System and method for synthesizing acetic acid by directionally converting carbon monoxide through photoelectrocatalysis and application

Abstract

The invention relates to a system and a method for synthesizing acetic acid by directionally converting carbon monoxide through photoelectrocatalysis and application of the system, the system is a photo-assisted electrocatalysis reaction system and comprises a cathode and anode reaction tank and a photo-assisted component, and a cathode catalyst adopted by the cathode and anode reaction tank is a copper-based catalyst directly loaded on the surface of carbon paper; the photo-assisted assembly comprises a light source and a quartz glass plate, visible light is used as an excitation light source, the cathode catalyst layer is directly irradiated through the quartz glass plate, the evolution path of a surface reaction intermediate is changed, and carbon monoxide is promoted to be directionally converted into acetic acid. Compared with the prior art, the maximum current density exceeds 900 mA / cm < 2 >, excellent acetic acid selectivity and production efficiency are still kept after continuous operation for 270 hours or above, and the reaction system is more efficient and stable.

Description

Technical Field

[0001] This invention belongs to the field of carbon-1 substrate conversion for acid preparation, and in particular relates to a system, method and application of photoelectrocatalytic directed conversion of carbon monoxide to acetic acid. Background Technology

[0002] Acetic acid is a major chemical with an annual production exceeding 18 million tons and a market value exceeding US$10 billion annually. Current acetic acid production processes typically employ chemical synthesis or starch fermentation, requiring multiple steps. One step involves the thermocatalytic conversion of syngas into methanol at 50-100 bar and 500°C. Methanol then undergoes methyl carbonylation with CO to form acetic acid. This process, derived from fossil fuels, generates 1.6 tons of carbon dioxide for every ton of acetic acid produced. Directly synthesizing acetic acid from carbon dioxide (carbon monoxide) using renewable electricity and water is a way to reduce carbon emissions from the chemical industry.

[0003] Electrochemical systems powered by renewable electricity have enabled the synthesis of acetic acid using CO2 or CO and water as reagents. However, currently reported highly selective electrocatalytic reductions of carbon monoxide to acetic acid have current densities below 500 mA / cm². 2 However, performance barriers still exist before widespread industrial application. This is because as the current density increases, the effect of improving the active site for specific intermediates becomes minimal, leading to a decrease in product selectivity at high current densities.

[0004] Patent CN202111188530.X discloses an electrocatalyst for the electrocatalytic reduction of carbon monoxide to acetic acid and its application. First, a copper-palladium alloy nanoparticle electrocatalyst for the electrocatalytic reduction of carbon monoxide to acetic acid is prepared. Then, this electrocatalyst is used as the cathode of the catalytic reaction, employing potassium hydroxide electrolyte, to electrocatalyze the reduction of carbon monoxide and selectively generate acetic acid. The partial current density for the electroreduction of carbon monoxide to acetic acid using this catalyst can reach 425 mA / cm². 2 The catalyst achieves a Faraday efficiency of 70% and can operate stably and continuously for 500 hours in a membrane electrode assembly with a total current of 2.5 A while maintaining a high Faraday efficiency for acetic acid. However, this technology, which modulates the adsorption energy of intermediates by modifying the catalyst, can improve the selectivity of acetic acid to some extent, but is limited by the Sabatier principle, making further efficiency breakthroughs difficult. This method of controlling the active sites of the catalyst targeting preferred intermediates is random and has limited effect, resulting in a low actual bias current density for acetic acid production and a Faraday efficiency below 80%. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology by providing a system, method, and application for the photoelectrocatalytic directed conversion of carbon monoxide to acetic acid. By utilizing an extended photoexcited plasmon resonance process to regulate the catalytic interface, a dual breakthrough in current density and selectivity is achieved. The maximum current density of this system exceeds 900 mA / cm². 2 It maintains excellent acetic acid selectivity and production efficiency even after running continuously for more than 270 hours, making it a more efficient and stable reaction system compared to currently reported electrocatalytic technologies.

[0006] The objective of this invention can be achieved through the following technical solution: a system for the photoelectrocatalytic directional conversion of carbon monoxide into acetic acid. This system is a photo-assisted electrocatalytic reaction system, comprising an anode and cathode reaction cell and a photo-assisted component. The cathode catalyst used in the anode and cathode reaction cell is a copper-based catalyst directly loaded on the surface of carbon paper. Carbon monoxide reaction gas is introduced through the back of the carbon paper. The photo-assisted component includes a light source and a quartz glass plate. Visible light is used as the excitation light source, directly irradiating the cathode catalyst layer through the quartz glass plate, thereby changing the evolution path of the surface reaction intermediates and promoting the directional conversion of carbon monoxide into acetic acid.

