Electrochemical reactor and method for co-utilization of sodium chloride and carbon dioxide

Abstract

The application discloses an electrochemical reactor and method for sodium chloride and carbon dioxide cooperative resource utilization, and belongs to the technical field of electrochemistry. The reactor comprises an anode chamber, an intermediate chamber and a cathode chamber. The intermediate chamber is provided with through holes on both sides, and the through holes of the anode chamber and the cathode chamber correspond to the through holes of the intermediate chamber. The three-chamber electrolytic cell is powered under normal temperature, the intermediate chamber is used as an electrolyte circulation area, and sodium chloride aqueous solution is introduced for ion conduction. The anode chamber is provided with a nitrogen gas inlet channel, and nitrogen gas is introduced for separation and recovery of generated chlorine. The cathode chamber is provided with a carbon dioxide inlet channel, and carbon dioxide is introduced to make generated sodium bicarbonate or sodium carbonate precipitate in a solid crystalline form on a hydrophobic layer of a negative electrode, while hydrogen gas escapes. The application constructs a specific structure of an electrolysis system, adopts high-efficiency electrode materials, realizes carbon dioxide conversion and sodium chloride electrolysis reaction under normal temperature and pressure conditions, and co-produces chlorine, hydrogen and sodium carbonate or sodium bicarbonate.

Description

Technical Field

[0001] This application relates to the field of electrochemical technology, specifically to an electrochemical reactor and method for the synergistic resource utilization of sodium chloride and carbon dioxide. Background Technology

[0002] With the continued growth of global industrial activity, carbon dioxide (CO2) emissions are rising steadily, exacerbating the greenhouse effect. On the one hand, while existing carbon capture and storage (CCS) technologies can temporarily alleviate carbon emissions, their high cost and lack of resource recovery limit their widespread commercial application. On the other hand, chlorine and hydrogen, as basic chemical raw materials, are widely used in polyvinyl chloride (PVC), bleaching agents, disinfectants, and ammonia synthesis. Traditional chlorine production methods primarily involve energy-intensive brine electrolysis, while hydrogen is obtained through natural gas reforming or water electrolysis, resulting in high energy consumption and heavy pollution. Meanwhile, sodium carbonate (Na2CO3), a crucial raw material for industries such as glass and detergents, relies on the Solvay process, a mainstream production method, for its production. This process generates numerous byproducts and a heavy environmental burden. Traditional alkali production processes suffer from significant resource utilization efficiency issues, with low raw material utilization rates leading to resource waste.

[0003] Taking the ammonia-soda process and the Hou's process for alkali production as examples, these processes not only require high-purity brine with near-saturation concentration as raw material, but also rely on synthetic ammonia as an auxiliary reactant. The production of synthetic ammonia is itself a high-energy-consuming and high-cost process, with enormous carbon emissions, placing a heavy burden on the environment.

[0004] Therefore, developing a novel electrochemical method that can couple CO2 and NaCl under green and low-carbon conditions to co-produce three high-value-added chemicals is of great practical significance for achieving closed-loop resource utilization. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a resource utilization method based on electrochemical coupling conversion. By constructing an electrolysis system with a specific structure and using high-efficiency electrode materials, carbon dioxide conversion and sodium chloride electrolysis are simultaneously achieved under ambient temperature and pressure conditions, producing chlorine, hydrogen, and sodium carbonate or sodium bicarbonate.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of the present invention discloses an electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide, comprising an anode chamber, an intermediate chamber and a cathode chamber connected in sequence; The intermediate chamber has through holes on both sides. The through hole of the anode chamber corresponds to the through hole on one side of the intermediate chamber, and the hydrophobic layer of the positive electrode is connected to the through hole of the anode chamber. The through hole of the cathode chamber corresponds to the other side of the intermediate chamber, and the hydrophobic layer of the negative electrode is connected to the through hole of the cathode chamber. The area of ​​each through hole is smaller than the area of ​​the positive electrode and the negative electrode. The three-chamber electrolytic cell is powered on at room temperature. The middle chamber serves as the electrolyte circulation zone, through which sodium chloride aqueous solution is introduced for ion conduction. The anode chamber is equipped with a nitrogen inlet channel, through which nitrogen is introduced for the immediate separation and recovery of generated chlorine. The cathode chamber is equipped with a carbon dioxide inlet channel, through which carbon dioxide is introduced to cause the generated sodium bicarbonate or sodium carbonate to precipitate in solid crystal form on the hydrophobic layer of the negative electrode, while hydrogen escapes at the same time.

