Method and reactor for producing hydrogen and chlorine by electrolysis of seawater by sequential electric filtration

Abstract

The application provides a method and a reactor for producing hydrogen and chlorine by electrolyzing seawater through electric filtering in sequence. The reactor comprises a shell, a first gas-permeable partition, a penetrating cathode unit, a second gas-permeable partition, a penetrating anode unit and a driving device. The shell has a closed reaction chamber, and is provided with an electrolyte inlet and a solution outlet. The first gas-permeable partition, the penetrating cathode unit, the second gas-permeable partition and the penetrating anode unit are all in the reaction chamber. The two gas-permeable partitions are respectively arranged on the two sides of the penetrating cathode unit, and the second gas-permeable partition is between the penetrating cathode unit and the penetrating anode unit. The two gas-permeable partitions are used for allowing hydrogen generated by the cathode to be discharged and preventing liquid electrolyte from leaking. The driving device is connected to the electrolyte inlet, and is used for pumping electrolyte into the reaction chamber and driving the electrolyte to form a one-way flow which sequentially penetrates and flows through the first gas-permeable partition, the penetrating cathode unit, the second gas-permeable partition and the penetrating anode unit and then flows out from the solution outlet.

Description

Technical Field

[0001] This invention relates to the field of seawater electrolysis technology, and in particular to a method and reactor for producing hydrogen and chlorine from seawater by sequential electrofiltration and electrolysis. Background Technology

[0002] Hydrogen energy, as a clean and efficient secondary energy source, is considered an important component of the future energy system. Electrolysis of water is one of the key methods for obtaining high-purity hydrogen. However, traditional freshwater electrolysis for hydrogen production faces challenges such as scarce freshwater resources and high costs. In contrast, with over 70% of the Earth's surface covered by seawater, direct seawater electrolysis for hydrogen production has enormous potential due to its unlimited resources and low cost, and has become a research hotspot in the fields of energy and catalysis.

[0003] In the direct electrolysis of seawater, in addition to the oxygen evolution reaction, the chlorine evolution reaction is more likely to occur at the anode, generating highly oxidizing active chlorine (such as Cl2, HClO, ClO). - Active chlorine is an important chemical product widely used in water treatment, disinfection, and bleaching. Therefore, developing a seawater electrolysis unit capable of simultaneously producing hydrogen and active chlorine offers both economic and environmental benefits.

[0004] However, existing seawater electrolysis technologies, especially those involving the production of active chlorine, face two core challenges:

[0005] 1. Reverse Chlorine Corrosion Problem: In traditional electrolyzers (such as integrated or non-unidirectional flow reactors), active chlorine generated at the anode migrates to the cathode region through diffusion and convection. These highly oxidizing active chlorine species directly attack and corrode the cathode catalyst material (such as platinum, non-precious metal alloys, etc.), leading to rapid catalyst deactivation, a sharp shortening of electrode life, and consequently, rapid performance degradation and shortened lifespan of the device. It may also contaminate the generated hydrogen gas. This "reverse chlorine corrosion" problem severely restricts the long-term operational stability and commercial prospects of the device.

[0006] 2. Mass Transfer Limitations and Reaction Efficiency Issues: Conventional electrolyzer designs typically rely on natural convection or slow flow of reactants at the electrode surface, resulting in low mass transfer efficiency. For seawater electrolysis, a process involving complex ion migration and transformation, limited mass transfer restricts the reaction of reactants (such as Cl-). - The rate at which ions reach the electrode surface and the rate at which products (such as active chlorine) leave the electrode surface cause concentration polarization, thereby increasing energy consumption and reducing overall electrocatalytic efficiency and product yield.

[0007] Currently, although some studies have attempted to alleviate the above problems by improving electrode materials, most solutions have failed to fundamentally solve the problem of corrosion caused by active chlorine in the reactor. Therefore, there is an urgent need for an innovative reactor design and process engineering strategy that can achieve precise control over the electrolyte flow path and reaction process, thereby improving reaction efficiency while fundamentally solving the technical bottleneck of reverse corrosion.