[0007] Furthermore, the electrolyte is a 0.1–5 M KOH solution.

[0008] Furthermore, the light-assisted component uses a single-wavelength LED light source with an adjustable light power density range of 0.5–3.5 W / cm². 2 The wavelength is 532nm.

[0009] Furthermore, the reaction pressure is 0.5-5 bar.

[0010] Furthermore, the copper-based catalyst is prepared by the following method: copper acetate is dissolved in deionized water, NaOH is added, and the mixture is subjected to hydrothermal reaction at 100-300℃ for 2-5 hours. After cooling to room temperature, the mixture is removed and vacuum dried to obtain copper oxide nanoparticles.

[0011] Furthermore, the copper-based catalyst is directly loaded onto the carbon paper surface by mixing copper oxide nanoparticles in a Nafion solution, dispersing them evenly, and then drop-coating them onto the carbon paper surface. The loading amount of copper oxide nanoparticles is 6-12 mg / cm³. 2 .

[0012] Furthermore, the anode and cathode reaction tank is provided with an ion exchange membrane, an anode catalyst, and a cathode catalyst, wherein the anode catalyst is placed on the side of the ion exchange membrane and perpendicular to the cathode catalyst; or the anode catalyst and the cathode catalyst are arranged on both sides of the ion exchange membrane.

[0013] This invention also provides a method for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid using the aforementioned system, characterized by comprising the following steps:

[0014] Electrolyte enters between the cathode catalyst and the quartz glass plate. Carbon monoxide is introduced through the back of the cathode catalyst. The flow rate of electrolyte is controlled at 1-15 mL / min, and the flow rate of carbon monoxide gas is controlled at 2-50 mL / min. Visible light is added for irradiation during the electrocatalytic reaction to promote the directional conversion of carbon monoxide into acetic acid.

[0015] Furthermore, the photoelectrocatalytic reaction conditions include: a current density of 50–1000 mA / cm². 2 The reaction area is 0.2–1 cm². 2 The lighting conditions include: adjustable light power density ranging from 0.5 to 3.5 W / cm². 2 The wavelength is 532nm.

[0016] The present invention also provides an application of the system described herein, in which the system is used to convert carbon monoxide into acetic acid.

[0017] Compared with the prior art, the present invention has the following superior effects:

[0018] (1) This invention utilizes an extended photo-excited plasmon resonance process to regulate the catalytic interface. A copper-based catalyst is employed in conjunction with a photo-assisted electrocatalytic reaction system. The cathode reaction cell is based on a gas diffusion electrode system, and the copper-based catalyst is directly loaded onto the surface of carbon paper. Carbon monoxide reaction gas is introduced through the back of the carbon paper. Visible light is used as the excitation source, directly irradiating the catalyst layer through quartz glass to alter the evolution path of surface reaction intermediates, promoting the directional conversion of carbon monoxide to acetic acid. By regulating the local interface through the photo-excited reaction process, a novel photo-assisted electrocatalytic reaction system is developed. The hot electron-hole pairs generated by the plasmon resonance effect are utilized to alter the formation path of reaction intermediates, thereby achieving the directional reduction of carbon monoxide to acetic acid.

[0019] The maximum current density of this system exceeds 900 mA / cm². 2 (Currently reported technologies are all below 500 mA / cm) 2 It maintains excellent acetic acid selectivity and production efficiency even after running continuously for more than 270 hours, making it a more efficient and stable reaction system compared to currently reported electrocatalytic technologies.

[0020] (2) Based on pure copper catalyst, this invention does not pre-modify the active sites, but uses the photo-excited plasmon resonance effect of copper-based materials to generate hot electrons and holes to change the evolution path of reaction intermediates. This technology can avoid the performance degradation caused by catalyst reconstruction during the reaction process, thereby realizing the preparation of acetic acid with industrial-grade current density.

[0021] (3) The technical solution of the present invention utilizes a photo-assisted electrocatalytic carbon monoxide electrolyzer to produce acetic acid with high selectivity. This technical solution successfully realizes the value-added conversion from carbon monoxide to acetic acid, and at the same time achieves high stability in a novel photoelectric membrane electrode system.