[0008] Preferably, the nitrogen purging flow rate in the anode chamber is 5-50 mL / min, ensuring that the partial pressure of chlorine is below the explosion limit during the reaction.

[0009] Preferably, the CO2 intake rate of the cathode chamber is 3-30 mL / min, and it is uniformly distributed through either a porous titanium plate or hydrophobic carbon paper on the back side of the cathode; the sodium chloride aqueous solution is a 0.5-3 M NaCl solution.

[0010] Preferably, the method for preparing the electrode includes the following steps: Substrate preparation: Select a substrate material, ultrasonically clean the substrate sequentially with deionized water and anhydrous ethanol, and then dry it in an oven for later use; Catalytic layer coating: The catalyst is coated on the surface of the substrate and dried to form a catalytic layer; Hydrophobic layer treatment: PTFE emulsion is coated onto one side of the catalyst layer, and heat treatment is performed after coating to form a hydrophobic layer; Preparation of cation exchange layer: Nafion ® The solution is coated on the other side of the catalyst layer, and after curing and annealing, a selective ion channel is formed.

[0011] Preferably, the matrix material, serving as a conductive framework, is any one of the matrix materials with a stable water reduction potential.

[0012] Preferably, the catalyst loading is 1.0-2.0 mg / cm².

[0013] Preferably, the PTFE emulsion has a loading of 0.8-1.2 mg / cm² and a hydrophobic layer contact angle ≥150°.

[0014] Preferably, in the preparation of the cation exchange layer, commercially available Nafion membranes can be used instead of Nafion membranes. ® Solution coating is used to tightly adhere the commercial Nafion membrane to the other side of the catalyst layer.

[0015] A second aspect of the present invention discloses an electrochemical method for the synergistic resource utilization of sodium chloride and carbon dioxide, based on the aforementioned electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide, comprising the following steps: Place the assembled three-chamber electrolytic cell at room temperature; NaCl solution is injected into the intermediate chamber, nitrogen gas is pre-purified into the anode chamber, and carbon dioxide gas is pre-purified into the cathode chamber to remove air. Connect a DC power supply, set the current density, introduce nitrogen gas into the anode chamber, introduce carbon dioxide gas into the cathode chamber, and collect the product.

[0016] Preferably, the set current density is 100-500 mA / cm².

[0017] Compared with the prior art, the beneficial effects of the present invention include at least the following: This process innovatively employs a composite electrode structure design, a technological breakthrough with multiple significant advantages. Firstly, in terms of catalytic performance, the specially designed catalytic layer provides excellent electrocatalytic activity, significantly improving reaction efficiency. More importantly, the innovative design of introducing a hydrophobic layer not only achieves rapid desorption and separation of reaction products but also constructs an effective physical barrier, ensuring strict independence between each reaction chamber. System performance testing shows that this hydrophobically modified electrode structure can improve product separation efficiency by more than 30%, while extending electrode lifespan by 2-3 times compared to traditional designs. This provides a solid technical guarantee for the long-term stable operation of the entire reaction system. This design successfully overcomes two major technical challenges that have long existed in traditional electrochemical reactors: low product separation efficiency and cross-contamination between reaction chambers.

