Fe, Al-GC@Fe 0 Catalyst, process for its preparation and use

Abstract

The application discloses Fe, Al-GC@Fe 0 The application discloses a Fe, Al-GC@Fe 0 catalyst and a preparation method and application thereof, and belongs to the technical field of water treatment catalyst preparation. Ferric chloride hexahydrate and anhydrous aluminum chloride are dissolved in ultrapure water to form a solution A; trimesic acid is dissolved in a sodium hydroxide aqueous solution to form a solution B, the two are mixed and stirred at room temperature, pyrrole and ammonium persulfate are added, and the stirring is continued to obtain a suspension C; solid D is obtained by washing and drying; the solid D is mixed with urea and placed in a quartz boat, and the black solid is obtained by calcining in a tube furnace under the condition of nitrogen flow; and the Fe, Al-GC@Fe 0 catalyst is obtained by grinding. The preparation method is simple, the equipment requirement is low, the prepared catalyst can effectively and rapidly remove and degrade organic pollutants in water without other additional substances, the removal rate is greater than 80% within 60 min, the catalyst belongs to a solid catalyst, can be separated from water, can be recycled and utilized, and can maintain a high removal effect.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of water treatment catalyst preparation, in particular to a Fe, Al-GC@Fe 0 catalyst and a preparation method and application thereof. BACKGROUND

[0002] Fenton catalysis technology is a mature advanced oxidation water treatment method, and the core mechanism thereof is that divalent iron ions (Fe 2+ ) catalyze the decomposition of hydrogen peroxide (H2O2) to drive chain reactions to generate hydroxyl radicals with strong oxidizing properties. The radicals can non-selectively and efficiently degrade most organic matters in water bodies, and are especially suitable for treating organic wastewater which is difficult to be biodegraded or treated by conventional chemical oxidation. However, the traditional homogeneous Fenton technology has significant limitations: low catalytic activity under neutral pH conditions, poor system stability, a large amount of iron-containing sludge (iron sludge) generated in the reaction process to cause secondary pollution, and generally low hydrogen peroxide utilization rate. Therefore, it is crucial to overcome the bottlenecks of existing iron-based system catalysts, develop other metal materials which have similar oxidation-reduction properties to iron, do not need to add any other substances, and have a wider pH response range than iron to replace iron and become more excellent active centers of the heterogeneous catalyst. SUMMARY

[0003] The application aims to provide a Fe, Al-GC@Fe 0 catalyst and a preparation method and application thereof to solve the problems in the background.

[0004] To achieve the above-mentioned purpose, the application provides a preparation method of a Fe, Al-GC@Fe 0 catalyst, which comprises the following steps:

[0005] (1) dissolving ferric chloride hexahydrate and anhydrous aluminum chloride in ultrapure water to form a solution A;

[0006] (2) dissolving trimesic acid in a sodium hydroxide aqueous solution to form a solution B;

[0007] (3) fully mixing the solution B and the solution A, stirring at room temperature, adding pyrrole and ammonium persulfate, and continuing to stir to obtain a suspension C;

[0008] (4) centrifuging the suspension C, washing with ultrapure water, and drying to obtain a solid D;

[0009] (5) mixing the solid D and urea in a quartz boat, calcining in a tube furnace under the condition of nitrogen flow, grinding the obtained black solid to obtain the target product Fe, Al-GC@Fe 0 catalyst.

[0010] Preferably, in step (1), the amount of substance of the ferric chloride hexahydrate is 3-4 mmol, and the amount of substance of the aluminum chloride anhydrous is 0.9-1 mmol.

[0011] Preferably, in step (2), the amount of substance of the trimesic acid is 2-3 mmol, and the concentration of the sodium hydroxide aqueous solution is 1 M.

[0012] Preferably, in step (3), the amount of substance of the pyrrole is 2-3 mmol, and the amount of substance of the ammonium persulfate is 0.4-0.5 mmol.

[0013] Preferably, in step (4), the drying temperature is 80-100 DEG C, and the drying time is 8-12 hours.

