A metal-loaded MCM molecular sieve and its forming method and application

Abstract

The present invention discloses a metal-loaded MCM molecular sieve, its molding method, and application. The method comprises the following steps: 1) mixing MCM molecular sieve raw powder, a metal source, a first silicon source, and an alkaline solution, and performing a first drying process to obtain a dried product. The dried product is then mixed with a first water and molded, followed by a second drying process to obtain molecular sieve A; 2) mixing an organic template, a second water, a second silicon source, and an alkaline source to form a gel to obtain solution B; 3) mixing molecular sieve A and solution B, performing hydrothermal crystallization, filtering, washing, third drying, and calcining. This method can effectively extend the life of the catalyst and improve its activity.

Description

Technical Field

[0001] The invention relates to a metal-loaded MCM molecular sieve and a forming method and application thereof. Background Art

[0002] Organic dyes are a major pollutant in wastewater. Anthraquinone dyes, a type of organic dye, are widely used in the textile industry. Wastewater containing anthraquinone dyes is characterized by high chroma, difficulty in degradation, and complex composition. They also contain a variety of tri-organic compounds. Discharge into the environment not only damages the ecosystem but also has adverse effects on human health. Traditional catalytic oxidation treatment of refractory organic wastewater mainly relies on the Fenton reaction principle. However, these oxidation technologies usually use homogeneous catalysts. In homogeneous catalysis, the reaction substrate, final reaction product, intermediate products, and catalyst are mixed in the reaction solution, making it difficult to separate them, resulting in a large amount of secondary environmental pollutants and a waste of reaction raw materials. The difficulty in recovering and reusing the catalyst makes the oxidation technology very expensive, which is one of the main reasons limiting its application. Previous studies have shown that mesoporous molecular materials loaded with transition metal elements such as titanium, manganese, cobalt, chromium, nickel, copper, and iron all have certain catalytic oxidation activity. However, the loading of mesoporous molecular sieves is mostly achieved through "post-treatment" and "direct synthesis" methods. The "post-treatment" method generally first obtains a mesoporous molecular sieve of pure silicon, and then uses immersion, calcination, and other means to bond the hydroxyl groups on the surface of the mesoporous molecular sieve to heteroatoms. Since the metal in the catalyst obtained by this direct impregnation method is on the surface of the molecular sieve, it is very easy to cause the loss of metal components during the reaction, resulting in a shortened catalyst life and reduced catalytic effect. The "direct synthesis" principle adds heteroatoms at the initial stage of synthesis, which will facilitate the uniform dispersion of heteroatoms in the synthesis system, and the operation is simple and convenient for synthesis. However, the metal atoms synthesized by this method are generally in the molecular sieve framework and are suitable for reactions in which the metal is in a tetravalent state. At the same time, various complexing agents must be added to the in-situ synthesis, which is complicated and increases the cost. Summary of the Invention

[0003] To address the above-mentioned problems in the prior art, the present invention provides a new method for forming metal-loaded MCM molecular sieves. This method directly adds a metal source during the molecular sieve forming stage, eliminating the need to impregnate the molecular sieve with a metal solution. The forming and metal impregnation processes are completed in a one-step process. Moreover, this method does not use a binder to form the molecular sieve. During the catalyst kneading process, this method adds a raw silicon source used to synthesize the molecular sieve, and then hydrolyzes the silicon source into a viscous silica gel to bond the catalyst. At the same time, in this process, the secondary pore distribution of the molecular sieve is improved. This method effectively extends the life of the catalyst and improves the activity of the catalyst.

[0004] The first aspect of the present invention provides a method for forming a metal (M)-loaded MCM molecular sieve, comprising the following steps:

[0005] 1) Mixing MCM molecular sieve raw powder, a metal source, a first silicon source and an alkaline solution, and performing a first drying to obtain a dry product, then mixing the dry product with a first water and forming it, and performing a second drying to obtain molecular sieve A;

[0006] 2) mixing the organic template, the second water, the second silicon source and the alkali source into a gel to obtain solution B;

[0007] 3) mixing the molecular sieve A and the solution B and performing hydrothermal crystallization, filtering, washing, third drying and calcining.