[0008] It should be noted that the information disclosed in the background section above is only for understanding the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0009] To address the issue that existing seawater electrolysis devices cannot stably and efficiently co-produce hydrogen and active chlorine over a long period, this invention provides a method and reactor for sequential electrofiltration and electrolysis of seawater to produce hydrogen and chlorine.

[0010] The present invention adopts the following technical solution:

[0011] In a first aspect, a reactor for sequential electrofiltration and electrolysis of seawater to produce hydrogen and chlorine is provided, comprising a shell, a first permeable baffle, a through-type cathode unit, a second permeable baffle, a through-type anode unit, and a driving device; the shell has a sealed reaction chamber inside, and is provided with an electrolyte inlet and a solution outlet communicating with the reaction chamber; the first permeable baffle, the through-type cathode unit, the second permeable baffle, and the through-type anode unit are all disposed in the reaction chamber; the first permeable baffle and the second permeable baffle are respectively disposed on both sides of the through-type cathode unit, and the second permeable baffle is located between the through-type cathode unit and the through-type anode unit, the first permeable baffle and the second permeable baffle are used to allow hydrogen gas generated by the through-type cathode unit to be discharged but to prevent leakage of liquid electrolyte; the driving device is connected to the electrolyte inlet and is used to pump electrolyte into the reaction chamber and drive the electrolyte to form a unidirectional flow that sequentially penetrates through the first permeable baffle, the through-type cathode unit, the second permeable baffle, and the through-type anode unit and flows out from the solution outlet.

[0012] Secondly, a method for producing hydrogen and chlorine through sequential electrofiltration and seawater electrolysis is provided, comprising the following steps:

[0013] S1. Apply voltage to the penetrating anode unit and penetrating cathode unit of the reactor described in the first aspect;

[0014] S2. Using seawater or simulated seawater as the electrolyte, the drive device is controlled to operate, so that the electrolyte is pumped in from the electrolyte inlet at a set flow rate, and flows through the first ventilated baffle, the through-type cathode unit, the second ventilated baffle and the through-type anode unit in sequence, and flows out from the solution outlet. Hydrogen gas is generated in the through-type cathode unit and a solution containing active chlorine is generated in the through-type anode unit.

[0015] This invention offers the following advantages: It provides a method and reactor for long-term, stable, and efficient seawater electrolysis to produce hydrogen and co-produce active chlorine, fundamentally solving the problem of active chlorine corrosion of the cathode and significantly improving the mass transfer efficiency of reactants and the product yield rate. Specifically, by setting a driving device connected to the electrolyte inlet, the driving device pumps the electrolyte into the reaction chamber and drives the electrolyte to form a unidirectional flow that sequentially penetrates through the through-hole cathode unit and the through-hole anode unit and flows out of the solution outlet. This represents a significant breakthrough in concept, structure, and performance, while simultaneously solving the two long-standing problems of "reverse corrosion" and "mass transfer limitation" in the prior art. The advanced nature of this invention is specifically reflected in the following aspects:

[0016] 1. From "static mixing" to "unidirectional flow"

[0017] Traditional electrolyzers place the anode and cathode in a relatively open or interconnected space, where reactants and products coexist in a static mixing mode. This is the root cause of reverse chlorine corrosion and slow mass transfer. This invention introduces the core process design concepts of "sequential electrofiltration" and "unidirectional flow." The electrolyte is forcibly pumped in from one end, flowing sequentially and directionally through specific functional units (such as the anode and cathode regions). The entire reaction process resembles a precisely controlled "electrofiltration" process. This design achieves spatial sequencing and directionality of the reaction process, preventing reverse mixing of products from the very beginning of the process engineering.

[0018] 2. Fundamentally solved the problem of "reverse chlorine corrosion".

[0019] Existing technologies largely focus on developing more corrosion-resistant cathode materials, a "passive defense" strategy that only addresses the symptoms, not the root cause. This invention, however, utilizes a unidirectional flow physical design. The electrolyte first passes through the cathode, then the anode, establishing a directional hydraulic barrier between the two electrodes. This prevents the active chlorine generated at the anode from back-corroding the cathode. The active chlorine generated at the anode is rapidly carried away from the electrode surface by the flowing electrolyte and "pushed" out of the reactor along the liquid flow direction, significantly reducing its diffusion into the cathode region. This greatly extends the lifespan of the cathode catalyst and electrodes, solving the core problem that has long plagued the stability of seawater electrolysis hydrogen production technology.

