Novel electrochemical reduction carbon dioxide reaction electrolytic tank and reaction system

Abstract

The utility model discloses a novel electrochemical reduction carbon dioxide reaction electrolytic tank and reaction system, which comprises a cathode chamber and an anode chamber, the cathode chamber and the anode chamber are fixedly connected through a detachable sealing connecting piece, and a proton exchange membrane is arranged at the joint of the cathode chamber and the anode chamber; a carbon dioxide inlet pipe is arranged at the bottom of the cathode chamber, so that CO2 can be better dissolved in a solution, the top of the cathode chamber is movably connected with a first sealing cover, a working electrode and a reference electrode are arranged in the first sealing cover, a gas outlet pipe is arranged on one side, close to the working electrode, in the first sealing cover, and a liquid-phase liquid extractor is arranged on one side, close to the reference electrode, in the first sealing cover; a reaction solution can be directly taken; the top of the anode chamber is movably connected with a second sealing cover, and a counter electrode is arranged in the second sealing cover. Compared with a traditional H-type electrolytic tank, the conversion rate of carbon dioxide and the accuracy of product content detection can be obviously improved, meanwhile, operation is easy, and calculation is convenient.

Description

Technical Field

[0001] The utility model relates to the field of electrochemical reduction of carbon dioxide, and in particular to a novel electrochemical reduction carbon dioxide reaction electrolytic cell and a reaction system. Background Art

[0002] Carbon dioxide is a colorless, non-toxic gas at room temperature and pressure. It is non-flammable and slightly soluble in water. Currently, the technologies for recovering and utilizing carbon dioxide are mainly divided into absorption, storage, catalytic hydrogenation, photocatalytic reduction, and electrochemical reduction. Among them, electrochemical reduction of carbon dioxide is a hot topic in current research. 2 Converted into valuable fuels and chemicals. It has many advantages among many conversion technologies, including mild reaction conditions at room temperature and pressure, recyclable electrolytes, and sustainable development potential driven by renewable energy. Its main principle is: by applying a certain voltage to the electrolytic cell, water oxidation reaction occurs on the anode side, losing electrons and generating oxygen and protons; carbon dioxide reduction reaction occurs on the cathode side, gaining electrons and protons and generating reduction products. Common electrochemical reduction products of carbon dioxide include formic acid, methanol, carbon monoxide, ethylene, etc.

[0003] Currently, in CO 2 The electrolytic cell used in electrochemical research is a conventional H-type electrolytic cell, in which the cathode chamber and the anode chamber are connected by an ion exchange membrane. 2 The CO dissolved in the electrolyte is bubbled into the cathode chamber. 2 Then diffuse to the electrode surface and undergo electrochemical reduction reaction. Tests have found that CO 2 The solubility in different solvents varies greatly. At room temperature, the solubility in a near-neutral electrolyte with water as the solvent is only 0.033M, which is equivalent to 1 / 2 of its solubility in methanol and more than 10 times lower than its solubility in ionic liquids. In acidic electrolyte aqueous solutions, CO 2 When the electrochemical reaction current is large, severe mass transfer polarization will occur on the electrode surface, accompanied by the intensification of the competitive hydrogen evolution side reaction, which directly leads to a significant reduction in the ERC efficiency.

[0004] Authorization number CN 217298035 U discloses an H-type electrolysis device for electrocatalytic carbon dioxide reduction. The utility model mainly includes a U-shaped knob clamp including a U-shaped base, a first external joint and a second external joint installed in the U-shaped base, one end of the U-shaped base is connected to a fixed column, and a limit column is provided above the other end. An adjusting screw is connected between the fixed column and the limit column, and the adjusting screw is used to adjust the position of the limit column so that the limit column presses and fixes the first external joint and the second external joint. The device provided by the utility model has good sealing effect, high installation stability, and repeatable operation, but it does not change the problem of removing the liquid phase for product detection during the experiment.

