A method for electrochemical oxidation of 2,2,3,3-tetrafluoropropanol to produce sodium 2,2,3,3-tetrafluoropropanoate based on a stacked bipolar cell electrolyzer

Abstract

The application discloses a method for preparing sodium 2,2,3,3-tetrafluoropropionate by electrochemically oxidizing 2,2,3,3-tetrafluoropropanol based on a stacked bipolar plate electrolytic cell, in which 2,2,3,3-tetrafluoropropanol is electrochemically oxidized into 2,2,3,3-tetrafluoropropionic acid by the stacked bipolar plate electrolytic cell, and the 2,2,3,3-tetrafluoropropionic acid reacts with NaOH in an electrolyte to generate sodium 2,2,3,3-tetrafluoropropionate; in the process, a NiCo-OH / NF electrode and a NiFe-OH / NF electrode are used as a catalytic anode and a catalytic cathode; the yield of the sodium 2,2,3,3-tetrafluoropropionate can reach more than 85%, and the Faraday efficiency is more than 90%; the process route is simple, the reaction condition is mild, the chemical synthesis method with low yield and high consumption can be completely replaced, and the method has the potential for large-scale production and application.

Description

Technical Field

[0001] This invention belongs to the field of organic electrochemical synthesis technology, and particularly relates to a stacked bipolar plate electrolyzer and a method for preparing sodium 2,2,3,3-tetrafluoropropanol by electrochemical oxidation based on the stacked bipolar plate electrolyzer. Background Technology

[0002] With increasing environmental awareness and increasingly stringent standards, promoting the application of environmentally friendly products is an inevitable trend. Fluorine-containing fine chemicals have become a high-end application in the fluorochemical industry, mainly including fluorine-containing pharmaceuticals, pesticides, and surfactants. Fluorine-containing herbicides account for approximately 45% of all herbicides. Among them, sodium 2,2,3,3-tetrafluoropropionate (STFP) is a selective herbicide with long-lasting, biodegradable, non-toxic, and harmless characteristics, primarily used for weed control in pastures, tropical grasslands, rubber plantations, and tea gardens. Furthermore, sodium 2,2,3,3-tetrafluoropropionate is also an important fine chemical intermediate. In the Kolbe electrolytic cell, sodium 2,2,3,3-tetrafluoropropionate undergoes bimolecular decarboxylation coupling to generate octafluorobutane (HFC-318), a highly effective cleaning agent that does not damage the atmospheric ozone layer. This is the ideal replacement for the banned highly effective cleaning agent CFC-113 (1,1,2-trichlorotrifluoroethane). Therefore, sodium 2,2,3,3-tetrafluoropropionate has a promising market prospect.

[0003] Traditional methods for synthesizing sodium 2,2,3,3-tetrafluoropropionate mainly fall into the following categories: First, sodium 2,2,3,3-tetrafluoropropionate is synthesized through an addition reaction between tetrafluoroethylene and sodium cyanide, followed by decomposition in an alkaline medium. This process uses sodium cyanide, a highly toxic substance, which has significant environmental and safety impacts. Furthermore, the product contains cyanide ions, greatly limiting its use. Second, sodium 2,2,3,3-tetrafluoropropionate is synthesized by oxidizing 2,2,3,3-tetrafluoropropanol with hydrogen peroxide as an oxidant. This process requires high temperature and pressure, and has a long reaction cycle. Third, a clean route using tetrafluoroethylene and methanol as starting materials involves polymerization, oxidation, and neutralization. However, this process has low product yield, requires high reaction temperatures and pressures, is difficult to control, carries the risk of explosion, and has a complex operation and high production costs. Compared to chemical methods, there are currently few reports on the electrosynthesis of sodium 2,2,3,3-tetrafluoropropionate. One known electrosynthesis method uses a tubular porous titanium membrane as a substrate, coated with manganese oxide (MnO4). xA composite titanium membrane anode is prepared and vertically fixed to the center of the reactor with its lower end sealed. A stainless steel mesh cathode surrounds the anode in a ring shape. The cathode and anode are connected to a DC power supply via wires to form an electrocatalytic membrane reactor system. Although this reactor has the advantage of integrated catalysis and separation, the membrane electrode preparation process is complex, and the porous structure leads to uneven fluid distribution, limiting the reaction efficiency and hindering its large-scale industrial application. To address the above problems, this invention designs a stacked bipolar plate electrolytic cell. In this electrolytic cell, 2,2,3,3-tetrafluoropropanol is electrooxidized to 2,2,3,3-tetrafluoropropionic acid. Tetrafluoropropionic acid then undergoes a neutralization reaction with sodium hydroxide solution to prepare sodium tetrafluoropropionate. Summary of the Invention

