapidly to dissolve, obtaining a transparent cellulose solution; then add it dropwise to a coagulation bath composed of sulfuric acid and sodium sulfate at room temperature, forming spheres, filter, wash with water until neutral, to obtain white wet cellulose microspheres; dry the wet cellulose microspheres to obtain cellulose microspheres CM with a surface rich in amino groups; Step 3: Preparation of HPMoV@CM composite material: Disperse HPMoV obtained in Step 1 and CM obtained in Step 2 in an organic solvent at a preset mass ratio, stir to fully load them, and after washing and drying, obtain HPMoV@CM(n) composite material, where n represents the theoretical mass loading percentage of HPMoV. Step 4: Preparation of Cu-BTC / HPMoV@CM ternary composite material: At room temperature, HPMoV@CM obtained in step 3 was dispersed in methanol and ultrasonically treated to ensure uniform dispersion; copper nitrate was added to the suspension and stirred at room temperature, which was recorded as solution A; 1,3,5-benzenetricarboxylic acid was dissolved in another part of methanol, which was recorded as solution B. Step 5: Slowly add solution B to solution A and stir continuously at room temperature; observe the formation of a blue-green precipitate, let stand overnight; collect the precipitate by centrifugation, wash and dry to obtain the final ternary composite material Cu-BTC / HPMoV@CM.

[0006] Further, in step one, sodium molybdate, sodium metavanadate, and hydrogen phosphate are weighed in a molar ratio of 10:2:1; concentrated sulfuric acid is added dropwise to adjust the pH of the solution to about 2.0 while stirring, and the mixture is stirred at 90°C for 6 hours.

[0007] Further, after cooling, the reaction solution was extracted with diethyl ether, and the lower layer of bright red oily substance was collected. After the diethyl ether was blown off, it was dissolved in a small amount of water and concentrated in a concentrated sulfuric acid atmosphere until a crystalline film appeared. It was then crystallized at 4°C to obtain red crystals of HPMoV.

[0008] Furthermore, in step two, a mixed solvent of sodium hydroxide, urea and water in a mass ratio of 7:12:81 is pre-cooled to -10°C, and then cellulose is added to this pre-cooled solvent and quickly stirred to dissolve, resulting in a transparent cellulose solution. Furthermore, in step two, the wet cellulose microspheres are dispersed in a mixed aqueous solution containing glutaraldehyde and triethylenetetramine, and stirred at 50°C for 1.5 hours. After the reaction is completed, the mixture is filtered, thoroughly washed with flowing deionized water, and dried to obtain cellulose microspheres with amino groups on the surface.

[0009] Furthermore, in step three, the material is magnetically stirred at room temperature for 12 hours to allow HPMoV to be fully loaded onto the pores and surface of CM through ionic and hydrogen bonding. The solid is then collected by centrifugation or filtration, washed several times with acetonitrile to remove physically adsorbed impurities, and dried to obtain a series of HPMoV@CM(n) composite materials.

[0010] Furthermore, the HPMoV loading was 10% to 50%, and the loading process was carried out in acetonitrile solvent with stirring at room temperature for 12 hours.

[0011] Furthermore, a ternary composite catalyst was added to a water sample containing organic pollutants; ozone was introduced to carry out a catalytic oxidation reaction; after the reaction, the composite material was separated and the water sample was treated. Among them, the ternary composite catalyst activates ozone through the V(IV) / V(V) redox pair of vanadium in HPMoV, generating ·OH, 1 O2 and ·O2 - Active oxygen species; at the same time, the Cu-BTC framework adsorbs and enriches pollutants and accelerates electron transfer, while ozone selectively attacks the unsaturated bonds of the benzene ring of pollutants, thus synergistically achieving the degradation and mineralization of pollutants.

[0012] Furthermore, the organic pollutant is a phthalate compound, including one or more of diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate.