[0020] 3. Significantly enhances mass transfer effect

[0021] The reactor of this invention is a through-type reactor. Driven by a driving device, the electrolyte passes through the reaction interface near the through-type electrode, greatly enhancing the reaction of reactants (such as Cl). - This forced convection mass transfer mode effectively reduces the concentration polarization of the electrode surface, allowing the reaction to proceed stably at higher current densities. This significantly improves the efficiency of hydrogen and active chlorine production per unit time, reduces the reaction overpotential, and achieves energy-saving and efficient operation.

[0022] 4. Integrated structure and function

[0023] The reactor of this invention is modular, highly airtight, and safe. It is easy to assemble, disassemble, and maintain, while ensuring safe operation under high-pressure electrolysis conditions. Attached Figure Description

[0024] Figure 1 This is an exploded schematic diagram of the reactor for sequential electrofiltration and electrolysis of seawater to produce hydrogen and chlorine according to Embodiment 1 of the present invention.

[0025] Figure 2 This is a three-dimensional schematic diagram of the reactor body for sequential electrofiltration and electrolysis of seawater to produce hydrogen and chlorine according to Embodiment 1 of the present invention.

[0026] Figure 3 This is an exploded view of the first breathable partition in Embodiment 1 of the present invention.

[0027] Figure 4 The data are LSV test data for direct seawater electrolysis to produce hydrogen and chlorine, conducted in the through-flow reactor and H-type electrolyzer of Example 1 of this invention.

[0028] Figure 5 The data represent LSV test data for hydrogen and chlorine production by electrolysis of 1.04 mol / L sodium chloride solution in the through-flow reactor and H-type electrolyzer of Example 1 of this invention, respectively.

[0029] Figure 6 The data are LSV test data at different flow rates during the direct electrolysis of seawater to produce hydrogen and chlorine in the through-flow reactor of Example 1 of this invention. Detailed Implementation

[0030] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0031] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component. Furthermore, a connection can be used for fixing, coupling, or communication.

[0032] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] This invention provides a reactor for sequential electrofiltration and electrolysis of seawater to produce hydrogen and chlorine, comprising a shell, a first permeable baffle, a through-type cathode unit, a second permeable baffle, a through-type anode unit, and a driving device. The shell has a sealed reaction chamber with an electrolyte inlet and a solution outlet communicating with it. The first permeable baffle, the through-type cathode unit, the second permeable baffle, and the through-type anode unit are all disposed within the reaction chamber. The first and second permeable baffles are respectively disposed on opposite sides of the through-type cathode unit, with the second permeable baffle located between the through-type cathode unit and the through-type anode unit. The first and second permeable baffles allow hydrogen gas generated by the through-type cathode unit to escape but prevent leakage of liquid electrolyte. The driving device is connected to the electrolyte inlet and pumps electrolyte into the reaction chamber, driving the electrolyte to form a unidirectional flow that sequentially penetrates the first permeable baffle, the through-type cathode unit, the second permeable baffle, and the through-type anode unit, exiting from the solution outlet.

[0035] The electrolyte is driven by a drive device to form a unidirectional flow from the cathode to the anode, which avoids the reverse corrosion of the cathode by the active chlorine generated at the anode. The breathable baffle is used to discharge the hydrogen produced at the cathode out of the reactor and to separate the distance between the anode and the cathode, thereby optimizing the electric field distribution.

[0036] In some embodiments, the through-cathode unit includes a cathode conductive plate and a through-cathode disposed on the cathode conductive plate; the through-anode unit includes an anode conductive plate and a through-anode disposed on the anode conductive plate.