[0008] According to some embodiments of the method of the present invention, preferably, the metal source is selected from at least one of an iron source, a cobalt source, and a nickel source. That is, the metal atoms in the metal source are selected from at least one of an iron atom, a cobalt atom, and a nickel atom.

[0009] According to some embodiments of the method of the present invention, preferably, the iron source is selected from one of potassium ferrocyanide, potassium ferrocyanide and ferric nitrate.

[0010] According to some embodiments of the method of the present invention, preferably, the cobalt source is selected from at least one of cobalt nitrate, cobalt oxide and cobalt hydroxide.

[0011] According to some embodiments of the method of the present invention, preferably, the nickel source is selected from at least one of nickel nitrate, nickel oxide and nickel hydroxide.

[0012] According to some embodiments of the method described in the present invention, preferably, the weight ratio of the metal source to the molecular sieve raw powder is ≤10 weight %, more preferably ≤8 weight %.

[0013] According to some embodiments of the method of the present invention, preferably, the MCM molecular sieve is MCM-41 molecular sieve.

[0014] According to some embodiments of the method of the present invention, preferably, the first silicon source includes at least one of tetraethyl orthosilicate, silica sol and water glass.

[0015] According to some embodiments of the method of the present invention, preferably, the weight ratio of the first silicon source to the molecular sieve raw powder is 1:5 to 2:5.

[0016] According to some embodiments of the method of the present invention, preferably, the alkaline solution is a sodium hydroxide solution.

[0017] According to some embodiments of the method of the present invention, preferably, the amount of the alkaline solution used is 20 to 50 weight % of the first silicon source, wherein the concentration of the alkaline solution is 0.1 mol / L.

[0018] According to some embodiments of the method of the present invention, preferably, the amount of the first water is 10 to 30 weight %, preferably 15 to 25 weight % of the dried product.

[0019] According to some embodiments of the method of the present invention, preferably, the solution B satisfies, on a molar basis, SiO2:d H2O:e R:c OH - , wherein R is an organic template, d is 80 to 160, preferably 100 to 140; e is 0.1 to 0.7, preferably 0.2 to 0.5; c is 2 to 7, preferably 4 to 5. In the present invention, the silicon source is calculated as SiO2, the iron source is calculated as Fe, the cobalt source is calculated as Co, the nickel source is calculated as Ni, and the alkali is calculated as OH. - The solvent is calculated as H2O, and the organic template is calculated as R.

[0020] According to some embodiments of the method of the present invention, preferably, the organic template is selected from at least one of cetyltrimethylammonium bromide, cetyltrimethylammonium chloride and cetyltriethylammonium bromide, preferably cetyltrimethylammonium chloride.

[0021] According to some embodiments of the method of the present invention, preferably, the second silicon source is selected from at least one of white carbon black, tetraethyl orthosilicate (TEOS), sodium silicate and silica sol, preferably tetraethyl orthosilicate.

[0022] According to some embodiments of the method of the present invention, preferably, the alkaline source is selected from at least one of sodium hydroxide, tetramethylammonium hydroxide and ammonia water, preferably ammonia water.

[0023] According to some embodiments of the method of the present invention, preferably, the conditions for the first drying, the second drying and the third drying each independently include: a temperature of 100-150° C., preferably 120-130° C.; and a time of 4-6 hours.

[0024] According to some embodiments of the method of the present invention, preferably, the hydrothermal crystallization conditions include: a temperature of 110 to 140° C., preferably 120 to 130° C.; and a time of 72 to 108 hours, preferably 84 to 100 hours.

[0025] According to some embodiments of the method of the present invention, preferably, the calcination conditions include: a temperature of 400 to 600° C.; and a calcination time of 2 to 10 hours.

