Flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst, its preparation method and application

Abstract

This invention provides a method for preparing a flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst, comprising the following steps: adding ammonia water to an aqueous solution of magnesium salt and allowing the reaction to proceed to obtain a magnesium hydroxide slurry; adding ammonium salt and a growth inducer to the magnesium hydroxide slurry and stirring the reaction; then adding a silicate solution dropwise to the magnesium hydroxide slurry and sonicating the solution after the addition is complete; transferring the sonicated slurry to a hydrothermal reactor and heating it with microwaves; after the reaction is complete, cooling it to room temperature, washing it with deionized water by centrifugation, and drying the resulting filter cake to obtain magnesium silicate powder; adding the magnesium silicate powder to a sodium hydroxide solution and stirring the reaction; after the reaction is complete, washing and drying the mixture to obtain the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst. The flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared by this invention is green, environmentally friendly, non-toxic, and harmless, and has advantages such as high catalytic activity, good selectivity, and long service life.

Description

Technical Field

[0001] This application relates to the field of catalyst technology, and more specifically, to a flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst, its preparation method, and its application. Background Technology

[0002] In the anthraquinone process for producing H2O2, due to the complexity of organic reactions, even with the most selective catalysts, some anthraquinone substances that lose their ability to produce H2O2 will still be generated; these substances are collectively referred to as anthraquinone degradation products. With continuous circulation of the working fluid, these degradation products gradually accumulate. Excessive anthraquinone degradation products can affect hydrogenation, oxidation, and extraction operations to varying degrees, and increase the organic carbon content in the product, severely impacting the yield and quality of H2O2, thereby affecting the catalytic efficiency of palladium-based catalysts. Furthermore, excessive anthraquinone degradation products also increase the viscosity and density of the working fluid, increasing the resistance of pipeline conveying devices, thus raising product costs. Therefore, it is necessary to regenerate the anthraquinone degradation products to restore their production capacity.

[0003] Currently, the commonly used treatment method is to use solid alkaline catalysts. However, due to the easy loss of their alkaline components, they suffer from poor regeneration performance and short service life. In actual production, to ensure stable product output, frequent replacement of the regenerated catalyst is required, leading to working fluid loss and the generation of a large amount of spent catalyst solid waste. Magnesium silicate has abundant surface hydroxyl groups, a large specific surface area, and low solubility, and has broad application prospects in adsorption, catalysis, and other fields, attracting close attention from researchers. For example, patent CN117602636A discloses a method for preparing an attapulgite-based magnesium silicate anthraquinone regeneration catalyst, the anthraquinone regeneration catalyst, and its application. Using attapulgite and magnesium chloride as silicon and magnesium sources, respectively, a hydrothermal method is used to prepare attapulgite-based magnesium silicate at 140℃ for 12 hours, which is then applied to the regeneration of anthraquinone degradation products. However, the magnesium silicate prepared by this patent has a small pore size, which is not conducive to the diffusion of reactants and products, resulting in low utilization of active sites and unsatisfactory catalytic activity. Furthermore, its preparation process is relatively complex. The hard template method requires the use of attapulgite, involves a two-step reaction, has an excessively long reaction cycle, and a low yield, which is not conducive to industrial production. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application employs a self-templating and growth-inducing method to prepare porous magnesium silicate microspheres, which, upon alkali activation, yield flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst. The porous magnesium silicate microspheres synthesized in this application have a specific surface area of ​​550-650 m² / g. 2 ·g -1 The pore volume is 0.80-1.0 cm³. 3 ·g -1With an average pore size of 6-7 nm, it exhibits excellent anthraquinone regeneration activity. The flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in this application does not require the use of other templates, has a short reaction time, is green, environmentally friendly, non-toxic, and harmless, and has advantages such as high catalytic activity, good selectivity, and long service life.

[0005] To achieve the above objectives, in a first aspect, this application provides a method for preparing a regenerated catalyst from flower-shaped magnesium anthraquinone silicate degradation products, comprising the following steps:

[0006] Step 1: Add ammonia water to the aqueous solution of magnesium salt, and let it stand to react to obtain magnesium hydroxide slurry;

[0007] Step 2: Add ammonium salt and growth inducer to magnesium hydroxide slurry, stir and react, then add silicate solution dropwise to magnesium hydroxide slurry, and sonicate after the addition is complete;

[0008] Step 3: Transfer the ultrasonically treated slurry to a hydrothermal reactor, microwave heat the reaction, and after the reaction is complete, cool it to room temperature, wash it with deionized water by centrifugation, and dry the obtained filter cake to obtain magnesium silicate powder.

[0009] Step 4: Add magnesium silicate powder to sodium hydroxide solution, stir and react. After the reaction is complete, wash and dry to obtain flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst.