[0018] Compared to traditional alkali production processes, this process exhibits significant technological advantages. Currently, the widely used ammonia-soda process and combined alkali production methods not only require near-saturation concentration of the raw brine but also necessitate the use of multiple raw materials such as synthetic ammonia and carbon dioxide, resulting in complex processes and high raw material costs. In contrast, this process only requires a combination of raw brine and carbon dioxide, and significantly reduces the concentration requirements for the brine. Particularly noteworthy is that even under relatively low concentration conditions, this process can still efficiently promote the solid crystallization of sodium bicarbonate or sodium carbonate. This characteristic simplifies the process flow and reduces energy consumption. This groundbreaking process design opens new avenues for the development of electrochemical alkali production technology and has significant industrial application value. Attached Figure Description

[0019] Figure 1 This is a model diagram of the electrochemical reactor in this invention; Figure 2 This is a schematic diagram of the electrochemical method in this invention; In the diagram: 1. Anode chamber; 2. Intermediate chamber; 3. Cathode chamber. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0021] Example 1 of the present invention provides an electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide, such as... Figure 1-2 As shown, the reactor is a custom-designed three-chamber electrolytic cell, comprising an anode chamber 1, an intermediate chamber 2, and a cathode chamber 3 connected in sequence; Both sides of the intermediate chamber 2 are provided with through holes. The through hole of the anode chamber 1 corresponds to the through hole on one side of the intermediate chamber 2, and the anode is located between the two through holes. The through hole of the cathode chamber 3 corresponds to the other side of the intermediate chamber 2, and the cathode is located between the two through holes. The area of ​​each through hole is smaller than the area of ​​the anode and the cathode.

[0022] The three-chamber electrolytic cell is placed in a normal temperature environment. The middle chamber 2 serves as the electrolyte circulation zone, through which sodium chloride aqueous solution is introduced for ion conduction. The anode chamber 1 is equipped with a nitrogen inlet channel, through which nitrogen is introduced for the immediate separation and recovery of generated chlorine. The cathode chamber 3 is equipped with a carbon dioxide inlet channel, through which carbon dioxide is introduced to cause the generated sodium bicarbonate or sodium carbonate to spontaneously precipitate in solid crystal form on the back surface of the cathode, while hydrogen escapes from the back side of the cathode.

[0023] In a preferred but non-limiting embodiment of the present invention, the three-chamber electrolytic cell is preferably made of polytetrafluoroethylene.

[0024] The volume ratio of the anode chamber 1, intermediate chamber 2, and cathode chamber 3 is optimized to 1:0.1:1 (e.g., 50 mL:5 mL:50 mL).

[0025] The nitrogen purging flow rate in the anode chamber is 5-50 mL / min (precisely controlled by a mass flow meter) to ensure that the chlorine partial pressure is below the explosion limit (<5%).

[0026] The CO2 inlet rate of the cathode chamber is 3-30 mL / min, which is uniformly distributed through either a porous titanium plate or hydrophobic carbon paper on the back side, increasing the gas-liquid contact area by 40%. Preferably, the CO2 concentration is >20%.

[0027] The sodium chloride aqueous solution is a 0.5-3 M NaCl solution (prepared with deionized water).

[0028] Temperature and pressure: The reaction is maintained at 25±1℃ throughout, and operated at atmospheric pressure to avoid the need for high-pressure equipment.

[0029] The three-chamber electrochemical reactor of this invention achieves efficient and synergistic resource utilization of sodium chloride and carbon dioxide through zoned control. The reactor adopts a unique chamber separation design. The anode chamber 1 achieves instant separation and recovery of chlorine through nitrogen purging technology. The intermediate chamber 2 serves as the electrolyte circulation zone and is circulated with refined salt water solution. The cathode chamber 3 innovatively has a carbon dioxide inlet channel set on the back side of the cathode.

[0030] During the reaction, chlorine gas generated at the anode is efficiently separated from the anode chamber and continuously discharged from the system under nitrogen carrying capacity. In the cathode region, by precisely controlling the reaction conditions, sodium bicarbonate or sodium carbonate is spontaneously precipitated as solid crystals on the backwater surface of the cathode, achieving automatic separation of the product from the reaction solution. The three-chamber partition design not only effectively prevents cross-contamination of products but also simplifies the subsequent product purification process through physical separation, significantly improving reaction efficiency and product yield.