[0014] Preferably, in step (5), the temperature rising rate of the tube furnace is 5 DEG C / min, the calcination temperature is 900 DEG C, and the calcination time is 2h.

[0015] The application further provides a Fe,Al-GC@Fe 0 catalyst prepared by the preparation method. 0 The Fe,Al-GC@Fe 0 catalyst is a black solid powder, and the structural composition of the catalyst is mainly aluminum-based MIL-100 metal organic carbon, and the microstructure is a hexahedral crystal structure material. The zero-valent iron of the catalyst prepared by the application is tightly coated by the carbonized organic framework, and the iron content on the surface of the material is almost undetectable, so that the iron catalytic performance is more stable and is not easy to be dissolved out of the water body.

[0016] The application further provides a Fe,Al-GC@Fe 0 catalyst in removing organic pollutants in degraded water.

[0017] Preferably, the organic pollutants are one or more of chlorophenol (4-CP), atrazine (ATZ), methylene blue (MB), 2,4-dichlorophenol (2,4-DCP), bisphenol A (BPA), ciprofloxacin (CIP), bisphenol F epoxy resin (BPF), sulfamethoxazole (SMZ), and tetracycline (TC).

[0018] Therefore, the Fe,Al-GC@Fe 0 catalyst, the preparation method and the application thereof have the following beneficial effects:

[0019] (1) The catalyst is prepared by two-step synthesis, that is, a simple room-temperature stirring precipitation method is first used, and then a calcination method is used, so that the preparation method is simple.

[0020] (2) The Fe,Al-GC@Fe 0 The catalyst has excellent catalytic performance for degradation of organic pollutants in water. The zero-valent iron is coated in the carbonized organic framework, mainly plays a role in regulating the internal electron distribution of the material, and the zero-valent iron as an active center does not directly react with the pollutants, and has small dissolution.

[0021] (3) The Fe,Al-GC@Fe 0 The catalyst can effectively and quickly remove organic pollutants such as 4-chlorophenol (4-CP), atrazine (ATZ), methylene blue (MB), 2,4-dichlorophenol (2,4-DCP), bisphenol A (BPA), ciprofloxacin (CIP), and bisphenol F epoxy resin (BPF) in water without other additional substances, and the removal rate is greater than 80% within 60 min.

[0022] (4) The Fe,Al-GC@Fe 0 The catalyst is a solid catalyst, which is convenient to separate from water, recycle and reuse, and maintains high removal effect.

[0023] (5) In the degradation experiment, the Fe,Al-GC@Fe 0 The catalyst reaction system does not need to adjust pH and can be carried out under neutral conditions.

[0024] The technical solutions of the present application will be further described in detail below by means of the accompanying drawings and examples. DESCRIPTION OF DRAWINGS

[0025] Figure 1 The Fe,Al-GC@Fe 0 XRD spectrum of the catalyst prepared in Example 1 of the present application;

[0026] Figure 2 The Fe,Al-GC@Fe 0 High-magnification scanning electron microscope (SEM) image of the catalyst prepared in Example 1 of the present application; wherein (a) is 500 nm; (b) is 200 nm; (c) is 100 nm;

[0027] Figure 3 The Fe,Al-GC@Fe 0 Transmission electron microscope (TEM) image and element distribution of iron and carbon of the catalyst prepared in Example 1 of the present application; wherein (a) is 100 nm; (b) is 50 nm; (c) is 10 nm;

[0028] Figure 4 The Fe,Al-GC@Fe 0Catalyst for different organic pollutants catalytic degradation curve;

[0029] Figure 5 Fe, Al-GC@Fe prepared for the embodiment 1 of the present application 0 Catalyst degradation curve of starting reaction degradation of BPA under different initial concentration conditions;

[0030] Figure 6 Fe, Al-GC@Fe prepared for the embodiment 1 of the present application 0 Catalyst starting reaction degradation of BPA cycle repeated use activity evaluation results graph. DETAILED DESCRIPTION

[0031] The technical solutions of the present application are further described below by means of the accompanying drawings and examples. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application, and any changes, modifications, substitutions, combinations, simplifications made without deviating from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application. In addition, it should be understood that after reading the content of the present application, those skilled in the art can make various modifications or modifications to the present application, and these equivalent forms also fall within the scope defined by the appended claims of the present application, and are within the scope of protection of the present application.

