Preparation method and application of heterogeneous catalytic composite material
By constructing a molybdenum-copper bimetallic catalytic composite material on graphite felt, the problem of unstable active metal sites in the catalyst was solved, enabling efficient degradation of p-nitrophenol and stable recycling of the material, which exhibits good catalytic activation performance and long lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-03-27
AI Technical Summary
The active metal sites in existing catalysts are unstable and difficult to recover, resulting in low catalytic activation efficiency, material deactivation, and reduced lifespan, making it difficult to effectively degrade toxic pollutants such as p-nitrophenol.
A heterogeneous catalytic composite material was constructed on graphite felt by combining molybdenum and copper bimetals. Cu3(Mo2O9) oxide was formed through hydrothermal synthesis and calcination. The protective effect of molybdenum and the synergistic effect of the active center of copper were utilized to improve catalytic activity and stability. Graphite felt facilitates the recovery and recycling of catalytic materials.
This method achieves efficient mineralization of p-nitrophenol. The catalyst material has a long service life and good stability, can be recycled multiple times, and has high degradation efficiency. The graphite felt substrate provides a low-cost and environmentally friendly loading platform.
Smart Images
Figure CN121732181A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of heterogeneous catalysis technology, specifically to a method for preparing and applying heterogeneous catalytic composite materials. Background Technology
[0002] p-Nitrophenol is a common phenolic pollutant. Exposure to p-nitrophenol can cause central nervous system damage and harm the kidneys, liver, and blood cells. In particular, due to the strong electron affinity of the nitro functional group (-NO2), p-nitrophenol is highly stable and toxic, making it difficult to directly degrade through conventional biochemical treatment, which poses a significant challenge to wastewater treatment processes.
[0003] Persulfate-mediated advanced oxidation processes can generate various highly reactive species through the activation of persulfate, thereby enabling the degradation of emerging pollutants in complex aquatic matrices, such as the effective mineralization of p-nitrophenol. In this process, highly efficient and stable catalytic activation materials are crucial for technology implementation. Transition metals are recognized as catalysts with high catalytic activation activity for persulfate; however, in practical applications, the instability and difficulty in recovering active metal sites in common catalysts lead to problems such as low catalytic activation efficiency, material deactivation, and reduced lifetime, which urgently need to be addressed. Summary of the Invention
[0004] To address the problems of instability and difficulty in recycling of active metal sites in common catalysts in existing technologies, which lead to low catalytic activation efficiency, material deactivation, and reduced lifespan, this invention provides a heterogeneous catalytic composite material, its preparation method, and its application. The preparation method of this invention utilizes the synergistic effect of molybdenum and copper bimetals to construct a heterogeneous catalytic composite material by compositing molybdenum and copper bimetals on graphite felt. This heterogeneous catalytic composite material has the effects of high-efficiency and stable catalysis, and is recyclable.
[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention provides a method for preparing heterogeneous catalytic composite materials, the innovation of which lies in the following steps: (1) Oxidation treatment of graphite felt: oxidize graphite felt by treating the solution or by using an electrochemical process; (2) Hydrothermal synthesis of composite materials: Na2MoO4 2H2O and Cu(NO3)2·3H2O are dissolved in deionized water to obtain a homogeneous solution, namely the precursor solution. The pH of the precursor is adjusted by dilute nitric acid or dilute sulfuric acid to make the pH of the precursor between 3 and 7. Then, the oxidized graphite felt is placed in the precursor solution for hydrothermal reaction. (3) Preparation of heterogeneous catalytic composite material: The product of hydrothermal reaction is transferred to a muffle furnace for calcination to obtain heterogeneous catalytic composite material.
[0006] Preferably, before step (1), the graphite felt is pretreated. Specifically, the graphite felt is placed in a pretreatment detergent and ultrasonically treated for 14-16 minutes, rinsed repeatedly with deionized water, and dried for later use.
[0007] Preferably, in the graphite felt pretreatment, the pretreatment detergent is anhydrous ethanol.
[0008] Preferably, in step (1), when the graphite felt is oxidized using a treatment solution, the treatment solution is dilute sulfuric acid with a concentration of 0.4-0.6 mol / L and a treatment time of 11-13 h.
