Three-chamber electrochemical reactor

Abstract

The present invention discloses a three-chamber electrochemical reactor, comprising an anode chamber, an intermediate chamber and a cathode chamber; the anode chamber and the intermediate chamber are separated by a cation exchange membrane, the anode chamber comprises an anode frame plate and an anode plate; the intermediate chamber comprises an intermediate frame plate and an internal flow field; the cathode chamber and the intermediate chamber are separated by an anion exchange membrane, the cathode chamber comprises a catalytic reaction layer, a cathode plate and a cathode frame plate; wherein the cathode frame plate and the anode frame plate are both provided with electrode potential test holes, and the electrode potential test holes expose the cation exchange membrane or the anion exchange membrane. In the three-chamber electrochemical reactor of the present invention, the cathode frame plate and the anode frame plate are both provided with potential test holes, which can accurately diagnose and monitor the operating state of the reactor, and appropriately adjust the corresponding parameters to achieve the purpose of controlling product selectivity and improving current efficiency, thereby making it possible to increase production.

Description

Technical Field

[0001] The invention relates to the field of electrochemistry, and in particular to a three-chamber electrochemical reactor. Background Art

[0002] Electrochemical conversion is an important way to realize the resource reuse of carbon dioxide, and the electrolytic cell is the key equipment to complete this conversion. At present, the electrochemical conversion technology of carbon dioxide generally adopts a single membrane two-chamber electrolytic cell structure, anion membrane or cation membrane. The anion membrane two-chamber cell and the cation membrane two-chamber electrolytic cell each have their own advantages and disadvantages. One of the conflicting points is that the utilization rate and selectivity of carbon dioxide cannot be taken into account at the same time. The cation membrane two-chamber electrolytic cell is a traditional carbon dioxide electrochemical reactor that has been studied more. In this reactor, the utilization rate of carbon dioxide is high because the transmembrane transport behavior of carbon dioxide from the cathode to the anode is quite slight, but because the cathode electrolyte environment is more favorable to hydrogen evolution than to carbon dioxide electroreduction, the selectivity of carbon dioxide electrochemical conversion is not high. Although the anion membrane two-chamber electrolytic cell entered the research field later, this reactor overcomes the obstacles of electrolyte environment and carbon dioxide solubility, so it has a high carbon dioxide electroreduction selectivity. However, due to the limitations of the nature of anion conductivity, the anion membrane two-chamber electrolytic cell has serious transmembrane transport of carbon dioxide and products, so the utilization efficiency of carbon dioxide is low.

[0003] The two-membrane three-chamber electrolytic cell structure with both anionic and cationic membranes has become a technical hotspot in the development of electrochemical reactors in recent years. For example, the paper (Electrochemical conversion of CO2 to formic acid utilizing Sustainion TM membranes, Journal of CO2Utilization 2017, 20, 208-217.), a two-membrane three-chamber electrolyzer with a fiber-filled intermediate chamber has obtained a higher carbon dioxide utilization rate and conversion current efficiency, successfully overcame the contradictions faced by the single-membrane two-chamber electrolyzer, and exerted their advantages. However, this new type of electrolyzer has a complex structure, and there are many factors that affect the performance of the electrolyzer, such as the internal resistance of each chamber, electrode activity, component matching, fluid flow resistance of the intermediate chamber, etc., as well as various potential factors that may be revealed during long-term operation. Therefore, it is impossible to feedback and determine the working state of the electrolyzer or even each chamber by monitoring the polarization curve and the current density alone, and it is difficult to diagnose and adjust the performance parameter changes of the electrolyzer as a whole or even each chamber during operation. For this reason, it is necessary to add necessary monitoring and diagnostic functions to this new type of electrolyzer, especially to a large-scale battery stack composed of a large area of ​​multiple single cells, so as to predict and timely discover, diagnose, anchor, solve and improve problems. Summary of the invention

[0004] To solve the above problems, the main purpose of the present invention is to provide a three-chamber electrochemical reactor.

[0005] The present invention provides a three-chamber electrochemical reactor, comprising an anode chamber, an intermediate chamber and a cathode chamber; the anode chamber and the intermediate chamber are separated by a cation exchange membrane, the anode chamber comprises an anode frame plate and an anode plate; the intermediate chamber comprises an intermediate frame plate and an internal flow field; the cathode chamber and the intermediate chamber are separated by an anion exchange membrane, the cathode chamber comprises a catalytic reaction layer, a cathode plate and a cathode frame plate; wherein both the cathode frame plate and the anode frame plate are provided with an electrode potential test hole, the electrode potential test hole leaks the anode plate or the cathode plate electrode.