[0013] Furthermore, the reaction system pH was 4.0–9.0, the ozone injection rate was 30 mL / min, the catalyst dosage was 0.2 g / L, and the reaction temperature range was 5–35°C.

[0014] The beneficial effects of this invention are reflected in: 1) This invention constructs a ternary core-shell composite structure of "cellulose microsphere carrier - HPMoV catalytic core - Cu-BTC enrichment and protection layer". The cellulose microspheres provide macroscopic size and mechanical strength, facilitating recycling. HPMoV, as a highly active catalytic center, can efficiently catalyze the decomposition of ozone to generate strong oxide species such as hydroxyl radicals through its vanadium (V) V(IV) / V(V) redox pair. The in-situ grown Cu-BTC can preferentially adsorb and enrich hydrophobic PAEs pollutants through its high specific surface area and porosity, increasing the local concentration. Its metal nodes can also serve as electron transport channels, accelerating the redox cycle of HPMoV and producing a significant catalytic synergistic effect with HPMoV. At the same time, the Cu-BTC shell provides physical protection and stability for the internal HPMoV, effectively preventing the leaching and loss of active components in the aqueous phase.

[0015] 2) The entire preparation process of this invention (CM amination, HPMoV loading, Cu-BTC in-situ growth) is carried out at room temperature or a low temperature (≤50°C), without the need for high temperature, high pressure or complex equipment. The process is simple, energy consumption is low, it conforms to the principles of green chemistry, and it is easy to scale up production.

[0016] 3) This invention exhibits highly efficient and broad-spectrum catalytic performance: The composite material demonstrates extremely high efficiency in catalytic ozone degradation of typical PAE pollutants. Under optimized conditions, it can achieve near-complete degradation of 50 mg / L DEP within 25 minutes, with total organic carbon and chemical oxygen demand removal rates exceeding 70% and 72%, respectively. The material also exhibits excellent degradation capabilities for DBP, DEHP, and mixed PAE systems. More importantly, the material maintains a degradation efficiency of over 90% even at low temperatures (5°C), overcoming the limitations of traditional catalysts' low-temperature deactivation and providing a solution for water treatment in cold regions.

[0017] 4) This invention exhibits outstanding stability and recyclability: Through chemical bonding (ionic / hydrogen bonds between amine groups and HPMoV) and physical coating (Cu-BTC shell), water-soluble HPMoV is firmly confined within the support and MOF framework. After 10 consecutive uses, the catalytic activity remains above 90%, and the structure is intact with no significant loss of active components, demonstrating excellent cycle stability and practical application potential.

[0018] 5) This invention, through electron paramagnetic resonance, free radical quenching experiments, X-ray photoelectron spectroscopy analysis, and comprehensive reaction kinetic modeling, deeply reveals the catalytic and degradation processes of the material; it mainly relies on HPMoV activation of O3 to generate ·OH, 1 O2 and ·O2 - The presence of various reactive oxygen species, along with the selective attack of unsaturated benzene ring bonds in PAEs by O3 itself, and the introduction of Cu-BTC enhances pollutant adsorption and electron transfer efficiency. The synergistic effect of multiple pathways achieves highly efficient mineralization of PAEs and significantly reduces the ecotoxicity of degradation intermediates.

[0019] Therefore, this application solves the technical problems of convenient composite of POMs and MOFs on porous supports, simple composite conditions, and a balance between stability and catalytic activity. Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention; the main objectives and other advantages of the invention can be realized and obtained by means of the methods particularly pointed out in the description. Attached Figure Description

