Preparation method of deuterated alkali

Abstract

The invention provides a preparation method of deuterated alkali, which comprises the following steps: under the action of an electric field, dissociating heavy water molecules into deuterium ions and deuterium oxide ions by adopting a bipolar membrane device, and combining the deuterium oxide ions with cations passing through a cation exchange membrane to form the deuterated alkali in an alkali chamber. Compared with the prior art, the preparation method provided by the invention has the advantages that specific process steps are adopted, specific condition limitation is matched, overall better interaction is realized, adverse conditions such as violent reaction or redundant process are avoided while phase change is not involved, and green, environment-friendly, mild and controllable preparation of the deuterated base is realized.

Description

Technical Field

[0001] The invention relates to the technical field of electrochemical synthesis, and more specifically to a method for preparing a deuterated base. Background Art

[0002] Deuterated acids and bases are the basis of deuterated reagents and are widely used in the synthesis of deuterated drugs, modification of optoelectronic materials, and basic scientific research, including isotope tracing, nuclear magnetic resonance characterization, and nuclear reactions. As an important raw material for converting heavy water into downstream products, the current preparation process of deuterated acids and bases is complex and extremely unfriendly to the environment. Taking deuterated sulfuric acid (D2SO4) as an example, the current process is the same as sulfuric acid (H2SO4). SO2 prepared by heating pyrite with oxygen is oxidized to obtain SO3, which is then contacted with heavy water and concentrated by an absorption tower. There is currently a lack of mature and stable processes for converting heavy water into deuterated acids in a green and efficient manner.

[0003] By dissociation of heavy water in the bipolar membrane interface (D2O→OD - +D + ), providing deuterium ions and deuteroxide ions in situ under mild conditions, and combining with other ion exchange membranes to directly convert salts into corresponding deuterated acids and bases. Under reverse voltage, heavy water molecules in the bipolar membrane are split into deuterium ions (D + ) and deuterium oxide ion (OD - ), can directly realize the one-step method to convert inorganic salts into corresponding deuterated acids and bases, without the consumption of other chemical reagents and the generation of by-products in the process, so the use of bipolar membrane devices to prepare deuterated acids and bases has good industrial prospects. At present, there are few patents for the preparation of deuterated acids and bases. For example, Chinese patent CN115784159B mixes phenyltrichlorosilane and dispersant in a reactor, and adds heavy water to produce deuterium chloride gas. This process has the advantage of large-scale preparation, but the introduction of dispersant in the synthesis process will consume organic solvents. In addition, Chinese patent CN114751380A directly reacts heavy water with phosphorus trichloride to prepare deuterium chloride gas, and then uses heavy water to absorb and prepare deuterated hydrochloric acid. The process flow is relatively cumbersome and involves violent phase reactions. As for other deuterated acid and base preparation processes, they are complex and diverse, and a universal process is urgently needed to achieve them. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing deuterated base, which adopts a bipolar membrane device to prepare the deuterated base, while not involving phase change, avoiding unfavorable conditions such as violent reaction or complicated process, and realizing green, environmentally friendly, mild and controllable preparation of deuterated base.

[0005] The present invention provides a method for preparing a deuterated base, comprising the following steps:

[0006] Under the action of the electric field, a bipolar membrane device is used to dissociate heavy water molecules into deuterium ions and deuterium oxide ions, and then the deuterium oxide ions are combined with cations passing through the cation exchange membrane to form deuterated bases in the base chamber.

[0007] Preferably, the bipolar membrane device comprises:

[0008] Bipolar membrane stack, power supply, peristaltic pump;

[0009] The bipolar membrane stack is composed of bipolar membranes, cation exchange membranes, anion exchange membranes, which are alternately arranged and separated by a plastic grid, and cathode and anode electrode plates on both sides; the cathode and anode electrode plates are respectively connected to the positive and negative electrodes of a power source, wherein an anode chamber is formed between the anode electrode plate and the bipolar membrane, and a cathode chamber is formed between the cathode electrode plate and the bipolar membrane; the arrangement order from the anode to the cathode of the bipolar membrane stack is bipolar membrane-anion exchange membrane-cation exchange membrane-bipolar membrane to form a repeating unit, forming an acid chamber-salt chamber-alkali chamber in sequence; the anode chamber is connected to the cathode chamber, and is connected to a polar chamber liquid storage tank containing a strong electrolyte, and under the drive of a peristaltic pump, the solutions in the feed liquid chamber, the acid chamber, the alkali chamber, the anode chamber and the cathode chamber form a circulation flow between the bipolar membrane stack and the connected storage tanks.