[0006] According to one embodiment of the present invention, one or more of the middle frame plate, the cathode frame plate and the anode frame plate is provided with a membrane potential test hole, and the membrane potential test hole exposes the anion exchange membrane and / or the cation exchange membrane.

[0007] According to another embodiment of the present invention, the cation exchange membrane and / or the anion exchange membrane includes an ion lead formed by extending in one direction of the electrochemical reactor to the outside of the reactor in a long line or strip, and the tail of the ion lead and the reference electrode are installed in a container containing an electrolyte solution.

[0008] According to another embodiment of the present invention, the ion lead is formed by cation exchange membranes and / or anion exchange membranes cut into long lines or strips and laminated to the corresponding cation exchange membranes and / or anion exchange membranes of the electrochemical reactor.

[0009] According to another embodiment of the present invention, the ion lead is formed integrally by the cation exchange membrane and / or the anion exchange membrane. According to another embodiment of the present invention, the anode plate is a three-dimensional anode.

[0010] According to another embodiment of the present invention, the cathode plate is a three-dimensional cathode.

[0011] According to another embodiment of the present invention, the electrochemical reactor is a battery or an electrolytic cell.

[0012] According to another embodiment of the present invention, the three-chamber electrochemical reactor is used for electrolysis of carbon dioxide to produce any one of synthesis gas, formic acid and oxalic acid.

[0013] According to another embodiment of the present invention, the anode chamber uses water as a raw material, the intermediate chamber uses an alkali metal carbonate or bicarbonate solution as an electrolyte, and the cathode chamber uses either a carbon dioxide-saturated alkali metal bicarbonate solution or a humidified gas containing carbon dioxide as a raw material, and electrolysis produces synthesis gas.

[0014] According to another embodiment of the present invention, the anode chamber uses water or any one of alkali metal hydroxide, carbonate or bicarbonate solutions as raw materials, the intermediate chamber uses formic acid solution as electrolyte, and the cathode chamber uses carbon dioxide saturated alkali metal bicarbonate solution as raw material, and formic acid is produced by electrolysis.

[0015] According to another embodiment of the present invention, the anode chamber contains water or any one of alkali metal hydroxide, carbonate or bicarbonate solutions as raw materials, the intermediate chamber contains oxalic acid solution as electrolyte, and the cathode chamber contains carbon dioxide saturated alkali metal bicarbonate solution as raw materials, and oxalic acid is produced by electrolysis.

[0016] The present invention also provides a battery stack comprising the electrochemical reactor.

[0017] The present invention further provides an electrolytic cell stack comprising the electrochemical reactor.

[0018] In the three-chamber electrochemical reactor of the present invention, both the cathode frame plate and the anode frame plate are provided with membrane potential test holes and electrode potential test holes, wherein the membrane potential test holes expose the anion exchange membrane or the cation exchange membrane, and the electrode potential test holes leak out of the cathode plate or the anode plate, so that the potential difference of each single-slot reactor constituting the stack can be accurately measured, and the potential of any pole of any slot, or the potential between the cation exchange membrane and the anion exchange membrane of any slot can be measured in conjunction with a reference electrode, so that the operating state of the reactor can be accurately diagnosed and monitored, and the corresponding parameters can be appropriately adjusted to achieve the purpose of controlling product selectivity and improving current efficiency, thereby making it possible to increase production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0020] Figure 1 It is a schematic structural diagram of an electrochemical reactor according to one embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of bipolar plate assembly of an electrochemical reactor according to another embodiment of the present invention.

[0022] Figure 3 It is a schematic diagram of the internal flow field of the middle frame plate of the electrochemical reactor according to one embodiment of the present invention.

[0023] Figure 4 Schematic diagram of the cathode and anode frames of an electrochemical reactor according to one embodiment of the present invention.

[0024] Figure 5It is a schematic diagram of a reference electrode access method of an electrochemical reactor according to one embodiment of the present invention.

[0025] Figures 6 to 10 The schematic diagrams of the structures and operations of the electrochemical reactors of Examples 1-5 are respectively shown.