[0032] In this paper, "embodiment" means that the specific features, structures or characteristics described in conjunction with the embodiment can be included in at least one embodiment of the present application. The word "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association between other embodiments. In principle, in this application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form a corresponding implementable technical solution.

[0033] Unless otherwise defined, the meaning of the technical terms used herein is the same as that generally understood by those skilled in the art to which the present application belongs; the use of related terms herein is only for the purpose of describing specific embodiments, and is not intended to limit the present application.

[0034] Unless otherwise specified, the reagents, instruments, equipment and performance test methods used in the present application are conventional reagents, instruments, equipment and methods used by those skilled in the art.

[0035] Embodiment 1

[0036] The present embodiment provides a Fe, Al-GC@Fe 0 The preparation method of the catalyst specifically comprises the following steps:

[0037] (1) 3-4 mmol of ferric chloride hexahydrate and 0.9-1 mmol of anhydrous aluminum chloride were weighed and dissolved in ultrapure water to form solution A.

[0038] (2) 2-3 mmol of trimesic acid was weighed and dissolved in a 1 mol / L sodium oxide aqueous solution to form solution B.

[0039] (3) Solution B was mixed with solution A and stirred at room temperature for 12 h, 2-3 mmol of pyrrole and 0.4-0.5 mmol of ammonium persulfate were added and stirring was continued for 1 h to obtain suspension C.

[0040] (4) Suspension C was centrifuged, washed with ultrapure water, and dried at 90°C for 10 h to obtain solid D.

[0041] (5) Solid D was mixed with 8 g of urea in a quartz boat, and the temperature was raised to 900°C at a rate of 5°C / min in a tube furnace under nitrogen atmosphere, and calcination was carried out for 2 hours. After calcination, a black solid was obtained, which was ground to obtain Fe,Al-GC@Fe 0 catalyst.

[0042] The Fe,Al-GC@Fe 0 catalyst prepared in this example was characterized, and the results are shown in Figures 1-3 .

[0043] Figure 1 The XRD spectrum of the Fe,Al-GC@Fe 0 catalyst prepared in this example is shown in the figure, and it is found that the characteristic diffraction peak (110) of elemental Fe is consistent with the standard card.

[0044] Figure 2 The scanning electron microscope (SEM) image of the Fe,Al-GC@Fe 0 catalyst prepared in this example is shown in the figure, and it can be observed from the figure that it is a hexagonal crystal material.

[0045] Figure 3 The transmission electron microscope (TEM) image of the Fe,Al-GC@Fe 0 catalyst prepared in this example is shown in the figure, and element analysis found that the black nanoparticles in the figure are iron.

[0046] Example 2

[0047] This example provides the application of the Fe,Al-GC@Fe 0 catalyst prepared in Example 1 in the degradation of organic pollutants in water. Specifically, 0.015 g of the Fe,Al-GC@Fe 0The catalyst was put into 50 mL of 5 mg / L organic pollutant solution, and the adsorption and degradation reaction was started under continuous stirring in a water bath at 35℃. The pollutant concentration was measured at different time points.

[0048] The organic pollutants were chlorophenol (4-CP), atrazine (ATZ), methylene blue (MB), 2,4-dichlorophenol (2,4-DCP), bisphenol A (BPA), ciprofloxacin (CIP), bisphenol F epoxy resin (BPF), sulfamethoxazole (SMZ), and tetracycline (TC).

[0049] Figure 4 Fe,Al-GC@Fe prepared in Example 1 0 The degradation curves of the catalyst for 4-CP, ATZ, MB, 2,4-DCP, CIP, BPF, SMZ, and TC are shown in FIG. 2. Figure 4 As can be seen from the degradation rates of different organic pollutants, the removal rates of the above pollutants all exceeded 80% at 60 min.

