Method for preparing diethylene glycol by adopting composite catalyst

Abstract

The invention discloses a method for preparing diethylene glycol by adopting a composite catalyst, which comprises the following steps: carrying out contact reaction on ethylene glycol and a catalyst to obtain diethylene glycol, the catalyst is modified perfluorinated sulfonic acid resin / SiO2. The catalyst provided by the invention is applied to a reaction for preparing diethylene glycol through ethylene glycol dehydration reaction, so that the conversion rate of ethylene glycol and the selectivity of the generated diethylene glycol are improved.

Description

Technical Field

[0001] The present application relates to a method for preparing diethylene glycol by using a composite catalyst, and belongs to the technical field of chemical industry. Background Art

[0002] Diethylene glycol is a colorless, odorless, transparent, hygroscopic viscous liquid. It is easily soluble in polar solvents such as water, alcohol, acetone, ether, etc., and its chemical properties are similar to those of ethylene glycol. It can be directly used as a natural gas dehydration dryer, aromatic separation and extraction agent, textile lubricant, softener and finishing agent. It is also used as an antifreeze component in brake fluid and compressor lubricant. It can also be used to prepare cleaning agents and as a dispersant solvent in other daily cosmetics such as inks. The molecular structure of diethylene glycol contains two functional groups, ether bonds and hydroxyl groups, which give it unique physical and chemical properties. Therefore, using diethylene glycol as a raw material, a variety of chemical products such as ethers, acids, esters, and amines can be produced. It is widely used in petrochemical, rubber, plastics, textiles, coatings, adhesives, pharmaceuticals and other industries.

[0003] Diethylene glycol can be prepared by dehydrating ethylene glycol. In this reaction, the liquid catalyst not only corrodes the equipment, but also causes serious side reactions. At the same time, the large amount of waste acid and wastewater produced by this method is difficult to handle, which not only increases industrial costs but also causes some waste of resources. Therefore, the development of a catalyst with high activity, good stability, low cost and environmental protection has good industrial application prospects.

[0004] Solid acid catalysts have become the focus of researchers due to their many advantages such as high activity, high selectivity and easy separation. There are still few solid acid catalysts reported in the literature for catalyzing the dehydration reaction of ethylene glycol. With the advancement of science and technology and the improvement of people's environmental awareness, in chemical production, a solid acid catalyst with advantages such as recyclability and reuse is gradually replacing traditional proton acid catalysts. Summary of the invention

[0005] This application will modify the perfluorosulfonic acid resin / SiO 2 The application of the catalyst in the preparation process of diethylene glycol is of great significance. The catalyst has good activity, high ethylene glycol conversion rate and diethylene glycol selectivity, and good stability.

[0006] According to one aspect of the present application, a method for preparing diethylene glycol using a composite catalyst is provided, the method comprising:

[0007] Under nitrogen conditions, ethylene glycol is contacted with a catalyst to react to obtain the diethylene glycol;

[0008] The catalyst is modified perfluorosulfonic acid resin / SiO 2 ;

[0009] The modified perfluorosulfonic acid resin is prepared by modifying the perfluorosulfonic acid resin with a modifying compound;

[0010] The modifying compound is selected from at least one of an inorganic acid, an ammonium salt, and a metal salt.

[0011] Optionally, the mass of the modified compound is the modified perfluorosulfonic acid resin / SiO 2 1~10wt.% of mass.

[0012] Optionally, the mass of the modified compound (metal salt in terms of oxide mass) is the modified perfluorosulfonic acid resin / SiO 2 1 to 10 wt% of the catalyst mass.

[0013] Optionally, the mass of the modified compound (metal salt in terms of oxide mass) is the modified perfluorosulfonic acid resin / SiO 2 The mass of the catalyst is independently selected from any value among 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt% or a range between any two of the above.

[0014] Optionally, the perfluorosulfonic acid resin is selected from at least one of Nafion-NR50, Nafion-501, Nafion-xr, Nafion-425, Nafion-xr500, and Nafion-H.

[0015] Optionally, the inorganic acid is selected from phosphoric acid and / or boric acid.

[0016] Optionally, the ammonium salt is selected from diammonium hydrogen phosphate and / or ammonium fluoride.

[0017] Optionally, the metal salt is selected from at least one of zinc nitrate, lanthanum nitrate, magnesium nitrate and potassium nitrate.

[0018] Optionally, the reaction temperature is 80-200°C.

[0019] Optionally, the reaction temperature is independently selected from any value of 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C or a range between any two of the above.

[0020] Optionally, in the reaction, N 2 The flow rate is 0-30ml / min.