[0020] Figure 1 A schematic diagram of the SEM portion of the "SEM-EDX spectrum of Cu-BTC / HPMoV@CM"; Figure 2 The images are scanning electron microscope images of the prepared catalyst; where (a) is the SEM spectrum of CM, (bc) are the SEM spectra of HPMoV@CM(n) at different sizes, and (d) is the SEM-EDX spectrum of HPMoV@CM(n). Figure 3 Infrared spectra of cellulose, CM, HPMoV, and HPMoV@CM(n); Figure 4 Infrared spectra of Cu-BTC, HPMoV, and Cu-BTC / HPMoV@CM; Figure 5 For HPMoV and HPMoV@CM(n) 31 pMAS NMR spectrum Figure 6 For HPMoV and Cu-BTC / HPMoV@CM 31 PMAS NMR characterization showed that the Keggin structure of HPMoV after loading and recombination remained intact. Figure 7 The degradation kinetics curves of diethyl phthalate (DEP) for different catalytic systems are shown. Figure 8 The linear relationship between different catalysts and Cu-BTC / HPMoV@CM / O3 in the system is shown. Figure 9 The curves showing the changes in DEP concentration, total organic carbon (TOC), and chemical oxygen demand (COD) over time during the degradation of DEP in the HPMoV@CM(30) / O3 system are shown. Figure 10 The curves showing the changes in DEP concentration, total organic carbon (TOC), and chemical oxygen demand (COD) over time during the degradation of DEP in the Cu-BTC / HPMoV@CM / O3 system are shown. Figure 11 The graph shows a comparison of the degradation efficiency of PAEs (DEP, DBP, DEHP) with different side chain lengths in the Cu-BTC / HPMoV@CM / O3 system. C / C0 represents the ratio of reactant concentration change over time, where C0 is the initial concentration and C is the concentration at subsequent time points.

[0021] Figure 12 Degradation kinetics curves of Cu-BTC / HPMoV@CM / O3 system for treating mixed PAEs pollution; Figure 13 To detect the electron paramagnetic resonance (EPR) spectrum of hydroxyl radicals (·OH) generated in the Cu-BTC / HPMoV@CM / O3 system; Figure 14To detect singlet oxygen generated in the Cu-BTC / HPMoV@CM / O3 system ( 1 Electron paramagnetic resonance (EPR) spectrum of O2; Figure 15 The recycling performance of Cu-BTC / HPMoV@CM is shown in the graph. Figure 16 The graph shows the removal efficiency of the Cu-BTC / HPMoV@CM / O3 system in treating mixed PAEs in reclaimed water at low temperature (5°C). Figure 17 Comparison of the V2p fine spectrum in X-ray photoelectron spectroscopy (XPS) of Cu-BTC / HPMoV@CM before degradation reaction; where 2p1 / 2 represents the high-energy peak with total angular momentum j=1 / 2 after spin-orbit coupling of p orbital electrons in XPS; 2p3 / 2 represents the low-energy peak with total angular momentum j=3 / 2 after spin-orbit coupling of p orbital electrons in XPS. Figure 18 Comparison of the fine V2p spectra of Cu-BTC / HPMoV@CM in X-ray photoelectron spectroscopy (XPS) after degradation reaction. Detailed Implementation

[0022] The technical solutions of the present invention will be described in detail below through embodiments. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solutions of the present invention, and should not be construed as limiting the technical solutions of the present invention.

[0023] The preparation method of HPMoV@CM (30%) includes the following steps: Step 1: Preparation of HPMoV: Accurately weigh 3.58 g (0.01 mol) of disodium hydrogen phosphate dodecahydrate (Na₂HPO₄·12H₂O) and 24.2 g (0.1 mol) of sodium molybdate dihydrate (Na₂MoO₄·2H₂O), and add them together to a beaker containing 120 mL of deionized water. Stir magnetically at room temperature until completely dissolved. Add 3.64 g (0.02 mol) of sodium metavanadate (NaVO₃) to the clear solution and continue stirring. Then, while continuously stirring, add concentrated sulfuric acid dropwise to the reaction solution until the pH of the mixed solution is approximately 2.0. Transfer the acidified reaction solution to an oil bath and stir at 90°C for 6 hours. After the reaction is complete, turn off the heating and allow the reaction solution to cool naturally to room temperature, then let it stand overnight at room temperature. Transfer the cooled reaction solution to a separatory funnel, add 60 mL of diethyl ether, shake thoroughly, and allow to separate into layers. After the layers are clearly separated, carefully collect the lower layer, which is a bright red oily substance. Place the collected red oily substance in a ventilated area and slowly blow away any residual ether solvent with an airflow. Add 50 mL of deionized water to the residue to dissolve it, and then concentrate this aqueous solution in a vacuum desiccator containing concentrated sulfuric acid. Stop concentration when a crystalline film appears on the surface of the solution. Remove the container and place it in a 4°C refrigerator for crystallization. After filtering and drying, the precipitated red crystals yield the target product H5PMo. 10 V2O 40 , denoted as HPMoV.

