CN116200765A - A Novel Electrode Rod to Promote Efficient Electroreduction of CO2 - Google Patents

Abstract

The invention relates to a novel electrode rod for promoting high-efficiency electroreduction of _CO2 , which belongs to the technical field of _CO2 electrochemistry. The novel electrode rod includes an electrode collector part, a gas diffusion channel part and an electrode rod main body, wherein the electrode collector part includes a signal connector, a built-in conductive wire, a working electrode current collector, and a three-dimensional porous working electrode; the gas diffusion channel part includes a gas Inlet, gas channel; the main body of the electrode rod includes the upper rod body and the working electrode pressure cap, and the rubber gasket is used to seal the working electrode pressure cap and the upper rod body to avoid _CO2 gas leakage. The present invention proposes for the first time the idea of integrating the working electrode, CO ₂ gas path and electrode rod, and adopts a three-dimensional porous material as the working electrode and gas diffusion layer, so that the gas must diffuse from the inside of the three-dimensional porous working electrode to the electrolyte system to form a CO ₂ ‑Electrolyte‑electrode gas-liquid-solid three-phase reaction interface, changes the CO ₂ transmission path, increases the CO ₂ concentration on the electrode surface, significantly enhances the CO ₂ mass transfer efficiency compared with the traditional CO ₂ dissolution and diffusion method, improves the reduction current density, and overcomes the The low solubility of _CO2 in the electrolyte of traditional reactors causes most of the gas to remain unreacted and the conversion efficiency is low. It is a core component design of a reactor with great application potential.

Description

A Novel Electrode Rod to Promote Efficient Electroreduction of CO2

technical field

The invention belongs to the technical field of _CO2 electrochemistry, and specifically relates to a novel electrode rod _for high-efficiency electric reduction that integrates electrode collectors, _CO2 gas paths and electrode rods. Internal diffusion into the electrolyte system, constructing a new gas-liquid-solid (CO ₂ -electrolyte-electrode) three-phase reaction interface, strengthening the CO ₂ concentration on the electrode surface, and significantly enhancing the CO ₂ concentration compared with the traditional CO ₂ dissolution and diffusion method. Mass transfer efficiency, improve the current density of the CO ₂ electroreduction process system. In addition, since all _CO2 gas needs to _diffuse into the electrolyte through the three-dimensional porous working electrode, the single-pass conversion rate of _CO2 electroreduction is greatly improved, and the low solubility of _CO2 in the electrolyte in the traditional reactor is overcome. Problems such as not participating in the reaction and low conversion efficiency.

Background technique

Since the industrial revolution, human beings have over-reliance on fossil energy, resulting in a large amount of _CO2 emissions into the atmosphere. In December 2021, the concentration of _CO2 in the atmosphere exceeded 415ppm for the first time, far exceeding the atmospheric _CO2 concentration of 280ppm in the pre-industrial revolution. The change of CO ₂ concentration has caused the global temperature to rise close to 2°C, posing a serious threat to human life. However, _CO2 is also an important and inexpensive C1 resource, which can be further converted by chemical reduction methods to obtain important chemicals such as CO, acids, alcohols, and alkenes. Due to the relatively mild reaction conditions of the electrochemical reduction method, and with the continuous expansion of the scale of renewable electric energy, this method provides a sustainable development path for low-cost, large-scale, and economical activation and conversion of CO ₂ , and also makes CO ₂ electrochemical Research on reduction transformation has become a global hotspot.