[0026] According to some embodiments of the method of the present invention, preferably, the forming is extrusion forming. The extrusion forming can be performed in an extrusion forming machine.

[0027] According to some specific embodiments of the method of the present invention, preferably, the method of encapsulating the nano-metal atoms (M) in the MCM-41 molecular sieve includes but is not limited to the following steps:

[0028] (1) Molecular sieve MCM-41 raw powder, metal source, first silicon source and alkaline solution are mixed in proportion, dried after mixing evenly, and the dried catalyst and a certain amount of deionized water are put into an extruder to form and extrude strips, which are then dried. The dried and formed molecular sieve is recorded as A;

[0029] (2) The organic template, water, the second silicon source and the alkali source are uniformly mixed to form a gel, and the molar ratio of the obtained reaction mixture is SiO2:d H2O:e R:c OH - , wherein R is an organic template, the value of d is 80 to 160, the value of e is 0.1 to 0.7, and the value of c is 2 to 7. The mixed solution is B;

[0030] (3) Add B to A and hydrothermally crystallize at a certain temperature for a period of time. The product is filtered, washed, dried and calcined to obtain M / MCM-41.

[0031] The second aspect of the present invention provides a metal M-loaded MCM molecular sieve prepared according to the above method, preferably a metal M-loaded MCM-41 molecular sieve, denoted as M / MCM-41.

[0032] M@MCM-41 refers to MCM-41 molecular sieve encapsulated with nano-metal atoms M.

[0033] According to some embodiments of the molecular sieve of the present invention, preferably, the outer surface of the M / MCM-41 has a layer of silicon dioxide protective film.

[0034] According to some embodiments of the molecular sieve of the present invention, preferably, the M / MCM-41 has a core-shell structure, and the shell size measured by SEM is 40-150 nm.

[0035] The M / MCM-41 prepared according to the method of the present invention has a silicon dioxide protective film on its outer surface, which is a shell structure from the SEM perspective. The shell size is 40 to 150 nm. The shell can protect the metal source from being easily lost during the reaction.

[0036] The third aspect of the present invention provides a method for forming the metal-loaded MCM molecular sieve or the use of the metal-loaded MCM molecular sieve in dye adsorption, for example, dye adsorption in water.

[0037] Beneficial effects of the present invention:

[0038] In the method provided by the present invention, the first silicon source is hydrolyzed under the action of an alkaline solution to generate a silica gel mesh with a sticky structure. The sticky silica gel mesh bonds the molecular sieve particles to each other. After extrusion, these silica gel meshes are transformed into silica films under high-temperature calcination conditions, covering the silanol structure on the outer surface of the molecular sieve. Due to the silicon-oxygen structure type of the molecular sieve's own skeleton structure, the outer surface of the molecular sieve will not be covered and blocked. In actual applications, the reactants will enter the outer surface of the molecular sieve from the silica film by diffusion. However, due to the presence of metal on the outer surface of the molecular sieve, the formed silica film will have a gap at the metal position. At this time, a template, water, a second silicon source and an alkaline source mixed solution are added for secondary crystallization, and the gap position is crystallized and grown to form a complete silica film. These silica films make it difficult for the metal active sites to be lost during the reaction, effectively extending the life of the catalyst and improving the activity of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the XPS graph of the catalyst obtained in Example 3 of the present invention;

[0040] Figure 2 This is a scanning electron microscope image obtained in Example 3 of the present invention. DETAILED DESCRIPTION

[0041] In order to make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are only for illustration and do not limit the scope of application of the present invention.

[0042] The test method of the present invention and the equipment used in the test are as follows:

[0043] (1) XPS uses Thermo Scientific's ESCALAB 250 spectrometer to measure the bonding of metal particles.

[0044] (2) The scanning electron microscope used was a Hitachi S-4700 scanning electron microscope.

[0045] (3) The concentration of KN-R was measured using a UV752 ultraviolet-visible spectrophotometer from Shanghai Leici Company.