[0004] To address the problems of traditional chemical synthesis of sodium 2,2,3,3-tetrafluoropropionate, such as highly toxic raw materials, long process requiring pressurization and heating, low product yield, harsh reaction conditions prone to flash explosion, and complex operation, as well as the problems of existing electrochemical methods such as complex membrane electrode preparation and uneven fluid distribution leading to limited reaction efficiency, this invention provides a stacked bipolar plate electrolytic cell and its application in the electrochemical oxidation of 2,2,3,3-tetrafluoropropanol to prepare sodium 2,2,3,3-tetrafluoropropionate.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing sodium 2,2,3,3-tetrafluoropropanol by electrochemical oxidation using a stacked bipolar plate electrolyzer, specifically comprising the following steps:

[0007] (1) Assembling the electrolytic cell: The stacked bipolar plate electrolytic cell includes an anode plate, a cathode plate, bipolar plates, and rubber gaskets. The bipolar plates include a nickel-plated stainless steel disc, a catalytic anode, and a catalytic cathode. Grooves for accommodating the catalytic anode and cathode are provided on both sides of the stainless steel disc. Gas-liquid flow holes and electrolyte flow holes are respectively provided at the upper and lower ends of the stainless steel disc near the grooves. Electrolyte inlets and outlets are respectively provided on the anode and cathode plates. N bipolar plates are arranged sequentially and clamped and fixed between the anode and cathode plates. All bipolar plates in the electrolytic cell... The electrolyte guide holes are aligned, the gas-liquid guide holes are aligned, the electrolyte guide holes are connected to the electrolyte inlet, and the gas-liquid guide holes are connected to the electrolyte outlet. Rubber gaskets are installed between the anode end plate and the bipolar plate, between two adjacent bipolar plates, and between the bipolar plate and the cathode end plate. Anode tabs and cathode tabs are installed on the anode end plate and the cathode end plate, respectively. The free ends of the anode tabs and cathode tabs are inserted into the electrolyte in the electrolytic cell. The anode tabs and cathode tabs are connected to the positive and negative terminals of the power supply, respectively. The outlet of the storage tank is connected to the electrolyte inlet through a circulation pump, and the electrolyte outlet is connected to the inlet of the storage tank.

[0008] (2) Preparation of electrolyte: Add 2,2,3,3-tetrafluoropropanol and sodium phosphate to NaOH solution. The molar ratio of 2,2,3,3-tetrafluoropropanol and sodium phosphate is 1:1 to 1:1.5 to obtain the electrolyte.

[0009] (3) Electrolysis: Pour the prepared electrolyte into the storage tank, turn on the circulation pump to fill the electrolytic cell with liquid and carry out electrolysis. 2,2,3,3-tetrafluoropropanol is converted into 2,2,3,3-tetrafluoropropionic acid. 2,2,3,3-tetrafluoropropionic acid then reacts with NaOH in the solution to generate sodium 2,2,3,3-tetrafluoropropionate.

[0010] (4) Extraction: After electrolysis, sulfuric acid is added to the electrolyte, and the organic phase is removed by extraction with ethyl acetate. After separation, the remaining product is distilled under reduced pressure to obtain sodium 2,2,3,3-tetrafluoropropionate solid.

[0011] The catalytic anode is a catalytic anode material with good oxygen evolution performance, and the catalytic cathode is a catalytic cathode material with good hydrogen evolution performance. The catalytic anode and catalytic cathode are NiMn-OH / NF electrodes, NiMo-OH / NF electrodes, NiCo-OH / NF electrodes, or NiFe-OH / NF electrodes, preferably NiCo-OH / NF electrodes and NiFe-OH / NF electrodes.

[0012] The preparation methods of NiCo-OH / NF electrode and NiFe-OH / NF electrode are as follows: (1) Place commercial foamed nickel NF in 3M HCl solution, remove the oxide on the surface of NF by ultrasonication, and then rinse the surface of NF thoroughly with deionized water; (2) Add a transition metal soluble salt to hydrochloric acid aqueous solution to prepare a 0.01 mol / L salt solution, wherein the transition metal soluble salt is Fe salt or Co salt, immerse the pretreated foamed nickel in the corresponding metal salt solution, and react for 6 hours under magnetic stirring to complete the preparation of the transition metal doped nickel hydroxide electrode.