At present, the research on _CO2 electroreduction mainly focuses on the laboratory scale, and H-type electrolytic cells are often used for research. This type of electrolytic cell divides the electrolytic cell into a cathode chamber and an anode chamber through an ion exchange membrane. During the _CO2 electroreduction process, the gas enters the catholyte through bubbling, and then diffuses to the electrode surface to participate in the reaction. This _CO2 dissolution and diffusion process The mass transfer mode is limited by conditions such as solubility, resulting in a low current density in the reaction system. For example, the Chinese invention patent CN110273164A reported the research on the electroreduction of CO ₂ in an H-type electrolytic cell to produce oxalate. Due to the structure of the electrolytic cell and the low mass transfer efficiency of CO ₂ , the current density of the reaction system was lower than 10 mA cm ^-2 ; Chinese invention patent CN113430567A reported a preparation method of carbon nanotube-supported gold nanocluster catalyst and performed performance tests in an H-type electrolytic cell. Due to the low solubility _{of CO2} in aqueous solution and the limitation of mass transfer, the best at 95% The current density is only 2mA cm ^-2 under the condition of CO Faradaic efficiency. In addition to the low current density, most of the CO ₂ gas bubbled into the cathode chamber was directly discharged due to the failure of mass transfer to the vicinity of the electrode to participate in the electroreduction reaction, resulting in a one-way conversion rate of CO ₂ below 20%. In summary, the poor _CO2 mass transfer efficiency in H-type electrolyzers leads to low reaction current density and _CO2 single-pass conversion, which severely limits its large-scale application.

To solve the _CO2 mass transfer problem in H-type electrolytic cells, gas diffusion electrodes (gas diffusion electrodes, GDEs) were developed and used to enhance the _CO2 mass transfer and increase the _CO2 concentration on the electrode surface. GDE uses carbon paper as the substrate, and the catalyst is sprayed on the carbon paper as the working electrode. The side where the catalyst is sprayed contacts the catholyte, and the other side faces the _CO2 gas chamber. _CO2 in the gas chamber diffuses through the gas diffusion layer of the carbon paper to the The catalyst undergoes an electroreduction reaction with the surface of the electrolyte. The design of GDE significantly improved the _CO2 mass transfer efficiency, and the current density of the reaction system was significantly improved. As in the literature Green Chem. (2021, 23, 5461-5466), the catalyst was sprayed on carbon paper, and GDE was used for _CO2 electroreduction, and a 98.7% CO product Faradaic efficiency was achieved at a current density of 234.3mA cm ^-2 . Although this type of electrode solves the _CO2 mass transfer problem in the traditional H-type electrolytic cell to a certain extent, it cannot ensure that all _CO2 gas diffuses to the surface of the catalyst and electrolyte to participate in the reaction due to the pressure drop change between the gas inlet and outlet in the gas chamber. , where most of the CO ₂ did not participate in the reaction, resulting in a single-pass conversion rate of only 20 to 30%. In addition, due to the pressure difference between the gas chamber on both sides of the GDE and the catholyte layer, the GDE will soon be "flooded" by the catholyte under high current density, which prevents the diffusion of _CO2 gas and causes a decrease in electroreduction performance and poor stability. , which is also unfavorable for the large-scale application of _CO2 electroreduction. Therefore, how to solve the problems of _CO2 mass transfer, single-pass conversion rate and working electrode stability in the reactor is the key to promote the large-scale application of this technology.

Contents of the invention

Aiming at the problems existing in the above _CO2 electroreduction technology, the present invention proposes a new type of electrode rod to promote efficient _CO2 electroreduction, which integrates the working electrode, _CO2 gas path and electrode rod part of the traditional reactor One, and use three-dimensional porous material as the working electrode and gas diffusion layer, so that _CO2 gas diffuses from the inside of the three-dimensional porous working electrode to the electrolyte system, and due to the pressure of _CO2 gas above the three-dimensional porous working electrode, there is no electrolyte "flooding""The working electrode causes the problem of decreased stability, and at the same time has the advantages of high _CO2 mass transfer efficiency and a significant increase in single-pass conversion rate.

