Method for stable electrolytic hydrogen production of high-salt water body based on assistance of ferrous cyanide cyclic regeneration

Abstract

The invention discloses a ferrocyanide radical cyclic regeneration assistance-based high-salt water body stable electrolytic hydrogen production method, and belongs to the field of water electrolysis hydrogen production. The method comprises the following steps: adding a ferrocyanide solution into an anolyte storage tank, taking a pretreated graphite felt as an anode, and replacing a traditional oxygen evolution reaction with a ferrocyanide anode oxidation reaction; and a chlorine-resistant reduction catalyst is added into the anolyte storage tank, so that a ferrocyanide oxidation product ferricyanide is efficiently reduced into ferrocyanide, and closed-loop circulation of the redox couple in the system is realized. According to the method, the ferrocyanide anodic oxidation reaction which is lower in theoretical oxidation potential and more advantageous in dynamics is introduced to replace the oxygen evolution reaction, the potential difference with the chlorine evolution reaction is greatly enlarged, and the selectivity under the conditions of large current and high chlorine concentration is improved. Meanwhile, the chlorine-resistant reduction catalyst is added into the anolyte storage tank and heated to catalyze the reduction and regeneration of ferrocyanide radicals, and continuous and stable low-power-consumption hydrogen production can be realized without continuously adding substances.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production by water electrolysis, and in particular, it is a stable electrolysis method for hydrogen production in high saline water based on the auxiliary function of ferrocyanide cyclic regeneration. Background Technology

[0002] Hydrogen, as an ideal "zero-carbon" clean energy source and an important chemical raw material, holds significant strategic importance in global energy transition and sustainable development. Hydrogen production through water electrolysis is considered the most promising hydrogen production technology due to its clean process and high product purity. However, water electrolysis consumes large amounts of pure water, and with the continued growth in energy demand, this process will inevitably further exacerbate the global shortage of freshwater resources. Therefore, researchers have proposed using highly saline bodies such as seawater for direct electrolysis to produce hydrogen, in order to alleviate resource competition between domestic water use and industrial hydrogen production.

[0003] Compared to hydrogen production through electrolysis of pure water, the Cl- content in high-salinity water... - The chlorine evolution reaction (chlorine evolution reaction) readily occurs at the anode, replacing the oxygen evolution reaction. This not only increases anode energy consumption but also leads to electrode corrosion, severely impacting electrolytic stability. Although the theoretical potential difference between the oxygen evolution reaction and the chlorine evolution reaction is approximately 480 mV under alkaline conditions, the slow kinetics of the oxygen evolution reaction and the limited activity of existing anode catalysts further narrow the potential difference in actual operation, making it difficult to avoid chlorine evolution under high current and high Cl- concentrations. - The chlorine evolution reaction occurs at certain concentrations.

[0004] To address this issue, some researchers have designed and optimized the anode catalyst and increased the alkalinity of the electrolyte. This has enhanced the catalytic activity of the oxygen evolution reaction while suppressing the chlorine evolution reaction to some extent, bringing the actual potential difference between the two close to the theoretical maximum value of 480mV, while ensuring the high selectivity of the oxygen evolution reaction under high current.

[0005] CN120465054A discloses a porous IrRu alloy nanosheet array electrocatalyst, which exhibits high OER activity and corrosion resistance in seawater electrolysis due to its high density of active sites and excellent charge transport performance. However, this catalyst relies on precious metals such as Ir and Ru, resulting in high costs and hindering industrial application.

[0006] CN120485824A discloses a CoFP / NF catalyst that exhibits low overpotential and good stability in the oxygen evolution reaction, but its synthesis process involves multiple hydrothermal reactions, high-temperature phosphating, and the use of fluorine / phosphorus sources, which limits its potential for large-scale application.

[0007] Although the above methods widen the potential difference between the oxygen evolution reaction and the chlorine evolution reaction, and improve the catalytic activity and selectivity of the oxygen evolution reaction under high current to some extent, they are still limited by the upper limit of the theoretical potential difference and the intrinsic kinetic disadvantages of the oxygen evolution reaction, making it difficult to avoid high current and high Cl- content.- The occurrence of chlorine evolution reaction at certain concentrations and its corrosion of the anode.

