High-exposure-density monatomic fenton catalyst, green scale-up preparation method and application thereof
A high-exposure-density single-atom catalyst was prepared by a mixed pyrolysis method of inexpensive metal salts and polymerizable monomers, solving the problem of large-scale preparation and achieving efficient and green preparation and high-efficiency catalytic performance. It is suitable for various metal single-atom loading and multiple recycling.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ANHUI UNIV
- Filing Date
- 2023-04-13
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies are insufficient for the large-scale preparation of single-atom catalysts with high loading and high exposure sites, and the preparation process may cause secondary pollution, making it difficult to meet practical needs.
A high-exposure-density single-atom Fenton-like catalyst was prepared by mixing inexpensive metal salts with polymerizable monomers and through polymerization and pyrolysis. Sodium chloride was used as a pore-forming agent and the catalyst was washed and dried to form a highly efficient single-atom supported porous carbon material.
It has achieved efficient and green large-scale preparation of single-atom catalysts with high loading and high exposure density. It is suitable for mixed loading of various metal single atoms, has excellent catalytic performance, and is applicable to a wide range of oxidants and target pollutants. It still maintains high activity after multiple cycles.
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Figure CN116726964B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of materials synthesis technology, and in particular to a high-exposure-density single-atom Fenton catalyst, its green large-scale preparation method, and its application. Background Technology
[0002] Water is the source of life and an indispensable substance for human survival and development. Advanced oxidation technologies are an effective means of treating organic pollutants in water bodies. Among them, heterogeneous Fenton catalytic reactions have attracted great attention. This reaction can be carried out under normal temperature and pressure conditions, and has the advantages of high efficiency and simple operation, while also being green and pollution-free.
[0003] The development of Fenton-like catalysts has always been a key focus for scientists. From carbon-based catalysts to metal-based and metal-supported catalysts, and then to single-atom catalysts, the evolution has been remarkable. While pure carbon-based catalysts are inexpensive and environmentally friendly, their activity is insufficient. Traditional metal catalysts contain only a small fraction of the active material, resulting in poor selectivity, low efficiency, high metal consumption, potential secondary pollution, and increased costs. Single-atom catalysts effectively overcome these challenges, maximizing metal dispersion and atom utilization while exhibiting significant catalytic performance. Currently, single-atom catalysts demonstrate extremely high atomic efficiency and catalytic performance, and are widely used in the Fenton reaction.
[0004] Extensive research has been conducted on the synthesis strategies of single-atom catalysts, and numerous synthetic methods have been reported. However, single-atom sites are prone to mobility and aggregation, often requiring specialized methods to stabilize the metal atoms. Therefore, the large-scale preparation of single-atom catalysts with high loading and high exposed sites remains a challenge. For example, classic MOF precursor synthesis routes have limited loading and low yields (Angew. Chem. Int. Ed. 2016, 55, 10800-10805;). Batch synthesis routes, while offering high loading, suffer from low specific surface areas, resulting in low site accessibility (Adv. Mater. 2020, 32, 2000896; CN111450868A). Alternatively, these routes may be environmentally unfriendly, causing secondary pollution during the preparation process (Adv. Mater. 2020, 32, 2000896), all of which fail to meet practical requirements.
[0005] The above background information is provided to facilitate understanding of the present invention and is not intended to be publicly known technology disclosed to the general public prior to the application of this invention. Summary of the Invention
[0006] To address the aforementioned shortcomings, this invention provides a high-exposure-density single-atom Fenton catalyst. This invention offers a new approach for preparing single-atom catalysts with application potential. At the same time, the stability of the single-atom catalyst is improved through the interaction between the metal and the support, reducing losses during the Fenton reaction.
[0007] The technical solution is: a high-exposure-density single-atom Fenton catalyst, which is obtained by polymerizing and coordinating an inexpensive metal salt, followed by pyrolysis, water washing, and drying.
[0008] Furthermore, the inexpensive metal is one of Fe, Co, Ni, Cu, Mn, or a mixture thereof.
[0009] Furthermore, the salt is a nitrate or a chloride.
[0010] On the other hand, the present invention provides a method for preparing a high-exposure-density single-atom Fenton catalyst.