[0026] The reference numerals are described as follows:

[0027] 1 Anode frame 2 Sealing ring

[0028] 3 Cation exchange membrane 4 Three-dimensional anode

[0029] 5 Three-dimensional cathode 6 Cathode frame plate

[0030] 7 Anion exchange membrane 8 Middle frame plate

[0031] 9 Sealing pad 10 Anode chamber outlet

[0032] 11 Middle chamber outlet 12 Cathode chamber outlet

[0033] 13 Cathode chamber feed port 14 Intermediate chamber feed port

[0034] 15 Anode chamber feed port 16 Intermediate chamber flow field

[0035] 17 Electrolyte solution 18 Ion lead

[0036] 19 Reference electrode 20 Electrode potential test hole

[0037] 21 Three-dimensional positive and negative double electrodes 30 Anode clamp

[0038] 30a Anode chamber 33 Cation exchange membrane

[0039] 34 Three-dimensional anode 40a Middle chamber

[0040] 50 cathode clamping plate 50a cathode chamber

[0041] 55 Three-dimensional cathode 57 Anion exchange membrane

[0042] 58 membrane potential test holes DETAILED DESCRIPTION

[0043] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. In the figures, the thickness of regions and layers are exaggerated for clarity. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0044] Figure 1 The schematic diagram of the three-chamber electrochemical reactor of one embodiment of the present invention is shown, including an anode frame plate 1, an intermediate frame plate 8 with internal flow field in the middle part, and a cathode frame plate 6. Wherein the anode frame plate 1 is connected to one side of a cation exchange membrane 3 by a sealing gasket 9, and the other side of the cation exchange membrane 3 is connected to the intermediate frame plate 8 by a sealing gasket 9. The cathode frame plate 6 is connected to one side of an anion exchange membrane 7 by a sealing gasket 9, and the anion exchange membrane 7 is connected to the intermediate frame plate 8 by a sealing gasket 9 on the other side. An intermediate chamber is defined between the cation exchange membrane 3 and the anion exchange membrane 7. The other side of the anode frame plate 1 is connected to the three-dimensional anode 4 by a sealing ring 2, thereby forming an anode chamber. The cathode frame plate 6 is connected to the three-dimensional cathode 5 by a sealing ring, thereby forming a cathode chamber.

[0045] Figure 1 The structure of a single-tank electrochemical reactor is shown. The inventive concept of the present invention is also applicable to a stack composed of multiple single-tank reactors connected in series and / or in parallel. When forming a stack, bipolar plates can also be used between adjacent single-tank reactors, such as Figure 2 As shown. One side of the three-dimensional yin and yang double electrode 21 is connected to the anode frame plate 1 through a sealing ring 2, and the other side of the anode frame plate 1 is connected to the cation exchange membrane 3 through a sealing gasket 9, thereby forming an anode chamber. The other side of the three-dimensional yin and yang double electrode 21 is connected to the cathode frame plate 6 through a sealing ring 2, and the other side of the cathode frame plate 6 is connected to the anion exchange membrane 7 through a sealing gasket 9, thereby forming a cathode chamber. The three-dimensional yin and yang double electrode 21 is used as a bipolar plate, which can reduce internal resistance and is beneficial to electronic conduction, save raw materials, and is easy to assemble.

[0046] Those skilled in the art can Figure 1 and Figure 2 The structural units can be combined in various ways to form a fuel cell stack containing any number of single-tank reactors.

[0047] like Figure 3 The schematic diagram of the structure of the middle frame plate 8 is shown. Figure 4The cathode and cathode frame plates 1 and 6 are shown (because the structures of the cathode and cathode plates are the same, only one is shown in the figure). The middle frame plate 8 and the cathode and cathode frame plates 1 and 6 all include an anode chamber discharge port 10, an intermediate chamber discharge port 11, a cathode chamber discharge port 12, a cathode chamber feed port 13, an intermediate chamber feed port 14, and an anode chamber feed port 15. The middle frame plate 8 also includes an intermediate chamber flow field 16. The middle frame plate 8 is also provided with a membrane potential test hole 58, which exposes the cation exchange membrane 3 and / or the anion exchange membrane 7 after being assembled into a reactor. The cathode and cathode frame plates 1 and 6 also include an electrode potential test hole 20, which exposes the three-dimensional cathode and cathode bielectrode 21 after being assembled into a reactor. After being assembled into a reactor, only the anode chamber discharge port 10 and the anode chamber feed port 15 on the anode frame plate 1 are connected to the flow field on the frame plate, and the other holes are all conduction holes. On the cathode frame plate 6, only the cathode chamber outlet 12 and the cathode chamber feed port 13 are connected to the flow field on the frame plate, and the other holes are all conduction holes. On the intermediate frame plate 8, only the intermediate chamber outlet 11 and the intermediate chamber feed port 14 are connected to the flow field on the frame plate, and the other holes are all conduction holes. Except for the potential test holes 20 and 58, the other conduction holes are only used to allow materials to flow through, and they will not leak out to other places after being sealed.