Realize the concrete technical scheme of the present invention as follows:

A novel electrode rod for promoting high-efficiency electroreduction of _CO2 , including an electrode current collector part, a gas diffusion channel part, and an electrode rod main body. In a typical flow-type or batch-type _CO2 electroreduction reactor, the lower end of the electrode rod is placed in the catholyte, and the signal connector, built-in conductive wire, working electrode current collector, and three-dimensional porous working electrode form the current collector. The connector is connected to an external workstation to supply electrons for CO ₂ electroreduction; the gas diffusion channel part includes a gas interface and a gas channel, and the gas entry is controlled by an external CO ₂ gas mass flow meter, and the CO ₂ gas is connected to the three-dimensional porous working electrode at the outlet through the gas channel. CO ₂ diffuses through the electrode and contacts with the electrolyte, which promotes the formation of a three-phase reaction interface of CO ₂ - electrolyte - electrode, and is reduced to high value-added chemicals by further obtaining electrons.

Optionally, the electrode rod body includes an upper rod body and a working electrode pressure cap, and a rubber gasket is used to seal between the working electrode pressure cap and the upper rod body to prevent _CO2 gas from leaking out, so that _CO2 diffuses to the electrolytic electrode through the three-dimensional porous working electrode. solution to participate in the electroreduction reaction.

Optionally, when the main body of the electrode rod is installed, the working electrode pressure cap and the upper rod body are pressed together, and the three-dimensional porous working electrode is fixed at the outlet of the gas channel, and at the same time contacts with the working electrode current collector to form a passage. By adjusting the size of the pressing pressure, the thickness of the diffusion layer of the three-dimensional porous working electrode can be set within a range of 0.1-5 mm and any thickness of the electrode rod can be enlarged in the same proportion.

Optionally, in the typical flow type or batch type _CO2 electroreduction reactor, the ion exchange membrane divides the reactor into two chambers, the anode and the cathode, the anode uses a proton donor solution as the electrolyte, and the oxygen evolution electrode as the counter electrode, The cathode uses a metal salt solution as the electrolyte, the reference electrode is optional, and the new electrode rod is placed in the catholyte as the working electrode. CO ₂ passes through the new electrode rod and diffuses to the interface between the three-dimensional porous working electrode and the electrolyte for reduction. reaction.

Optionally, the lower end of the electrode rod is placed in the catholyte, so that during the _CO2 electroreduction process, the workstation—signal joint—built-in conductive wire—working electrode current collector—three-dimensional porous working electrode—catholyte—anolyte—pair Electrode-workstation forms a closed loop.

Optionally, one end of the signal connector is connected to an external workstation, and the other end is connected to a built-in conductive wire inside the rod body.

Optionally, one end of the built-in conductive wire is connected to the signal connector, and the other end is connected to the current collector of the working electrode.

Optionally, the shape of the working electrode current collector is circular, with a width of 0.1-10 mm and any size enlarged in the same proportion as the electrode rod. One side of the circular ring is connected to the built-in conductive wire and fixed at the outlet of the gas channel, and its inner diameter is the same as The diameter of the gas channel is the same, and the other side touches the fixed three-dimensional porous working electrode.

Optionally, the three-dimensional porous working electrode has a cylindrical shape, a diameter φ of 5 to 25 mm and any size of the electrode rod enlarged in the same proportion, and a thickness setting range of 0.1 to 5 mm and any size of the electrode rod enlarged in the same proportion. The electrode pressure cap is fixed at the outlet of the gas channel, and placed in the catholyte with the lower end of the new electrode rod. The upper surface of the three-dimensional porous working electrode is in contact with the current collector of the working electrode, and the other parts are in contact with the catholyte. _CO2 diffuses inside the three-dimensional porous working electrode for electroreduction reaction.

Optionally, the three-dimensional porous working electrode can be detachably replaced according to different product requirements, such as Ag foam, Pb@3D porous titanium fiber or Cu foam, etc. The _CO2 electroreduction process is:

Optionally, one end of the gas channel is connected to a gas interface, and the other end is connected to a three-dimensional porous working electrode.

Optionally, the high value-added chemicals such as CO, formate, oxalate, alcohols and olefin compounds, etc.