[0011] A green, large-scale preparation method for high-exposure-density single-atom Fenton-like catalysts includes the following steps:
[0012] S1, mixing polymerizable monomers that are coordinated with a metal to form a polymerizable monomer solution that is coordinated with a metal;
[0013] S2, a mixed aqueous solution of a high melting point soluble salt, a salt of an inexpensive metal, and water is added to a solution of a polymerizable monomer that coordinates with the metal to react. After the reaction, the solvent is removed by drying to obtain a solid powder with metal ion coordination filled with high melting point soluble salt particles.
[0014] S3, pyrolysis of solid powder with metal ion coordination filled with high melting point soluble salt particles to obtain carbon-nitrogen carrier anchored single-atom material containing high melting point soluble salt particles.
[0015] S4, a carbon-nitrogen carrier anchored single-atom material containing high-melting-point soluble salt particles, washed with water;
[0016] S5 is a dried, high-exposure-density single-atom Fenton catalyst.
[0017] Furthermore, the polymerizable monomer combination having metal coordination is one of the following: a combination of dicyandiamide and formaldehyde, a combination of melamine and formaldehyde, or a combination of 3-aminophenol and formaldehyde.
[0018] Furthermore, the high-melting-point soluble salt is one or more of sodium chloride, KCl, NaBr, and KBr.
[0019] Furthermore, the inexpensive metal is one of Fe, Co, Ni, Cu, Mn, or a mixture thereof.
[0020] Furthermore, the salt is a nitrate or a chloride.
[0021] Furthermore, in the metal-coordinated polymerizable monomer combination, the molar ratio between the polymerizable monomers is 1:1 to 3; the molar ratio of the inexpensive metal salt to the metal-coordinated polymerizable monomer combination is 0 to 1:7, wherein the molar ratio of the inexpensive metal salt to the metal-coordinated polymerizable monomer combination is not 0; in S2, the amount of high-melting-point soluble salt added is 10 to 20 g.
[0022] Furthermore, the pyrolysis is calcination pyrolysis at a temperature of 400–800°C for 2–4 hours; in S2, the drying is carried out at 80–110°C for 10–16 hours; in S4, the water washing is carried out with deionized water by stirring or ultrasonic water washing for 2–8 hours.
[0023] Furthermore, the present invention also provides a high-exposure-density single-atom Fenton catalyst.
[0024] A high-exposure-density single-atom Fenton catalyst, said high-exposure-density single-atom Fenton catalyst is prepared by the method described above.
[0025] Furthermore, this invention also provides an application of a high-exposure-density single-atom Fenton catalyst.
[0026] An application of the above-mentioned high exposure density single-atom Fenton-like catalyst, wherein the high exposure density single-atom Fenton catalyst is applied to Fenton-like reactions.
[0027] Furthermore, the pH of the Fenton-like reaction solution is 3-11, the oxidant is selected from hydrogen peroxide, potassium persulfate, potassium hydrogen persulfate, and sodium percarbonate, and the dosage of the high exposure density single-atom Fenton-like catalyst is 0.1-0.4 g / L.
[0028] The inventive principle of this invention:
[0029] Using inexpensive metal salts, a homogeneous mixed solution is first prepared by mixing dicyandiamide, formaldehyde, and an aqueous solution of metal ions, with sodium chloride added simultaneously. Heating initiates a polymerization reaction, and the metal ions coordinate with each other to achieve fixation. During solvent evaporation, sodium chloride precipitates and fills the polymer. After pyrolysis, simple washing and drying yield the single-atom-loaded porous carbon material. The preparation process is simple and convenient, yields a large quantity of product, and uses a non-toxic solvent and recyclable sodium chloride pore-forming agent, making the entire process green and environmentally friendly. Compared with existing technologies, this invention overcomes the problems of insufficient single-atom loading, low site accessibility, and inability to scale up preparation. It is also applicable to the mixed loading of one or more different metal single atoms.
[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0031] ①The process of this invention has a simple synthesis route, low cost, green and no secondary pollution, large synthesis product quantity, high single atom loading, and high site exposure density.
[0032] ②The single-atom material of the present invention, as a Fenton-like reaction catalyst, can achieve catalytic reaction within a certain reaction condition range, and can still retain most of the catalytic activity after multiple cycles of use, and is applicable to a wide range of oxidants and target pollutants.