[0046] (4) The residual total organic carbon (TOC) value in the water sample was determined using a Japanese Shimadzu 5000A organic carbon analyzer.

[0047] The silicon source of the present invention is calculated as SiO2, the iron source is calculated as Fe, the cobalt source is calculated as Co, the nickel source is calculated as Ni, and the alkali is calculated as OH -The solvent is calculated as H2O, and the organic template is calculated as R.

[0048] [Example 1]

[0049] 40 g of MCM-41 molecular sieve raw powder, 0.8 g of potassium ferricyanide, 8 g of TEOS and 1.6 g of 0.1 mol / L NaOH solution were added to a mortar and mixed. After mixing evenly, the mixture was dried at 100°C. Subsequently, 30 g of the dried sample was put into an extruder, and 3 g of deionized water was added and stirred evenly before starting to form. The formed molecular sieve was dried at 100°C and recorded as A.

[0050] 4.4 g of hexadecyltrimethylammonium bromide (CTAB) and 38.9 g of deionized water were added to the reactor in sequence, stirred evenly, and 5 g of tetraethyl orthosilicate (TEOS) was slowly added dropwise. Finally, 4.8 g of NaOH was added to adjust the pH of the solution to 11-13, which was solution B. The molar ratio of the reaction mixture was SiO2: 90 H2O: 0.5 R: 5 OH. - After mixing B and A, transfer them to a crystallization kettle, raise the temperature to 110°C, and crystallize at this constant temperature for 72 hours. After complete crystallization, the temperature is lowered to room temperature. The reaction mixture is separated, washed, and dried at 100°C. Finally, the final sample is obtained after calcination at 400°C for 3 hours.

[0051] [Example 2]

[0052] The difference from Example 1 is that the iron source is changed to potassium ferrocyanide in an amount of 1.6 g, the silicon source is changed to silica sol in an amount of 12 g, the amount of alkaline solution is changed to 3.6 g, the amount of deionized water is changed to 6 g, the drying temperature is changed to 110 ° C, the template agent is changed to hexadecyltrimethylammonium chloride (CTAC) in an amount of 1.8 g, the amount of water is changed to 20.3 g, the silicon source is changed to sodium silicate in an amount of 4 g, the amount of NaOH is changed to 3.4 g, the crystallization temperature is changed to 120 ° C, the crystallization time is changed to 80 h, the calcination temperature is changed to 450 ° C, the calcination time is changed to 4 h, and the other components and synthesis conditions remain unchanged. The molar ratio of the reaction mixture obtained is SiO2: 80H2O: 0.4R: 6OH - .

[0053] [Example 3]

[0054] The difference from Example 1 is that the iron source is changed to ferric nitrate, the amount is 3.2 g, the amount of TEOS is changed to 12 g, the amount of alkaline solution is changed to 4.8 g, the amount of deionized water is changed to 7.5 g, the drying temperature is changed to 120 ° C, the template agent is changed to hexadecyltrimethylammonium chloride (CTAC), the amount is 1.4 g, the amount of water is changed to 25.9 g, the amount of TEOS is changed to 3 g, the alkaline source is changed to ammonia water, the amount is 2.0 g, the crystallization temperature is changed to 130 ° C, the crystallization time is changed to 90 h, the calcination temperature is changed to 500 ° C, the calcination time is changed to 5 h, and the other components and conditions remain unchanged. The molar ratio of the reaction mixture obtained is SiO2: 100H2O: 0.3R: 4OH - , the state of iron atoms in the molecular sieve is analyzed by XPS. Figure 1 , SEM images are shown in Figure 2 .

[0055] [Example 4]

[0056] 40 g of MCM-41 molecular sieve powder, 3.2 g of cobalt nitrate, 12 g of TEOS and 4.8 g of 0.1 mol / L NaOH solution were added to a mortar and mixed. After mixing evenly, the mixture was dried at 120°C. Subsequently, 30 g of the dried sample was put into an extruder, and 7.5 g of deionized water was added and stirred evenly before forming. The formed molecular sieve was dried at 120°C and recorded as A.