[0021] Optionally, in the reaction, N 2The flow rate is independently selected from any value among 0 ml / min, 5 ml / min, 10 ml / min, 15 ml / min, 20 ml / min, 25 ml / min, 30 ml / min or a range between any two of the above values.

[0022] Optionally, the mass space velocity of the reaction is 0.2 to 2 h -1 .

[0023] Optionally, the mass space velocity of the reaction is independently selected from 0.2h -1 、0.4h -1 、0.6h -1 、0.8h -1 , 1.0h -1 , 1.2h -1 , 1.4h -1 , 1.6h -1 , 1.8h -1 , 2.0h -1 Any value in or a range between any two of the above.

[0024] Optionally, the modified perfluorosulfonic acid resin / SiO 2 The preparation method comprises the following steps:

[0025] (1) A mixture containing tetraethyl orthosilicate, hydrochloric acid and water is referred to as solution A;

[0026] (2) Mixing solution A with NaOH solution and perfluorosulfonic acid resin solution, drying I, performing ion exchange with hydrochloric acid solution, drying II, and obtaining perfluorosulfonic acid resin / SiO 2 ;

[0027] (3) Perfluorosulfonic acid resin / SiO 2 Immerse in the modified compound in equal volume, stir, immerse, and dry III to obtain the modified perfluorosulfonic acid resin / SiO 2 .

[0028] Optionally, perfluorosulfonic acid resin / SiO 2 The preparation method comprises:

[0029] The silicon source, hydrochloric acid and deionized water are mixed and stirred to obtain a transparent silica sol, which is recorded as solution A;

[0030] The NaOH solution was slowly added to the perfluorosulfonic acid resin solution, which was recorded as solution B; solution A was quickly poured into solution B, and stirring was stopped after about 30 seconds. After oven drying I, ion exchange was performed with HCl solution, and repeated washing was performed and oven drying II to obtain perfluorosulfonic acid resin / SiO 2 .

[0031] Optionally, the modified perfluorosulfonic acid resin / SiO 2 The preparation method comprises: mixing perfluorosulfonic acid resin / SiO 2 The modified perfluorosulfonic acid resin / SiO 2 .

[0032] Optionally, in step (1), the concentration of the hydrochloric acid is 0.1 to 0.3 mol / L.

[0033] Optionally, the concentration of the hydrochloric acid is independently selected from any value among 0.1 ml / min, 0.15 ml / min, 0.2 ml / min, 0.25 ml / min, 0.3 ml / min or a range between any two of the above.

[0034] Optionally, the volume ratio of tetraethyl orthosilicate, hydrochloric acid and water is 15:4:1 to 15:1:1.

[0035] Optionally, the volume ratio of tetraethyl orthosilicate, hydrochloric acid and water is independently selected from any value of 15:4:1, 15:3:1, 15:2:1, 15:1:1 or a range between any two of the above. Optionally, in step (2), the concentration of the NaOH solution is 0.1-0.3 mol / L.

[0036] Optionally, the concentration of the NaOH solution is independently selected from any value among 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L or a range between any two of the above.

[0037] Optionally, the mass concentration of the perfluorosulfonic acid resin solution is 0.05 to 0.2 g / ml.

[0038] Optionally, the mass concentration of the perfluorosulfonic acid resin solution is independently selected from any value among 0.05 g / ml, 0.1 g / ml, 0.15 g / ml, 0.2 g / ml or a range between any two of the above values.

[0039] Optionally, the volume ratio of solution A, NaOH solution and perfluorosulfonic acid resin solution is 4:3:3 to 4:1:1.

[0040] Optionally, the volume ratio of the solution A, the NaOH solution and the perfluorosulfonic acid resin solution is independently selected from any value of 4:3:3, 4:2:2, 4:1:1 or a range between any two of the above.

[0041] Optionally, in step (2), the temperature of the drying I is 80 to 130° C., and the time of the drying I is 6 to 24 hours.

[0042] Optionally, the drying temperature I is independently selected from any value of 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or a range between any two of the above values.

[0043] Optionally, the drying time I is independently selected from any value among 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, or a range value between any two of the above.

[0044] Optionally, the concentration of the hydrochloric acid solution is 1 to 4 mol / L.

[0045] Optionally, the concentration of the hydrochloric acid solution is independently selected from any value among 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L or a range between any two of the above.

[0046] Optionally, the ion exchange time is 1 to 4 hours.

[0047] Optionally, the ion exchange time is independently selected from any value of 1 hour, 2 hours, 3 hours, 4 hours, or a range between any two of the above.

[0048] Optionally, the temperature of the drying II is 80 to 130° C., and the time of the drying II is 6 to 24 hours.