[0048] The electrode potential test hole 20 exposes a three-dimensional positive and negative double electrode. By inserting a multimeter probe into the hole, the potential difference between any two positive and negative electrodes, that is, the total potential between any two positive and negative electrodes, can be measured to determine whether the internal flow field distribution is uniform.

[0049] At the same time Figure 5 The membrane potential test hole 58 provided in the middle frame plate 8 shown in the figure exposes the cation exchange membrane 3 and the anion exchange membrane 7. The cation exchange membrane 3 and the anion exchange membrane 7 include an ion lead 18 formed by extending to the outside of the reactor in a long line or strip in one direction of the electrochemical reactor, and the tail of the ion lead 18 and the reference electrode 19 are installed in a container filled with an electrolyte solution 17. The ion lead 18 is formed by the cation exchange membrane 3 and the anion exchange membrane 7 cut into long lines or strips and superimposed on the corresponding cation exchange membrane 3 and the anion exchange membrane 7 of the electrochemical reactor. The ion lead 18 can also be directly formed by the cation exchange membrane 3 and the anion exchange membrane 7 as a whole. The potential of any electrode can be detected, i.e., the potential between the cation exchange membrane 3 and the double electrodes, the potential between the anion exchange membrane 7 and the double electrodes, or the voltage drop between the cation exchange membrane 3 and the anion exchange membrane 7, so as to understand the electrode, the intermediate chamber and the flow field distribution thereof.

[0050] The above is to set the membrane potential test hole 58 as an example with the middle frame plate 8, and the present invention is described.Certainly, the anode frame plate 1 and / or the cathode frame plate 6 can also be provided with the membrane potential test hole, to be used for testing the potential of the anion exchange membrane or the cation exchange membrane adjacent thereto.When the ion lead is formed as one with the ion exchange membrane, the reactor can also not be provided with the membrane potential test hole and can also realize purpose of the present invention.

[0051] The above method can realize the monitoring and diagnosis function of the electrochemical reactor, which can be used not only in the long-term operation of the reactor, but also in the construction and development of the reactor. In the construction and development of the reactor, the monitoring and diagnosis function can be used as an auxiliary tool to screen and improve the performance of the various functional components of the reactor and the entire reactor. During the operation of the reactor, in addition to diagnosing anchoring problems, the monitoring function can also be used to control the electrode potential and thus control the product selectivity. In order to improve the utilization rate of the gas source (such as CO2) and maintain the electro-reduction selectivity of the gas source gas, and increase its current density through reasonable flow field design.

[0052] The following embodiments take a single tank electrolytic cell as an example to illustrate the concept of the present invention.

[0053] Example 1

[0054] like Figure 6 As shown, it includes an anode clamp 30, a three-dimensional anode 34, a cation exchange membrane 33, an anion exchange membrane 57, a three-dimensional cathode 55 and a cathode clamp 50. Wherein an anode chamber 30a is formed between the anode clamp 30 and the three-dimensional anode 34, an intermediate chamber 40a is formed between the cation exchange membrane 33 and the anion exchange membrane 57, and a cathode chamber 50a is formed between the cathode clamp 50 and the three-dimensional cathode 55. Wherein the active area on the anode side of the cation exchange membrane 33 is sprayed with an iridium black catalyst, and the active area on the cathode side of the anion exchange membrane 57 is sprayed with a nano silver catalyst. The cation exchange membrane 33 and the anion exchange membrane 57 both include ion leads (not shown in the figure), and the cation exchange membrane 33 and the anion exchange membrane 57 are used to detect the cathode and cathode potentials in the working state, thereby accurately diagnosing and monitoring the operating state of the reactor, and appropriately adjusting the corresponding parameters to achieve control of product selectivity and improve current efficiency.