[0022] This invention presents a photo-assisted electrocatalytic system based on a membrane electrode reactor, employing visible light to excite copper-based catalytic materials to achieve the directional production of acetic acid from carbon monoxide. By efficiently utilizing visible light energy, the raw material cost is reduced by 30% compared to current pure electric processes. Furthermore, this technology operates under ambient temperature and pressure conditions, reducing energy consumption costs by 50% compared to existing thermal catalytic acetic acid production technologies. Overall, this technology reduces the comprehensive cost of acetic acid production by 40%, with an estimated cost below 3200 yuan per ton. Attached Figure Description

[0023] Figure 1 It is a photo-assisted electrocatalytic flow electrolysis cell reaction system;

[0024] Figure 2 This is a photo-assisted electrocatalytic membrane electrode electrolysis cell reaction system;

[0025] Figure 3 This is a comparison between Example 1 and the prior art technique for the selective electroreduction of carbon monoxide to prepare acetic acid;

[0026] Figure 4 To determine the Faraday efficiency of selective reduction of carbon monoxide to acetic acid at different current densities;

[0027] Figure 5 To assess the stability of selective reduction of carbon dioxide to acetic acid at industrial-grade current densities. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] This invention constructs a photo-assisted electrocatalytic reaction system, including anode and cathode reaction cells, using a 0.1–5 M KOH solution as the electrolyte. The cathode reaction cell is based on a gas diffusion electrode system, with a copper-based catalyst directly supported on the surface of carbon paper, and carbon monoxide reaction gas introduced through the back of the carbon paper. Visible light is used as the excitation source, directly irradiating the catalyst layer through quartz glass to alter the evolution pathway of surface reaction intermediates, promoting the directional conversion of carbon monoxide to acetic acid. The specific steps are as follows:

[0030] (1) Copper oxide nanoparticles were synthesized by a hydrothermal method. Specifically, copper acetate was dissolved in deionized water, and NaOH was added. The mass ratio of copper acetate to NaOH was 1-2:1. The mixture was hydrothermally reacted at 100-300℃ for 2-5 hours. After cooling to room temperature, the mixture was removed and vacuum dried to obtain copper oxide nanoparticles. Commercial carbon paper was used as the supporting electrode. The hydrothermally synthesized copper oxide nanoparticles were mixed with Nafion solution at a mass ratio of 10-20:1. The mixture was then ultrasonically dispersed to ensure uniform dispersion. The nanoparticles were then drop-coated onto the surface of the carbon paper. The catalyst loading was controlled at 6-12 mg / cm³. 2 The carbon paper-supported copper oxide was then calcined in air at a temperature of 100–300 °C for 2–4 hours. The resulting carbon paper-supported copper oxide was used as a cathode catalyst.

[0031] (2) The photo-assisted electrocatalytic flow electrolyzer adopts an opposing anode and cathode design. The anode catalyst and ion exchange membrane are placed sideways and perpendicular to the cathode catalyst. The upper part of the cathode catalyst is sealed with a quartz glass assembly to ensure light transmission and airtightness. Commercially available titanium felt-supported iridium oxide is used as the anode catalyst, and a commercially available anion exchange membrane separates the anode and cathode reaction chambers. The electrolyte for both the cathode and anode is 0.1–5 M KOH, with an electrolyte flow rate of 1–15 mL / min. Carbon monoxide gas is introduced into the cathode gas diffusion layer at a flow rate of 2–50 mL / min, measured using a 0.5–5 bar pressure gauge.

[0032] (3) The photo-assisted electrocatalytic membrane electrode system is an improvement over the traditional membrane electrode system. The anode catalyst is perforated in the middle to ensure visible light transmission. The intermediate ion exchange membrane is a high-transmittance Sustaining anion membrane that separates the anode and cathode catalysts. The cathode catalyst is placed close to the ion exchange membrane. The anode electrolyte is 0.1-5M KOH with an electrolyte flow rate of 1-15mL / min. Carbon monoxide gas is introduced into the cathode gas diffusion layer with a gas flow rate of 2-50mL / min, measured by a 1bar pressure gauge.