[0005] Authorization number CN 204097577 U discloses an electrolytic cell for electrochemical reduction of carbon dioxide. The utility model mainly includes: the cathode chamber is divided into two upper and lower cavities, the lower cavity is a container with an upper opening, the upper cavity is a container with a lower opening, the upper cavity is placed above the lower cavity, and a first flange is provided at the open ends of the two cavities, and the two cavities are connected by the first flange. Compared with the traditional H-type electrolytic cell, it can significantly improve the conversion rate of carbon dioxide, increase the electrochemical reaction speed, and is simple to operate, but it does not change the problem of removing the liquid phase for product detection during the experiment, and the sealing problem of connecting the interface of the two electrode chambers. Utility Model Content

[0006] The utility model aims to overcome the deficiencies in the prior art and provides an H-type electrolytic cell for electrocatalytic carbon dioxide reduction. The carbon dioxide in the cathode chamber is introduced through double pipes at the lower part of the cathode chamber body. The electrolytic cell has good sealing effect, high installation stability, and repeatable operation, thereby avoiding the problem that the carbon dioxide cannot be uniformly dissolved in the electrolyte. A liquid phase liquid extractor is provided at the upper part, which can remove the liquid phase reaction electrolyte for mid-product detection without terminating the experiment, thereby helping to improve the credibility and accuracy of subsequent experimental data. The device has a simple structure and is easy to operate, thereby helping to improve experimental efficiency.

[0007] The purpose of the utility model can be achieved through the following technical solutions:

[0008] A novel electrochemical carbon dioxide reduction reaction electrolytic cell comprises a cathode chamber and an anode chamber; the cathode chamber and the anode chamber are fixedly connected by a detachable sealing connector, and a proton exchange membrane is provided at the connection between the cathode chamber and the anode chamber; a carbon dioxide air inlet pipe is provided at the bottom of the cathode chamber, and the top is movably connected to a first sealing cover, a working electrode and a reference electrode are provided in the first sealing cover, an air outlet pipe is provided on one side of the first sealing cover close to the working electrode, and a liquid phase liquid extractor is provided on one side of the first sealing cover close to the reference electrode; the top of the anode chamber is movably connected to a second sealing cover, and a counter electrode is provided in the second sealing cover.

[0009] As a preferred embodiment of the present invention, the detachable sealing connector is a spiral clamp.

[0010] As a preferred embodiment of the present invention, seals are provided on both sides of the proton exchange membrane.

[0011] As a preferred embodiment of the present invention, the sealing member is a rubber ring.

[0012] As a preferred embodiment of the present invention, the movable connection between the first sealing cover and the cathode chamber and / or the second sealing cover and the anode chamber is a threaded connection.

[0013] As a preferred embodiment of the present invention, the carbon dioxide intake pipe is a double-pipe intake pipe.

[0014] As a preferred embodiment of the present invention, a gas flow control valve is provided at one end of the carbon dioxide inlet pipe connected to the carbon dioxide gas.

[0015] As a preferred embodiment of the present invention, the gas flow control valve is a spiral switch valve.

[0016] Another object of the utility model is to provide a novel electrochemical reduction of carbon dioxide reaction system, comprising the above-mentioned novel electrochemical reduction of carbon dioxide reaction electrolytic cell, a magnetic stirrer, a gas chromatograph and an electrochemical workstation; a cathode chamber is placed on the stirring table of the magnetic stirrer, a rotor is provided in the cathode chamber, the gas chromatograph is connected to one end of the outlet pipe, and the electrochemical workstation is respectively connected to the working electrode, the counter electrode and the reference electrode through wires.

[0017] In the technical solution of the utility model, the electrochemical workstation is connected to the working electrode through a first wire, connected to the reference electrode through a second wire, and connected to the counter electrode through a third wire.

[0018] The beneficial effects of the utility model are:

[0019] 1. The carbon dioxide in the cathode chamber is introduced from the lower part of the cathode chamber body through a double pipeline, and a magnetic stirrer is provided to avoid the problem that carbon dioxide cannot be uniformly dissolved in the electrolyte, thereby improving the conversion efficiency of carbon dioxide.

[0020] 2. A liquid extractor is provided on the screw cover on the upper part of the cathode chamber, which can extract liquid within the required time, so as to realize the transfer of liquid reaction electrolyte for mid-product detection without terminating the experiment, thereby improving the accuracy of liquid product detection and the credibility of subsequent experimental data. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the electrolysis work of reducing carbon dioxide reaction of the utility model.

[0022] Figure 2 It is a schematic diagram of the sealing at the connection between the anode and cathode chambers of the utility model.