[0009] Preferably, in step (1), when the graphite felt is oxidized by an electrochemical process, a constant voltage power supply is used in the electrochemical process, with the graphite felt as the anode and the platinum sheet as the cathode, and the oxidation is carried out. The oxidation voltage is 1.7-2.5V and the oxidation time is 8-12 minutes.
[0010] Preferably, the Na2MoO4 in the precursor solution in step (2) The molar ratio of Na₂MoO₄ to Cu(NO₃)₂·3H₂O is between 1-3:3-1. The concentration of 2H2O is 0.05-0.20 mol / L, and the concentration of Cu(NO3)2·3H2O is 0.05-0.20 mol / L.
[0011] Preferably, the temperature of the hydrothermal reaction in step (2) is 120-200℃ and the time is 8-12 h.
[0012] Preferably, the calcination process in step (3) in the muffle furnace is as follows: the temperature is raised to 280-320℃ at a heating rate of 4-6℃ / min, and calcined at the calcination temperature for 1.5-2.5h to obtain the heterogeneous catalytic composite material.
[0013] The heterogeneous catalytic composite material obtained by the preparation method of the present invention can be used as a material for catalytic activation of persulfate.
[0014] This invention provides a heterogeneous catalytic composite material, its preparation method, and its application, which have the following beneficial effects: (1) The preparation method of this invention utilizes the synergistic effect of two transition metal ions, molybdenum and copper, to form effective active sites on the surface of the prepared heterogeneous catalytic composite material: a large number of oxygen vacancies are formed on the hydrothermal synthesis composite material, and after calcination, some of the oxygen vacancies are covered by lattice oxygen. Oxygen vacancies are electron-rich regions, and after the addition of persulfate, they are adsorbed onto the oxygen vacancies. The presence of lattice oxygen further promotes electron transfer and increases the catalytic activity of the material. Cu(I) loses electrons to form Cu(II), and the lost electrons are transferred to persulfate, which activates the persulfate and generates various active oxygen substances that promote the degradation of p-nitrophenol. Lattice oxygen participates in the reaction under the Mars-van Krevelen mechanism. After the lattice oxygen loses electrons and leaves oxygen vacancies, the lost electrons reduce Cu(II) back to Cu(I). In this process, Mo(VI) in the lattice can effectively inhibit the detachment of Cu during the valence state change, thereby maintaining the catalyst activity and improving the catalytic efficiency.
[0015] (2) In this invention, transition metals Mo and Cu, which have good catalytic activity, are firmly supported on graphite felt through hydrothermal in-situ growth and calcined to form Cu3(Mo2O9) oxide crystals. Sodium molybdate can effectively slow down the leaching of metal ions in the synthesized material. In the heterogeneous catalytic composite material constructed in this invention, molybdenum, as a protective metal, can effectively protect copper, which is located at the active center. Copper, as the active center, is a key catalytic site for promoting PMS activation. The two work synergistically to ensure the stability and effectiveness of the material's catalysis. It can efficiently activate persulfate, thereby achieving the effect of mineralizing organic pollutants.
[0016] (3) This invention uses graphite felt as the substrate for the catalytic material. Firstly, graphite felt is low-cost and environmentally friendly. Secondly, loading the catalytic material onto a bulk graphite felt facilitates its immediate recovery and recycling. Graphite felt also has a good surface area, allowing it to support more catalysts and form more active sites on its surface, thereby improving catalytic efficiency.
[0017] (4) The heterogeneous catalytic composite material prepared by the present invention has a long service life and high stability, and can be used repeatedly for a long time. Attached Figure Description
[0018] Figure 1 This is a SEM image of the heterogeneous catalytic composite material prepared when the precursor solution pH was 5 in Example 1.
[0019] Figure 2 This is a SEM image of the heterogeneous catalytic composite material prepared when the precursor solution pH is 3 in Example 1.
[0020] Figure 3 This is a SEM image of the heterogeneous catalytic composite material prepared when the precursor solution pH was 7 in Example 1.