[0037] In some embodiments, the first permeable partition includes a first partition body with a window, a first permeable membrane, and a first permeable membrane fixing member. The first partition body has a first through hole, and the first permeable membrane fixing member fixes the first permeable membrane to cover the window of the first partition body. The first permeable membrane fixing member has a first hydrogen outlet communicating with the first permeable membrane. The second permeable partition includes a second partition body with a window, a second permeable membrane, and a second permeable membrane fixing member. The second partition body has a second through hole, and the second permeable membrane fixing member fixes the second permeable membrane to cover the window of the second partition body. The second permeable membrane fixing member has a second hydrogen outlet communicating with the second permeable membrane. The positions of the electrolyte inlet, the first through hole, the second through hole, the penetrating cathode, the penetrating anode, and the solution outlet correspond to each other.

[0038] In some embodiments, the anode conductive plate has a third through hole, and the penetrating anode completely covers the third through hole; the cathode conductive plate has a fourth through hole, and the penetrating cathode completely covers the fourth through hole.

[0039] In some embodiments, the outer casing includes a first casing and a second casing, with the electrolyte inlet disposed on the first casing and the solution outlet disposed on the second casing; the first casing, the first ventilated baffle, the through-type cathode unit, the second ventilated baffle, the through-type anode unit, and the second casing are stacked and assembled.

[0040] In some embodiments, the reactor further includes an electrolyte storage device, a solution collection device containing active chlorine, an inlet pipe, and an outlet pipe. The electrolyte storage device is connected to the electrolyte inlet via the drive device and the inlet pipe, and the solution outlet is connected to the solution collection device containing active chlorine via the outlet pipe.

[0041] In some embodiments, the outer casing is secured and sealed using insulating fasteners (such as insulating flame-retardant nylon bolts and nuts) and seals (such as silicone gaskets). The insulating flame-retardant nylon bolts and nuts secure various parts of the reactor, ensuring a stable and airtight overall structure while providing insulation to prevent short circuits inside the reactor. Silicone gaskets can be placed at various interfaces and connections requiring sealing to prevent electrolyte and gas leakage.

[0042] In some embodiments, the driving device is a peristaltic pump.

[0043] In some embodiments, the through-hole cathode includes a titanium mesh and a hydrogen evolution catalyst grown in situ on the titanium mesh; the through-hole anode includes a titanium mesh and a chlorine evolution catalyst grown in situ on the titanium mesh.

[0044] In some embodiments, after the hydrogen evolution catalyst or chlorine evolution catalyst is grown in situ on the titanium mesh, the gap between the titanium mesh wires is in the range of 1 micrometer to 5 micrometers.

[0045] In some embodiments, the thickness of both the first and second breathable partitions is 0.5-2 cm.

[0046] The present invention also provides a method for producing hydrogen and chlorine through sequential electrofiltration and seawater electrolysis, comprising the following steps:

[0047] S1. Apply voltage to the penetrating anode unit and the penetrating cathode unit of the reactor;

[0048] S2. Using seawater or simulated seawater as the electrolyte, the drive device is controlled to operate, so that the electrolyte is pumped in from the electrolyte inlet at a set flow rate, and flows through the first ventilated baffle, the through-type cathode unit, the second ventilated baffle and the through-type anode unit in sequence, and flows out from the solution outlet. Hydrogen gas is generated in the through-type cathode unit and a solution containing active chlorine is generated in the through-type anode unit.

[0049] In some embodiments, the flow rate of the electrolyte in step S2 is controlled to be greater than 0 mL / min and up to 10 mL / min. More preferably, the flow rate of the electrolyte is controlled to be 6 mL / min.

[0050] The following describes specific embodiments of the present invention.

[0051] Example 1

[0052] A reactor for sequential electrofiltration and seawater electrolysis to produce hydrogen and chlorine includes a reactor body, a peristaltic pump 7, an electrolyte storage device 8, a solution collection device containing active chlorine 9, an inlet pipe 10, and an outlet pipe 20. The reactor body comprises a first shell 3, a first permeable baffle 1, a penetrating cathode unit 5, a second permeable baffle 2, a penetrating anode unit 6, and a second shell 4, which are sequentially stacked and tightly attached together by insulating fasteners (such as insulating flame-retardant nylon bolts and nuts) and sealing components (such as silicone gaskets).