[0008] Therefore, researchers further proposed to replace the oxygen evolution reaction with an anodic oxidation reaction, which has a lower theoretical oxidation potential and better kinetics, thereby widening the potential difference with the chlorine evolution reaction and improving selectivity under high current.

[0009] Invention patent CN119932613A discloses a hydrazine-assisted seawater electrolysis hydrogen production technology, which significantly suppresses the chlorine evolution reaction through a hydrazine oxidation reaction at a lower potential, exhibiting good stability and corrosion resistance. However, this method relies on high-cost and highly toxic hydrazine, and requires continuous replenishment during operation, limiting its large-scale promotion.

[0010] Jia et al. (ACS Catalysis 2023) reported a method for producing hydrogen from seawater by electrolysis using ferrocyanide ions and Prussian blue / white electrodes. Although this method introduces low-cost and non-toxic ferrocyanide ions to assist in the electrolysis of seawater, it still requires the continuous addition of ferrocyanide ions to maintain the cycle, which increases the complexity and cost of operation.

[0011] Invention patent CN117535695A discloses a method for assisted electrolysis of seawater using a ferrocyanide / ferricyanide redox couple. Unlike the method reported by Jia et al., this method achieves the regeneration and circulation of the auxiliary agent within the system through an external oxygen evolution reactor, avoiding frequent replenishment of the auxiliary agent. However, the reduction catalyst used lacks sufficient corrosion resistance, making it difficult to operate stably in high-salt environments such as long-term circulating seawater or brine lake water.

[0012] In summary, existing technologies have made some progress in improving the chlorine resistance of seawater electrolysis for hydrogen production, but are still limited to optimizing chlorine resistance under low to medium salinity conditions. In water bodies with higher salinity, even near-saturated saline lakes, and shale gas backflow, there is still a lack of electrolysis hydrogen production schemes that can balance low energy consumption, chlorine corrosion resistance, and long-term stability, necessitating the development of new solutions. Summary of the Invention

[0013] The purpose of this invention is to address the shortcomings of existing water electrolysis hydrogen production methods in high-salinity water bodies, such as high energy consumption, easy occurrence of chlorine evolution side reactions, and the need for continuous replenishment of redox couples, which prevent long-term stable operation. This invention provides a stable electrolysis hydrogen production method in high-salinity water bodies based on ferrocyanide cyclic regeneration assistance, so as to achieve low power consumption, corrosion resistance, and long-term continuous and stable hydrogen production.

[0014] To achieve the above objectives, the present invention adopts the following technical solution:

[0015] A stable electrolytic hydrogen production method based on ferrocyanide recycling in high-salt environments is disclosed. The method involves adding a ferrocyanide solution to the anolyte tank and using pretreated graphite felt as the anode. The ferrocyanide anodic oxidation reaction, with its lower theoretical oxidation potential and superior kinetics, replaces the traditional oxygen evolution reaction, widening the potential difference with the chlorine evolution reaction. This significantly suppresses the chlorine evolution side reaction and reduces energy consumption in a high-salt environment. A chlorine-resistant reduction catalyst is added to the anolyte tank to efficiently reduce the ferrocyanide oxidation product, ferricyanide, back to ferrocyanide, achieving a closed-loop redox couple within the system. This eliminates the need for continuous external additives, ensuring long-term, low-cost, and stable operation of the system.

[0016] Furthermore, the anolyte is a mixed solution of ferrocyanide and saturated NaCl, and the catholyte is a KOH and saturated NaCl solution with the same pH. Typically, only KOH and NaOH are added to the anolyte to maintain alkalinity. Ferrocyanide ions are stable under alkaline conditions, and OH... - It is one of the reactants.

[0017] Furthermore, the anode is a pretreated graphite felt electrode, and the cathode is a platinum sheet, a platinum-loaded nickel felt, and carbon paper.

[0018] Further, the ferrocyanide is one or more of potassium ferrocyanide, sodium ferrocyanide, or lithium ferrocyanide, with a concentration of 0.1~0.6M, for example 0.1M, 0.2M, 0.4M, or 0.6M.