[0010] Furthermore, the settling time in step 1 is 0.5-3 hours.

[0011] Furthermore, in step 1, the magnesium salt is any one or more combinations of magnesium chloride, magnesium nitrate, or magnesium sulfate.

[0012] Furthermore, in step 1, the concentration of the aqueous solution of the magnesium salt is 0.2-0.5 mol / L, the concentration of the ammonia water is 6-8 mol / L, and the molar ratio of Mg to ammonia water in the magnesium salt is 1-2:1.

[0013] Furthermore, the ammonium salt mentioned in step 2 is any one or more combinations of ammonium chloride, ammonium nitrate, or ammonium sulfate.

[0014] Furthermore, the silicate mentioned in step 2 is sodium silicate or potassium silicate.

[0015] Furthermore, the growth inducer mentioned in step 2 is any one or a combination of dodecyl ethoxysulfonate betaine, sodium lauryl ether sulfate, and lauryl glucoside.

[0016] Furthermore, the ultrasound time in step 2 is 10-30 minutes.

[0017] Furthermore, the stirring reaction time in step 2 is 1-4 hours.

[0018] Furthermore, in step 2, the concentration of silicate is 0.2-0.5 mol / L, the molar ratio of Si to Mg is 1-1.5:1, the molar ratio of ammonium salt to Mg is 1:2-1, and the molar ratio of growth inducer to Mg is 0.05-0.5:1.

[0019] Furthermore, the microwave heating reaction procedure in step 3 is to react at 120-150℃ for 2-4 hours, then raise the temperature to 180-240℃ and continue the reaction for 6-12 hours.

[0020] Furthermore, the drying conditions in step 3 are drying at 100-150℃ for 12-24 hours.

[0021] Furthermore, in step 4, the concentration of the sodium hydroxide solution is 5-10 mol / L; the stirring temperature is 80-150℃, and the time is 2-4 h.

[0022] Secondly, the present invention provides a flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst, prepared by the above-described preparation method, wherein the chemical formula of the flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst is Mg4Si6O. 15 (OH)2·6H2O.

[0023] Thirdly, the present invention provides the application of the above-mentioned flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst or the method for preparing the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst in the regeneration of anthraquinone degradation products.

[0024] The technical solution provided in this application has at least the following advantages compared to the prior art:

[0025] 1) This invention provides a method for preparing a flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst, which has the advantages of wide availability of raw materials, simple preparation process, green and environmentally friendly, low production cost, and easy industrial production.

[0026] 2) The flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared by this invention is green, environmentally friendly, non-toxic, and harmless. It has the advantages of high catalytic activity, good selectivity, and long service life. The regeneration capacity of anthraquinone degradation products can reach 9.33 g / L within 72 hours. After 6 months of use, the regeneration capacity can still reach 8.87 g / L. Attached Figure Description

[0027] Figure 1 The X-ray diffraction pattern of the flower-shaped magnesium anthraquinone silicate degradation product regenerated catalyst prepared in Example 1;

[0028] Figure 2 This is a scanning electron microscope image of the flower-shaped magnesium anthraquinone silicate degradation product regenerated catalyst prepared in Example 1;

[0029] Figure 3 The diagram shows the regeneration performance of the flower-shaped magnesium silicate anthraquinone degradation product regenerated catalyst prepared in Example 1. Detailed Implementation

[0030] To enable those skilled in the art to better understand this application, the following detailed description is provided in conjunction with embodiments and accompanying drawings. However, it should be understood that the following embodiments are merely preferred embodiments of this application, and the scope of protection claimed in this application shall be determined by the scope defined in the claims.

[0031] In the description of this invention, it should be noted that unless specific conditions are specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0032] <Example>

[0033] Example 1

[0034] A flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst is prepared by the following method:

[0035] Step 1: Weigh 10.03g (0.0400mol) of magnesium nitrate and dissolve it in 200mL of deionized water to obtain a magnesium nitrate solution. Add 3mL (8mol / L) of ammonia water to the magnesium nitrate solution and let it stand for 1h to react and obtain magnesium hydroxide slurry.

[0036] Step 2: Add 1.00 g (0.0211 mol) ammonium chloride and 1.50 g (0.00520 mol) lauryl glucoside to magnesium hydroxide slurry and stir for 2 hours; dissolve 15.06 g (0.0521 mol) sodium silicate in 150 mL of deionized water to obtain sodium silicate solution, and add the sodium silicate solution dropwise to magnesium hydroxide slurry using a circulating pump, and stir and sonicate for 20 minutes.

[0037] Step 3: Transfer the ultrasonically treated slurry to a hydrothermal reactor, microwave it to 130 degrees and react for 3 hours, then raise the temperature to 200 degrees and continue the reaction for 8 hours. Cool it naturally to room temperature, centrifuge and wash it 4 times with deionized water, dry the obtained filter cake in an oven at 120 degrees for 24 hours, grind it through a 100-mesh sieve to obtain magnesium silicate powder.