[0031] Of particular note is that the carbon dioxide back-side design of the cathode chamber optimizes the gas-liquid mass transfer efficiency, while the nitrogen purging system of the anode ensures efficient chlorine recovery and safe operation. The entire system achieves the co-production of three high-value-added products: chlorine, hydrogen, and sodium bicarbonate or sodium carbonate, and has significant industrial application value.

[0032] Example 2 of the present invention provides a method for preparing an electrode in an electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide, comprising the following steps: Step 1, substrate preparation: Select a substrate material, use deionized water and anhydrous ethanol to ultrasonically clean the substrate in sequence to remove surface impurities, and then dry it in an oven for later use. The substrate material serves as a conductive framework and can be any one of the following substrate materials that are stable in water reduction potential: hydrophobic carbon paper, titanium felt, titanium mesh, or stainless steel; the cleaning time is 15 minutes each time, and the oven temperature is 60°C.

[0033] Step 2, Catalyst coating: The catalyst is coated onto the substrate surface and dried to form a catalyst layer; In a preferred but non-limiting embodiment of the present invention, step 2 specifically includes: Step 2.1: Mix the catalyst with the solvent, and then disperse it ultrasonically to form a uniform slurry; More preferably, the catalyst is any one of IrO2 catalyst, Pt / C catalyst, or other catalysts that catalyze anode and cathode reactions; The solvent can be any one of organic solvents such as methanol, ethanol, or isopropanol, or even pure water. The mass ratio of the catalyst to the solvent is set according to different solvents.

[0034] Step 2.2: The slurry is uniformly coated onto the substrate surface using a spraying method, and the catalyst loading is controlled to be 1.0-2.0 mg / cm². Step 2.3: After coating, place the electrode in an 80°C oven for initial drying for 10 minutes, and repeat the spraying 3 times to ensure uniform coverage.

[0035] The catalyst layer, serving as the intermediate layer of the working surface, is responsible for the reduction of water to produce H2 and OH. - .

[0036] Step 3, Hydrophobic layer (PTFE layer) treatment: Apply PTFE emulsion to one side of the electrode, and heat-treat after coating to form a hydrophobic layer; In a preferred but non-limiting embodiment of the present invention, step 3 specifically includes: Step 3.1: Dilute the PTFE emulsion (60 wt%) to 10 wt% and add a small amount of surfactant (such as Triton X-100) to improve dispersibility; Step 3.2: Apply PTFE emulsion to the back side of the electrode (Nafion) using a spraying method. ® On the other side of the layer), the load is controlled at 0.8-1.2 mg / cm²; Step 3.3: After coating, place the electrode in a muffle furnace at 250°C for 1 hour to form a nanoscale hydrophobic structure with a contact angle ≥150°.

[0037] H2 directional discharge: The hydrophobic layer (PTFE layer) forms a gas diffusion channel. When H2 bubbles escape from the back side, they carry the NaHCO3 microcrystals (particle size 1-5 μm) generated in the reaction, realizing the self-exfoliation of the product and reducing scale formation on the electrode surface.

[0038] Step 4, cation exchange layer (Nafion) ® Layer preparation: Nafion ® The solution is coated on the other side of the electrode and cured and annealed to form a selective ion channel; or a similar effect can be achieved by directly using a commercial Nafion membrane tightly bonded to the electrode side. In a preferred but non-limiting embodiment of the present invention, step 4 specifically includes: Step 4.1, Nafion ® The solution (Dupont™ D520) was diluted to 5 wt% and sonicated for 20 minutes to eliminate air bubbles. Step 4.2: Use a spray gun to evenly spray Nafion onto the surface of the catalyst layer. ®The solution was cured and dried at 80°C for 10 minutes after each spraying, and a total of 3 sprayings were applied. The final dry film thickness was controlled at 5-8 μm. Step 4.3: Anneal the electrode at 120°C for 1 hour to enhance the Nafion ® Mechanical strength of the membrane (peel force ≥ 1.5 N / cm).