[0023] In the figure: 1 is a cathode chamber, 1.1 is a working electrode, 1.2 is a reference electrode, 2 is an anode chamber, 2.1 is a counter electrode, 3 is a proton exchange membrane, 4 is a rotor, 5 is a carbon dioxide inlet pipe, 6 is a spiral switch valve, 7 is an outlet pipe, 8 is a liquid phase liquid extractor, 9 is a magnetic stirrer, 10 is a gas chromatograph, 11 is an electrochemical workstation, 12.1 is a first wire, 12.2 is a second wire, 12.3 is a third wire, and 13 is a rubber ring. DETAILED DESCRIPTION

[0024] The instruments and equipment used in the present invention are all commercially available products, among which the gas chromatograph is a GC128 gas chromatograph, the magnetic stirrer is a YT001-B15-3 intelligent constant temperature magnetic stirrer, and the electrochemical workstation is a Shanghai Chenhua CHI400C electrochemical workstation.

[0025] The present invention is further described below in conjunction with the embodiments, but the protection scope of the present invention is not limited thereto:

[0026] like Figure 1 , 2As shown, the utility model provides a novel electrochemical reduction carbon dioxide reaction electrolytic cell, including a cathode chamber 1 and an anode chamber 2; a carbon dioxide inlet pipe 5 is provided at the bottom of the cathode chamber 1, and the top is connected and sealed with a first sealing cover by a threaded connection, and a working electrode 1.1 and a reference electrode 1.2 are provided on the first sealing cover, the working electrode is a carbon paper electrode coated with a CuNi-based alloy catalyst loaded with carbon nanotubes, and the reference electrode is an Ag / AgCl electrode; at the same time, an outlet pipe 7 is provided on the first sealing cover, and one end of the outlet pipe 7 is connected to a gas chromatograph 10 for analyzing the composition and concentration of gas products, and finally calculating the Faraday efficiency. The carbon dioxide inlet pipe 5 is a double-pipe inlet pipe, which is used to pass high-purity carbon dioxide from both sides, and a spiral switch valve 6 is provided at one end of the carbon dioxide inlet pipe 5 connected to the carbon dioxide gas, which can control the size of the gas introduced, so that the carbon dioxide enters the electrolyte as a smaller bubble, adjusts the direction of the gas outlet to be upward, and makes the carbon dioxide dissolve in the aqueous solution in a large amount, absorbs saturation quickly, and has a high reduction product yield. In addition, a liquid phase liquid extractor 8 is also provided on the first sealing cover, and the liquid phase electrolyte can be removed according to the reaction time for liquid phase product analysis without interrupting the reaction. The top of the anode chamber 2 is sealed with the second sealing cover by threaded connection, and a counter electrode 2.1 is provided in the second sealing cover, and the counter electrode 2.1 used is a Pt sheet electrode. A proton exchange membrane 3 is provided at the connection between the positive and negative pole chambers, and rubber rings 13 are provided on both sides of the proton exchange membrane 3 to enhance the sealing performance, and the two pole chambers are clamped with spiral clamps. Both electrolytic cells are made of transparent quartz glass material, and the state of bubbles and electrolyte can be observed, so that abnormal conditions occurring in the air inlet pipe or electrolyte can be handled in time.

[0027] like Figure 1 As shown, the utility model also provides a novel electrochemical reduction of carbon dioxide reaction system, comprising the above-mentioned novel electrochemical reduction of carbon dioxide reaction electrolytic cell, a magnetic stirrer 9, a gas chromatograph 10 and an electrochemical workstation 11; a cathode chamber 1 is placed on the stirring table of the magnetic stirrer 9, and a rotor 4 is provided in the cathode chamber 1 for stirring the electrolyte in the electrolytic cell; the gas chromatograph 10 is connected to one end of the gas outlet pipe 7, and the electrochemical workstation 11 is connected to the working electrode 1.1 through a first wire 12.1, connected to the reference electrode 1.2 through a second wire 12.2, and connected to the counter electrode 2.1 through a third wire 12.2.