[0013] All electrolysis was carried out under constant current with a current density of 20-100 mA·cm⁻¹. -2 Preferably 40mA·cm -2 .

[0014] The N bipolar plates can be three, four, five, or six, preferably four.

[0015] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0016] (1) The present invention adopts a stacked bipolar plate electrolytic cell, in which a catalytic anode with good electro-oxidation performance and a catalytic cathode with good electro-reduction performance are embedded in the bipolar plate. By setting multiple bipolar plates as electrocatalysts between the anode and cathode end plates and using the electrolyte as the conductive medium, an electrocatalytic mode is formed in which the liquid flow is in parallel and the current is in series. This effectively reduces the distance between the electrodes, lowers the liquid resistance and reduces power consumption, and also reduces the size of the reactor, reduces the investment in equipment cost, and realizes the miniaturization and integration of the electrosynthesis reactor.

[0017] (2) The electrode in this invention is prepared using a simple "one-pot method," exhibiting significant catalytic activity and good cycle stability. Taking the Fe-doped nickel hydroxide electrode as an example, SEM images show that the surface morphology of the electrode before (a) and after (b) cycling is basically consistent. 40 mA·cm -2 Chronopotential testing at current density showed no significant decay of the electrode surface voltage within 60 hours. Furthermore, the electrodes doped with metals such as Fe and Co exhibited lower onset potentials for tetrafluoropropanol oxidation, achieving higher current densities at lower voltages, indicating good catalytic activity and optimized energy efficiency.

[0018] (3) Through the optimization of the flow field structure and the efficient electrocatalytic effect of the catalyst, tetrafluoropropanol is efficiently converted into tetrafluoropropionic acid. Tetrafluoropropionic acid then reacts with sodium hydroxide solution to generate sodium tetrafluoropropionate. In this process, the yield of sodium tetrafluoropropionate can reach more than 85%, the Faraday efficiency exceeds 90%, the process route is simple, the reaction conditions are mild, and it can completely replace the low-yield and high-consumption chemical synthesis method, and has the potential for large-scale production and application. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a stacked bipolar plate electrolyzer.

[0020] Figure 2 This is a partial disassembly diagram of a stacked bipolar plate electrolyzer.

[0021] Figure 3 The oxidation polarization curves are for nickel hydroxide catalytic anodes doped with different transition metals.

[0022] Figure 4 For Fe-doped nickel hydroxide electrodes at a current density of 40 mA·cm -2 Below are SEM images of the catalytic anode before (a) and after three cycles of electrolysis (b).

[0023] Figure 5 The Fe-doped nickel hydroxide catalytic anode was tested in a mixed solution containing 0.5 M 2,2,3,3-tetrafluoropropanol and 0.5 M NaOH at 40 mA·cm⁻¹. -2Stability test diagram under current density (chronopotential test).

[0024] Figure 6 The liquid chromatograms of 2,2,3,3-tetrafluoropropionic acid at different concentrations (left) and the standard curve of 2,2,3,3-tetrafluoropropionic acid (right).

[0025] Figure 7 The graph shows the yield of sodium 2,2,3,3-tetrafluoropropionate as a function of current density.

[0026] Figure 8 The graph shows the yield of sodium 2,2,3,3-tetrafluoropropionate as a function of the number of bipolar plates.

[0027] Figure 9 Liquid chromatograms of 2,2,3,3-tetrafluoropropionic acid obtained after electrolysis with and without the addition of a catalytic anode and catalytic cathode. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Unless otherwise stated, endpoint values ​​are included when describing numerical ranges herein. When two or more preferred or exemplary numerical values ​​or ranges are given, it is self-evident that all ranges formed by combining different numerical values ​​or endpoints are also included within the scope of this invention.

[0030] These and other aspects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description. In this context, any feature or embodiment derived from one aspect of the invention may be used in any other aspect of the invention. Furthermore, it is self-evident that the embodiments contained herein are intended to describe and illustrate the invention, and not to limit it, and in particular, the invention is not limited to these embodiments.

[0031] Example 1

[0032] This embodiment relates to a method for preparing a nickel hydroxide electrode doped with a transition metal, comprising the following steps:

[0033] (1) NF pretreatment: Commercial nickel foam (NF) was placed in 3M HCl solution and sonicated for 20 minutes to remove oxides on the NF surface. Then the NF surface was thoroughly rinsed with deionized water.