[0057] 1.4 g of hexadecyltrimethylammonium chloride (CTAC) and 25.9 g of deionized water were added to the reactor in sequence, stirred evenly, and 3 g of tetraethyl orthosilicate (TEOS) was slowly added dropwise. Finally, 2.0 g of ammonia water was added to adjust the pH of the solution to 11-13. The molar ratio of the reaction mixture was SiO2: 100 H2O: 0.3 R: 4 OH. - , which is solution B. B and A were mixed and transferred to a crystallization kettle. The temperature was raised to 130°C and crystallized at this constant temperature for 90 hours. After complete crystallization, the temperature was lowered to room temperature. The reaction mixture was separated, washed, and dried at 120°C. Finally, the final sample was obtained after calcination at 500°C for 5 hours.

[0058] [Example 5]

[0059] 40 g of MCM-41 molecular sieve powder, 3.2 g of nickel nitrate, 12 g of TEOS and 4.8 g of 0.1 mol / L NaOH solution were added to a mortar and mixed. After mixing evenly, the mixture was dried at 120°C. Subsequently, 30 g of the dried sample was put into an extruder, and 7.5 g of deionized water was added and stirred evenly before starting to form. The formed molecular sieve was dried at 120°C and recorded as A.

[0060] 1.4 g of hexadecyltrimethylammonium chloride (CTAC) and 25.9 g of deionized water were added to the reactor in sequence, stirred evenly, and 3 g of tetraethyl orthosilicate (TEOS) was slowly added dropwise. Finally, 2.0 g of ammonia water was added to adjust the pH of the solution to 11-13. The molar ratio of the reaction mixture was SiO2: 100 H2O: 0.3 R: 4 OH. - , which is Solution B. B and A were mixed and transferred to a crystallization kettle. The temperature was raised to 130°C and crystallized at this constant temperature for 90 hours. After complete crystallization, the temperature was lowered to room temperature. The reaction mixture was separated, washed, and dried at 120°C. Finally, it was calcined at 500°C for 5 hours to obtain the final sample. The resulting sample was used in dye adsorption experiments. The results are shown in Table 1.

[0061] [Comparative Example 1]

[0062] 40 g of MCM-41 molecular sieve raw powder and 14.2 g of pseudo-boehmite (Al2O3 content of 70 wt%) were added to a mixer and mixed. After mixing evenly, 25.8 g of dilute nitric acid (HNO3 content of 6.3 wt%) was added and kneaded, followed by adding 15.5 g of deionized water and continuing to knead. The kneaded material was then placed in an extruder for molding. The molded molecular sieve was dried at 120°C and then calcined at 500°C for 5 h. The molded molecular sieve sample was then mixed with 3.2 g of ferric nitrate solution for 4 h, dried at 120°C, and then calcined at 500°C for 5 h to obtain a Fe / MCM-41 molecular sieve sample.

[0063] [Comparative Example 2]

[0064] 40 g of MCM-41 molecular sieve raw powder, 3.2 g of ferric nitrate, 12 g of TEOS and 8.4 g of 0.1 mol / L NaOH solution were added to a mortar and mixed. After mixing evenly, the mixture was dried at 120°C. Subsequently, 30 g of the dried sample was put into an extruder, and 7.5 g of deionized water was added and stirred evenly before starting to form. The formed molecular sieve was dried at 120°C and recorded as A.

[0065] 1.4 g of hexadecyltrimethylammonium chloride (CTAC) and 25.9 g of deionized water were added to the reactor in sequence, stirred evenly, and 3 g of tetraethyl orthosilicate (TEOS) was slowly added dropwise. Finally, 2.0 g of ammonia water was added to adjust the pH of the solution to 11-13. The molar ratio of the reaction mixture was SiO2: 100 H2O: 0.3 R: 4 OH. -, which is solution B. B and A were mixed and transferred to a crystallization kettle. The temperature was raised to 130°C and crystallized at this constant temperature for 90 hours. After complete crystallization, the temperature was lowered to room temperature. The reaction mixture was separated, washed, and dried at 120°C. Finally, the final sample was obtained after calcination at 500°C for 5 hours.