[0033] (4) Irradiation with visible light is added during the electrocatalytic reaction, wherein the electrocatalytic conditions include a current density of 50–1000 mA / cm². 2 The reaction area is 0.2–1 cm². 2 The illumination conditions include: an adjustable light power density range of 0.5–3.5 W / cm². 2 The wavelength is 532nm.

[0034] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field. Specific embodiments are described below.

[0035] Example 1

[0036] A system and method for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid, comprising the following steps:

[0037] (1) The specific steps for preparing cathode copper oxide nanoparticles are as follows:

[0038] Weigh 0.9 g of copper acetate and dissolve it in deionized water. Add 6 M NaOH and bring the volume to 6 mL. Transfer the solution to a 50 mL hydrothermal reactor and react it hydrothermally at 200 °C for 3 h. Cool to room temperature and remove the solution. Wash five times with deionized water and vacuum dry at 60 °C to obtain copper oxide nanoparticles.

[0039] (2) The preparation of cathode and anode electrocatalysts, the specific steps are as follows:

[0040] Commercial carbon paper was used as the supporting electrode. The copper oxide nanoparticles synthesized in step (1) were mixed with Nafion solution (the mass ratio of copper oxide nanoparticles to Nafion solution was 10:1). Under ultrasonic conditions, the mixture was dispersed evenly and then drop-coated onto the surface of the carbon paper. The loading of copper oxide nanoparticles was controlled at 10 mg / cm³. 2 The carbon paper-supported copper oxide was then calcined in air at 200°C for 3 hours. The resulting carbon paper-supported copper oxide was used as the cathode catalyst. Commercially available titanium felt-supported iridium oxide was used as the anode catalyst. The catalyst was directly loaded into the anode chamber and led out via a copper conductive tape.

[0041] (3) Construction of a photo-assisted electrocatalytic flow electrolysis cell reaction system

[0042] The specific structure of the photo-assisted electrocatalytic flow electrolyzer is as follows: Figure 1 As shown, the cathode reaction cell 1 includes a first chamber plate 11 and a second chamber plate 12, two gaskets 13 located between the first chamber plate 11 and the second chamber plate 12, and a diffusion layer with cathode catalyst attached sandwiched between the two gaskets 13, namely the cathode catalyst 14 obtained in step (2). The first chamber plate 11 is provided with a cathode electrolyte inlet 15, a cathode electrolyte outlet 16 and a reference electrode 17, and the second chamber plate 12 is provided with a gas inlet 18 and a gas outlet 19;

[0043] The anode reaction tank 2 is located on the side of the cathode reaction tank 1, facing it. It includes an anode plate 20 and an ion exchange membrane 22 (i.e., the commercial anion exchange membrane from step (2)) located between the anode plate 20 and the side of the cathode reaction tank 1. Sealing rings 23 are provided on both sides of the ion exchange membrane 22, wherein the ion exchange membrane 22 is perpendicular to the cathode catalyst 14. The anode plate 20 is provided with an anode electrolyte inlet 24 and an anode electrolyte outlet 25. The anode catalyst 21 (i.e., the commercial titanium felt-supported iridium oxide from step (2)) is placed in the center of the anode plate 20 and located on one side of the ion exchange membrane 22.

[0044] A light-assisted component 3 is provided at the center of the cathode reaction cell 1, including a light source (not shown in the figure), a quartz glass plate 31, a sealing ring 32, and an O-ring 33. The quartz glass plate 31 is fixed at the center of the first chamber plate 11 of the cathode reaction cell 1 by the O-ring 33 and faces the cathode catalyst 14 through the center hole of the pad 13.

[0045] The upper part of the cathode catalyst is sealed with a quartz glass assembly to ensure good light transmittance. An electrolyte layer, using a 1M KOH solution as the electrolyte, is introduced between the cathode catalyst 14 and the quartz glass plate 31. The electrolyte enters from the cathode electrolyte inlet 15 and exits from the cathode electrolyte outlet 16 after use. Carbon monoxide, i.e., CO gas, is introduced through the back of the cathode catalyst 14. It enters from the gas inlet 18 and enters the back of the cathode catalyst 14 along the gas channel located in the second chamber plate 12. The gas after reaction exits from the gas outlet 19. Both the anode and cathode catalysts use conductive copper tape for current collection and electrolysis.

[0046] Similarly, a 1M KOH solution is used as the anolyte, which enters the membrane electrode side from the anolyte inlet 24 and is discharged from the anolyte outlet 25 after the reaction.