[0019] Furthermore, the pretreatment method for the anodic graphite felt includes acid oxidation treatment (such as concentrated nitric acid or concentrated sulfuric acid), hydrogen peroxide oxidation treatment, thermochemical nitrogen / oxygen doping treatment, electrochemical oxidation activation, or chemical etching / exfoliation treatment. The purpose of the anodic graphite felt pretreatment is to optimize the pore structure and increase the specific surface area, thereby improving hydrophilicity, enhancing interfacial mass transfer, and strengthening the ferrocyanide oxidation activity.

[0020] (1) Acid oxidation treatment:

[0021] Place the graphite felt in concentrated nitric acid (65%–70% by mass) or concentrated sulfuric acid (95%–98% by mass) and react at 60–120°C for 2–6 hours; or use a mixed acid system (e.g., H₂SO₄:HNO₃, volume ratio 3:1) and react at 80–100°C for 1–4 hours. After thorough washing until neutral, dry at 80–100°C.

[0022] (2) Hydrogen peroxide treatment:

[0023] The graphite felt was immersed in a 30% H2O2 solution and treated at room temperature to 80°C for 2 to 10 hours.

[0024] (3) Thermochemical nitrogen doping treatment:

[0025] Calcine at 600-900°C for 1-3 hours in an ammonia (NH3) or urea atmosphere.

[0026] (4) Thermochemical oxygen doping treatment:

[0027] The content and distribution of oxygen-containing functional groups on the surface can be controlled by heat treatment at 400~700℃ for 1~3 hours in an oxygen-containing atmosphere (air or CO2).

[0028] (5) Electrochemical oxidation activation treatment:

[0029] The graphite felt was placed as the working electrode in a 1.0 M H2SO4 or 0.5 M Na2SO4 electrolyte and cyclically activated for 50 to 200 cycles within a potential range of 1.0-2.0 V (vs. Ag / AgCl).

[0030] (6) Chemical etching / stripping treatment:

[0031] Etch at 60-90°C for 1-3 hours using KOH (1-3M) or NH4HF2 (0.1-1M) solution.

[0032] Through these pretreatment methods, functional groups such as -OH, -COOH, C=O, and N-heteroatoms can be introduced into the surface of graphite felt, forming a rougher structure and microporous channels that are more conducive to electrochemical reactions, while maintaining good conductivity, thereby improving its electrochemical activity and stability in ferrocyanide oxidation.

[0033] Furthermore, the chlorine-resistant reduction catalyst is one of CoFe-LDH, NiFe-LDH, PtC, or PdC. SO4 is preferred. 2- / CoFe-LDH, SO4 2- / NiFe-LDH, CO3 2- Catalysts with high chlorine resistance, such as Ni(OH)₂, or combinations thereof, and their derivative composites, are used. The reducing catalyst catalyzes the reduction of ferricyanide, the anolysin of ferrocyanide, back to ferrocyanide. The specific mechanism involves first reducing the OH⁻ in the solution... - Adsorbed and activated into active substances (such as...) , , Subsequently, the active material reacts with ferricyanide to generate ferrocyanide and release oxygen. The regeneration rate is affected by the total amount of anolyte, the amount of ferrocyanide added, and the hydrogen production current. The amount of reduction catalyst added determines the ferrocyanide regeneration rate, which should be greater than or equal to the rate of ferrocyanide ion consumption during electrolysis. Empirical data: At a current of 200 mA, the anolyte is 100 mL of 0.6 M potassium ferrocyanide solution, and the catalyst (CoFe-LDH) is at least 10 cm³. 2 .

[0034] Furthermore, the heating temperature of the anolyte storage tank is 60~100℃, for example, 60℃, 70℃, 80℃, or 100℃. This is intended to accelerate the reduction reaction of ferricyanide ions.

[0035] Furthermore, the systems to which the method is applicable include:

[0036] An electrolyzer is used to electrolyze water into hydrogen and oxygen.

[0037] The anolyte circulation system is connected to the anode zone of the electrolyzer and is used to supply the anode zone of the electrolyzer with an electrolyte containing ferrocyanide.