[0049] Optionally, the temperature of the drying II is independently selected from any value of 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or a range between any two of the above values.

[0050] Optionally, the drying time II is independently selected from any value among 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, or a range between any two of the above.

[0051] Optionally, in step (3), the stirring time is 5 to 20 minutes.

[0052] Optionally, the stirring time is independently selected from any value of 5 minutes, 10 minutes, 15 minutes, 20 minutes, or a range between any two of the above.

[0053] Optionally, the immersion time is 4 to 10 hours.

[0054] Optionally, the immersion time is independently selected from any value of 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, or a range between any two of the above.

[0055] Optionally, the temperature of the drying III is 80 to 130° C., and the time of the drying III is 6 to 24 hours.

[0056] Optionally, the drying temperature of III is independently selected from any value of 80°C, 90°C, 100°C, 110°C, 120°C, 130°C or a range between any two of the above values.

[0057] Optionally, the drying time of III is independently selected from any value among 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, 24 hours, or a range between any two of the above.

[0058] The beneficial effects of this application include:

[0059] 1) The catalyst provided in the present application can be used in the dehydration reaction of ethylene glycol to prepare diethylene glycol, and can improve the conversion rate of ethylene glycol and the selectivity of the generated diethylene glycol.

[0060] 2) The preparation method of the catalyst provided in this application is stable, controllable and reproducible.

[0061] 3) The ethylene glycol dehydration preparation method provided in the present application has a fast reaction speed, a high yield, and can be applied to large-scale production. DETAILED DESCRIPTION

[0062] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0063] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0064] The gas chromatograph is a 7890B gas chromatograph from Agilent.

[0065] In the examples of this application, the conversion rate and selectivity are calculated as follows:

[0066] The conversion rate and selectivity calculation formula in the examples of the present application are as follows (with ethylene glycol conversion rate as the evaluation index):

[0067] Ethylene glycol conversion rate = (initial carbon number of ethylene glycol - carbon number of ethylene glycol in the product) * 100 / initial mole number of ethylene glycol

[0068] Diethylene glycol selectivity = carbon number of diethylene glycol*100 / ∑(carbon number of diethylene glycol+carbon number of other products).

[0069] Example 1

[0070] TEOS, 0.15 mol / L hydrochloric acid and deionized water (volume ratio of 15:4:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.2 mol / L NaOH solution was slowly added to a Nafion-NR50 solution (mass concentration of 0.05 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (the volume ratio of solution A, NaOH solution and Nafion-NR50 solution was 4:3:3), and stirring was stopped after about 30 seconds. After drying in an oven at 110°C for I10 hours, ion exchange was performed with a 2 mol / L HCl solution for 2 hours, and after repeated washing, drying in an oven at 110°C for II10 hours, Nafion-NR50 / SiO 2 Prepare a 5% phosphoric acid solution, weigh 10g of the solution, and add 20g of the synthesized Nafion-NR50 / SiO 2 The catalyst was transferred to the solution, stirred for 10 minutes, immersed for 6 hours, and dried in an oven at 110°C for 10 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 1 # .

[0071] Example 2

[0072] TEOS, 0.2 mol / L hydrochloric acid and deionized water (volume ratio of 15:3:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.25 mol / L NaOH solution was slowly added to a Nafion-501 solution (mass concentration of 0.1 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (volume ratio of solution A, NaOH solution and Nafion-501 solution was 4:2:2), stirring was stopped after about 30 seconds, and the mixture was dried in an oven at 100°C for 12 hours. After that, ion exchange was performed with a 1 mol / L HCl solution for 3 hours. After repeated washing, the mixture was dried in an oven at 100°C for 12 hours to obtain Nafion-501 / SiO 2 Prepare a 4% diammonium phosphate solution, weigh 10g of the solution, and add 20g of the synthesized Nafion-501 / SiO 2 The catalyst was transferred to the solution, stirred for 15 minutes, immersed for 8 hours, and dried in an oven at 100°C for 12 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 2 # .

[0073] Example 3

[0074] TEOS, 0.3 mol / L hydrochloric acid and deionized water (volume ratio of 15:2:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.15 mol / L NaOH solution was slowly added to a Nafion-xr solution (mass concentration of 0.15 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (the volume ratio of solution A, NaOH solution and Nafion-xr solution was 4:1:1), and stirring was stopped after about 30 seconds. After drying in an oven at 120°C for 18 hours, ion exchange was performed with a 3 mol / L HCl solution for 1 hour, and after repeated washing, drying in an oven at 120°C for 18 hours, Nafion-xr / SiO 2 Prepare a 3% lanthanum nitrate solution, weigh 10g of the solution, and add 20g of the synthesized Nafion-xr / SiO 2 The catalyst was transferred to the solution, stirred for 5 minutes, immersed for 9 hours, and dried in an oven at 120°C for 18 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 3 # .