[0039] OH - Local confinement: cation exchange layer (Nafion) ® (layer) allows Na + Passes through but blocks OH - Diffusion causes the local pH on the cathode surface to rise to 12-13, promoting the CO2→CO3² transition. - Transformation (reaction formula: CO2 + 2OH-) - → CO3² - + H2O), while avoiding OH - The diffusion into the bulk phase results in excessively low supersaturation of sodium carbonate or sodium bicarbonate.

[0040] Step 5, Performance Verification: Performance is tested using a scanning electron microscope and an electrochemical workstation; In a preferred but non-limiting embodiment of the present invention, step 5 specifically includes: Step 5.1: Observe the morphology of each layer using a scanning electron microscope (SEM) to confirm that there are no cracks or delamination. Step 5.2: Use an electrochemical workstation to test the hydrogen evolution performance of the cathode in 1 M NaCl solution to ensure that the potential meets the design requirements (e.g., ≤-0.8 V vs. SHE) when the current density reaches 200 mA / cm².

[0041] It is worth noting that the inventors recognized the impact of Nafion loading on product separation efficiency. Therefore, they designed an experiment to fix other conditions (such as current density of 200 mA / cm², CO₂ flow rate of 15 mL / min) and only change the Nafion loading (0.5 / 1.0 / 1.5 mg / cm²) to evaluate the efficiency of H₂ in carrying NaHCO₃ microcrystals. The solid mass after catholyte evaporation was calculated, as shown in the table below:

[0042] Therefore, it can be concluded that the Nafion loading is 1.0 mg / cm², which results in the best overall performance.

[0043] This patent proposes an innovative technical solution in electrode material and structural design. The main electrode uses specially treated titanium felt as the substrate material, and a composite electrode structure is formed by uniformly depositing an IrO2 catalytic layer on the surface of the titanium felt. The optimized loading of IrO2 is controlled within the range of 0.5-2 mg / cm², and this parameter range has been experimentally verified to balance catalytic activity and economy. In particular, a hydrophobic functional layer is innovatively constructed on the back side of the electrode using PTFE nanoparticle spraying technology, and the hydrophobic performance is significantly improved by a heat treatment process at 200-250℃. This temperature range has been proven to effectively enhance the hydrophobic effect of PTFE nanoparticles without damaging the electrode substrate.

[0044] This composite electrode structure offers multiple technological advantages: the IrO2 coating on the front provides excellent electrocatalytic activity, ensuring the efficient execution of the chlorine evolution reaction and the sodium bicarbonate formation reaction; the nano-PTFE hydrophobic layer on the back not only promotes the rapid desorption and separation of products (such as chlorine bubbles) but also forms an effective physical barrier, preventing the brine solution in the middle chamber from permeating and diffusing into the cathode and anode chambers, thus maintaining the chamber independence of the three-chamber reactor. Experimental data show that this hydrophobically modified electrode structure can improve product separation efficiency by more than 30% while extending electrode lifespan by 2-3 times, providing a reliable guarantee for the long-term stable operation of the system. This electrode design cleverly combines catalytic activity and interface control, solving the technical bottlenecks of difficult product separation and chamber cross-contamination in traditional electrochemical reactors.

[0045] Example 3 of the present invention provides an electrochemical method for the synergistic resource utilization of sodium chloride and carbon dioxide, comprising the following steps: Step 1: Place the assembled electrolytic cell in a constant temperature water bath; The temperature of the constant temperature water bath is 25±1℃; Step 2: Inject NaCl solution into the intermediate chamber, pre-purge N2 into the anode chamber, and pre-purge CO2 into the cathode chamber for 5 minutes to remove air; Step 3: Connect the DC power supply, set the current density, and set the time to collect the product.

[0046] The DC power supply is a CHI 760E electrochemical workstation with a current density of 100-500 mA / cm².

[0047] In a preferred but non-limiting embodiment of the present invention, the obtained product is analyzed and characterized: Cl2 quantification: The anolyte exhaust gas was absorbed by 10% KI solution and titrated by iodometric titration (GB / T 15437-2019). The Faraday efficiency was calculated to be 95±1.5% (n=3).