[0055] The cathode side is fed with a KHCO3 solution with a concentration of 0.3 mol / L and a flow rate of 150 L / h and a CO2 gas with a flow rate of 5 L / min. Deionized water is fed into the anode side. A low-concentration 0.1 mol / L KHCO3 solution is fed into the middle chamber 40a. After power is turned on, the cathode outlet discharges KHCO3 solution, excess CO2 gas and synthesis gas, the anode outlet discharges water and O2, and the middle chamber 40a discharges KHCO3 solution and CO2. During the electrolysis process, the outlet solution temperatures of the cathode chamber, the anode chamber and the middle chamber are all controlled at 50°C. The data in Table 1 show that the optimization of current efficiency is achieved by adjusting the total potential of the electrolytic cell and the partial potential of each electrode. In this embodiment, the cathode partial potential and the anode partial potential are both relative to the standard hydrogen electrode, and the intermediate chamber voltage drop is the voltage drop between the cation exchange membrane and the anion exchange membrane.

[0056] Table 1

[0057]

[0058] It can be seen from the data shown in Table 1 that when the potential of the electrolytic cell is 3.79V, the cathode partial potential is -1.4V, the anode partial potential is 1.92V, and the intermediate chamber potential is 0.47V, the current efficiency of the electrolytic cell is the largest.

[0059] Example 2

[0060] like Figure 7 As shown, the structure is the same as that of Example 1. The raw materials introduced into and discharged from the anode side and the middle chamber 40a are the same as those of Example 1. The humidified CO2 gas of 5 L / min is introduced into the cathode side, and the synthesis gas and CO2 gas are discharged from the cathode outlet. The solution temperature at the liquid outlet of each chamber is also controlled at 50°C. The data in Table 2 show that the optimization of current efficiency is achieved by adjusting the total potential of the electrolytic cell.

[0061] Table 2

[0062]

[0063] From the data shown in Table 2, it can be seen that when the cathode potential and the intermediate chamber potential of the electrolytic cell are -1.26V and 0.47V respectively, the current efficiency of the electrolytic cell is the largest. At this time, the total potential and the anode potential of the electrolytic cell are 3.64V and 1.91V respectively.

[0064] Example 3

[0065] like Figure 8As shown, the structure is the same as in Example 1, but the three-dimensional cathode 55 is a three-dimensional titanium electrode sprayed with a nano-tin catalyst by the anion membrane side. The cathode side feeds a KHCO solution with a concentration of 0.3mol / L and a flow rate of 150L / h and a 5L / minCO gas. The anode side feeds deionized water. The middle chamber 40a feeds a low-concentration HCOOH solution of 0.1mol / L. After energization, the cathode outlet discharges KHCO solution and unnecessary CO gas and a small amount of byproduct H, the anode outlet discharges water and O, and the middle chamber 40a discharges a high-concentration HCOOH solution and a small amount of CO gas, and the electrolysis temperature is the same as in Example 1. Table 3 data shows the optimization of current efficiency by regulating the total potential of the electrolytic cell.

[0066] Table 3

[0067]

[0068] It can be seen from the data shown in Table 3 that when the potential of the electrolytic cell is 3.82 V, the cathode and anode potentials and the intermediate chamber potential are -1.31 V, 1.9 V and 0.61 V respectively, the electrolytic cell obtains the maximum current efficiency.

[0069] Example 4

[0070] like Fig. 9 As shown, the structure is the same as in Example 1, but wherein the three-dimensional anode 34 and the three-dimensional cathode 55 are titanium electrodes coated with iridium-ruthenium coating catalyst and sprayed with nano-tin catalyst respectively on the membrane side. The electrolysis temperature and the raw materials and materials discharged by the cathode side are the same as in Example 3. The anode side is fed with a KOH solution with a concentration of 2mol / L, and the middle chamber 40a is fed with a KCOOH solution of low concentration 0.1mol / L. After the energization, the anode outlet discharges residual KOH solution and O2, and the middle chamber 40a discharges high-concentration KCOOH solution and a small amount of CO2 gas. The data in Table 4 show the optimization of current efficiency by adjusting the total potential of the electrolytic cell.

[0071] Table 4

[0072]

[0073]

[0074] It can be seen from the data shown in Table 4 that when the total voltage of the electrolytic cell is 3.4V and the cathode potential is -1.35V, the current efficiency of the electrolytic cell is the largest.