[0050] Figure 5 Fe,Al-GC@Fe prepared in Example 1 0 The degradation curves of the catalyst for BPA under different initial concentrations are shown in FIG. 3. Figure 5 As can be seen from FIG. 3, when the catalyst was put into a solution with a concentration of 0.1-0.3 g / L, the degradation rate of BPA gradually increased with the increase of the catalyst concentration. When the catalyst concentration was greater than 0.3 g / L, the degradation rate of BPA decreased with the increase of the catalyst concentration, indicating that 0.3 g / L was the optimal catalyst concentration for the experiment. Considering the cost of material addition, 0.3 g / L was considered as the catalyst concentration for subsequent experiments.

[0051] Example 3

[0052] This example provides Fe,Al-GC@Fe prepared in Example 1 0 The stability of the catalyst in the degradation and treatment of organic pollutants in water was explored, and the method included the following steps:

[0053] (1) 0.015 g of Fe,Al-GC@Fe prepared in Example 1 was put into 50 mL of 5 mg / L BPA solution, and the adsorption and degradation reaction was started under continuous stirring in a water bath at 35℃. 0 The catalyst was put into 50 mL of 5 mg / L organic pollutant solution, and the adsorption and degradation reaction was started under continuous stirring in a water bath at 35℃. The pollutant concentration was measured at different time points.

[0054] (2) After 60 min of reaction, the concentration of BPA was detected.

[0055] (3) The Fe,Al-GC@Fe after step (2) was separated by suction filtration and dried. 0 After the catalyst was separated by suction filtration and dried, the dried catalyst was repeatedly subjected to steps (1-3).

[0056] Figure 6 Fe,Al-GC@Fe prepared in Example 3 0 The figure shows the evaluation of the repeated use of the catalyst for the degradation of BPA. It can be observed that the effect of the catalyst prepared does not decrease significantly after successive cycles of reaction for the degradation of BPA, and in 6 repeated experiments, the removal effect can reach more than 90%.

[0057] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, but not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can still be modified or equivalently replaced, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A Fe,Al-GC@Fe 0 A method for preparing a catalyst, characterized in that, Includes the following steps: (1) Dissolve ferric chloride hexahydrate and anhydrous aluminum chloride in ultrapure water to form solution A; (2) Dissolve pyromellitic acid in an aqueous sodium hydroxide solution to form solution B; (3) Mix solution B and solution A thoroughly at room temperature and stir. Add pyrrole and ammonium persulfate and continue stirring to obtain suspension C; (4) After centrifuging the suspension C, wash it with ultrapure water and dry it to obtain solid D; (5) Mix solid D with urea and place it in a quartz boat. Calcinate the mixture in a tube furnace under nitrogen atmosphere. Grind the resulting black solid to obtain the target product Fe,Al-GC@Fe. 0 catalyst; In step (1), the amount of ferric chloride hexahydrate is 3~4 mmol, and the amount of anhydrous aluminum chloride is 0.9~1 mmol; In step (2), the amount of pyromellitic acid is 2-3 mmol, and the concentration of the sodium hydroxide aqueous solution is 1 M; In step (3), the amount of pyrrole is 2-3 mmol and the amount of ammonium persulfate is 0.4-0.5 mmol; In step (5), the heating rate of the tube furnace is 5℃ / min, the calcination temperature is 900℃, and the calcination time is 2h.

2. The Fe,Al-GC@Fe according to claim 1 0 A method for preparing a catalyst, characterized in that: In step (4), the drying temperature is 80~100℃ and the drying time is 8~12 hours.

3. A Fe,Al-GC@Fe 0 The catalyst is characterized by: The catalyst is prepared by any one of the preparation methods according to claims 1-2.

4. The Fe,Al-GC@Fe as described in claim 3 0 The application of catalysts is characterized by: The catalyst is used to degrade and remove organic pollutants from water.

5. The Fe,Al-GC@Fe according to claim 4 0 The application of catalysts is characterized by: The organic pollutant is one or more of the following: p-chlorophenol, atrazine, methylene blue, 2,4-dichlorophenol, bisphenol A, ciprofloxacin, bisphenol F epoxy resin, sulfamethoxazole, and tetracycline.

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