[0047] (4) Control the electrolyte flow rate to 10 mL / min, and introduce carbon monoxide gas into the cathode gas diffusion layer at a flow rate of 10 mL / min, measured using a 1 bar pressure gauge. CO enters the back of the catalyst and reacts to produce acetic acid. The specific reaction formula is as follows:

[0048] Cathode reaction: 2CO + 3H₂O + 4e － →CH3COO － +3OH －

[0049] Anode reaction: 2OH - →O2+2H + +4e －

[0050] (5) Using a single-wavelength LED as the light source, visible light was added for irradiation during the electrocatalytic reaction. The photoelectrocatalytic conditions included: constant current testing with a current density of 1000 mA / cm². 2 The reaction area of ​​the cathode catalyst 14 is controlled to be 0.2 cm². 2 The lighting conditions include: a light power density of 3.5 W / cm². 2 The wavelength is 532nm.

[0051] (6) Performance testing

[0052] Figure 3This is a comparison between Example 1 and the prior art technique for the selective electroreduction of carbon monoxide to prepare acetic acid; as can be seen from the figure, this work can achieve a reduction rate of 1000 mA / cm². 2 At the given current density, the selectivity for acetic acid reached as high as 90%, far exceeding the levels reported in other literature.

[0053] Figure 4 The figure shows the Faraday efficiency of selective reduction of carbon dioxide to acetic acid at different current densities. As can be seen from the figure, the selectivity of acetic acid is higher than 65% at all current densities, reaching a maximum of 90%, indicating that this technology is universal under all current conditions.

[0054] Example 2

[0055] (1) Construction, design, and assembly of the photo-assisted electrocatalytic membrane electrode reaction cell:

[0056] Design and assembly of photo-assisted electrocatalytic membrane electrode reaction cell, such as Figure 2 As shown: It includes a first electrode plate 11 and a second electrode plate 12, an ion exchange membrane 41 located between the first electrode plate 11 and the second electrode plate 12, an anode catalyst layer 42 located on one side of the ion exchange membrane 41 and a cathode catalyst layer 43 located on the other side. The anode catalyst layer 42 and the cathode catalyst layer 43 used in this embodiment are the same as those in Example 1.

[0057] The first electrode plate 11 is provided with a cathode electrolyte inlet 15 and a cathode electrolyte outlet 16, and the second electrode plate 12 is provided with a gas inlet 18 and a gas outlet 19.

[0058] The first electrode plate 11 is provided with a light-assisted component 3 at its center, including a light source (not shown in the figure), a quartz glass plate 31, a sealing ring 32, and an O-ring 33. The quartz glass plate 31 is fixed to the center of the first electrode plate 11 of the cathode reaction cell 1 by the O-ring 33 and faces the anode catalyst layer 42 through the central hole of the first electrode plate 11.

[0059] The anode catalyst layer 42 has a hole in the middle to ensure visible light transmission. The ion exchange membrane 41 is a high-transmittance sustainability anion membrane that separates the anode and cathode. The cathode catalyst layer is placed in close contact with the ion exchange membrane. Both the anode and cathode catalysts are electrolyzed through the first and second electrode plates.

[0060] Using the aforementioned reaction apparatus as the experimental platform, the anolyte is 1M KOH. The electrolyte enters from the anolyte inlet 15 between the anolyte catalyst layer 42 and the quartz glass plate 31 at a flow rate of 10 mL / min. After electrolysis, it exits from the anolyte outlet 16. Carbon monoxide (CO) gas is introduced into the back of the cathode catalyst layer 43 through the gas inlet 18 at a flow rate of 10 mL / min. The gas enters along the gas channel located within the second electrode plate 12 and exits from the gas outlet 19. Both the anode and cathode catalysts are current-collecting electrolyzers using conductive copper tape.

[0061] (2) Performance testing

[0062] Figure 5 The stability of the selective reduction of carbon monoxide to acetic acid at industrial-grade current densities was assessed. The figure shows that at 300 mA / cm²... 2 Under the current density, after 270 hours of continuous electrolysis, the Faraday efficiency and total cell pressure of the obtained acetic acid did not change significantly with time, and the average Faraday efficiency of acetic acid was greater than 75%.