[0075] Example 4

[0076] TEOS, 0.1 mol / L hydrochloric acid and deionized water (volume ratio of 15:1:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.1 mol / L NaOH solution was slowly added to a Nafion-425 solution (mass concentration of 0.2 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (the volume ratio of solution A, NaOH solution and Nafion-425 solution was 4:1:1), and stirring was stopped after about 30 seconds. The mixture was dried in an oven at 90°C for 20 hours, and then ion exchange was performed with a 4 mol / L HCl solution for 4 hours. After repeated washing, the mixture was dried in an oven at 90°C for 20 hours to obtain Nafion-425 / SiO 2 Prepare a 7% boric acid solution, weigh 10g of the solution, and mix 20g of the synthesized Nafion-425 / SiO 2 The catalyst was transferred to the solution, stirred for 20 minutes, immersed for 5 hours, and dried in an oven at 90°C for 20 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 4 # .

[0077] Example 5

[0078] Ethyl orthosilicate, 0.25 mol / L hydrochloric acid and deionized water (volume ratio of 15:2:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.3 mol / L NaOH solution was slowly added to a Nafion-xr500 solution (mass concentration of 0.05 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (the volume ratio of solution A, NaOH solution and Nafion-xr500 solution was 4:2:2), and stirring was stopped after about 30 seconds. After drying in an oven at 80°C for 24 hours, ion exchange was performed with a 2 mol / L HCl solution for 4 hours, and after repeated washing, drying in an oven at 80°C for 24 hours, Nafion-xr500 / SiO 2 Prepare a 6% magnesium nitrate solution, weigh 10g of the solution, and add 20g of synthesized Nafion-xr500 / SiO 2 The catalyst was transferred to the solution, stirred for 10 minutes, immersed for 7 hours, and dried in an oven at 80°C for 24 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 5 # .

[0079] Example 6

[0080] TEOS, 0.2 mol / L hydrochloric acid and deionized water (volume ratio of 15:3:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.2 mol / L NaOH solution was slowly added to a Nafion-H solution (mass concentration of 0.15 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (volume ratio of solution A, NaOH solution and Nafion-H solution was 4:3:3), stirring was stopped after about 30 seconds, and the mixture was dried in an oven at 130°C for I 8 hours, and then ion exchange was performed with a 3 mol / L HCl solution for 2 hours. After repeated washing, the mixture was dried in an oven at 130°C for II 8 hours to obtain Nafion-H / SiO 2 Prepare a 2% ammonium fluoride solution, weigh 10g of the solution, and add 20g of the synthesized Nafion-H / SiO 2 The catalyst was transferred to the solution, stirred for 15 minutes, immersed for 10 hours, and dried in an oven at 130°C for 8 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 6 # .

[0081] Example 7

[0082] TEOS, 0.15 mol / L hydrochloric acid and deionized water (volume ratio of 15:1:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.15 mol / L NaOH solution was slowly added to a Nafion-NR50 solution (mass concentration of 0.1 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (the volume ratio of solution A, NaOH solution and Nafion-NR50 solution was 4:2:2), and stirring was stopped after about 30 seconds. After drying in an oven at 110°C for 16 hours, ion exchange was performed with a 4 mol / L HCl solution for 3 hours, and after repeated washing, drying in an oven at 110°C for 16 hours, Nafion-NR50 / SiO 2 Prepare a 1% zinc nitrate solution, weigh 10g of the solution, and add 20g of the synthesized Nafion-NR50 / SiO 2 The catalyst was transferred to the solution, stirred for 20 minutes, immersed for 4 hours, and dried in an oven at 110°C for 16 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 7 # .

[0083] Example 8

[0084] TEOS, 0.3 mol / L hydrochloric acid and deionized water (volume ratio of 15:4:1) were mixed and stirred to obtain a transparent silica sol, which was recorded as solution A. A 0.3 mol / L NaOH solution was slowly added to a Nafion-501 solution (mass concentration of 0.2 g / ml), which was recorded as solution B. Solution A was quickly poured into solution B (volume ratio of solution A, NaOH solution and Nafion-501 solution was 4:3:3), and stirring was stopped after about 30 seconds. After drying in an oven at 100°C for 14 hours, ion exchange was performed with a 1 mol / L HCl solution for 1 hour, and after repeated washing, drying in an oven at 110°C for 10 hours, and Nafion-501 / SiO 2 Prepare 8% potassium nitrate solution, weigh 10g of the solution, and add 20g of synthesized Nafion-501 / SiO 2 The catalyst was transferred to the solution, stirred for 5 minutes, immersed for 8 hours, and dried in an oven at 110°C for 10 hours to obtain a modified perfluorosulfonic acid resin / SiO 2 Catalyst, denoted as catalyst 8 # .