[0028] The specific working process and principle of this utility model:

[0029] Place the Nafion117 proton exchange membrane on both sides of the rubber ring and place it at the connection between the anode and cathode chambers and clamp it with a screw clamp; then add KHCO into the cathode chamber and the anode chamber respectively. 3The solution is used as the electrolyte, and a rotor is placed in the cathode chamber and placed on a digital display magnetic stirrer; the working electrode, the reference electrode Ag / AgCl electrode and the outlet pipe are installed on the first sealing cover of the cathode electrolytic cell, the sealing cover is tightened through the thread on the sealing cover, and the counter electrode Pt electrode is installed on the second sealing cover of the anode chamber. The three electrodes are connected to the electrochemical workstation, and the digital display magnetic stirrer is turned on; the double-pipe gas spiral switch valve at the bottom of the cathode chamber is opened, and high-purity carbon dioxide is input from the air inlet pipe. After ventilation to saturation, the corresponding voltage clamps are added to the three electrodes, and the outlet pipe is connected to the gas chromatograph to start the test. During the test, the reaction electrolyte is removed using a liquid phase liquid extractor to analyze and determine the liquid phase product. After the reaction is completed, turn off the electrochemical workstation, stop magnetic stirring and ventilation; then remove the outlet pipe, close the inlet pipe spiral switch, loosen the sealing cover, remove the three electrodes, clean the electrodes, pour out the electrolyte, and take out the rotor; turn the spiral clamp to take out the rubber ring and Nafion117 proton exchange membrane; finally, remove the two electrolytic cells for cleaning.

[0030] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

[0031] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings attached to this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented, so they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical contents disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention.

Claims

1. A novel electrochemical reduction carbon dioxide reaction electrolytic cell, characterized in that: The invention comprises a cathode chamber (1) and an anode chamber (2); the cathode chamber (1) and the anode chamber (2) are fixedly connected via a detachable sealing connector, and a proton exchange membrane (3) is provided at the connection between the cathode chamber (1) and the anode chamber (2); a carbon dioxide inlet pipe (5) is provided at the bottom of the cathode chamber (1), and the top is movably connected to a first sealing cover, a working electrode (1.1) and a reference electrode (1.2) are provided in the first sealing cover, an outlet pipe (7) is provided on one side of the first sealing cover close to the working electrode (1.1), and a liquid phase extractor (8) is provided on one side of the first sealing cover close to the reference electrode (1.2); the top of the anode chamber (2) is movably connected to a second sealing cover, and a counter electrode (2.1) is provided in the second sealing cover.

2. The novel electrochemical carbon dioxide reduction reaction electrolytic cell according to claim 1 is characterized in that: The detachable sealing connector is a spiral clamp.

3. The novel electrochemical carbon dioxide reduction reaction electrolytic cell according to claim 1 is characterized in that: Sealing elements are provided on both sides of the proton exchange membrane (3).

4. The novel electrochemical carbon dioxide reduction reaction electrolytic cell according to claim 3 is characterized in that: The sealing element is a rubber ring.

5. The novel electrochemical carbon dioxide reduction reaction electrolytic cell according to claim 1 is characterized in that: The movable connection between the first sealing cover and the cathode chamber (1) and / or the second sealing cover and the anode chamber (2) is a threaded connection.

6. A novel electrochemical carbon dioxide reduction reaction system, characterized in that: It comprises the novel electrochemical carbon dioxide reduction reaction electrolytic cell as claimed in claim 1, a magnetic stirrer (9), a gas chromatograph (10) and an electrochemical workstation (11); a cathode chamber (1) is placed on the stirring table of the magnetic stirrer (9), a rotor (4) is arranged in the cathode chamber (1), the gas chromatograph (10) is connected to one end of the gas outlet pipe (7), and the electrochemical workstation (11) is respectively connected to the working electrode (1.1), the counter electrode (2.1) and the reference electrode (1.2) through wires.

7. The novel electrochemical carbon dioxide reduction reaction system according to claim 6 is characterized in that: The carbon dioxide intake pipe (5) is a double-pipe intake pipe.

8. The novel electrochemical carbon dioxide reduction reaction system according to claim 6 is characterized in that: The electrochemical workstation is connected to the working electrode (1.1) via a first wire (12.1), connected to the reference electrode (1.2) via a second wire (12.2), and connected to the counter electrode (2.1) via a third wire (12.3).

9. The novel electrochemical carbon dioxide reduction reaction system according to claim 6, characterized in that: A gas flow control valve is provided at one end of the carbon dioxide inlet pipe (5) connected to the carbon dioxide gas.

10. The novel electrochemical carbon dioxide reduction reaction system according to claim 9, characterized in that: The gas flow control valve is a spiral switch valve (6).

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