[0021] Figure 4 This is a comparison chart showing the activation effect of PMS on the degradation of p-nitrophenol by the blank graphite felt material in Example 1 and the heterogeneous catalytic composite material prepared in Example 1.
[0022] Figure 5 Different amounts of Na2MoO4 were used in Example 2. Comparison of the activation effects of heterogeneous catalytic composite materials prepared by 2H2O and Cu(NO3)2·3H2O on the degradation of p-nitrophenol by PMS.
[0023] Figure 6 This is a comparison of the activation effect of heterogeneous catalytic composite materials prepared at different hydrothermal reaction temperatures in Example 3 on the degradation of p-nitrophenol by PMS.
[0024] Figure 7 The diagram shows the cycle life of the heterogeneous catalytic composite material of the present invention in Example 9.
[0025] Figure 8 This is a SEM image of the heterogeneous catalytic composite material obtained using graphite powder as a substrate in Example 10.
[0026] Figure 9 This is a SEM image of the heterogeneous catalytic composite material obtained using graphite powder as a substrate in Example 10. Detailed Implementation
[0027] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.
[0028] All chemical reagents not described in the embodiments and comparative examples of this invention were commercially available analytical grade reagents used in the experiments.
[0029] Example 1 This embodiment provides a method for preparing heterogeneous catalytic composite materials, including the following steps: (1) Place the graphite felt with dimensions of 2 cm × 4 cm × 0.5 cm into 50 mL of anhydrous ethanol and sonicate for 15 minutes. Rinse repeatedly with deionized water and dry for later use.
[0030] (2) The graphite felt was oxidized with dilute sulfuric acid with a concentration of 0.5 mol / L for 12 h.
[0031] (3) Add 5 mmol Na2MoO4 2H2O and 10 mmol Cu(NO3)2·3H2O were dissolved in 60 mL of deionized water to obtain a homogeneous solution, i.e., the precursor solution. The pH of the precursor solution was adjusted to 5 by dilute nitric acid. Then, the precursor solution was transferred to a stainless steel reactor with a polytetrafluoroethylene liner. The oxidized graphite felt was placed in the precursor solution and hydrothermally dried in a vacuum drying oven at 180℃ for 10 h.
[0032] (4) After the hydrothermal reaction is complete, the product of the hydrothermal reaction is transferred to a muffle furnace for calcination. The temperature is increased to 300°C at a heating rate of 5°C / min, and calcined at 300°C for 2 h to obtain the heterogeneous catalytic composite material, which is named the preferred composite material. The SEM image of the obtained heterogeneous catalytic composite material is shown below. Figure 1 As shown.
[0033] In this embodiment, the pH of the homogeneous solution in step (3) was adjusted to 3 and 7 respectively using dilute nitric acid, and the rest was the same as the above steps. The SEM images of the heterogeneous catalytic composite materials (named composite material pH=3 and composite material pH=7 respectively) are shown below. Figure 2 and 3 As shown.
[0034] In this embodiment, the three heterogeneous catalytic composite materials obtained were used to activate the degradation of p-nitrophenol by persulfate (PMS) as follows: (1) Prepare a solution containing 50 mg L at a temperature of 25°C. –1 A 150 ml simulated wastewater degradation solution consisting of p-nitrophenol and 7 mM PMS was prepared, and the pH of the simulated wastewater degradation solution was adjusted to 11 before the degradation began.
[0035] (2) The prepared heterogeneous catalytic composite material (2 cm × 4 cm × 0.5 cm) was fixed with a polytetrafluoroethylene clip and then placed in the degradation solution for catalytic activation of PMS to degrade p-nitrophenol.
[0036] The degradation time was 5 min. At given intervals (30 seconds for 0-3 minutes, 60 seconds for 3-5 minutes), 1 ml samples were taken into colorimetric tubes and diluted to 10 mL with dilute sulfuric acid solution (pH < 3). Deionized water was used as the reference solution. The relationship between absorbance and p-nitrophenol concentration was determined using a UV-Vis spectrophotometer, and a standard curve was obtained using the corresponding absorbance and concentration data. Finally, the absorbance of the diluted solution was measured using a UV-Vis spectrophotometer. Lower p-nitrophenol concentrations indicated better degradation and reflected better catalytic performance of the material.