[0010] Preferably, the cathode and anode electrode plates are made of titanium coated with ruthenium.

[0011] Preferably, the bipolar membrane in the bipolar membrane stack is a special ion exchange membrane with a sandwich structure consisting of a cation membrane layer, a catalyst layer, and a cathodic membrane layer. When assembled, the cation membrane layer faces the cathode and the cathodic membrane layer faces the anode.

[0012] Preferably, all ion exchange membranes in the bipolar membrane device are first subjected to system transition; the system transition is specifically carried out as follows:

[0013] Transition from water system to heavy water system.

[0014] Preferably, the process of transitioning from the water system to the heavy water system is specifically as follows:

[0015] The ion exchange membrane was sequentially soaked in 20% heavy water, 40% heavy water, 60% heavy water, and 80% heavy water for 1 h to 3 h respectively, and then soaked in 100% heavy water for 20 h to 30 h.

[0016] Preferably, the bipolar membrane device is placed in a glove box during operation to prevent water molecules in the air from dissolving in the prepared deuterated base.

[0017] Preferably, the solvent in the system is heavy water.

[0018] Preferably, the anions are provided by a strong electrolyte; the strong electrolyte is selected from one or more of K2SO4, Na2SO4, Li2SO4, KNO3, NaNO3, LiNO3, KCl, NaCl, LiCl, LiF, NaF, and KF.

[0019] Preferably, the flow rate of the liquid in each chamber is 1 cm / s to 10 cm / s, and the current density is 40 mA / cm 2 ~120mA / cm 2 , the current is set to 1A~1.2A.

[0020] The present invention provides a method for preparing a deuterated base, comprising the following steps: under the action of an electric field, using a bipolar membrane device to dissociate heavy water molecules into deuterium ions and deuterium oxide ions, and then combining the deuterium oxide ions with cations passing through a cation exchange membrane to form a deuterated base in an alkali chamber. Compared with the prior art, the preparation method provided by the present invention adopts specific process steps and is limited by specific conditions to achieve overall good interaction. While not involving phase change, it avoids unfavorable conditions such as violent reactions or complicated processes, and achieves green, environmentally friendly, mild and controllable preparation of deuterated bases; at the same time, the preparation method provided by the present invention can realize the preparation of a variety of deuterated acids and bases, such as deuterated hydrochloric acid, deuterated sulfuric acid, deuterium fluoride, deuterated phosphoric acid, lithium deuteride, sodium deuteride, deuterium gas and potassium deuteride. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the bipolar membrane device in Examples 1 and 2 of the present invention;

[0022] Figure 2 This is a schematic diagram of the concentration changes of potassium deuterium oxide and deuterated sulfuric acid in Example 1 of the present invention;

[0023] Figure 3 Schematic diagram of changes in concentrations of potassium deuterium oxide and deuterated sulfuric acid in Example 2 of the present invention;

[0024] Figure 4 Schematic diagram of a bipolar membrane device in Example 3 of the present invention;

[0025] Figure 5 This is a schematic diagram of the concentration changes of lithium deuterium oxide and deuterated hydrochloric acid in Example 3 of the present invention;

[0026] Figure 6 Schematic diagram of a bipolar membrane device in Example 4 of the present invention;

[0027] Figure 7 Schematic diagram of the change in deuterated fluoride concentration in Example 4 of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The present invention provides a method for preparing a deuterated base, comprising the following steps:

[0030] Under the action of the electric field, a bipolar membrane device is used to dissociate heavy water molecules into deuterium ions and deuterium oxide ions, and then the deuterium oxide ions are combined with cations passing through the cation exchange membrane to form deuterated bases in the base chamber.

[0031] The invention provides a method for preparing a deuterated base. The method utilizes the dissociation characteristics of heavy water in a bipolar membrane middle layer, adopts a bipolar membrane device with a BP-AC configuration, and uses a heavy water solution as a solvent in the system. A strong electrolyte is introduced into a feed liquid chamber of the bipolar membrane device as a raw material. Deuterium ions and deuterium oxide ions dissociated from the heavy water in the bipolar membrane middle layer form a deuterated base with metal cations passing through a cation exchange membrane along an electric field direction. The method adopts a saturated feed mode and a high current density to prepare a high-concentration deuterated base, and the method is simple to operate, green and environmentally friendly, and can be used to prepare a variety of deuterated bases.