[0024] Step 2, Preparation of CM: First, a mixed solvent consisting of sodium hydroxide, urea, and water in a mass ratio of 7:12:81 was pre-cooled to -10°C. A certain amount of cellulose was added to this pre-cooled solvent and rapidly stirred until completely dissolved, yielding a transparent cellulose solution. This cellulose solution was then loaded into a syringe equipped with a 0.5 mm diameter needle. At room temperature, the cellulose solution was added dropwise at a uniform rate to a coagulation bath consisting of 1 mol / L sulfuric acid and 0.56 mol / L sodium sulfate, while simultaneously applying vigorous mechanical stirring. The cellulose droplets instantly solidified into spherical shapes in the coagulation bath, forming white cellulose microspheres. The microspheres were collected by filtration and washed with copious amounts of deionized water until neutral. 10 g of the wet cellulose microspheres were dispersed in a mixed aqueous solution containing 7 g glutaraldehyde and 2 g triethylenetetramine. The mixture was placed in a 50°C water bath and stirred continuously for 1.5 hours. After the reaction, the microspheres were separated by filtration and repeatedly washed with flowing deionized water until the wash solution was neutral and free of aldehyde / amine odor. Finally, the obtained microspheres are freeze-dried or dried at 60°C to obtain cellulose microspheres with a surface rich in amine groups, denoted as CM.

[0025] Step 3: Preparation of HPMoV@CM(30): 0.3 g of HPMoV and 1.0 g of CM were weighed and dispersed in 50 mL of acetonitrile. The mixture was magnetically stirred at room temperature for 12 hours. After the reaction was complete, the solid was collected by centrifugation, washed three times with acetonitrile, and dried in a vacuum drying oven at 60 °C for 6 hours to obtain an HPMoV@CM (30%) composite material with an HPMoV loading of 30%. Its morphology is as follows. Figure 2 As shown in (b), the FTIR spectrum is shown below. Figure 3 and Figure 4 Corresponding curve in the middle, solid 31 The pNMR spectrum confirmed the successful loading of HPMoV (P NMR spectrum). Figure 5 and Figure 6 ).

[0026] Step 4: Preparation method of Cu-BTC / HPMoV@CM Disperse 0.25 g of HPMoV@CM (30%) prepared in Example 1 in 50 mL of methanol and sonicate for 30 minutes. Add 0.9 g of Cu(NO3)2·3H2O and continue stirring for 30 minutes (solution A). Separately dissolve 0.43 g of 1,3,5-benzenetricarboxylic acid in 50 mL of methanol (solution B).

[0027] Step 5: Slowly add solution B dropwise to solution A, and stir continuously at room temperature for 12 hours. A blue-green precipitate was observed to form, and the mixture was allowed to stand overnight. The precipitate was collected by centrifugation, washed three times with methanol, and dried at 60°C for 12 hours to obtain the final product Cu-BTC / HPMoV@CM. Its morphology is as follows. Figure 1 As shown, the surface becomes rougher and is covered with nanocrystals; X-ray diffraction and infrared spectroscopy further confirmed the successful Cu-BTC composite.