[0037] For all three heterogeneous catalytic composite materials, a blank graphite felt material was set up for comparison. The experimental results are as follows: Figure 4 As shown.
[0038] In contrast, blank graphite felt material (with graphite felt replacing the heterogeneous catalytic composite material of the present invention under unchanged parameters and other conditions, as a comparative test material for catalytic activation of PMS to degrade p-nitrophenol in simulated wastewater degradation liquid) was used in the degradation liquid for degradation. Obviously, the degradation curve showed a flat trend, and the degradation effect of graphite felt material was less than 3% within 0-5 minutes.
[0039] When the precursor solution was at pH 5, the degradation curve of the prepared heterogeneous catalytic composite material rapidly decreased in the degradation solution within 0-3 minutes. Within 3-5 minutes, the degradation curve ceased to change, indicating that the heterogeneous catalytic composite material had been fully activated to degrade p-nitrophenol using PMS.
[0040] When the precursor solution was at pH 3, the degradation curve of the prepared heterogeneous catalytic composite material gradually decreased in the degradation solution from 0 to 5 minutes. At 5 minutes, the degradation rate of p-nitrophenol was 74.33%. When the precursor solution pH was 7, the degradation curve of the prepared heterogeneous catalytic composite material rapidly decreased in the degradation solution from 0 to 3 minutes, with a degradation rate of 93.83%. After that, the degradation curve became flat, and the degradation rate of p-nitrophenol was 96.49% at 5 minutes.
[0041] Comparing the degradation effects of the three materials, it is clear that the prepared heterogeneous catalytic composite material exhibits faster and more thorough degradation when the precursor solution pH is 3, 5, or 7. This indicates that the prepared heterogeneous catalytic composite material possesses superior catalytic activation performance for PMS.
[0042] Example 2 This embodiment provides a method for preparing a heterogeneous catalytic composite material, which specifically includes the following steps: (1) Place the graphite felt with dimensions of 2 cm × 4 cm × 0.5 cm into 50 mL of anhydrous ethanol and sonicate for 15 minutes. Rinse repeatedly with deionized water and dry for later use.
[0043] (2) The graphite felt was oxidized with dilute sulfuric acid with a concentration of 0.5 mol / L for 12 h.
[0044] (3) Add 3.75 mmol Na2MoO4 2H2O and 11.25 mmol Cu(NO3)2·3H2O were dissolved in 60 mL of deionized water to obtain a homogeneous solution, i.e., the precursor solution. The pH of the precursor solution was adjusted to 5 by dilute nitric acid. Then, the precursor solution was transferred to a stainless steel reactor with a polytetrafluoroethylene liner. The oxidized graphite felt was placed in the precursor solution and hydrothermally dried in a vacuum drying oven at 180℃ for 10 h.
[0045] (4) After the hydrothermal reaction is complete, the product of the hydrothermal reaction is transferred to a muffle furnace for calcination, and the temperature is increased to 300°C at a heating rate of 5°C / min. Calcination at 300°C for 2 h yields a heterogeneous catalytic composite material (named composite material 1:3).
[0046] This embodiment also includes Na2MoO4 in step (3). The molar ratio of 2H2O and Cu(NO3)2·3H2O was adjusted to 3:1 (11.25 mmol Na2MoO4). 2H2O and 3.75 mmol Cu(NO3)2·3H2O were dissolved in 60 mL, and the rest of the steps were the same as above to obtain a heterogeneous catalytic composite material (named composite material 3:1).
[0047] The heterogeneous catalytic composite material obtained in Example 2 was used to activate persulfate PMS to degrade p-nitrophenol, following the steps in Example 1. The experimental results are as follows: Figure 5 As shown.