[0033] ③The non-precious metal single-atom catalyst of this invention has the potential to be widely used in Fenton-like efficient degradation of water pollutants. Attached Figure Description
[0034] Figure 1 These are TEM and aberration-corrected electron microscopy images of the Fe single-atom catalyst prepared by the route of this invention;
[0035] Figure 2 This is the nitrogen adsorption-desorption isotherm of the Fe single-atom catalyst prepared by the route of this invention. Detailed Implementation
[0036] The invention will now be further described with reference to the accompanying drawings.
[0037] In the following embodiments, unless otherwise specified, all reagents and other materials involved are commercially available products, and all methods involved are conventional methods known to those skilled in the art.
[0038] Example 1: Preparation of Fe single-atom materials, the specific steps are as follows:
[0039] S1. Dicyandiamide powder (2.5g, 29.7mmol) and formaldehyde aqueous solution (2.2ml, of which 29.7mmol of formaldehyde) were added to 25ml of water and stirred vigorously by ultrasonication until homogeneous. The molar ratio of dicyandiamide to formaldehyde in the formaldehyde aqueous solution was 1:1. The reaction time was 30 minutes. Finally, the reaction was transformed into a clear and transparent dicyandiamide-formaldehyde aqueous solution.
[0040] S2: Fe(NO3)3·9H2O (1.713 g, 4.24 mmol) and 10 g sodium chloride (sodium chloride as a pore-forming agent) were completely dissolved in 25 ml of water. After dissolution, the solution was added to the dicyandiamide-formaldehyde aqueous solution formed in S1 and mixed. The mixture was then ultrasonically stirred for 20 minutes. The resulting solution was poured into a watch glass and dried in a drying oven at 110 °C for 10 hours.
[0041] S3: Collect and grind the solids on the surface of the dried S2 plate. After grinding evenly, place it in a porcelain boat and calcine it in a tube furnace at 5℃ / min to 600℃ for 2 hours. Then, allow it to cool naturally to room temperature under a nitrogen inert atmosphere.
[0042] S4. Grind the calcined product of S3 until it is uniform, put it into a round-bottom flask, add 400ml of water, stir at room temperature for 2 hours, and then filter.
[0043] S5. The filtered solid is dried at 60°C to obtain a black powder, which is the Fe single-atom material.
[0044] Example 2
[0045] The Fe single-atom material prepared in Example 1 was analyzed by ICP-OES, and the Fe loading was 12.3 wt%.
[0046] Example 3: Preparation of pore-free Fe single-atom materials, the specific steps are as follows:
[0047] S1. Dicyandiamide powder (2.5g, 29.7mmol) and formaldehyde aqueous solution (2.2ml, of which 29.7mmol of formaldehyde) were added to 25ml of water and stirred vigorously by ultrasonication until homogeneous. The molar ratio of dicyandiamide to formaldehyde in the formaldehyde aqueous solution was 1:1. The reaction time was 30 minutes. Finally, the reaction was transformed into a clear and transparent dicyandiamide-formaldehyde aqueous solution.
[0048] S2: Fe(NO3)3·9H2O (1.713 g, 4.24 mmol) was completely dissolved in 25 ml of water. After dissolution, it was added to the dicyandiamide-formaldehyde aqueous solution formed in S1 and mixed. The mixture was then ultrasonically stirred for 20 minutes. The resulting solution was poured into a watch glass and dried in a drying oven at 110 °C for 10 hours.
[0049] S3: Collect and grind the solids on the surface of the dried S2 plate. After grinding evenly, place it in a porcelain boat and calcine it in a tube furnace at 5℃ / min to 600℃ for 2 hours. Then, allow it to cool naturally to room temperature under a nitrogen inert atmosphere.
[0050] S4. Grind the calcined product of S3 until it is uniform, put it into a round-bottom flask, add 400ml of water, stir at room temperature for 2 hours, and then filter.
[0051] S5. The filtered solid is dried at 60°C to obtain a black powder, which is the Fe single-atom material.
[0052] Example 4
[0053] The Fe single-atom material prepared in Example 1 was characterized by electron microscopy and its specific surface area was measured. The electron microscopy characterization results are as follows: Figure 1 It was found that the metals were mainly distributed in atomic form.
[0054] Specific surface area according to Figure 2 The nitrogen adsorption-desorption isotherm was obtained at 324.5 m. 2 / g. The specific surface area of the Fe single-atom material of the present invention is 33.09 m² compared to the specific surface area of the non-porous Fe single-atom material in Example 3. 2 / g showed a significant improvement.