The beneficial effects of the present invention are:

(1) The present invention proposes for the first time the idea of integrating the working electrode, the _CO2 gas pipeline and the electrode rod in the traditional reactor, and uses a three-dimensional porous material as the working electrode and the gas diffusion layer, so that the _CO2 gas flows from the three-dimensional The internal diffusion of the porous working electrode into the electrolyte system promotes the construction of a gas-liquid-solid (CO ₂ -electrolyte-electrode) three-phase reaction interface, and strengthens the CO ₂ concentration on the surface of the working electrode. Compared with the traditional CO ₂ bubbling dissolution and diffusion method, Significantly enhanced the CO ₂ mass transfer efficiency and increased the current density of the CO ₂ electroreduction system.

(2) The present invention makes the _CO2 gas need to be diffused into the electrolyte through the three-dimensional porous working electrode in the new electrode rod to react, which overcomes the _CO2 solubility in the electrolyte of the traditional reactor and causes most of the _CO2 gas not to participate in the reaction, The problem of low conversion efficiency can significantly improve the single-pass conversion rate of the _CO2 electroreduction process.

(3) The present invention uses a three-dimensional porous structure material as the working electrode and acts as a gas diffusion layer at the same time, which has the characteristics of low cost, and at the same time, due to the gas pressure of CO in the gas channel connected above the three _- dimensional porous working electrode, there is no traditional gas diffusion Electrolyte "flooding" in the electrode causes the decrease of electroreduction performance, and it has excellent stability under high current density conditions, showing great industrial application prospects.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic diagram of the internal structure of the present invention;

Fig. 2 is a schematic diagram of a top view of the present invention;

Fig. 3 is a schematic view of the bottom view of the present invention;

Fig. 4 is the overall appearance schematic diagram of the present invention;

Fig. 5 is the structural representation that the present invention is applied in reactor;

Figure 6 is a schematic structural view of a conventional reactor as a comparative example.

Detailed ways

The technical solutions of the present invention will be described in more detail below through specific examples, but the present invention is not limited to the following examples, and within the range described before and after, changes are included in the technical scope of the present invention.

Wherein, the accompanying drawings are for illustrative purposes only, and represent only schematic diagrams, rather than physical drawings, and should not be construed as limiting the present invention; in order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, Enlargement or reduction does not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings.

Please refer to Figure 1-Figure 5, the component numbers in the drawings are respectively indicated as: signal connector 1, built-in conductive wire 2, working electrode current collector 3, three-dimensional porous working electrode 4, gas interface 5, gas channel 6, upper rod body 7. Working electrode pressure cap 8, rubber gasket 9.

The present invention relates to a novel electrode rod for promoting high-efficiency electric reduction of _CO2 , comprising an electrode current collector part (1-4), a gas diffusion channel part (5-6) and an electrode rod main body (7-8). In a typical flow-type or batch-type _CO2 electroreduction reactor, the lower end of the electrode rod is placed in the catholyte, and the signal connector 1, the built-in conductive wire 2, the working electrode current collector 3, and the three-dimensional porous working electrode 4 form the current collector In the part, the Chenhua CHI660e electrochemical workstation is connected externally through the signal connector 1 to supply electrons for CO ₂ electroreduction; the gas diffusion channel part includes the gas interface 5 and the gas channel 6, and the gas entry is controlled by an external CO ₂ gas mass flow meter, and the CO ₂ gas passes through The gas channel is connected to the three-dimensional porous working electrode 4 at the outlet. CO ₂ diffuses through the electrode and contacts with the electrolyte, which promotes the construction of a CO ₂ -electrolyte-electrode gas-liquid-solid three-phase reaction interface, and is reduced to high Value-added chemicals.

In this embodiment, preferably, the electrode rod body includes an upper rod body 7 and a working electrode pressure cap 8, the material of which is polytetrafluoroethylene (PTFE), and the working electrode pressure cap and the upper rod body are sealed by a rubber gasket. Avoid CO ₂ gas leakage, so that CO ₂ diffuses into the electrolyte through the three-dimensional porous working electrode 4 to participate in the electroreduction reaction.