[0048] Using the composite material preferred in Example 1 as a comparison, it is clear that different proportions of Na2MoO4... The heterogeneous catalytic composite materials prepared by 2H2O and Cu(NO3)2·3H2O all showed a gradual decrease in degradation curve trend. The preferred composite material exhibited the fastest degradation curve decline, reaching a plateau after 3 minutes, indicating that the heterogeneous catalytic composite material had fully activated PMS to degrade p-nitrophenol. The degradation curve of the 1:3 composite material showed a slower decline compared to the preferred composite material, achieving a p-nitrophenol degradation rate of 82.18% after 5 minutes. The degradation curve of the 1:3 composite material also showed a slower decline compared to the 1:3 composite material, achieving a p-nitrophenol degradation rate of 45.95% after 5 minutes.
[0049] Example 3 This embodiment provides a method for preparing a heterogeneous catalytic composite material, which specifically includes the following steps: (1) Place the graphite felt with dimensions of 2 cm × 4 cm × 0.5 cm into 50 mL of anhydrous ethanol and sonicate for 15 minutes. Rinse repeatedly with deionized water and dry for later use.
[0050] (2) The graphite felt was oxidized with dilute sulfuric acid with a concentration of 0.5 mol / L for 12 h.
[0051] (3) Add 5 mmol Na2MoO4 2H2O and 10 mmol Cu(NO3)2·3H2O were dissolved in 60 mL of deionized water to obtain a homogeneous solution, i.e., the precursor solution. The pH of the precursor solution was adjusted to 5 by dilute nitric acid. Then, the precursor solution was transferred to a stainless steel reactor with a polytetrafluoroethylene liner. The oxidized graphite felt was placed in the precursor solution and hydrothermally dried in a vacuum drying oven at 150℃ for 10 h.
[0052] (4) After the hydrothermal reaction is complete, the composite material is transferred to a muffle furnace for calcination, and the temperature is increased to 300°C at a heating rate of 5°C / min. After calcination at 300°C for 2 h, a heterogeneous catalytic composite material (named Composite Material 150) is obtained.
[0053] In this embodiment, the hydrothermal temperature in step (3) is adjusted to 120°C, and the rest is the same as the above steps, to obtain a heterogeneous catalytic composite material (named composite material 120).
[0054] The heterogeneous catalytic composite material obtained in Example 3 was used to activate persulfate PMS to degrade p-nitrophenol, following the steps in Example 1. The experimental results are as follows: Figure 6 As shown.
[0055] In comparison, it is clear that the degradation curves of the heterogeneous catalytic composite materials prepared at different hydrothermal temperatures all showed a gradual downward trend. The preferred composite material exhibited the fastest degradation curve decline, reaching a standstill after 3 minutes, indicating that the heterogeneous catalytic composite material had fully activated PMS to degrade p-nitrophenol. The degradation curve of composite material 150 showed a relatively slower downward trend compared to the preferred composite material, with a p-nitrophenol degradation rate of 93.71% after 3 minutes and 97.70% after 5 minutes. The degradation curve of composite material 120 showed an even gentler downward trend compared to composite material 150, with a p-nitrophenol degradation rate of 65.26% after 5 minutes.
[0056] Comparing the degradation effects of the three materials, it is clear that the composite material with a hydrothermal temperature of 180℃ exhibits superior catalytic activation performance of PMS. Secondly, the composite material with a hydrothermal temperature of 150℃ demonstrates a degradation efficiency comparable to the preferred composite material. Considering the unnecessary costs and equipment requirements for further increasing the hydrothermal temperature to prepare the heterogeneous catalytic composite material, a hydrothermal temperature of 180℃ is adopted as the preferred hydrothermal temperature for material preparation.
[0057] Example 4 This embodiment provides a method for preparing a heterogeneous catalytic composite material, which specifically includes the following steps: (1) Place the graphite felt with dimensions of 2 cm × 4 cm × 0.5 cm into 50 mL of anhydrous ethanol and sonicate for 14 minutes. Rinse repeatedly with deionized water and dry for later use.
[0058] (2) The graphite felt was oxidized with dilute sulfuric acid with a concentration of 0.4 mol / L for 13 h.