[0032] In the present invention, the bipolar membrane device preferably comprises:

[0033] Bipolar membrane stack, power supply, peristaltic pump;

[0034] The bipolar membrane stack is composed of bipolar membranes, cation exchange membranes, anion exchange membranes, which are alternately arranged and separated by a plastic grid, and cathode and anode electrode plates on both sides; the cathode and anode electrode plates are respectively connected to the positive and negative electrodes of a power source, wherein an anode chamber is formed between the anode electrode plate and the bipolar membrane, and a cathode chamber is formed between the cathode electrode plate and the bipolar membrane; the arrangement order from the anode to the cathode of the bipolar membrane stack is bipolar membrane-anion exchange membrane-cation exchange membrane-bipolar membrane to form a repeating unit, forming an acid chamber-salt chamber-alkali chamber in sequence; the anode chamber is connected to the cathode chamber, and is connected to a polar chamber liquid storage tank containing a strong electrolyte, and under the drive of a peristaltic pump, the solutions in the feed liquid chamber, the acid chamber, the alkali chamber, the anode chamber and the cathode chamber form a circulation flow between the bipolar membrane stack and the connected storage tanks.

[0035] In the present invention, the bipolar membrane device (see Figure 1 As shown) comprises a bipolar membrane stack, a power supply, and a peristaltic pump, and preferably consists of a bipolar membrane stack, a power supply, and a peristaltic pump.

[0036] In the present invention, the bipolar membrane stack is composed of bipolar membranes, cation exchange membranes, anion exchange membranes, which are alternately arranged and separated by a plastic grid, and cathode and anode electrode plates on both sides; the cathode and anode electrode plates are respectively connected to the positive and negative electrodes of the power supply, wherein an anode chamber is formed between the anode electrode plate and the bipolar membrane, and a cathode chamber is formed between the cathode electrode plate and the bipolar membrane; the arrangement order from the anode to the cathode of the bipolar membrane stack is bipolar membrane-anion exchange membrane-cation exchange membrane-bipolar membrane to form a repeating unit, forming an acid chamber-salt chamber-alkali chamber in sequence; the anode chamber is connected to the cathode chamber, and is connected to a polar chamber liquid storage tank containing a strong electrolyte. Under the drive of a peristaltic pump, the solutions in the feed liquid chamber, acid chamber, alkali chamber, anode chamber and cathode chamber form a circulation flow between the bipolar membrane stack and the connected storage tanks.

[0037] In the present invention, the material of the cathode and anode electrode plates is preferably titanium coated with ruthenium.

[0038] In the present invention, the bipolar membrane in the bipolar membrane stack is preferably a special ion exchange membrane with a sandwich structure consisting of a cation membrane layer, a catalyst layer, and a cathodic membrane layer. When assembled, the cation membrane layer faces the cathode and the cathodic membrane layer faces the anode.

[0039] In the present invention, all ion exchange membranes in the apparatus for preparing deuterated acid using the bipolar membrane device are preferably first subjected to system transition; the system transition is preferably carried out in the following manner:

[0040] Transition from water system to heavy water system.

[0041] In the present invention, the process of transitioning from the water system to the heavy water system is preferably as follows:

[0042] The ion exchange membrane is sequentially soaked in 20% heavy water, 40% heavy water, 60% heavy water, and 80% heavy water for 1 hour to 3 hours respectively, and then soaked in 100% heavy water for 20 hours to 30 hours;

[0043] More preferably:

[0044] The ion exchange membrane was sequentially soaked in 20% heavy water, 40% heavy water, 60% heavy water, and 80% heavy water for 2 hours each, and then soaked in 100% heavy water for 24 hours.

[0045] In the present invention, the bipolar membrane device is preferably placed in a glove box during operation to prevent water molecules in the air from dissolving in the prepared deuterated base.

[0046] In the present invention, in the bipolar membrane device, the solvent in the system is all heavy water.