In this embodiment, preferably, when the main body of the electrode rod is installed, the working electrode pressure cap 8 and the upper rod body 7 are pressed together by pressure, and the three-dimensional porous working electrode 4 is fixed at the outlet of the gas channel 6, and at the same time it is connected with the working electrode. The electrode current collecting pieces 3 are in contact to form a via. The thickness of the diffusion layer of the three-dimensional porous working electrode 4 used is 1 mm.

In this embodiment, preferably, the material of the signal connector 1 is pure copper, the size of which is a copper signal connector with a diameter of 2 mm, one end of which is externally connected to the electrode clip of Chenhua CHI660e electrochemical workstation, and the other end is connected to the inside of the rod body 7 Built-in conductive wire 2.

In this embodiment, preferably, the built-in conductive wire 2 is made of pure silver and has a diameter φ of 1 mm built-in conductive silver wire, one end of which is connected to the copper signal connector 1 and the other end is connected to the working electrode current collector 3 .

In this embodiment, preferably, the material of the working electrode current collector 3 is pure silver, which is circular in shape and has a width of 2mm. One side of the circular ring is connected to the built-in conductive silver wire 2 and fixed at the outlet of the gas channel 6. Its inner diameter is the same as that of the gas channel 6 , and the other side contacts the fixed three-dimensional porous working electrode 4 .

In this example, preferably, the H-type CO ₂ electroreduction batch reactor is used, and the Nafion 117 proton exchange membrane divides the reactor into two chambers, the anode and the cathode. The anode uses 0.1M H ₂ SO ₄ as the electrolyte, and IrO ₂ @ Ti mesh is used as the counter electrode, the cathode uses 0.5M KHCO ₃ aqueous solution as the electrolyte, Ag/AgCl is used as the reference electrode, the new electrode rod is immersed in the 0.5M KHCO ₃ aqueous electrolyte as the working electrode, and CO ₂ passes through the gas interface 5 The gas enters the gas channel 6 and diffuses to the interface between the three-dimensional porous working electrode 4 and the electrolyte to undergo a reduction reaction.

In this embodiment, preferably, the lower end of the electrode rod is immersed in the 0.5M KHCO ₃ aqueous electrolyte, so that Chenhua CHI660e electrochemical workstation—copper signal connector 1—built-in conductive silver wire 2—works during the CO ₂ electroreduction process Electrode current collector 3—three-dimensional porous working electrode 4—0.5M KHCO ₃ catholyte—0.1MH ₂ SO ₄ anolyte—IrO ₂ @Ti mesh counter electrode—Chenhua CHI660e electrochemical workstation to form a closed loop.

In this embodiment, preferably, the three-dimensional porous working electrode 4 is cylindrical in shape, with a diameter φ of 15 mm and a thickness setting range of 1 mm. The lower end of the rod is placed in the catholyte, the upper surface of the three-dimensional porous working electrode 4 is in contact with the working electrode current collector 3, and the other parts are in contact with the catholyte. The effective geometric active area exposed in the electrolyte is 1 cm ² , and the diameter φ is 11.3 mm, the CO ₂ introduced into the gas channel 6 diffuses inside the three-dimensional porous working electrode 4 to carry out the electroreduction reaction.

In this embodiment, preferably, the three-dimensional porous working electrode 4 is made of a three-dimensional metal foam material or a catalyst material plated on a three-dimensional porous material substrate, and the three-dimensional porous working electrode 4 is detachable and replaceable according to different product requirements. Foamed Ag, Pb@three-dimensional porous titanium fibers or foamed Cu are used as the three-dimensional porous working electrode 4, and are described in detail in Examples 1-3.

In this embodiment, preferably, one end of the gas channel 6 is connected to the gas interface 5, and the other end is connected to the three-dimensional porous working electrode 4, and its inner diameter adopts a variable diameter channel from 6mm to 11.3mm, which is used to adjust the three-dimensional The gas velocity at the outlet of the porous working electrode 4 .

In this embodiment, preferably, the CO ₂ gas mass flow meter is controlled to be 30 mL min ^-1 .

In this embodiment, preferably, the high value-added chemicals such as CO, formate and C2 olefin products are described in detail in Examples 1-3.