[0059] (3) Add 5 mmol Na2MoO4 2H2O and 10 mmol Cu(NO3)2·3H2O were dissolved in 60 mL of deionized water to obtain a homogeneous solution, i.e., the precursor solution. The pH of the precursor solution was adjusted to 5 by dilute nitric acid. Then, the precursor solution was transferred to a stainless steel reactor with a polytetrafluoroethylene liner. The oxidized graphite felt was placed in the precursor solution and hydrothermally dried in a vacuum drying oven at 120℃ for 12 h.
[0060] (4) After the hydrothermal reaction is complete, the composite material is transferred to a muffle furnace for calcination, and the temperature is increased to 280°C at a heating rate of 4°C / min. Calcination at 280°C for 2.5 h yields the heterogeneous catalytic composite material.
[0061] Example 5 This embodiment provides a method for preparing a heterogeneous catalytic composite material, which specifically includes the following steps: (1) Place the graphite felt with dimensions of 2 cm × 4 cm × 0.5 cm into 50 mL of anhydrous ethanol and sonicate for 16 minutes. Rinse repeatedly with deionized water and dry for later use.
[0062] (2) The graphite felt was oxidized with dilute sulfuric acid with a concentration of 0.6 mol / L for 11 h.
[0063] (3) Add 5 mmol Na2MoO4 2H2O and 10 mmol Cu(NO3)2·3H2O were dissolved in 60 mL of deionized water to obtain a homogeneous solution, i.e., the precursor solution. The pH of the precursor solution was adjusted to 5 by dilute nitric acid. Then, the precursor solution was transferred to a stainless steel reactor with a polytetrafluoroethylene liner. The oxidized graphite felt was placed in the precursor solution and hydrothermally dried in a vacuum drying oven at 200℃ for 8 hours.
[0064] (4) After the hydrothermal reaction is complete, the composite material is transferred to a muffle furnace for calcination, and the temperature is increased to 320°C at a heating rate of 6°C / min. Calcination at 320°C for 1.5 h yields the heterogeneous catalytic composite material.
[0065] The heterogeneous catalytic composite materials obtained in Examples 4 and 5 were used to activate persulfate PMS to degrade p-nitrophenol. The experimental procedures were the same as in Example 1. The heterogeneous catalytic composite materials obtained in Examples 4 and 5 showed good results in degrading p-nitrophenol.
[0066] Example 6 Replace step (2) in Example 1 with: electrochemical oxidation of graphite felt: using a constant voltage power supply, graphite felt as the anode and platinum sheet as the cathode, electrochemical oxidation is performed, wherein the oxidation voltage is 2V and the oxidation time is 10 minutes.
[0067] Steps (1), (3) and (4) are the same as in Example 1, and heterogeneous catalytic composite material is obtained.
[0068] Example 7 Replace step (2) in Example 4 with: electrochemical oxidation of graphite felt: using a constant voltage power supply, graphite felt as the anode and platinum sheet as the cathode, electrochemical oxidation is performed, wherein the oxidation voltage is 1.7V and the oxidation time is 12 minutes.
[0069] Steps (1), (3) and (4) are the same as in Example 4, and heterogeneous catalytic composite material is obtained.
[0070] Example 8 Replace step (5) in Example 5 with: electrochemical oxidation treatment of graphite felt: using a constant voltage power supply, with graphite felt as the anode and platinum sheet as the cathode, electrochemical oxidation is performed, wherein the oxidation voltage is 2.5V and the oxidation time is 8 minutes.
[0071] Steps (1), (3) and (4) are the same as in Example 4, and heterogeneous catalytic composite material is obtained.
[0072] Comparing Examples 6, 7, and 8 with Examples 1, 4, and 5, it was found that the electrochemical oxidation process takes less time, and the dilute sulfuric acid oxidation process is simpler, but both can achieve the same treatment effect on the graphite felt surface.
[0073] Example 9 This invention also uses the composite material from Example 1 to perform a cyclic degradation experiment of p-nitrophenol. The heterogeneous catalytic composite material obtained in Example 1 is used to activate persulfate PMS to degrade p-nitrophenol according to the steps of Example 1, and the experiment is repeated 5 times. The experimental results are as follows. Figure 7 As shown.