[0047] In the present invention, the anion is preferably provided by a strong electrolyte; the strong electrolyte is preferably selected from one or more of K2SO4, Na2SO4, Li2SO4, KNO3, NaNO3, LiNO3, KCl, NaCl, LiCl, LiF, NaF, and KF. The present invention has no particular limitation on the source of the strong electrolyte, and commercially available products known to those skilled in the art can be used.

[0048] In a preferred embodiment of the present invention, the electrode chamber uses K2SO4 with a concentration of 0.3 mol as a strong electrolyte. The present invention has no special restrictions on its dosage, and any volume can be used, specifically 200 mL; the liquid chamber is a salt solution to be converted (K2SO4, Na2SO4, Li2SO4, etc.), and the present invention has no special restrictions on its concentration; the initial solution in the acid-base chamber is heavy water, and the present invention has no special restrictions on the chamber volume, and different volumes of heavy water solutions can be set according to the expected deuterated acid concentration.

[0049] In the present invention, the concentration of the prepared deuterated base is increased by ion implantation, specifically, the salt solution in the feed chamber is always kept in a supersaturated state; at the same time, the corresponding solution of each chamber is circulated in the membrane stack and the liquid storage tank by a peristaltic pump, and circulated inside the membrane stack for more than 10 minutes to eliminate the influence of bubbles in the membrane stack on the experiment, and then the power is turned on, and the experiment is stopped when the concentration of the acid chamber no longer increases; the flow rate of the liquid in each chamber is preferably 1cm / s~10cm / s, more preferably 3cm / s~5cm / s, constant current operation, and the current density is preferably 40mA / cm 2 ~120mA / cm 2 , more preferably 50 mA / cm 2 ~100mA / cm 2 The current setting is preferably 1A to 1.2A, more preferably 1.1A.

[0050] The invention provides a method for preparing a deuterated base, which can realize green, environmentally friendly, mild and controllable preparation of the deuterated base; at the same time, it can realize the preparation of various deuterated bases such as lithium deuteride, sodium deuteride, deuterium gas and potassium deuteride; compared with the prior art, the beneficial effects of the invention are: the preparation method provided by the invention is simple to operate, mild in conditions, does not involve a phase conversion process, has low energy consumption, has a high membrane stack integration, is flexible in use, can meet the requirements of online preparation of deuterated bases, and only consumes inorganic salts and heavy water, and does not need to introduce other toxic chemicals during the process, which is green and environmentally friendly; based on the invention, various deuterated bases are prepared respectively, and high-concentration deuterated bases are prepared by adopting saturated feed and high current density, which can meet various process requirements; therefore, preparing deuterated bases by using a bipolar membrane device is a green, environmentally friendly and economical production method, and has important industrial application prospects.

[0051] The present invention provides a method for preparing a deuterated base, comprising the following steps: under the action of an electric field, using a bipolar membrane device to dissociate heavy water molecules into deuterium ions and deuterium oxide ions, and then combining the deuterium oxide ions with cations passing through a cation exchange membrane to form a deuterated base in an alkali chamber. Compared with the prior art, the preparation method provided by the present invention adopts specific process steps and is limited by specific conditions to achieve overall good interaction. While not involving phase change, it avoids unfavorable conditions such as violent reactions or complicated processes, and achieves green, environmentally friendly, mild and controllable preparation of deuterated bases; at the same time, the preparation method provided by the present invention can realize the preparation of a variety of deuterated acids and bases, such as deuterated hydrochloric acid, deuterated sulfuric acid, deuterium fluoride, deuterated phosphoric acid, lithium deuteride, sodium deuteride, deuterium gas and potassium deuteride.

[0052] In order to further illustrate the present invention, the following examples are used for detailed description. In the following examples of the present invention, the anode plates and cathode plates on both sides of the membrane stack are made of corrosion-resistant titanium coated with ruthenium, the partition material is an acrylic plate with a thickness of 3 mm, the bipolar membrane used in the membrane stack is BP-1E sold by Astom, Japan, the anion exchange membrane is AMX sold by Astom, Japan, the cation exchange membrane is CMX sold by Astom, and the effective area of ​​a single membrane is 22 cm 2 ; In order to ensure that the entire system is operated in an anhydrous system, it is necessary to transition all ion membranes to be used from the water system to the heavy water system. The specific process is to soak the ion exchange membrane in 20% heavy water, 40% heavy water, 60% heavy water, and 80% heavy water for 2 hours each, and then soak it in 100% heavy water solution for 24 hours. At the same time, this experimental process needs to be isolated from the air and operated in a glove box.