[0028] In this embodiment, the catalytic degradation performance was evaluated using DEP as an example. An initial concentration of 50 mg / L diethyl phthalate (DEP) aqueous solution was prepared, and the pH was adjusted to 7.0 using dilute hydrochloric acid or sodium hydroxide solution. 25 mL of this water sample was placed in a glass reactor, and 5.0 mg (i.e., a dosage of 0.2 g / L) of the Cu-BTC / HPMoV@CM catalyst prepared in Example 2 was added. An ozone generator was turned on, and ozone was introduced into the bottom of the reactor at a stable flow rate of 30 mL / min (the ozone concentration in the outlet gas was approximately 20 mg / L). Simultaneously, magnetic stirring was activated to ensure catalyst suspension. Samples were accurately taken at the set reaction time points (e.g., 0, 2, 5, 10, 15, 20, 30 min), and immediately filtered through a 0.22 μm nylon membrane to separate the catalyst. The filtrate was analyzed by high-performance liquid chromatography (HPLC) (chromatographic conditions: C18 column; mobile phase: methanol:water = 4:1, v / v; flow rate: 0.8 mL / min; detection wavelength: 227 nm). Figure 7As shown, ozone oxidation alone achieved a degradation rate of only ~34% after 25 minutes. The addition of Cu-BTC / HPMoV@CM significantly increased the degradation rate, exceeding 88% after 10 minutes, and achieving complete DEP degradation (>99%) after 25 minutes. This system exhibits first-order reaction kinetics. Figure 8 The calculated apparent rate constant is much higher than that of the ozone system alone. Meanwhile, as... Figure 9 and 10 As shown, after 30 minutes of reaction, the removal rates of total organic carbon and chemical oxygen demand reached approximately 70% and 72%, respectively, indicating that the pollutants were effectively mineralized.

[0029] In this embodiment, the low-temperature performance and versatility of the catalyst were investigated. Low-temperature degradation: the steps of Example 3 were repeated, but the reaction system temperature was controlled at 5°C. Results ( Figure 8 The kinetic curves show that even at a low temperature of 5°C, the Cu-BTC / HPMoV@CM / O3 system can still achieve a degradation efficiency of over 96% for DEP within 25 minutes, demonstrating excellent low-temperature adaptability.

[0030] Degradation of different PAEs: 50 mg / L aqueous solutions of DBP and DEHP were prepared separately, and degradation experiments were conducted under the same conditions (pH 7, 25°C). Results are as follows: Figure 11 This indicates that the system also achieved degradation rates of over 97% and 95% for DBP and DEHP within 25 minutes, respectively, demonstrating a broad-spectrum removal capability for various PAE pollutants, such as... Figure 16 Figure. In this figure, DEP is di(2-ethylhexyl) phthalate, DBP is dibutyl phthalate, and DEHP is di(2-ethylhexyl) phthalate.

[0031] Practical water body application: Secondary effluent (reclaimed water) from a wastewater treatment plant was collected and its quality was tested (total nitrogen ~6 mg / L, chemical oxygen demand ~38 mg / L, pH ~7.7). DEP, DBP, and DEHP (0.5 mg / L each) were added to this actual water sample to create spiked reclaimed water. Degradation was carried out under constant ozone conditions and with a catalyst dosage of 0.2 g / L. Figure 12 As shown, after 25 minutes, the degradation rate of the three PAEs all exceeded 95%, and the total organic carbon removal rate exceeded 71%, proving that the system has good resistance to interference from complex aquatic matrix.

[0032] In this embodiment, for the catalyst cycle stability test, after completing one degradation experiment as described in Example 3, the catalyst was recovered by centrifugation, washed three times with deionized water, and dried at 60°C. Using this regenerated catalyst, the next degradation experiment was conducted under exactly the same conditions. This process was repeated 10 times. Figure 15As shown, during the 10th cycle, the degradation rate of DEP remained above 90% within 25 minutes. Infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy characterization of the cycled catalyst revealed no significant structural changes compared to the fresh catalyst, and no leaching of metal ions such as Mo, V, and Cu was detected in the reaction solution, confirming the material's excellent structural stability and recyclability.