[0048] H2 detection: The cathode gas was analyzed by gas chromatography (GC-2014, TCD detector, nitrogen carrier gas), and the H2 purity was >99.5%.

[0049] NaHCO3 characterization: The solid deposited at the cathode was washed with deionized water and dried at 60°C. XRD (Bruker D8 Advance) confirmed that the crystal form was pure phase NaHCO3. It is worth noting that this method can produce either sodium carbonate or sodium bicarbonate, depending on the amount of CO2 introduced (and the generated OH-). - (In comparison); if CO2 is in excess, sodium bicarbonate is produced; if CO2 is in small amounts, sodium carbonate is produced. Purity determination: After dissolution, the purity was determined by acid-base titration (GB / T 210.2-2004) to be 98.7 ± 0.3%.

[0050] Energy consumption calculation: Average cell voltage 4.8 V, energy consumption per ton of Cl2 is 1450 kWh (2500 kWh for traditional process).

[0051] More preferably, the electrochemical reactor is subjected to long-term stability testing: The reactor was run continuously for 120 hours, and key data were sampled and analyzed every 24 hours. Cl2 Faraday efficiency: Initially 95% → 92% after 120 h.

[0052] Cathode PTFE layer contact angle: initial 152° → 138° after 120 h (still superhydrophobic).

[0053] NaHCO3 purity fluctuates between 97.5% and 98.9%.

[0054] In summary, the electrochemical reactor described in this invention operates at ambient temperature and pressure, eliminating the need for high-pressure equipment. It co-produces three high-value-added chemicals, improving resource utilization by over 30%. Specifically, the Cl2 Faraday efficiency is ≥95%, H2 purity is >99.5%, and NaHCO3 purity is ≥98.7%. It demonstrates significant industrialization potential, with electrode lifespan exceeding 120 hours and energy consumption reduced by 42%. Furthermore, compared to existing ammonia-soda processes and Hou's process, this invention requires only a low-concentration sodium chloride aqueous solution for efficient operation, completely avoiding the use of synthetic ammonia and significantly reducing raw material costs and energy consumption. More importantly, this invention innovatively achieves the recycling of byproducts and co-produces chlorine, hydrogen, and sodium carbonate or sodium bicarbonate, among other high-value-added products. Chlorine and hydrogen, as basic chemical raw materials, can be widely used in the production of hydrochloric acid, polyvinyl chloride (PVC), pesticides, bleaching agents, and other products, and also have significant applications in water treatment, the electronics industry, and metal smelting. Of particular note is that this invention can efficiently promote the crystallization of sodium bicarbonate even under low-concentration sodium chloride solution conditions. This characteristic not only simplifies the process flow and reduces equipment investment and operating costs, but also significantly reduces energy consumption. Compared to the strict requirements of traditional processes for saturated brine, this process has greater adaptability to raw materials and lower operating costs.

[0055] Compared with the prior art, the beneficial effects of the present invention include at least the following: This process innovatively employs a composite electrode structure design, a technological breakthrough with multiple significant advantages. Firstly, in terms of catalytic performance, the specially designed catalytic layer provides excellent electrocatalytic activity, significantly improving reaction efficiency. More importantly, the innovative design of introducing a hydrophobic layer not only achieves rapid desorption and separation of reaction products but also constructs an effective physical barrier, ensuring strict independence between each reaction chamber. System performance testing shows that this hydrophobically modified electrode structure can improve product separation efficiency by more than 30%, while extending electrode lifespan by 2-3 times compared to traditional designs. This provides a solid technical guarantee for the long-term stable operation of the entire reaction system. This design successfully overcomes two major technical challenges that have long existed in traditional electrochemical reactors: low product separation efficiency and cross-contamination between reaction chambers.