[0075] Example 5

[0076] like Fig.10As shown, the structure is the same as Example 1, but the cation exchange membrane 33 anode side active area is sprayed with iridium black catalyst, and the anion exchange membrane 57 cathode side active area is sprayed with nano lead catalyst. The cathode side is fed with low concentration 0.1mol / L KHCO3 solution and 5L / min CO2 gas, the anode side is fed with deionized water, and the middle chamber 40a is fed with low concentration 0.1mol / L H2C2O4 solution. After energization, the cathode outlet discharges KHCO3 solution, CO2 and H2 gas, the anode outlet discharges water and O2, and the middle chamber 40a discharges high concentration H2C2O4 solution and a small amount of CO2. Table 5 data shows the optimization of current efficiency by adjusting the potential of each part of the electrolytic cell.

[0077] Table 5

[0078]

[0079] It can be seen from the data shown in Table 5 that when the total potential of the electrolytic cell is 3.82 V, and the potentials of the cathode, anode and middle chamber are -1.37 V, 1.91 V and 0.54 V respectively, the electrolytic cell obtains the optimal current efficiency.

[0080] In the above embodiments, the current efficiency is optimized by adjusting the total potential, the cathode and anode potentials, and the intermediate chamber potential of the electrolytic cell. However, those skilled in the art will appreciate that the current efficiency can also be optimized or the selectivity of the product can be improved by adjusting parameters such as the flow rate, flow velocity, pressure, and temperature of the raw materials.

[0081] The above embodiments take an electrolytic cell as an example. Of course, those skilled in the art can understand that the inventive concept of the present invention is also applicable to batteries, that is, by measuring the potential of the anode and cathode of the fuel cell under working conditions, the operating state of the battery can be accurately diagnosed and monitored, and the corresponding parameters such as potential, flow rate, flow rate, pressure and temperature can be appropriately adjusted to achieve the purpose of controlling product selectivity and improving current efficiency, thereby making it possible to increase production.

[0082] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A three-chamber electrochemical reactor, comprising an anode chamber, an intermediate chamber and a cathode chamber; The anode chamber and the intermediate chamber are separated by a cation exchange membrane, and the anode chamber comprises an anode frame plate and an anode plate; The intermediate chamber includes an intermediate frame plate and an internal flow field; The cathode chamber and the intermediate chamber are separated by an anion exchange membrane, and the cathode chamber comprises a catalytic reaction layer, a cathode plate and a cathode frame plate; One or more of the middle frame plate, the cathode frame plate and the anode frame plate is provided with a membrane potential test hole, wherein the membrane potential test hole exposes the anion exchange membrane and the cation exchange membrane; in, The cathode frame plate and the anode frame plate are both provided with an electrode potential test hole, and the electrode potential test hole exposes the anode plate or the cathode plate; The cation exchange membrane and the anion exchange membrane include ion leads extending in one direction of the electrochemical reactor to the outside of the reactor in the form of long lines or strips. The tail of the ion lead and the reference electrode are installed in a container containing an electrolyte solution.

2. The three-chamber electrochemical reactor according to claim 1, characterized in that: The ion lead is formed by stacking the cation exchange membrane and / or anion exchange membrane cut into long lines or strips onto the corresponding cation exchange membrane and / or anion exchange membrane of the electrochemical reactor.

3. The three-chamber electrochemical reactor according to claim 1, characterized in that: The ion lead is formed integrally with the cation exchange membrane and / or the anion exchange membrane.

4. The three-chamber electrochemical reactor according to claim 1, characterized in that: The electrochemical reactor is a battery or an electrolytic cell.

5. The three-chamber electrochemical reactor according to claim 1, characterized in that: It is the electrolysis of carbon dioxide to produce any one of synthesis gas, formic acid and oxalic acid.

6. The three-chamber electrochemical reactor according to claim 5, characterized in that: The anode chamber uses water as raw material, the intermediate chamber uses alkali metal carbonate or bicarbonate solution as electrolyte, and the cathode chamber uses either carbon dioxide saturated alkali metal bicarbonate solution or humidified gas containing carbon dioxide as raw material to generate synthesis gas through electrolysis.

7. The three-chamber electrochemical reactor according to claim 5, characterized in that: The anode chamber uses water or any one of alkali metal hydroxide, carbonate or bicarbonate solutions as raw materials, the intermediate chamber uses any one of formic acid or oxalic acid solutions as electrolyte, and the cathode chamber uses an alkali metal bicarbonate solution saturated with carbon dioxide as raw material, and electrolysis produces any one of formic acid or oxalic acid.

8. An electrolytic cell stack comprising the electrochemical reactor according to any one of claims 1 to 7.

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