[0038] The cathode electrolyte circulation system is connected to the cathode area of ​​the electrolytic cell and is used to supply cathode electrolyte to the cathode area of ​​the electrolytic cell;

[0039] The hydrogen processing system is connected to the hydrogen outlet of the electrolyzer and is used to condense, dry, and pressurize the hydrogen.

[0040] The gas storage system, connected to the hydrogen processing system, is used to collect and store processed high-purity hydrogen.

[0041] Furthermore, the electrolytic cell is equipped with an anion exchange membrane, which divides the electrolytic cell into an anode region and a cathode region; an anode is provided in the anode region, and a cathode is provided in the cathode region; the anode is connected to the positive terminal of the power supply, and the cathode is connected to the negative terminal of the power supply.

[0042] Furthermore, the anolyte circulation system includes an anolyte storage tank, a first circulation pump, and a second circulation pump. The anolyte storage tank is circulated to the anode area of ​​the electrolytic cell via the first and second circulation pumps. An oxygen outlet pipe is installed on the anolyte storage tank, with one end of the oxygen outlet pipe located inside the anolyte storage tank and the other end extending out of the anolyte storage tank and connected to the first condenser.

[0043] The anolyte storage tank contains anolyte and a chlorine-resistant reduction catalyst. The chlorine-resistant reduction catalyst is used to reduce ferricyanide to ferrous cyanide under weakly alkaline conditions.

[0044] A heating module is installed inside the anode electrolyte storage tank;

[0045] The cathode electrolyte circulation system includes a cathode electrolyte storage tank and a third circulation pump; the cathode electrolyte storage tank is connected to the cathode area of ​​the electrolytic cell through the third circulation pump to provide cathode electrolyte to the cathode area of ​​the electrolytic cell.

[0046] The gas storage system includes a gas storage tank and a high-pressure storage tank that are respectively connected to the hydrogen processing system; the hydrogen processing system includes a second condenser, a dryer, a first compressor, a second compressor, and a third condenser; the hydrogen outlet of the cathode area of ​​the electrolytic cell is connected in series via a pipeline to the second condenser, the dryer, the gas storage tank, the first compressor, the second compressor, the third condenser, and the high-pressure storage tank.

[0047] The advantages of this invention over existing technologies are as follows: This method introduces the ferrocyanide anodic oxidation reaction, which has a lower theoretical oxidation potential and more advantageous kinetics, to replace the oxygen evolution reaction, significantly widening the potential difference with the chlorine evolution reaction and improving selectivity under high current and high chlorine concentration. Simultaneously, by adding a chlorine-resistant reduction catalyst to the anolyte storage tank and heating it, the ferrocyanide is catalyzed for reduction and regeneration, achieving continuous and stable low-power hydrogen production without the need for constant external addition of substances. Attached Figure Description

[0048] Figure 1 Schematic diagrams of different reduction catalysts in Examples 1-4;

[0049] Figure 2 This is a comparison chart of the catalytic performance of different reduction catalysts in Examples 1-4;

[0050] Figure 3 The graphs show the polarization curves of Examples 1 and 5-7 at different potassium ferrocyanide concentrations.

[0051] Figure 4 This is a diagram of the variable current test in Example 9;

[0052] Figure 5 This is a schematic diagram of the system to which this invention applies;

[0053] The components include: 1. First condenser; 2. Reduction catalyst; 3. Anode electrolyte storage tank; 4. First circulation pump; 5. Power supply; 6. Electrolytic cell; 7. Second condenser; 8. Cathode electrolyte storage tank; 9. Dryer; 10. Gas storage tank; 11. First compressor; 12. Third condenser; 13. High-pressure gas storage tank; 14. Anion exchange membrane; 15. Anode; 16. Cathode; 17. Second circulation pump; 18. Third circulation pump; 19. Second compressor; 20. Heating module. Detailed Implementation

[0054] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0055] Example 1: The electrolytic stability of the system of the present invention to high-salinity water was verified using an H-type electrolyzer. The diaphragm was a W-75T anion exchange membrane, and the system operated in a three-electrode system at a working temperature of 60℃. The working electrode was a 1cm × 1cm pretreated graphite felt anode, the counter electrode was a 1cm × 1cm platinum sheet, and the reference electrode was a mercury / mercuric oxide electrode. The electrolyte on the anode side was a mixed solution of 0.6M potassium ferrocyanide and 2.5M sodium chloride, and the cathode was a mixed solution of KOH and 2.5M sodium chloride with the same pH. SO4 was added to the anode electrolyte storage tank. 2- / CoFe-LDH as a chlorine-resistant reduction catalyst.