[0066] Test Example

[0067] The samples obtained in Examples 1-5 and Comparative Examples 1-2 were respectively used in dye adsorption experiments. The results are shown in Table 1.

[0068] Adjust pH to 2.5 in 500 mL of 250 mg / L Reactive Brilliant Blue KN-R solution, add 4.0 g / L catalyst, and mix rapidly for 2 minutes under magnetic stirring. Then, add 50.0 mmol / L H2O2 solution and react for 30 minutes. Take out 5 mL of suspension in turn and immediately add 0.1 mL of 0.2 mol / L sodium thiosulfate solution to terminate the reaction. Centrifuge the water sample at 5000 r / min for 10 minutes, take the supernatant, and measure the residual dye concentration and TOC, respectively.

[0069] Table 1. Dye adsorption results

[0070] Decolorization rate (%) TOC removal rate (%) Example 1 78.1 18.2 Example 2 88.1 18.7 Example 3 ＞99.0 27.8 Example 4 ＞99.0 21.9 Example 5 ＞99.0 19.5 Comparative Example 1 90.3 10.5 Comparative Example 2 11.7 7.0

[0071] As can be seen from Examples 1-5 and Table 1, the catalyst obtained by this method exhibits excellent catalytic performance in terms of decolorization rate and TOC removal rate. As can be seen from Examples 1-3, both decolorization rate and TOC removal rate increase with increasing metal content. As can be seen from Examples 3-5 and Comparative Examples 1-2, the same content of three metal iron atoms, iron, cobalt, and nickel, exhibits better performance in terms of dye adsorption. In Comparative Example 1, a conventional molding method is used for loading and impregnation. First, due to the addition of an adhesive during the molding process, the active sites of the conventional method in catalysts of the same mass are relatively few. Second, due to the lack of protection from the outer surface silica film, the metals on the surface of these molecular sieves are very likely to be lost during the reaction, resulting in decreased catalyst activity. In Comparative Example 2, due to the addition of too much alkali, the collapse of the molecular sieve skeleton itself occurs while the silicon source hydrolyzes to form a silica film and a sticky network, resulting in very low catalytic activity.

[0072] Depend on Figure 1 and Figure 2 It can be seen that the catalyst metal obtained by the present invention is in the form of oxide (XPS iron oxide peak is 710.8eV) on the outer surface of the molecular sieve. Figure 2It can be clearly seen that the outer surface is a silica spherical membrane and no metal oxide can be seen in the entire field of view, indicating that the metal oxide is inside the membrane on the outer surface of the molecular sieve, and the outer surface is protected by a silica film, making it difficult for the metal on the outer surface of the molecular sieve to be lost during the reaction, thereby extending the service life of the catalyst.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, under the technical enlightenment provided by the present invention, as common knowledge in the art, other equivalent variations and improvements can be made, which should also be considered as the scope of protection of the present invention.

Claims

1. A method for forming a metal-loaded MCM molecular sieve, comprising the following steps: 1) Mixing MCM molecular sieve raw powder, a metal source, a first silicon source and an alkaline solution, and performing a first drying to obtain a dry product, then mixing the dry product with a first water and forming it, and performing a second drying to obtain molecular sieve A; 2) mixing the organic template, the second water, the second silicon source and the alkali source into a gel to obtain solution B; 3) mixing the molecular sieve A and the solution B and performing hydrothermal crystallization, filtering, washing, third drying and calcining; The first silicon source includes at least one of ethyl orthosilicate, silica sol and water glass; The amount of the alkaline solution used is 20-50% by weight of the first silicon source, wherein the concentration of the alkaline solution is 0.1 mol / L.