[0053] The method for preparing deuterated alkali using the above-mentioned bipolar membrane device of the present invention mainly comprises:

[0054] First, 200 mL of 0.3 mol / L inorganic salt heavy water solution was introduced into the feed liquid chamber of the bipolar membrane electrochemical reactor, and 100 mL of heavy water solution was introduced into the acid and alkali chambers respectively, and 0.3 mol / L K2SO4 solution was introduced into the electrode chamber; the feed liquids in each compartment were circulated for 10 min to 20 min by a peristaltic pump to remove the air in the bipolar membrane stack as much as possible; then the DC power supply connected to the anode and cathode of the membrane stack was turned on (current density was 10 mA / cm 2 ~120mA / cm 2 ), under the action of the electric field, heavy water dissociates at the interface layer of the bipolar membrane to produce deuterium oxide ions (OD - ) combines with metal cations passing through the cation exchange membrane to form deuterated bases, and the deuterium ions (D +) combines with anions passing through the anion exchange membrane to form deuterated acid in the acid chamber; therefore, the device can continuously convert inorganic salts into corresponding deuterated acids and bases, and the flow rate of the liquid in each chamber is controlled by a peristaltic pump to be 3cm / s to 10cm / s.

[0055] Example 1

[0056] Example 1: Figure 1 The bipolar membrane device was used. The solutions between the electrode chambers were connected in series. 200 mL of a heavy water solution containing 0.3 mol / L potassium sulfate was introduced into the feed liquid chamber. 200 mL of a 0.3 mol / L potassium sulfate solution was introduced into the acid and alkali chambers. 100 mL of heavy water was introduced into each chamber as a solution. During the experiment, the flow rate of the liquid in each chamber was 3 cm / s, and the constant current operation was performed with a current density of 50 mA / cm 2 , the current is set to 1.1A.

[0057] The experiment was stopped when the conductivity of the liquid chamber was lower than 10mS / cm. The concentration of deuterated sulfuric acid obtained in the acid chamber was 0.64mol / L, and the concentration of potassium deuteride obtained in the base chamber was 1.34mol / L. The energy consumption for preparing deuterated sulfuric acid was 49.65kWh / kg, and the energy consumption for preparing potassium deuteride was 51.75kWh / kg. It should be noted that this device is laboratory-sized, and the energy consumption is expected to be reduced to industrial 2kWh / kg (KOH) through process optimization. Figure 2 shown.

[0058] Example 2

[0059] The device and process steps for preparing potassium deuteride / deuterated sulfuric acid in Example 2 are the same as those in Example 1, except that the feed in the liquid chamber is always kept at a saturated concentration, and the current density is set to 100 mA / cm 2 Finally, 2.75 mol / L of deuterated sulfuric acid D2SO4 and 5.82 mol / L of potassium deuteride KOD were obtained, with energy consumption of 11.46 kWh / kg and 8.61 kWh / kg respectively. Figure 3 shown.

[0060] This embodiment adopts saturated feed and high current density to achieve the preparation of high-concentration deuterated base.

[0061] Example 3

[0062] Example 3 uses Figure 4The bipolar membrane device was used. The solutions between the electrode chambers were connected in series. 200 mL of 0.3 mol / L potassium sulfate solution was introduced into the feed chamber. 200 mL of a heavy water solution containing 0.6 mol / L lithium chloride was introduced into the feed chamber. 100 mL of heavy water was introduced into the acid and alkali chambers as solutions. During the experiment, the flow rate of the liquid in each chamber was 3 cm / s, and the constant current operation was performed with a current density of 50 mA / cm 2 , the current is set to 1.1A.

[0063] The experiment was stopped when the conductivity of the liquid chamber was lower than 10mS / cm. The concentration of deuterated hydrochloric acid DCl obtained in the acid chamber was 1.48mol / L, and the concentration of lithium deuteride LiOD was 1.20mol / L. The energy consumption for preparing deuterated hydrochloric acid was 19.16kWh / kg, and the energy consumption for preparing potassium deuteride was 27.86kWh / kg. Figure 5 shown.