[0074] In Example 1, the composite material preferably showed that after 5 cycles of degradation experiments, the degradation rate changed from 100% in 5 minutes to 90.91%, and the degradation rate remained above 90%, indicating that the heterogeneous catalytic composite material prepared under the preferred conditions has good stability.
[0075] Example 10 In this embodiment, graphite powder was used instead of graphite felt as the supporting substrate, and the other conditions were the same as in Example 1. The SEM image of the resulting heterogeneous catalytic composite material is shown below. Figure 8 and 9 As shown, where, Figure 9 The magnification is greater than Figure 8 ,from Figure 8 and 9 As can be seen from the magnified image, the graphite powder particles appear as small lumps surrounded by many spherical particles. These spherical particles are the molybdenum-copper catalyst formed after hydrothermal treatment. Clearly, the molybdenum-copper catalyst loading on the graphite powder particles is very low, even negligible. In contrast, for example... Figure 1-3 Using graphite felt as a substrate, the molybdenum-copper catalyst is almost entirely supported on the graphite felt. Therefore, using graphite felt as a substrate allows for the loading of more catalyst, forming more active sites on the surface, thereby improving catalytic efficiency.
[0076] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.
Claims
1. A method for preparing a heterogeneous catalytic composite material, characterized in that: Specifically, the following steps are included: (1) Oxidation treatment of graphite felt: oxidize graphite felt by treating the solution or by using an electrochemical process; (2) Hydrothermal synthesis of composite materials: Na2MoO4 2H2O and Cu(NO3)2·3H2O are dissolved in deionized water to obtain a homogeneous solution, namely the precursor solution. The pH of the precursor is adjusted by dilute nitric acid or dilute sulfuric acid to make the pH of the precursor between 3 and 7. Then, the oxidized graphite felt is placed in the precursor solution for hydrothermal reaction. (3) Preparation of heterogeneous catalytic composite material: The product of hydrothermal reaction is transferred to a muffle furnace for calcination to obtain heterogeneous catalytic composite material.
2. The method for preparing the heterogeneous catalytic composite material according to claim 1, characterized in that: Step (1) also includes pretreatment of the graphite felt. Specifically, the graphite felt is placed in a pretreatment detergent and ultrasonically treated for 14-16 minutes, rinsed repeatedly with deionized water, and dried for later use.
3. The method for preparing the heterogeneous catalytic composite material according to claim 2, characterized in that: In the pretreatment of graphite felt, the pretreatment detergent is anhydrous ethanol.
4. The method for preparing the heterogeneous catalytic composite material according to claim 1, characterized in that: In step (1), when the graphite felt is oxidized using a treatment solution, the treatment solution is dilute sulfuric acid with a concentration of 0.4-0.6 mol / L and a treatment time of 11-13 h.
5. The method for preparing the heterogeneous catalytic composite material according to claim 1, characterized in that: When the graphite felt is oxidized in step (1) using an electrochemical process, a constant voltage power supply is used in the electrochemical process, with the graphite felt as the anode and the platinum sheet as the cathode, and the oxidation is carried out. The oxidation voltage is 1.7-2.5V and the oxidation time is 8-12 minutes.
6. The method for preparing the heterogeneous catalytic composite material according to claim 1, characterized in that: Na2MoO4 in the precursor solution in step (2) The molar ratio of Na₂MoO₄ to Cu(NO₃)₂·3H₂O is between 1-3:3-1. The concentration of 2H2O is 0.05-0.20 mol / L, and the concentration of Cu(NO3)2·3H2O is 0.05-0.20 mol / L.
7. The method for preparing the heterogeneous catalytic composite material according to claim 1, characterized in that: The temperature of the hydrothermal reaction in step (2) is 120-200℃ and the time is 8-12 h.
8. The method for preparing the heterogeneous catalytic composite material according to claim 1, characterized in that: The calcination process in step (3) is as follows: the temperature is increased to 280-320℃ at a heating rate of 4-6℃ / min, and calcined at the calcination temperature for 1.5-2.5 h to obtain heterogeneous catalytic composite material.
9. The application of the heterogeneous catalytic composite material prepared by the preparation method of the material according to any one of claims 1-8 in the catalytic activation of persulfate.