[0056] Example 2: Unlike Example 1, no chlorine-resistant reduction catalyst was added to the anolyte storage tank.

[0057] Example 3: Unlike Example 1, the chlorine-resistant reduction catalyst in the anolyte storage tank was replaced with nickel foam.

[0058] Example 4: Unlike Example 1, the chlorine-resistant reduction catalyst in the anolyte storage tank was replaced with CoFe-LDH.

[0059] Figure 1 This serves as a control group for different chlorine-resistant reduction catalysts. Figure 2 This section compares the reduction performance of different catalytic reduction schemes described in Examples 1-4 for ferricyanide in high-salt water. Figure 2 The initial catalytic performance order is Example 4 > Example 1 > Example 3 > Example 2. However, the long-term stable catalytic performance order is Example 1 > Example 4 > Example 3 > Example 2. This indicates that although the catalyst without chlorine-resistant treatment has a better initial catalytic effect, its performance in high Cl⁻ concentrations is not optimal. - Under certain conditions, it is susceptible to corrosion, leading to a decrease in catalytic stability.

[0060] Example 5: Unlike Example 1, potassium ferrocyanide was not added to the electrolyte on the anode side.

[0061] Example 6: Unlike Example 1, the concentration of potassium ferrocyanide in the anode electrolyte is 0.2M.

[0062] Example 7: Unlike Example 1, the concentration of potassium ferrocyanide in the anode electrolyte is 0.4M.

[0063] The results showed that the addition of potassium ferrocyanide significantly improved the stable operating time of the device and reduced power consumption. Figure 3The polarization curves of the working electrodes in Examples 1 and 5-7 were recorded using a BioLogic-VMP3 electrochemical workstation. From... Figure 3 It can be seen that the order of low power consumption performance is Example 1 > Example 7 > Example 6 > Example 5.

[0064] Example 8: Unlike Example 1, the NaCl concentration in the electrolyte was 0M, 1M, and 2M.

[0065] The results showed that the electrolytic stability and low power consumption performance of the system were similar under different NaCl concentrations. - The introduction of [the substance] did not have a significant impact on the electrolysis system.

[0066] Example 9: Applying 10, 100, 500, and 900 mA / cm based on Example 3. 2 Constant current density.

[0067] Figure 4 The voltage of the working electrode was recorded using a BioLogic-VMP3 electrochemical workstation in Example 9. Figure 4 It can be seen that the system can stably electrolyze high-salt water at different current densities, reaching 10 / 100 / 500 / 900 mA / cm². 2 The current density required is only 0.98 / 0.99V / 1.05V / 1.12V vs. RHE.

[0068] Example 10: Unlike Example 1, the cathode is replaced with other common cathode hydrogen evolution materials such as graphite rods, nickel foam, and platinum sheets, all of which can achieve similar effects.

[0069] Example 11: The method was verified in a decoupled electrolysis system. The anolyte was a mixture of 0.6M potassium ferrocyanide and saturated NaCl, and the cathode electrolyte was a mixture of KOH and saturated NaCl at the same pH. The anode was a pretreated graphite felt electrode, and the cathode was a platinum-loaded nickel felt. SO4 was added to the anolyte storage tank. 2- / CoFe-LDH chlorine-resistant reduction catalyst was heated to 60°C to achieve simultaneous regeneration of ferrocyanide.

[0070] like Figure 4 As shown, the decoupled electrolysis system specifically includes:

[0071] Electrolyzer 6 is used to electrolyze water into hydrogen and oxygen;

[0072] An anolyte circulation system is connected to the anode zone of electrolytic cell 6 and is used to supply an electrolyte containing ferrocyanide to the anode zone of electrolytic cell 6.