[0064] Example 4

[0065] Example 4 uses Figure 6 The bipolar membrane device was used. The solutions between the electrode chambers were connected in series. 200 mL of a heavy water solution containing 0.3 mol / L potassium sulfate was introduced into the feed liquid chamber. 200 mL of a 0.6 mol / L sodium fluoride solution was introduced into the feed liquid chamber. 100 mL of heavy water was introduced into the acid and base chambers as solutions. During the experiment, the flow rate of the liquid in each chamber was 3 cm / s, and the constant current operation was performed with a current density of 50 mA / cm 2 , the current is set to 1.1A.

[0066] The experiment was stopped when the conductivity of the liquid chamber was lower than 10mS / cm. The concentration of deuterated fluoride in the acid chamber was 0.59mol / L, and the concentration of sodium deuteride was 0.50mol / L. Figure 7 shown.

[0067] It can be seen from the above embodiments that the present invention provides a simple preparation method of deuterated base, and a high-concentration deuterated base is prepared by optimizing the feeding method, current density, volume ratio, membrane surface flow rate, etc., which provides a new route for large-scale continuous preparation of deuterated base; this process does not require a catalyst, the conditions are mild and controllable, the equipment integration is high, and the heavy water used can be reused to the greatest extent, which has important industrial application value.

[0068] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a deuterated base, characterized in that: The following steps are involved: Under the action of the electric field, a bipolar membrane device is used to dissociate heavy water molecules into deuterium ions and deuterium oxide ions, and then the deuterium oxide ions are combined with cations passing through the cation exchange membrane to form deuterated bases in the base chamber.

2. The preparation method according to claim 1, characterized in that: The bipolar membrane device comprises: Bipolar membrane stack, power supply, peristaltic pump; The bipolar membrane stack is composed of bipolar membranes, cation exchange membranes, anion exchange membranes, which are alternately arranged and separated by a plastic grid, and cathode and anode electrode plates on both sides; the cathode and anode electrode plates are respectively connected to the positive and negative electrodes of a power source, wherein an anode chamber is formed between the anode electrode plate and the bipolar membrane, and a cathode chamber is formed between the cathode electrode plate and the bipolar membrane; the arrangement order from the anode to the cathode of the bipolar membrane stack is bipolar membrane-anion exchange membrane-cation exchange membrane-bipolar membrane to form a repeating unit, forming an acid chamber-salt chamber-alkali chamber in sequence; the anode chamber is connected to the cathode chamber, and is connected to a polar chamber liquid storage tank containing a strong electrolyte, and under the drive of a peristaltic pump, the solutions in the feed liquid chamber, the acid chamber, the alkali chamber, the anode chamber and the cathode chamber form a circulation flow between the bipolar membrane stack and the connected storage tanks.

3. The preparation method according to claim 2, characterized in that: The cathode and anode electrode plates are made of titanium coated with ruthenium.

4. The preparation method according to claim 2, characterized in that: The bipolar membrane in the bipolar membrane stack is a special ion exchange membrane with a sandwich structure consisting of a cation membrane layer, a catalyst layer, and a cathodic membrane layer. When assembled, the cation membrane layer faces the cathode, and the cathodic membrane layer faces the anode.

5. The preparation method according to claim 1, characterized in that: All ion exchange membranes in the bipolar membrane device first undergo system transition; the system transition is specifically performed as follows: Transition from water system to heavy water system.

6. The preparation method according to claim 5, characterized in that: The process of transitioning from the water system to the heavy water system is specifically as follows: The ion exchange membrane was sequentially soaked in 20% heavy water, 40% heavy water, 60% heavy water, and 80% heavy water for 1 h to 3 h respectively, and then soaked in 100% heavy water for 20 h to 30 h.

7. The preparation method according to claim 1, characterized in that: The bipolar membrane device is placed in a glove box during operation to prevent water molecules in the air from dissolving in the prepared deuterated base.

8. The preparation method according to claim 1, characterized in that: The solvent in the system is heavy water.

9. The preparation method according to claim 1, characterized in that: The anions are provided by a strong electrolyte; the strong electrolyte is selected from one or more of K2SO4, Na2SO4, Li2SO4, KNO3, NaNO3, LiNO3, KCl, NaCl, LiCl, LiF, NaF, and KF.

10. The preparation method according to claim 1, characterized in that: The flow rate of the liquid in each chamber is 1cm / s~10cm / s, constant current operation, and the current density is 40mA / cm 2 ~120mA / cm 2 , the current is set to 1A~1.2A.

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