[0034] (2) Preparation of nickel hydroxide electrodes doped with transition metals: A 0.01 mol / L solution of the corresponding salt was prepared by adding a transition metal soluble salt to a 3 L hydrochloric acid aqueous solution with pH = 3. The transition metal soluble salts were mainly Fe salts (such as FeCl3·6H2O), Co salts (such as Co(NO3)2·6H2O), and Mo salts (such as (NH4)6Mo7O). 24 The nickel hydroxide electrodes doped with transition metals include NiMn-OH / NF, NiMo-OH / NF, NiCo-OH / NF, NiFe-OH / NF, NiCu-OH / NF, and NiCr-OH / NF. After thorough mixing, the pretreated nickel foam is immersed in the corresponding metal salt solution and reacted for 6 hours under magnetic stirring to complete the preparation of transition metal-doped nickel hydroxide electrodes, including NiMn-OH / NF, NiMo-OH / NF, NiCo-OH / NF, NiFe-OH / NF, NiCu-OH / NF, and NiCr-OH / NF electrodes.

[0035] The above-mentioned nickel hydroxide electrode doped with transition metals was tested, and the results are as follows: Figure 3 As shown.

[0036] The LSV curves of anodes doped with different metals show that electrodes doped with Mn, Fe, Co, and Mo exhibit lower onset potentials for the electro-oxidation of tetrafluoropropanol compared to undoped materials. This indicates that anodes doped with these metals possess better catalytic activity for the electro-oxidation of tetrafluoropropanol. Furthermore, at relatively high current densities (40-100 mA·cm⁻¹), [the following data is also observed]. -2 Anodes doped with Co and Fe exhibit lower potentials, indicating higher catalytic activity. Conversely, anodes doped with Cu and Cr show poorer catalytic activity for tetrafluoropropanol.

[0037] like Figure 4 As shown, the surface morphology of the electrode is basically the same before and after use. Figure 5 As shown, 40mA·cm -2 The results of the chronopotential test at current density showed that the electrode surface voltage did not change significantly within 60 hours.

[0038] Example 2

[0039] (1) Assemble the electrolytic cell: such as Figure 1As shown, this embodiment employs a stacked bipolar plate electrolyzer, including an anode plate 1, a cathode plate 2, bipolar plates 3, and rubber gaskets 4. The bipolar plate 3 includes a stainless steel disc 5, a catalytic anode 6, and a catalytic cathode 7. Grooves for accommodating the catalytic anode 6 and catalytic cathode 7 are provided on both sides of the stainless steel disc 5. Gas-liquid flow holes 9 and electrolyte flow holes 8 are respectively provided at the upper and lower ends of the stainless steel disc 5 near the grooves. Electrolyte inlets 10 and electrolyte outlets 11 are respectively provided on the anode plate 1 and cathode plate 2. Four bipolar plates 3... The electrodes are arranged sequentially and clamped between the anode plate 1 and the cathode plate 2, ensuring that the electrolyte flow holes 8 and gas-liquid flow holes 9 of all bipolar plates 3 in the electrolytic cell are aligned. The electrolyte flow holes 8 are connected to the electrolyte inlet 10, and the gas-liquid flow holes 9 are connected to the electrolyte outlet 11. Rubber gaskets 4 are installed between the anode plate 1 and the bipolar plates 3, between the bipolar plates 3, and between the bipolar plates 3 and the cathode plate 2. The catalytic anode 6 and the catalytic cathode 7 are Fe-doped nickel hydroxide electrodes with a circular electrode area and a diameter of 20 cm. Anode tabs 12 and cathode tabs 13 are respectively installed on the anode plate 1 and the cathode plate 2. The free ends of the anode tabs 12 and 13 are inserted into the electrolyte in the electrolytic cell. The anode tabs 12 and 13 are connected to the positive and negative terminals of the power supply, respectively. The outlet of the storage tank is connected to the electrolyte inlet 10 through a circulation pump, and the electrolyte outlet 11 is connected to the inlet of the storage tank. For ease of description, the bipolar plates 3 from anode plate 1 to cathode plate 2 are bipolar plate one, bipolar plate two, bipolar plate three, and bipolar plate four, respectively.