[0033] In this embodiment, for the degradation mechanism analysis (in conjunction with the accompanying figures and characterization), the active center and electron transfer: X-ray photoelectron spectroscopy analysis shows that the vanadium (V) element in HPMoV in the catalyst after the reaction, and the V(IV) ratio, are significantly increased ( Figure 17 and Figure 18 This confirms the crucial role of V(IV) / V(V) redox in the ozone activation process. The Cu valence state in Cu-BTC remains essentially unchanged, indicating that its main role is not that of a direct redox center.

[0034] In this embodiment, for the identification of reactive oxygen species: electron paramagnetic resonance testing (… Figure 13 and Figure 14 As shown, ·OH (DMPO capture) was clearly detected in the Cu-BTC / HPMoV@CM / O3 system. 1 Characteristic signals of O2 (TEMPO capture). Free radical quenching experiments further confirm the presence of ·OH, 1 O2 and ·O2 - All three components participated in the degradation process, with ·OH contributing the most.

[0035] In this embodiment, regarding the synergistic pathway: Based on the above analysis, the degradation mechanism can be described as follows: a. The Cu-BTC framework rapidly adsorbs PAE molecules in water, enriching them on the catalyst surface; b. O3 molecules enriched near the HPMoV active sites are catalytically decomposed by the V(IV) / V(V) cycle, generating high concentrations of ·OH and singlet oxygen (…). 1 O2) and superoxide radicals (•O2) - c. Simultaneously, O3 molecules can also directly attack the unsaturated bonds on the benzene ring of PAEs, initiating ring-opening reactions; d. Reactive oxygen species non-selectively attack enriched PAE molecules and their ring-opening intermediates, ultimately mineralizing them into carbon dioxide and water through a series of reactions such as dealkylation, ester hydrolysis, hydroxylation, and ring opening. Cu-BTC also acts as an electron transport channel, accelerating the redox cycle of HPMoV and protecting it from loss.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a ternary composite catalyst, characterized in that, The ternary composite catalyst was used to synthesize Cu-BTC in situ on the surface of HPMoV@CM using Cu(NO3)2·3H2O and 1,3,5-benzenetricarboxylic acid as precursors, resulting in a Cu-BTC / HPMoV@CM ternary composite material; among which, the phosphomolybdenum-vanadium heteropolyacid H5PMo 10 V2O 40 HPMoV is denoted as HPMoV; aminated cellulose microspheres are denoted as CM; 1,3,5-benzenetricarboxylic acid is denoted as BTC; HPMoV is loaded onto CM to obtain HPMoV@CM; The specific steps are as follows: Step 1, Preparation of HPMoV: Sodium molybdate, sodium metavanadate and disodium hydrogen phosphate were used as raw materials. The raw materials were dissolved in deionized water, and the pH value was adjusted by stirring and then reacted at high temperature. After cooling, the reaction solution was extracted and the lower layer of bright red oily substance was collected. After blowing off the ether, it was dissolved in a small amount of water and concentrated until a crystal film appeared. After crystallization, red crystals of HPMoV were obtained. Step 2, Preparation of CM: Add cellulose to this pre-cooled solvent and stir rapidly to dissolve, obtaining a transparent cellulose solution; then add it dropwise to a coagulation bath composed of sulfuric acid and sodium sulfate at room temperature, forming spheres, filter, wash with water until neutral, to obtain white wet cellulose microspheres; dry the wet cellulose microspheres to obtain cellulose microspheres CM with a surface rich in amino groups; Step 3: Preparation of HPMoV@CM composite material: Disperse HPMoV obtained in Step 1 and CM obtained in Step 2 in an organic solvent at a preset mass ratio, stir to fully load them, and after washing and drying, obtain HPMoV@CM(n) composite material, where n represents the theoretical mass loading percentage of HPMoV. Step 4: Preparation of Cu-BTC / HPMoV@CM ternary composite material: At room temperature, HPMoV@CM obtained in step 3 was dispersed in methanol and ultrasonically treated to ensure uniform dispersion; copper nitrate was added to the suspension and stirred at room temperature, which was recorded as solution A; 1,3,5-benzenetricarboxylic acid was dissolved in another part of methanol, which was recorded as solution B. Step 5: Slowly add solution B to solution A and stir continuously at room temperature; observe the formation of a blue-green precipitate, let stand overnight; collect the precipitate by centrifugation, wash and dry to obtain the final ternary composite material Cu-BTC / HPMoV@CM.