[0055] Example 4
[0056] 12 mg of the Fe single-atom material prepared in Example 1 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. Potassium persulfate (PMS) was then injected to bring the PMS concentration in the solution to 0.4 g / L, initiating a Fenton-like reaction and starting the timer. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The residual tetracycline hydrochloride concentration (C) in the solution was measured. t The removal rate R% of tetracycline hydrochloride is calculated according to the following formula:
[0057] R% = 100% · (C0 – C) t ) / C0
[0058] The removal rate was 92% when the reaction time was 60 minutes.
[0059] The removal rate of this embodiment is much higher than the 38% removal rate of the catalyst without pores in Example 3, which was determined using the same method (only 12 mg of Fe single-atom material without pores in Example 3 was used to replace 12 mg of Fe single-atom material in this embodiment).
[0060] Example 5: Preparation of Co single-atom materials, the specific steps are as follows:
[0061] S1. Dicyandiamide powder (2.5g, 29.7mmol) and formaldehyde aqueous solution (2.2ml, of which 29.7mmol of formaldehyde) were added to 25mL of water and stirred vigorously by ultrasonication until homogeneous. The molar ratio of dicyandiamide to formaldehyde in the formaldehyde aqueous solution was 1:1. The reaction time was 30 minutes. Finally, the reaction was transformed into a clear and transparent dicyandiamide-formaldehyde aqueous solution.
[0062] S2: Co(NO3)2·6H2O (1.234 g, 4.24 mmol) and 10 g sodium chloride were added to 25 mL of water and completely dissolved. This dissolved solution was then added to the dicyandiamide-formaldehyde aqueous solution formed in S1 and mixed. After the addition was complete, the mixture was ultrasonically stirred for 20 minutes. The resulting solution was poured into a watch glass and dried in a drying oven at 110 °C for 10 hours.
[0063] S3: After drying S2, collect and grind the solid on the petri dish. Place the ground material evenly into a porcelain boat and calcine it in a tube furnace at 5℃ / min to 600℃ for 2 hours. Then, allow it to cool naturally to room temperature under a nitrogen inert atmosphere.
[0064] S4: Grind the calcined product of S3 evenly and put it into a round-bottom flask. Add 400 mL of water, stir at room temperature for 2 hours, and then filter.
[0065] S 5, dried at 60℃, finally yielded a black powder, which is a Co single-atom material.
[0066] Example 6
[0067] The Co single-atom material prepared in Example 5 was analyzed by ICP-OES, and the Co loading was 9.5 wt%.
[0068] Example 7
[0069] 12 mg of the Co single-atom material prepared in Example 5 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. PMS was then injected to bring the PMS concentration in the solution to 0.4 g / L to initiate a Fenton-like reaction and start timing. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The residual tetracycline hydrochloride concentration C in the solution was measured. t The results showed that the removal rate reached 89.6% when the reaction time was 60 minutes.
[0070] Example 8: Preparation of Fe and Co dual single-atom materials, the specific steps are as follows:
[0071] S1. Dicyandiamide powder (2.5g, 29.7mmol) and formaldehyde aqueous solution (2.2ml, of which 29.7mmol of formaldehyde) were added to 25mL of water and ultrasonically stirred vigorously until homogeneous. The molar ratio of dicyandiamide to formaldehyde in the formaldehyde aqueous solution was 1:1. The reaction time was 30 minutes. Finally, the reaction was transformed into a clear and transparent dicyandiamide-formaldehyde aqueous solution.
[0072] S2: Fe(NO3)3·9H2O (0.86 g, 2.12 mmol), Co(NO3)2·6H2O (0.62 g, 2.12 mmol), and 10 g of sodium chloride were completely dissolved in 25 mL of water. This solution was then added to the dicyandiamide-formaldehyde aqueous solution prepared in S1 and mixed. After the addition was complete, the mixture was ultrasonically stirred for 20 minutes. The resulting solution was then poured into a watch glass and dried in a drying oven at 110 °C for 10 hours.
[0073] S3: Collect and grind the solids on the surface dish after drying S2. Place the ground solids evenly into a porcelain boat and calcine them in a tube furnace at 5℃ / min to 600℃ for 2 hours. Then, allow it to cool naturally to room temperature under a nitrogen inert atmosphere.