[0073] The cathode electrolyte circulation system is connected to the cathode area of ​​electrolytic cell 6 and is used to supply cathode electrolyte to the cathode area of ​​electrolytic cell 6.

[0074] The hydrogen processing system is connected to the hydrogen outlet of the electrolyzer 6 and is used to condense, dry and pressurize the hydrogen.

[0075] The gas storage system, connected to the hydrogen processing system, is used to collect and store processed high-purity hydrogen.

[0076] The electrolytic cell 6 is equipped with an anion exchange membrane 14, which divides the electrolytic cell 6 into an anode region and a cathode region. An anode 15 is provided in the anode region, and a cathode 16 is provided in the cathode region. The anode 15 is connected to the positive terminal of the power supply 5, and the cathode 16 is connected to the negative terminal of the power supply 5.

[0077] The anolyte circulation system includes an anolyte storage tank 3, a first circulation pump 4, and a second circulation pump 17. The anolyte storage tank 3 is circulated to the anode area of ​​the electrolytic cell 6 via the first circulation pump 4 and the second circulation pump 17. An oxygen outlet pipe is installed on the anolyte storage tank 3, with one end of the oxygen outlet pipe located inside the anolyte storage tank 3 and the other end extending out of the anolyte storage tank 3 and connected to the first condenser 1.

[0078] The anolyte storage tank 3 is equipped with anolyte and reduction catalyst 2. The reduction catalyst 2 is used to reduce ferricyanide to ferrous cyanide under weakly alkaline conditions.

[0079] A heating module 20 is installed inside the anode electrolyte storage tank 3;

[0080] The cathode electrolyte circulation system includes a cathode electrolyte storage tank 8 and a third circulation pump 18; the cathode electrolyte storage tank 8 is connected to the cathode area of ​​the electrolytic cell 6 through the third circulation pump 18 to provide cathode electrolyte to the cathode area of ​​the electrolytic cell 6.

[0081] The gas storage system includes a gas storage tank 10 and a high-pressure storage tank 13, which are respectively connected to the hydrogen processing system; the hydrogen processing system includes a second condenser 7, a dryer 9, a first compressor 11, a second compressor 19, and a third condenser 12; the hydrogen outlet of the cathode area of ​​the electrolytic cell 6 is connected in series via pipelines to the second condenser 7, the dryer 9, the gas storage tank 10, the first compressor 11, the second compressor 19, the third condenser 12, and the high-pressure storage tank 13.

[0082] Testing showed that the system could stably produce hydrogen for hundreds of hours using a saturated NaCl solution as the electrolyte. No chlorine gas was detected in the hydrogen and oxygen produced, and no chlorine evolution products were detected in the electrolyte. Furthermore, this method exhibits significantly low power consumption, with the system achieving a power consumption of 100 mA cm⁻¹. -2The required current density is only 0.99V (vs RHE). This invention enables long-term stable electrolytic hydrogen production from high-salinity water.

Claims

1. A method for stable electrolytic hydrogen production from high-salinity water based on ferrocyanide recycling and regeneration, characterized in that: The method is as follows: a ferrocyanide solution is added to the anolyte storage tank, and the pretreated graphite felt is used as the anode. The ferrocyanide anodic oxidation reaction is used to replace the traditional oxygen evolution reaction. A chlorine-resistant reduction catalyst is added to the anolyte storage tank to promote the efficient reduction of ferrocyanide, the oxidation product of ferrocyanide, to ferrocyanide, thereby realizing a closed-loop cycle of the redox couple in the system.

2. The method for stable electrolytic hydrogen production in high-salinity water based on ferrocyanide recycling and regeneration assistance according to claim 1, characterized in that: The anolyte is a mixed solution of ferrocyanide and saturated NaCl, and the catholyte is a KOH and saturated NaCl solution with the same pH.

3. The method for stable electrolytic hydrogen production from high-salt water based on ferrocyanide recycling and regeneration assistance as described in claim 1, characterized in that: The anode is a pretreated graphite felt electrode, and the cathode is a platinum sheet, a platinum-loaded nickel felt, and carbon paper.