Comparative example: replace the novel electrode rod (accompanying drawing 5) in the embodiment with the traditional two-dimensional sheet electrode as working electrode and single-pass bubbling CO _gas pipeline (accompanying drawing 6), other experiments and operations The conditions are exactly the same as in the examples. Under the same experimental operating conditions, while obtaining the Faraday efficiency of the same product, adopting the electrode rod of the present invention can obtain higher current density and CO single _- pass conversion rate, and has better electroreduction stability, illustrating the present invention The designed new electrode rod can effectively enhance the mass transfer of CO ₂ , enhance the concentration of CO ₂ indicated by the electrode, and improve the advantages of the single-pass conversion rate of CO ₂ .

Example 1

In the H-type _CO2 electroreduction batch reactor, the Nafion117 proton exchange membrane was used to divide the reactor into _an anode chamber and a cathode chamber, and the anode used 0.1M _H2SO4 aqueous solution as the electrolyte, and _IrO2 @Ti mesh was used as the counter electrode , the cathode uses 0.5M KHCO ₃ aqueous solution as the electrolyte, _and the working electrode and the CO ₂ gas path are integrated with the new electrode rod designed by the present invention. The 1mm foam Ag is used as a three-dimensional porous working electrode and installed at 4 positions of the new electrode rod. The exposed active geometric area is 1cm ² . Under the condition of ~-2.5V potential, the electrochemical performance of CO ₂ electroreduction to CO products was tested. The gas products were detected online by gas chromatography, and the liquid products were analyzed by NMR calibration.

Example 2

In the H-type _CO2 electroreduction batch reactor, the Nafion117 proton exchange membrane was used to divide the reactor into _an anode chamber and a cathode chamber, and the anode used 0.1M _H2SO4 aqueous solution as the electrolyte, and _IrO2 @Ti mesh was used as the counter electrode , the cathode uses 0.5M KHCO ₃ aqueous solution as the electrolyte, _and the working electrode and the CO ₂ gas path are integrated with the new electrode rod designed by the present invention. The 1mm Pb@3D porous titanium fiber is used as the 3D porous working electrode and installed at 4 positions of the new electrode rod, the exposed active geometric area is 1cm ² , the system uses Ag/AgCl as the reference electrode, and Chenhua CHI660e electrochemical The electrochemical performance of the formate product produced by CO ₂ electroreduction was tested at the workstation under the potential condition of -1.5～-2.5V. The gas product was detected online by gas chromatography, and the liquid product was analyzed by NMR calibration.

Example 3

In the H-type _CO2 electroreduction batch reactor, the Nafion117 proton exchange membrane was used to divide the reactor into _an anode chamber and a cathode chamber, and the anode used 0.1M _H2SO4 aqueous solution as the electrolyte, and _IrO2 @Ti mesh was used as the counter electrode , the cathode uses 0.5M KHCO ₃ aqueous solution as the electrolyte, _and the working electrode and the CO ₂ gas path are integrated with the new electrode rod designed by the present invention. 1mm foamed Cu is used as a three-dimensional porous working electrode and installed at 4 positions of the new electrode rod. The exposed active geometric area is 1cm ² . Under the condition of ~-2.5V potential, the electrochemical performance of CO ₂ electroreduction to C2 olefin products was tested. The gas products were detected online by gas chromatography, and the liquid products were analyzed by NMR calibration.

Claims (12)