[0074] S4. Grind the calcined product until it is uniform, then put it into a round-bottom flask, add 400mL of water, stir at room temperature for 2 hours, and then filter.
[0075] S5, the filtered solid was dried at 60°C to obtain a black powder, which is a Fe and Co dual single-atom material.
[0076] Example 9
[0077] The Fe and Co dual single-atom material prepared in Example 8 was analyzed by ICP-OES, and the loading of Fe and Co elements was found to be 6.27 wt% and 4.78 wt%, respectively.
[0078] Example 10
[0079] 12 mg of the Fe / Co dual single-atom material prepared in Example 8 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. PMS was then injected to bring the PMS concentration in the solution to 0.4 g / L to initiate a Fenton-like reaction and start timing. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The concentration of residual tetracycline hydrochloride C in the solution was measured. t The results showed that the removal rate reached 94.6% when the reaction time was 60 minutes.
[0080] Example 11: Preparation of single-atom material from 20g NaCl template. The specific steps are as follows:
[0081] S1. Dicyandiamide powder (2.5g, 29.7mmol) and formaldehyde aqueous solution (2.2ml, of which 29.7mmol of formaldehyde) were added to 25ml of water and stirred vigorously by ultrasonication until homogeneous. The molar ratio of dicyandiamide to formaldehyde in the formaldehyde aqueous solution was 1:1. The reaction time was 30 minutes. Finally, the reaction was transformed into a clear and transparent dicyandiamide-formaldehyde aqueous solution.
[0082] S2: Dissolve 1.714 g (4.24 mmol) of Fe(NO3)3·9H2O and 20 g of sodium chloride in 25 ml of water. Then add the dissolved Fe(NO3)3·9H2O to the dicyandiamide-formaldehyde aqueous solution prepared in S1 and mix. After addition, stir the mixture with ultrasound for 20 minutes. Pour the resulting solution into a watch glass and dry it in a drying oven at 110°C for 10 hours.
[0083] S3: Collect and grind the solids on the surface of the dried S2 plate. After grinding evenly, place it in a porcelain boat and calcine it in a tube furnace at 5℃ / min to 600℃ for 2 hours. Then, allow it to cool naturally to room temperature under a nitrogen inert atmosphere.
[0084] S4: Grind the calcined product of S3 until homogeneous, then place it in a round-bottom flask, add 400 mL of water, stir at room temperature for 2 hours, and then filter.
[0085] S5. The filtered solid is dried at 60°C to obtain a black powder, which is a Fe single-atom material.
[0086] Example 12
[0087] The Fe single-atom material prepared in Example 11 was analyzed by ICP-OES, and the Fe loading was as high as 14.1 wt%.
[0088] Example 13
[0089] 12 mg of the Fe single-atom material prepared in Example 11 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. PMS was then injected to bring the PMS concentration in the solution to 0.4 g / L to initiate a Fenton-like reaction and start timing. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The concentration of residual tetracycline hydrochloride C in the solution was measured. t The results showed that the removal rate reached 93.1% when the reaction time was 60 minutes.
[0090] Example 14 Catalytic reaction of Fe single-atom Fenton catalyst (different oxidants)
[0091] 12 mg of the Fe single-atom material prepared in Example 1 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. Hydrogen peroxide (H₂O₂) was then added to bring the hydrogen peroxide concentration in the solution to 1.0 g / L to initiate a Fenton-like reaction and start timing. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The concentration C of residual tetracycline hydrochloride in the solution was measured. t The results showed that the removal rate reached 58% when the reaction time was 60 minutes.
[0092] Example 15 Catalytic reaction of Fe single-atom Fenton catalyst (different oxidants)
[0093] 12 mg of the Fe single-atom material prepared in Example 1 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. Potassium persulfate (PDS) was then injected to bring the PDS concentration in the solution to 0.4 g / L, initiating a Fenton-like reaction and starting the timing. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The residual tetracycline hydrochloride concentration (C) in the solution was measured. t The results showed that the removal rate reached 62% when the reaction time was 60 minutes.