2. The method for preparing the ternary composite catalyst as described in claim 1, characterized in that, In step one, sodium molybdate, sodium metavanadate, and hydrogen phosphate are weighed in a molar ratio of 10:2:

1. While stirring, concentrated sulfuric acid is added dropwise to adjust the pH of the solution to about 2.0, and the mixture is stirred at 90°C for 6 hours.

3. The method for preparing the ternary composite catalyst as described in claim 2, characterized in that, After cooling, the reaction solution was extracted with diethyl ether, and the lower layer of bright red oily substance was collected. After the diethyl ether was blown off, it was dissolved in a small amount of water and concentrated in a concentrated sulfuric acid atmosphere until a crystalline film appeared. The solution was then crystallized at 4°C to obtain red crystals of HPMoV.

4. The method for preparing the ternary composite catalyst as described in claim 3, characterized in that, In step two, a mixed solvent of sodium hydroxide, urea and water in a mass ratio of 7:12:81 is pre-cooled to -10°C. Then, cellulose is added to this pre-cooled solvent and stirred rapidly to dissolve, resulting in a transparent cellulose solution.

5. The method for preparing the ternary composite catalyst as described in claim 4, characterized in that, In step two, wet cellulose microspheres are dispersed in a mixed aqueous solution containing glutaraldehyde and triethylenetetramine and stirred at 50°C for 1.5 hours. After the reaction is completed, the mixture is filtered, thoroughly washed with flowing deionized water, and dried to obtain cellulose microspheres with amino groups on the surface.

6. The method for preparing the ternary composite catalyst as described in claim 5, characterized in that, In step three, the material is magnetically stirred at room temperature for 12 hours to allow HPMoV to be fully loaded onto the pores and surface of CM through ionic and hydrogen bonding. The solid is then collected by centrifugation or filtration, washed several times with acetonitrile to remove physically adsorbed impurities, and dried to obtain a series of HPMoV@CM(n) composite materials.

7. The method for preparing the ternary composite catalyst as described in claim 6, characterized in that, The HPMoV loading was 10% to 50%, and the loading process was carried out in acetonitrile solvent with stirring at room temperature for 12 hours.

8. The application of the ternary composite catalyst as described in claim 7 for the catalytic degradation of organic pollutants, characterized in that, A ternary composite catalyst was added to a water sample containing organic pollutants; ozone was introduced to carry out a catalytic oxidation reaction; after the reaction, the composite material was separated and the water sample was treated. Among them, the ternary composite catalyst activates ozone through the V(IV) / V(V) redox pair of vanadium in HPMoV, generating ·OH, 1 O2 and ·O2 - Active oxygen species; at the same time, the Cu-BTC framework adsorbs and enriches pollutants and accelerates electron transfer, while ozone selectively attacks the unsaturated bonds of the benzene ring of pollutants, thus synergistically achieving the degradation and mineralization of pollutants.

9. The application of the ternary composite catalyst for the catalytic degradation of organic pollutants as described in claim 8, characterized in that, The organic pollutant is a phthalate compound, including one or more of diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate.

10. The application of the ternary composite catalyst as described in claim 8 for the catalytic degradation of organic pollutants, characterized in that, The reaction system had a pH of 4.0–9.0, an ozone flow rate of 30 mL / min, a catalyst dosage of 0.2 g / L, and a reaction temperature range of 5–35°C.

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