2. The method according to claim 1, characterized in that The metal source is selected from at least one of an iron source, a cobalt source and a nickel source.

3. The method according to claim 2, characterized in that The iron source is selected from one of potassium ferrocyanide, potassium ferrocyanide and ferric nitrate.

4. The method according to claim 2, characterized in that The cobalt source is selected from at least one of cobalt nitrate, cobalt oxide and cobalt hydroxide.

5. The method according to claim 2, characterized in that The nickel source is selected from at least one of nickel nitrate, nickel oxide and nickel hydroxide.

6. The method according to any one of claims 1 to 5, characterized in that The weight ratio of the metal source to the molecular sieve raw powder is ≤10 weight %.

7. The method according to claim 6, characterized in that The weight ratio of the metal source to the molecular sieve raw powder is ≤8 weight %.

8. The method according to any one of claims 1 to 5, characterized in that The MCM molecular sieve is MCM-41 molecular sieve.

9. The method according to any one of claims 1 to 5, characterized in that The weight ratio of the first silicon source to the molecular sieve raw powder is 1:5 to 2:

5.

10. The method according to any one of claims 1 to 5, characterized in that The alkaline solution is a sodium hydroxide solution.

11. The method according to any one of claims 1 to 5, characterized in that The amount of the first water used is 10-30% by weight of the dried product.

12. The method according to claim 11, characterized in that The amount of the first water used is 15-25% by weight of the dried product.

13. The method according to any one of claims 1 to 5, characterized in that The solution B satisfies, on a molar basis, SiO2:d H2O:e R:c OH - , where R is an organic template, the value of d is 80~160; the value of e is 0.1~0.7; and the value of c is 2~7.

14. The method according to claim 13, characterized in that The solution B satisfies, on a molar basis, SiO2:d H2O:eR:c OH - , where R is an organic template, the value of d is 100~140; the value of e is 0.2~0.5; and the value of c is 4~5.

15. The method according to any one of claims 1 to 5, characterized in that The organic template is at least one selected from cetyltrimethylammonium bromide, cetyltrimethylammonium chloride and cetyltriethylammonium bromide; and / or, The second silicon source is selected from at least one of white carbon black, ethyl orthosilicate, sodium silicate and silica sol; and / or, The alkali source is selected from at least one of sodium hydroxide, tetramethylammonium hydroxide and ammonia water.

16. The method according to any one of claims 1 to 5, characterized in that The conditions for the first drying, the second drying and the third drying independently include: a temperature of 100-150° C.; a time of 4-6 h; and / or, The hydrothermal crystallization conditions include: temperature of 110-140° C.; time of 72-108 h; and / or, The calcination conditions include: a temperature of 400-600°C; a calcination time of 2-10 h; and / or, The forming is extrusion forming.

17. The method according to claim 16, characterized in that The conditions for the first drying, the second drying and the third drying independently include: a temperature of 120-130° C.; and / or, The hydrothermal crystallization conditions include: temperature of 120-130° C.; time of 84-100 h.

18. The metal-supported MCM molecular sieve prepared by the method according to any one of claims 1 to 17.

19. The metal-supported MCM molecular sieve according to claim 18, characterized in that: It is metal M loaded MCM-41 molecular sieve, denoted as M / MCM-41.

20. The metal-supported MCM molecular sieve according to claim 19, characterized in that: The outer surface of the M / MCM-41 is provided with a silicon dioxide protective film.

21. The metal-supported MCM molecular sieve according to claim 19, characterized in that The M / MCM-41 has a core-shell structure, and the shell size measured by SEM is 40-150 nm.

22. Use of the metal-loaded MCM molecular sieve obtained by the method for forming the metal-loaded MCM molecular sieve according to any one of claims 1 to 17 or the metal-loaded MCM molecular sieve according to any one of claims 18 to 21 in dye adsorption.

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