[0094] Example 16 Catalytic reaction of Fe single-atom Fenton catalyst (secondary cycle)
[0095] Approximately 12 mg of the used Fe single-atom material from Example 4 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. PMS was then injected to bring the PMS concentration in the solution to 0.4 g / L to initiate a Fenton-like reaction and start timing. After the expected reaction time, a certain amount of solution was taken out, filtered using a syringe filter, and the residual tetracycline hydrochloride concentration C in the solution was measured. t The results showed that the removal rate reached 90.5% when the reaction time was 60 minutes.
[0096] Example 17 Catalytic reaction of Fe single-atom Fenton catalyst (three cycles)
[0097] Approximately 12 mg of the used Fe single-atom material from Example 16 was dispersed in 40 mL of a tetracycline hydrochloride solution with an initial concentration (CO) of 40 mg / L and an initial pH of 6.5. PMS was then injected to bring the PMS concentration in the solution to 0.4 g / L to initiate a Fenton-like reaction and start timing. After the expected reaction time, a certain amount of solution was taken out and filtered using a syringe filter. The residual tetracycline hydrochloride concentration (C) in the solution was measured.t The results showed that the removal rate reached 88.1% when the reaction time was 60 minutes.
[0098] As demonstrated in Examples 1-17, various non-metallic single-atom catalyst materials with high exposed sites can be simply and efficiently prepared by using NaCl salt templates and the coordination between dicyandiamide-formaldehyde resin and metal ions via high-temperature pyrolysis. The obtained materials exhibit good catalytic performance and stability. The single-atom catalyst materials obtained according to this invention can be widely applied in Fenton-like reaction fields.
[0099] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An application of a high-exposure-density single-atom Fenton catalyst, characterized in that, The high-exposure-density single-atom Fenton-like catalyst is applied to a Fenton-like reaction, which is the degradation of tetracycline hydrochloride in solution. The high-exposure-density single-atom Fenton catalyst is prepared by polymerization reaction of inexpensive metal salts, high-melting-point soluble salts, and polymerizable monomers with the ability to coordinate with metal ions, followed by pyrolysis, water washing, and drying. The polymerizable monomer combination with the ability to coordinate with metal ions is a combination of dicyandiamide and formaldehyde; The high-melting-point soluble salt is one or more of sodium chloride, KCl, NaBr, and KBr; The inexpensive metal is Fe or a mixture of Fe and Co; The Fenton-like reaction solution has a pH of 6.5, and the oxidant is potassium persulfate.
2. The application of the high exposure density single-atom Fenton catalyst according to claim 1, characterized in that, The high-exposure-density single-atom-like Fenton catalyst is prepared by the following steps: S1, a polymerizable monomer combination solution with the ability to coordinate with metal ions is formed by mixing polymerizable monomer combination with the ability to coordinate with metal ions. S2, a mixed aqueous solution of a high melting point soluble salt, a salt of an inexpensive metal, and water is added to a polymerizable monomer combination solution with the ability to coordinate with metal ions and reacted. After the reaction, the solvent is removed by drying to obtain a solid powder with metal ion coordination filled with high melting point soluble salt particles. S3, pyrolysis of solid powder with metal ion coordination filled with high melting point soluble salt particles to obtain carbon-nitrogen carrier anchored single-atom material containing high melting point soluble salt particles. S4, a carbon-nitrogen carrier anchored single-atom material containing high-melting-point soluble salt particles, washed with water; S5 is a dried, high-exposure-density single-atom Fenton catalyst.
3. The application of the high exposure density single-atom Fenton catalyst according to claim 2, characterized in that, In the polymerizable monomer combination with the ability to coordinate with metal ions, the molar ratio between the polymerizable monomers is 1:1~3; the molar ratio of the inexpensive metal salt to the polymerizable monomer combination with the ability to coordinate with metal ions is 0~1:7, wherein the molar ratio of the inexpensive metal salt to the polymerizable monomer combination with the ability to coordinate with metal ions is not 0; in S2, the amount of high melting point soluble salt added is 10~20g.
4. The application of the high exposure density single-atom Fenton catalyst according to claim 2, characterized in that, The pyrolysis is calcination pyrolysis at a temperature of 400~800℃ for 2~4 hours; in S2, drying is carried out at 80~110℃ for 10~16 hours; in S4, water washing is carried out with deionized water by stirring or ultrasonic water washing for 2~8 hours.
5. The application of the high exposure density single-atom Fenton catalyst according to claim 1, characterized in that, The dosage of the high exposure density single-atom Fenton catalyst is 0.1~0.4 g / L.