1. A novel electrode rod for promoting _CO2 high-efficiency electric reduction, characterized in that: the novel electrode rod includes an electrode current collector part, a gas diffusion channel part and an electrode rod main body. In a typical flow-type or batch-type _CO2 electroreduction reactor, the lower end of the electrode rod is placed in the electrolyte, and the signal connector, built-in conductive wire, working electrode current collector, and three-dimensional porous working electrode form the current collector part of the new electrode rod , _connected to an external workstation through a signal connector; _{the gas diffusion channel part includes a gas interface and a gas channel, and the gas entering is controlled through an external CO 2 gas} mass flow meter. Internal diffusion and contact with the electrolyte promotes the formation of a CO ₂ -electrolyte-electrode three-phase reaction interface, which is reduced to high value-added chemicals by further obtaining electrons. 2. The novel electrode rod as claimed in claim 1, characterized in that: the electrode rod main body includes an upper rod body and a working electrode pressure cap, and the working electrode pressure cap and the upper rod body are sealed by a rubber gasket to avoid _CO2 gas Leakage, so that CO ₂ diffuses through the three-dimensional porous working electrode to the electrolyte to participate in the electroreduction reaction. 3. The new electrode rod as claimed in claim 1, characterized in that: when the main body of the electrode rod is installed, the working electrode pressure cap and the upper rod body are pressed together by pressure, and the three-dimensional porous working electrode is fixed at the outlet of the gas channel At the same time, it is in contact with the current collector of the working electrode to form a path. By adjusting the size of the pressing pressure, the thickness of the diffusion layer of the three-dimensional porous working electrode can be set within a range of 0.1-5 mm and any thickness of the electrode rod can be enlarged in the same proportion. 4. The novel electrode rod as claimed in claim 1, characterized in that: in the typical flow type or intermittent _CO2 electroreduction reactor, the ion exchange membrane divides the reactor into two chambers, the anode and the cathode, and the anode adopts a mass The sub-donor solution is used as the electrolyte, the oxygen-evolving electrode is used as the counter electrode, the cathode uses a metal salt solution as the electrolyte, the reference electrode is optional, the new electrode rod is placed in the catholyte as the working electrode, and _CO2 is passed through the new electrode rod And diffuse to the interface between the three-dimensional porous working electrode and the electrolyte to undergo a reduction reaction. 5. The novel electrode rod as claimed in claim 1, characterized in that: the lower end of the electrode rod is placed in the catholyte, so that during the _CO2 electric reduction process the workstation—signal joint—built-in conductive wire—working electrode current collector— The three-dimensional porous working electrode-catholyte-anolyte-counter electrode-workstation forms a closed loop. 6. The new electrode rod as claimed in claim 1, characterized in that: one end of the signal connector is connected to an external workstation, and the other end is connected to a built-in conductive wire inside the rod body. 7. The novel electrode rod as claimed in claim 1, characterized in that one end of the built-in conductive wire is connected to the signal connector, and the other end is connected to the current collector of the working electrode. 8. The new electrode rod as claimed in claim 1, characterized in that: the shape of the working electrode current collector is circular, with a width of 0.1-10mm and any size enlarged in the same proportion as the electrode rod, and one side of the circular ring is connected The built-in conductive wire is fixed at the outlet of the gas channel, and its inner diameter is the same as that of the gas channel, and the other side contacts the fixed three-dimensional porous working electrode. 9. The new electrode rod as claimed in claim 1, characterized in that: the three-dimensional porous working electrode is cylindrical in shape, the diameter φ is 5-25 mm and any size enlarged in the same proportion as the electrode rod, and the thickness setting range is 0.1 ~5mm and any size enlarged in the same proportion as the electrode rod, is fixed at the outlet of the gas channel by the working electrode pressure cap, and placed in the catholyte with the lower end of the new electrode rod, the upper surface of the three-dimensional porous working electrode and the working electrode current collector The other parts are in contact with the catholyte, and the CO ₂ introduced into the gas channel diffuses inside the three-dimensional porous working electrode to carry out the electroreduction reaction. 10. The new electrode rod as claimed in claim 1, characterized in that: the three-dimensional porous working electrode can be detachably replaced according to different product requirements, such as foam Ag, Pb@ three-dimensional porous titanium fiber or foam Cu et al., the _CO2 electroreduction process is:

11. The novel electrode rod as claimed in claim 1, characterized in that: one end of the gas channel is connected to the gas interface, and the other end is connected to the three-dimensional porous working electrode. 12. The new electrode rod as claimed in claim 1, characterized in that: the high value-added chemicals such as CO, formate, oxalate, alcohols and olefin compounds, etc.

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