[0038] Step 4: Add 5.00g (0.05mol) magnesium silicate powder to 100mL (5mol / L) sodium hydroxide solution, stir and react at 130℃ for 3h, cool to room temperature, centrifuge and wash four times with deionized water, dry the resulting filter cake in an oven at 60℃ for 12h, and grind it through a 100-mesh sieve to obtain the final product.

[0039] Characterization and testing:

[0040] 1. XRD analysis was performed on the flower-shaped magnesium silicate anthraquinone degradation product regenerated catalyst prepared in Example 1. The obtained XRD diffraction pattern is shown below. Figure 1 As shown. By Figure 1 It can be seen that its XRD diffraction peaks are similar to those of Mg4Si6O. 15 This corresponds to the standard card (JCPDS:29-1492) for (OH)2·6H2O.

[0041] 2. The morphology of the flower-shaped magnesium silicate anthraquinone degradation product regenerated catalyst prepared in Example 1 was characterized by scanning electron microscopy. The morphology is as follows: Figure 2 As shown. By Figure 2 It can be seen that the catalyst has a multi-level flower-shaped structure assembled from nanosheets.

[0042] 3. The regeneration catalytic performance of the anthraquinone-degraded magnesium silicate obtained in Example 1 was tested. The test steps were as follows: 5.00 g of the anthraquinone-degraded magnesium silicate regeneration catalyst was added to 50 mL of working solution. After 72 h, 50 μL of the anthraquinone regeneration solution was taken, placed in a 10 mL volumetric flask, and diluted to volume with anhydrous methanol. The anthraquinone regeneration amount was tested by liquid chromatography. The test results are as follows. Figure 3 As shown. By Figure 3 It can be seen that the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 1 has high regeneration performance for anthraquinone degradation products, with a regeneration capacity of 9.33 g / L within 72 hours. After 6 months of use, the regeneration capacity can still reach 8.87 g / L.

[0043] Example 2

[0044] A flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst is prepared by the following method:

[0045] Step 1: Weigh 12.06g (0.0480mol) of magnesium nitrate and dissolve it in 200mL of deionized water to obtain a magnesium nitrate solution. Add 3.5mL (7mol / L) of ammonia water to the magnesium nitrate solution and let it stand for 1h to react and obtain magnesium hydroxide slurry.

[0046] Step 2: Add 1.21g (0.0225mol) ammonium chloride and 1.50g (0.0048mol) dodecylethoxysulfonate to magnesium hydroxide slurry and stir for 2h; dissolve 16.13g (0.0540mol) sodium silicate in 150mL of deionized water to obtain sodium silicate solution, and add the sodium silicate solution dropwise to magnesium hydroxide slurry using a circulating pump, and stir and sonicate for 20min.

[0047] Step 3: Transfer the ultrasonically treated slurry to a hydrothermal reactor, microwave it to 140 degrees and react for 2.5 hours, then raise the temperature to 220 degrees and continue the reaction for 10 hours. Let it cool naturally to room temperature, centrifuge and wash it 4 times with deionized water, dry the obtained filter cake in an oven at 130 degrees for 18 hours, grind it through a 100-mesh sieve to obtain magnesium silicate powder.

[0048] Step 4: Add 6.00g (0.06mol) magnesium silicate powder to 100mL (6mol / L) sodium hydroxide solution, stir and react at 140℃ for 2.5h, cool to room temperature, centrifuge and wash four times with deionized water, dry the resulting filter cake in an oven at 60℃ for 12h, and grind it through a 100-mesh sieve to obtain the final product.

[0049] test:

[0050] The regeneration catalytic performance of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 2 was tested. The test procedure was as follows: 5.00 g of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 2 was added to 50 mL of working solution. After 72 h, 50 μL of the anthraquinone regeneration solution was taken, placed in a 10 mL volumetric flask, and diluted to volume with anhydrous methanol. The anthraquinone regeneration amount was tested by liquid chromatography. The flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 2 showed high regeneration performance for anthraquinone degradation products, with a regeneration amount reaching 9.27 g / L within 72 h.

[0051] Example 3

[0052] A flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst is prepared by the following method:

[0053] Step 1: Weigh 13.01g (0.0560mol) of magnesium nitrate and dissolve it in 200mL of deionized water to obtain a magnesium nitrate solution. Add 4mL (6mol / L) of ammonia water to the magnesium nitrate solution and let it stand for 1h to react and obtain magnesium hydroxide slurry.