[0040] (2) Preparation of electrolyte: Add 2,2,3,3-tetrafluoropropanol and sodium phosphate to a 0.5 mol / L NaOH solution. The molar ratio of 2,2,3,3-tetrafluoropropanol to sodium phosphate is 1:1 to obtain the electrolyte. Sodium phosphate is used to stabilize the pH of the solution and prevent local pH drops that could lead to corrosion of the cathode, anode, and bipolar plates.

[0041] (3) Electrolysis: Pour the prepared electrolyte into the storage tank, turn on the circulation pump to fill the electrolytic cell with liquid, and set the current density to 40 mA·cm. -2 Electrolysis is performed, and 2,2,3,3-tetrafluoropropanol is converted into 2,2,3,3-tetrafluoropropionic acid. 2,2,3,3-tetrafluoropropionic acid then reacts with NaOH in the solution to produce sodium 2,2,3,3-tetrafluoropropionate.

[0042] The equation for the catalytic anode-side reaction is:

[0043] C3H4F4O-4e - +5OH - =C3HF4O2 - +4H2O

[0044] The equation for the catalytic cathode-side reaction is:

[0045] 2H2O+2e - =H2 + 2OH -

[0046] (4) Extraction: After electrolysis, sulfuric acid is added to the electrolyte to remove excess sodium hydroxide, followed by extraction with ethyl acetate to remove the organic phase. After separation, the remaining product is distilled under reduced pressure to obtain sodium 2,2,3,3-tetrafluoropropionate solid. The voltage between each electrode is measured with a multimeter, as shown in the table below. It can be seen that the voltage between all electrodes is not zero and the difference is small, indicating that all electrodes are working normally.

[0047]

[0048]

[0049] Example 3

[0050] In this embodiment, the current density in step (3) of embodiment 2 is set to 20, 60, 80, and 100 mA·cm⁻¹, respectively. -2 Except for the above, everything else is the same as in Examples 1 and 2.

[0051] Example 4

[0052] In this embodiment, the number of bipolar plates in step (1) of embodiment 2 is adjusted to three, five or six respectively, and everything else is the same as in embodiments 1 and 2.

[0053] The solids obtained from distillation in Examples 2-4 were dissolved, diluted, and filtered. The sodium tetrafluoropropionate content in the solution was determined by high-performance liquid chromatography (HPLC) with UV detection. The mobile phase for HPLC was a diammonium hydrogen phosphate solution at pH 3. A standard curve for 2,2,3,3-tetrafluoropropionic acid was fitted using the external standard method. Figure 6 ), calculate the final yield of sodium 2,2,3,3-tetrafluoropropionate, such as Figure 7 and 8 As shown.

[0054] like Figure 7As shown, the yield of sodium 2,2,3,3-tetrafluoropropionate initially increases and then decreases with increasing current density. Higher current densities provide more electrons, which helps to increase the rate of the electro-oxidation reaction. However, excessively high current densities may trigger anodic side reactions, such as oxygen release from water. Current density and electrode potential are positively correlated; excessively high current densities will cause the anodic potential to shift significantly in the positive direction, exceeding the potential required for the oxidation of organic matter, thereby triggering oxygen release from water and ultimately reducing the yield of the target product, sodium 2,2,3,3-tetrafluoropropionate. In addition, when the current density continues to increase, the Joule heating effect will cause the electrode surface temperature to rise. When the temperature is too high, the active sites on the electrode surface will collapse, leading to a decrease in catalytic activity, which in turn reduces the yield of sodium 2,2,3,3-tetrafluoropropionate.

[0055] like Figure 8 As shown, in the electrolysis of 2,2,3,3-tetrafluoropropanol, increasing the number of bipolar plates can expand the reaction area, but too many will lead to a decrease in the yield of sodium 2,2,3,3-tetrafluoropropionate. Firstly, the imbalance in electric field and current distribution, edge effects, and uneven current exacerbate side reactions and deplete active sites, interfering with the formation of the target product. Secondly, mass transfer efficiency decreases; too many bipolar plates increase flow channel resistance, leading to uneven concentration distribution and affecting the mass transfer rate. Thirdly, heat accumulation and temperature runaway occur; difficulty in heat dissipation and uneven temperature damage catalytic activity, promoting side reactions.

[0056] Comparative Example 1

[0057] The bipolar plate electrolyzer involved in this comparative example only has stainless steel discs as bipolar plates. The catalytic anode 6 and catalytic cathode 7 are not embedded in the grooves on the left and right sides of the stainless steel disc 5. Everything else is the same as in Example 1.