[0085] Example 9

[0086] Catalyst 1 prepared in Examples 1 to 8 was used # ~Catalyst 8 #The reaction of preparing diethylene glycol by dehydration of ethylene glycol was carried out, and the reaction parameters were changed. After the reaction was stable (reaction for 6 hours), the reaction raw materials and products were analyzed by gas chromatography online. The composition of the ethylene glycol dehydration reaction product was analyzed using Agilent 7890B gas chromatograph (FID detector, FFAP capillary column). The reaction results are shown in Table 1.

[0087] Table 1

[0088]

[0089]

[0090] As can be seen from Table 1, the reaction results # When unmodified perfluorosulfonic acid resin was reacted with ethylene glycol, the selectivity of diethylene glycol was 51.6%.

[0091] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing diethylene glycol using a composite catalyst, It is characterized in that The method comprises: Under nitrogen conditions, ethylene glycol is contacted with a catalyst to react to obtain the diethylene glycol; The catalyst is modified perfluorosulfonic acid resin / SiO 2 ; The modified perfluorosulfonic acid resin is prepared by modifying the perfluorosulfonic acid resin with a modifying compound; The modifying compound is selected from at least one of an inorganic acid, an ammonium salt, and a metal salt.

2. The method according to claim 1, It is characterized in that The mass of the modified compound is the modified perfluorosulfonic acid resin / SiO 2 1~10wt% of mass.

3. The method according to claim 2, It is characterized in that The perfluorosulfonic acid resin is selected from at least one of Nafion-NR50, Nafion-501, Nafion-xr, Nafion-425, Nafion-xr500, and Nafion-H; Preferably, the inorganic acid is selected from phosphoric acid and / or boric acid; Preferably, the ammonium salt is selected from diammonium hydrogen phosphate and / or ammonium fluoride; Preferably, the metal salt is selected from at least one of zinc nitrate, lanthanum nitrate, magnesium nitrate and potassium nitrate.

4. The method according to claim 1, It is characterized in that The reaction temperature is 80-200°C.

5. The method according to claim 1, It is characterized in that In the reaction, N 2 Flow rate: 0-30ml / min; Preferably, the mass space velocity of the reaction is 0.2 to 2 h -1 .

6. The method according to claim 1, It is characterized in that The modified perfluorosulfonic acid resin / SiO 2 The preparation method comprises the following steps: (1) A mixture containing tetraethyl orthosilicate, hydrochloric acid and water is referred to as solution A; (2) Mixing solution A with NaOH solution and perfluorosulfonic acid resin solution, drying I, performing ion exchange with hydrochloric acid solution, drying II, and obtaining perfluorosulfonic acid resin / SiO 2 ; (3) Perfluorosulfonic acid resin / SiO 2 Immerse in the modified compound in equal volume, stir, immerse, and dry III to obtain the modified perfluorosulfonic acid resin / SiO 2 .

7. The method according to claim 6, It is characterized in that In the step (1), the concentration of the hydrochloric acid is 0.1 to 0.3 mol / L; Preferably, the volume ratio of tetraethyl orthosilicate, hydrochloric acid and water is 15:4:1 to 15:1:

1.

8. The method according to claim 6, It is characterized in that In the step (2), the concentration of the NaOH solution is 0.1 to 0.3 mol / L; Preferably, the mass concentration of the perfluorosulfonic acid resin solution is 0.05 to 0.2 g / ml; Preferably, the volume ratio of the solution A, the NaOH solution and the perfluorosulfonic acid resin solution is 4:3:3 to 4:1:

1.

9. The method according to claim 6, It is characterized in that In the step (2), the temperature of the drying I is 80 to 130° C., and the drying time is 6 to 24 hours; Preferably, the concentration of the hydrochloric acid solution is 1 to 4 mol / L; Preferably, the ion exchange time is 1 to 4 hours; Preferably, the temperature of the drying II is 80 to 130° C., and the time of the drying II is 6 to 24 hours.

10. The method according to claim 6, It is characterized in that In the step (3), the stirring time is 5 to 20 minutes; Preferably, the immersion time is 4 to 10 hours; Preferably, the temperature of the drying III is 80 to 130° C., and the time of the drying III is 6 to 24 hours.

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