[0063] Example 3

[0064] The only difference from Example 1 is that the electrolyte is a 0.1M KOH solution; the electrolyte flow rate is 1 mL / min; and the carbon monoxide gas flow rate is 2 mL / min.

[0065] The photoelectrocatalytic reaction conditions include: a current density of 50 mA / cm². 2 The reaction area is 0.2 cm². 2 The lighting conditions include: adjustable light power density within a range of 0.5 W / cm². 2 The wavelength is 532nm.

[0066] Example 4

[0067] The only difference from Example 1 is that the electrolyte is a 5M KOH solution; the electrolyte flow rate is 15 mL / min; and the carbon monoxide gas flow rate is 50 mL / min.

[0068] The photoelectrocatalytic reaction conditions include: a current density of 1000 mA / cm². 2 Reaction area 1cm 2 The lighting conditions include: adjustable light power density within a range of 3.5 W / cm². 2 The wavelength is 532nm.

[0069] Comparative Example

[0070] The rest is the same as in Embodiment 1, except that no light source is used, that is, no light-assisted component 3 is provided.

[0071] The comparative product was tested using the same method as in Example 1, and the results are as follows:

[0072]

[0073] As can be seen from the table above, compared with the comparative example, using a light source for assistance, at the same current density of 1000 mA / cm², 2 Under these conditions, the battery voltage decreased by 180mV, and the acetic acid Faraday efficiency increased by 36%, demonstrating significant effects.

Claims

1. A system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid, characterized in that, This system is a photo-assisted electrocatalytic reaction system, including anode and cathode reaction cells and a photo-assisted component. The cathode catalyst used in the anode and cathode reaction cells is a copper-based catalyst directly loaded on the surface of carbon paper, and carbon monoxide reaction gas is introduced through the back of the carbon paper. The photo-assisted component includes a light source and a quartz glass plate. Visible light is used as the excitation source, which directly irradiates the cathode catalyst layer through the quartz glass plate, changing the evolution path of surface reaction intermediates and promoting the directional conversion of carbon monoxide into acetic acid.

2. The system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 1, characterized in that, The electrolyte is a 0.1-5M KOH solution.

3. The system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 1, characterized in that, The light-assisted component uses a single-wavelength LED light source with an adjustable light power density range of 0.5–3.5 W / cm². 2 The wavelength is 532nm.

4. The system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 1, characterized in that, The reaction pressure is 0.5-5 bar.

5. The system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 1, characterized in that, The copper-based catalyst was prepared by the following method: copper acetate was dissolved in deionized water, NaOH was added, and the mixture was hydrothermally reacted at 100-300℃ for 2-5 hours. After cooling to room temperature, the mixture was removed and vacuum dried to obtain copper oxide nanoparticles.

6. The system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 1, characterized in that, The copper-based catalyst is directly loaded onto the carbon paper surface by mixing copper oxide nanoparticles in a Nafion solution, dispersing them evenly, and then drop-coating them onto the carbon paper surface. The loading amount of copper oxide nanoparticles is 6-12 mg / cm³. 2 .

7. The system for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 1, characterized in that, The anode and cathode reaction tank is equipped with an ion exchange membrane, an anode catalyst, and a cathode catalyst, wherein the anode catalyst is placed on the side of the ion exchange membrane and perpendicular to the cathode catalyst; or the anode catalyst and the cathode catalyst are arranged on both sides of the ion exchange membrane.

8. A method for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid using the system as described in any one of claims 1-7, characterized in that, Includes the following steps: Electrolyte is fed into the anode and cathode reaction cell, and carbon monoxide is introduced into the back of the cathode catalyst. The electrolyte flow rate is controlled at 1-15 mL / min, and the carbon monoxide gas flow rate is controlled at 2-50 mL / min. Visible light is added to irradiate the electrocatalytic reaction process using a 1 bar pressure gauge to promote the directional conversion of carbon monoxide into acetic acid.

9. The method for the photoelectrocatalytic directional conversion of carbon monoxide to acetic acid according to claim 8, characterized in that, The photoelectrocatalytic reaction conditions include: current density of 50–1000 mA / cm². 2 The reaction area is 0.2–1 cm². 2 The lighting conditions include: adjustable light power density ranging from 0.5 to 3.5 W / cm². 2 The wavelength is 532nm.

10. An application of the system as described in any one of claims 1-7, characterized in that, The system was used to convert carbon monoxide into acetic acid.

Images