[0056] Compared to traditional alkali production processes, this process exhibits significant technological advantages. Currently, the widely used ammonia-soda process and combined alkali production methods not only require near-saturation concentration of the raw brine but also necessitate the use of multiple raw materials such as synthetic ammonia and carbon dioxide, resulting in complex processes and high raw material costs. In contrast, this process only requires a combination of raw brine and carbon dioxide, and significantly reduces the concentration requirements for the brine. Particularly noteworthy is that even under relatively low concentration conditions, this process can still efficiently promote the solid crystallization of sodium bicarbonate. This characteristic simplifies the process flow and reduces energy consumption. This groundbreaking process design opens new avenues for the development of electrochemical alkali production technology and has significant industrial application value.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. An electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide, characterized in that: It includes an anode chamber (1), an intermediate chamber (2), and a cathode chamber (3) connected in sequence; Both sides of the intermediate chamber (2) are provided with through holes. The through hole of the anode chamber (1) corresponds to the through hole on one side of the intermediate chamber (2), and the hydrophobic layer of the positive electrode is connected to the through hole of the anode chamber (1). The through hole of the cathode chamber (3) corresponds to the through hole on the other side of the intermediate chamber (2), and the hydrophobic layer of the negative electrode is connected to the through hole of the cathode chamber (3). The area of ​​each through hole is smaller than the area of ​​the positive electrode and the negative electrode. The three-chamber electrolytic cell is energized at room temperature. The middle chamber (2) serves as the electrolyte circulation zone, through which sodium chloride aqueous solution is introduced for ion conduction. The anode chamber (1) is equipped with a nitrogen inlet channel, through which nitrogen is introduced for the immediate separation and recovery of chlorine gas. The cathode chamber (3) is equipped with a carbon dioxide inlet channel, through which carbon dioxide is introduced to cause the generated sodium bicarbonate or sodium carbonate to precipitate in solid crystal form on the hydrophobic layer of the negative electrode, while hydrogen gas escapes. The electrode preparation method includes the following steps: Substrate preparation: Select a substrate material, ultrasonically clean the substrate sequentially with deionized water and anhydrous ethanol, and then dry it in an oven for later use; Catalytic layer coating: The catalyst is coated on the surface of the substrate and dried to form a catalytic layer; Hydrophobic layer treatment: PTFE emulsion is coated onto one side of the catalyst layer, and heat treatment is performed after coating to form a hydrophobic layer; Preparation of cation exchange layer: Nafion ® The solution is coated on the other side of the catalyst layer, and after curing and annealing, a selective ion channel is formed.

2. The electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 1, characterized in that: The nitrogen purging flow rate in the anode chamber is 5-50 mL / min, ensuring that the partial pressure of chlorine is below the explosion limit during the reaction.

3. The electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 1, characterized in that: The CO2 intake rate of the cathode chamber is 3-30 mL / min, and it is uniformly distributed through either a porous titanium plate or hydrophobic carbon paper on the back side of the cathode; the sodium chloride aqueous solution is a 0.5-3 M NaCl solution.

4. The electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 1, characterized in that: The matrix material serves as a conductive framework and can be any one of the matrix materials with a stable water reduction potential.

5. The electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 1, characterized in that: The catalyst loading is 1.0-2.0 mg / cm².

6. The electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 1, characterized in that: The PTFE emulsion has a loading of 0.8-1.2 mg / cm² and a hydrophobic layer contact angle ≥150°.

7. The electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 1, characterized in that: The cation exchange layer was prepared by replacing the Nafion ® Solution coating, a commercial Nafion membrane was tightly attached to the other side of the catalyst layer.

8. An electrochemical method for the synergistic resource utilization of sodium chloride and carbon dioxide, based on the electrochemical reactor for the synergistic resource utilization of sodium chloride and carbon dioxide according to any one of claims 1-7, characterized in that: Includes the following steps: Place the assembled three-chamber electrolytic cell at room temperature; NaCl solution is injected into the intermediate chamber (2), N2 is pre-circulated into the anode chamber (1), and CO2 is pre-circulated into the cathode chamber (3) to remove air; Connect a DC power supply, set the current density, introduce nitrogen into the anode chamber (1), introduce CO2 into the cathode chamber (2), and collect the product.

9. The electrochemical method for the synergistic resource utilization of sodium chloride and carbon dioxide according to claim 8, characterized in that: The set current density is 100-500 mA / cm².

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