4. A method for stable electrolytic hydrogen production in high-salinity water based on ferrocyanide recycling and regeneration assistance, as described in claim 1 or 2, characterized in that: The ferrocyanide is one or more of potassium ferrocyanide, sodium ferrocyanide, or lithium ferrocyanide, with a concentration of 0.1~0.6M, for example 0.1M, 0.2M, 0.4M, or 0.6M.

5. A method for stable electrolytic hydrogen production in high-salt water based on ferrocyanide recycling and regeneration assistance, as described in claim 1 or 3, characterized in that: The methods for pretreating the anodic graphite felt include acid oxidation treatment (such as concentrated nitric acid or concentrated sulfuric acid), hydrogen peroxide oxidation treatment, thermochemical nitrogen / oxygen doping treatment, electrochemical oxidation activation, or chemical etching / stripping treatment.

6. The method for stable electrolytic hydrogen production in high-salinity water based on ferrocyanide recycling and regeneration assistance according to claim 1, characterized in that: The chlorine-resistant reduction catalyst is one of CoFe-LDH, NiFe-LDH, PtC, or PdC.

7. The method for stable electrolytic hydrogen production in high-salinity water based on ferrocyanide recycling and regeneration assistance according to claim 1, characterized in that: The heating temperature of the anolyte storage tank is 60~100℃, for example, it can be 60℃, 70℃, 80℃, or 100℃.

8. A method for stable electrolytic hydrogen production from high-salinity water based on ferrocyanide recycling and regeneration assistance, as described in any one of claims 1 to 7, characterized in that: The system to which the method is applicable includes: Electrolyzer (6) is used to electrolyze water into hydrogen and oxygen; An anolyte circulation system is connected to the anode region of the electrolytic cell (6) and is used to supply an electrolyte containing ferrocyanide to the anode region of the electrolytic cell (6); The cathode electrolyte circulation system is connected to the cathode area of ​​the electrolytic cell (6) and is used to supply cathode electrolyte to the cathode area of ​​the electrolytic cell (6); The hydrogen processing system is connected to the hydrogen outlet of the electrolyzer (6) and is used to condense, dry and pressurize the hydrogen. The gas storage system, connected to the hydrogen processing system, is used to collect and store processed high-purity hydrogen.

9. The method for stable electrolytic hydrogen production in high-salinity water based on ferrocyanide recycling and regeneration assistance according to claim 1, characterized in that: The electrolytic cell (6) is provided with an anion exchange membrane (14), which divides the electrolytic cell (6) into an anode region and a cathode region. An anode (15) is provided in the anode region, and a cathode (16) is provided in the cathode region. The anode (15) is connected to the positive terminal of the power supply (5), and the cathode (16) is connected to the negative terminal of the power supply (5).

10. The method for stable electrolytic hydrogen production in high-salinity water based on ferrocyanide recycling and regeneration assistance according to claim 1, characterized in that: The anolyte circulation system includes an anolyte storage tank (3), a first circulation pump (4), and a second circulation pump (17). The anolyte storage tank (3) is connected to the anode area of ​​the electrolytic cell (6) through the first circulation pump (4) and the second circulation pump (17). An oxygen outlet pipe is installed on the anolyte storage tank (3), with one end of the oxygen outlet pipe located inside the anolyte storage tank (3) and the other end of the oxygen outlet pipe extending out of the anolyte storage tank (3) and connected to the first condenser (1). The anolyte storage tank (3) is equipped with anolyte and chlorine-resistant reduction catalyst (2). The chlorine-resistant reduction catalyst (2) is used to reduce ferricyanide to ferrous cyanide under weakly alkaline conditions. A heating module (20) is installed inside the anode electrolyte storage tank (3); The cathode electrolyte circulation system includes a cathode electrolyte storage tank (8) and a third circulation pump (18); the cathode electrolyte storage tank (8) is connected to the cathode area of ​​the electrolytic cell (6) through the third circulation pump (18) to provide cathode electrolyte to the cathode area of ​​the electrolytic cell (6).

Images