[0058] like Figure 9 As shown, compared with the addition of catalytic anode 6 and catalytic cathode 7, the liquid chromatography results show that the peak area of ​​tetrafluoropropionic acid prepared by electrolysis without the addition of catalytic anode 6 and catalytic cathode 7 was significantly reduced, the concentration decreased from the original 104.3 g / L to 45.7 g / L, and the power consumption increased from 1.8 kWh / kg to 4.1 kWh / kg. This indicates that the addition of nickel foam modified catalyst effectively improved the electrosynthesis reaction rate of tetrafluoropropionic acid and reduced energy consumption.

[0059] The limitations of the above embodiments, and any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention, shall be considered equivalent substitutions and are included within the protection scope of the present invention.

Claims

1. A method for preparing sodium 2,2,3,3-tetrafluoropropanol by electrochemical oxidation using a stacked bipolar plate electrolyzer, characterized in that, Specifically, the following steps are included: (1) Assembling the electrolytic cell: The stacked bipolar plate electrolytic cell includes an anode end plate, a cathode end plate, bipolar plates, and rubber gaskets. The bipolar plates include a nickel-plated stainless steel disc, a catalytic anode, and a catalytic cathode. Grooves for accommodating the catalytic anode and cathode are provided on both sides of the stainless steel disc. Gas-liquid flow holes and electrolyte flow holes are respectively provided at the upper and lower ends of the stainless steel disc near the grooves. Electrolyte inlets and outlets are respectively provided on the anode and cathode end plates. N bipolar plates are arranged sequentially and clamped and fixed between the anode and cathode end plates. All bipolar plates in the electrolytic cell... The electrolyte guide holes are aligned, the gas-liquid guide holes are aligned, the electrolyte guide holes are connected to the electrolyte inlet, and the gas-liquid guide holes are connected to the electrolyte outlet. Rubber gaskets are installed between the anode end plate and the bipolar plate, between two adjacent bipolar plates, and between the bipolar plate and the cathode end plate. Anode tabs and cathode tabs are installed on the anode end plate and the cathode end plate, respectively. The free ends of the anode tabs and cathode tabs are inserted into the electrolyte in the electrolytic cell. The anode tabs and cathode tabs are connected to the positive and negative terminals of the power supply, respectively. The outlet of the storage tank is connected to the electrolyte inlet through a circulation pump, and the electrolyte outlet is connected to the inlet of the storage tank. (2) Preparation of electrolyte: Add 2,2,3,3-tetrafluoropropanol and sodium phosphate to NaOH solution. The molar ratio of 2,2,3,3-tetrafluoropropanol and sodium phosphate is 1:1 to 1:1.5 to obtain the electrolyte. (3) Electrolysis: Pour the prepared electrolyte into the storage tank, turn on the circulation pump to fill the electrolytic cell with liquid and carry out electrolysis. 2,2,3,3-tetrafluoropropanol is converted into 2,2,3,3-tetrafluoropropionic acid. 2,2,3,3-tetrafluoropropionic acid then reacts with NaOH in the solution to generate sodium 2,2,3,3-tetrafluoropropionate. (4) Extraction: After electrolysis, sulfuric acid is added to the electrolyte, and the organic phase is removed by extraction with ethyl acetate. After separation, the remaining product is distilled under reduced pressure to obtain sodium 2,2,3,3-tetrafluoropropionate solid. The catalytic anode and catalytic cathode are NiMn-OH / NF electrodes, NiMo-OH / NF electrodes, NiCo-OH / NF electrodes, or NiFe-OH / NF electrodes; All electrolysis was carried out under constant current with a current density of 20-100 mA·cm⁻¹. -2 ; The number of N bipolar plates is 3-6.

2. The method for preparing sodium 2,2,3,3-tetrafluoropropanol by electrochemical oxidation based on a stacked bipolar plate electrolyzer according to claim 1, characterized in that, The preparation methods of NiCo-OH / NF electrode and NiFe-OH / NF electrode are as follows: (1) Place commercial foamed nickel NF in 3 M HCl solution, remove the oxide on the surface of NF by ultrasonication, and then rinse the surface of NF thoroughly with deionized water; (2) Add a transition metal soluble salt to hydrochloric acid aqueous solution to prepare a 0.01 mol / L salt solution, wherein the transition metal soluble salt is Fe salt or Co salt, immerse the pretreated foamed nickel in the corresponding metal salt solution, and react for 6 hours under magnetic stirring to complete the preparation of the transition metal doped nickel hydroxide electrode.

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