[0054] Step 2: Add 1.51g (0.0260mol) ammonium chloride and 1.51g (0.0056mol) sodium lauryl ether sulfate to the magnesium hydroxide slurry and stir for 2 hours; dissolve 17.02g (0.0560mol) sodium silicate in 150mL of deionized water to obtain a sodium silicate solution, and use a circulating pump to add the sodium silicate solution dropwise to the magnesium hydroxide slurry, and stir and sonicate for 20 minutes.

[0055] Step 3: Transfer the ultrasonically treated slurry to a hydrothermal reactor, microwave it to 150 degrees and react for 2 hours, then raise the temperature to 240 degrees and continue the reaction for 12 hours. Let it cool naturally to room temperature, centrifuge and wash it 4 times with deionized water, dry the obtained filter cake in an oven at 140 degrees for 16 hours, grind it through a 100-mesh sieve to obtain magnesium silicate powder.

[0056] Step 4: Add 7.00g (0.07mol) magnesium silicate powder to 100mL (7mol / L) sodium hydroxide solution, stir and react at 150℃ for 2h, cool to room temperature, centrifuge and wash four times with deionized water, dry the obtained filter cake in an oven at 60℃ for 12h, and grind it through a 100-mesh sieve to obtain the final product.

[0057] test:

[0058] The regeneration catalytic performance of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 3 was tested. The test procedure was as follows: 5.00 g of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 3 was added to 50 mL of working solution. After 72 h, 50 μL of anthraquinone regeneration solution was taken, placed in a 10 mL volumetric flask, and diluted to volume with anhydrous methanol. The anthraquinone regeneration amount was tested by liquid chromatography. The flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst prepared in Example 3 showed high regeneration performance for anthraquinone degradation products, with a regeneration amount reaching 9.21 g / L within 72 h.

[0059] Comparative Example 1

[0060] The catalytic performance of commercially available alumina-supported sodium hydroxide regenerated catalyst was tested. The test procedure was as follows: 5.00 g of commercially available alumina-supported sodium hydroxide regenerated catalyst was added to 50 mL of working solution. After 72 h, 50 μL of anthraquinone regenerated solution was taken and placed in a 10 mL volumetric flask and diluted to volume with anhydrous methanol. The anthraquinone regeneration amount was tested by liquid chromatography. The regeneration amount was 4.23 g / L within 72 h. After 3 months of use, the regeneration performance decreased to 2.36 g / L.

Claims

1. A method for preparing a regenerated catalyst from flower-shaped magnesium anthraquinone silicate degradation products, characterized in that, Includes the following steps: Step 1: Add ammonia water to the aqueous solution of magnesium salt and let it stand to react to obtain magnesium hydroxide slurry; the molar ratio of Mg to ammonia water in magnesium salt is 1-2:1; Step 2: Add ammonium salt and growth inducer to magnesium hydroxide slurry, stir and react, then add silicate solution dropwise to magnesium hydroxide slurry, and sonicate after addition; the growth inducer is any one or more combinations of dodecyl ethoxysulfonate betaine, sodium lauryl ether sulfate, and lauryl glucoside; the concentration of silicate is 0.2-0.5 mol / L, the molar ratio of Si to Mg is 1-1.5:1, the molar ratio of ammonium salt to Mg is 1:2-1, and the molar ratio of growth inducer to Mg is 0.05-0.5:1; Step 3: Transfer the ultrasonically treated slurry to a hydrothermal reactor, microwave heat the reaction, and after the reaction is complete, cool to room temperature, wash with deionized water by centrifugation, and dry the obtained filter cake to obtain magnesium silicate powder; the microwave heating reaction program is to react at 120-150℃ for 2-4 h, then raise the temperature to 180-240℃ and continue the reaction for 6-12 h. Step 4: Add magnesium silicate powder to sodium hydroxide solution, stir and react. After the reaction is complete, wash and dry to obtain flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst; the concentration of sodium hydroxide solution in step 4 is 5-10 mol / L.

2. The method for preparing the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst according to claim 1, characterized in that, In step 1, the magnesium salt is any one or a combination of magnesium chloride, magnesium nitrate, or magnesium sulfate.

3. The method for preparing the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst according to claim 1, characterized in that, The ammonium salt mentioned in step 2 is any one or a combination of ammonium chloride, ammonium nitrate, or ammonium sulfate; the silicate is sodium silicate or potassium silicate.

4. The method for preparing the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst according to claim 1, characterized in that, In step 4, the temperature of the stirring reaction is 80-150℃, and the time is 2-4 h.

5. A flower-shaped magnesium anthraquinone silicate degradation product regeneration catalyst, characterized in that, The catalyst was prepared using the method described in any one of claims 1 to 4 for the preparation of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst.

6. The preparation method of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst according to any one of claims 1 to 4, or the application of the flower-shaped magnesium silicate anthraquinone degradation product regeneration catalyst according to claim 5 in the regeneration of anthraquinone degradation products.

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