[0053] The outer shell, consisting of the first shell 3 and the second shell 4, has a sealed reaction chamber inside, and is provided with an electrolyte inlet 31 and a solution outlet 41 communicating with the reaction chamber. The electrolyte inlet 31 is located on the first shell 3, and the solution outlet 41 is located on the second shell 4. The electrolyte storage device 8 is connected to the electrolyte inlet 31 through a peristaltic pump 7 and an inlet pipe 10, and the solution outlet 41 is connected to the solution collection device 9 containing active chlorine through an outlet pipe 20.

[0054] The first venting baffle 1, the penetrating cathode unit 5, the second venting baffle 2, and the penetrating anode unit 6 are all disposed within the reaction chamber. The first venting baffle 1 and the second venting baffle 2 are respectively disposed on both sides of the penetrating cathode unit 5, and the second venting baffle 2 is located between the penetrating cathode unit 5 and the penetrating anode unit 6. The first venting baffle 1 and the second venting baffle 2 are used to allow hydrogen gas generated by the penetrating cathode unit to be discharged but to prevent leakage of liquid electrolyte. The peristaltic pump 7 pumps electrolyte into the reaction chamber and drives the electrolyte to form a unidirectional flow that sequentially penetrates through the first venting baffle 1, the penetrating cathode unit 5, the second venting baffle 2, and the penetrating anode unit 6 and flows out from the solution outlet 41.

[0055] The through-cathode unit 5 includes a cathode conductive plate 51 (a titanium conductive plate in this example) and a through-cathode 52 disposed on the cathode conductive plate 51. The cathode conductive plate 51 has a fourth through hole 514, and the through-cathode 52 completely covers the fourth through hole 514 (the area of ​​the through-cathode 52 is larger than the area of ​​the fourth through hole 514). In this example, the through-cathode 52 includes a titanium mesh and a hydrogen evolution catalyst grown in situ on the titanium mesh (a three-dimensional Co2NiO4 nanoneedle array grown in situ on the titanium mesh). The through-cathode 52 is prepared by the following steps: (1) The titanium mesh is ultrasonically cleaned with 1M hydrochloric acid, anhydrous ethanol and deionized water respectively, and then vacuum dried at 60°C. (2) Metal salts (2 mmol Co(NO3)2·6H2O and 1 mmol Ni(NO3)2·6H2O), 10 mmol urea and 6 mmol NH4F are weighed and dissolved in 60 mL of deionized water. The solution is magnetically stirred for 30 minutes until completely dissolved. (3) Place the titanium mesh in a 100 mL stainless steel high-pressure reactor lined with polytetrafluoroethylene, and pour in the above precursor solution (the titanium mesh is completely immersed in the precursor solution). After sealing the reactor, place it in a forced-air drying oven and react at 120 °C for 12 hours. After the reaction is completed, allow it to cool naturally, remove the titanium mesh, wash it thoroughly with deionized water and ethanol, and dry it in a forced-air drying oven at 60 °C for 12 hours to obtain a pinkish-purple CoNi-LDH precursor grown in situ on the titanium mesh. (4) Place the above titanium mesh loaded with the precursor in a tube furnace, and heat it to 400 °C at a rate of 5 °C / min under an air atmosphere, and hold it at this temperature for 3 hours. Then allow it to cool naturally to room temperature to obtain a black three-dimensional Co2NiO4 nanoneedle array.

[0056] The through-hole anode unit 6 includes an anode conductive plate 61 (in this example, a titanium conductive plate) and a through-hole anode 62 disposed on the anode conductive plate 61. The anode conductive plate 61 has a third through-hole 613, and the through-hole anode 62 completely covers the third through-hole 613 (the area of ​​the through-hole anode 62 is larger than the area of ​​the third through-hole 613). In this example, the through-hole anode 62 includes a titanium mesh and a chlorine evolution catalyst (cobalt-nickel bimetallic selenide (Co2NiSe4)) grown in situ on the titanium mesh. The through-hole anode 62 is prepared by the following steps: (1) the titanium mesh is ultrasonically cleaned with 1M hydrochloric acid, anhydrous ethanol and deionized water respectively, and then vacuum dried at 60°C. (2) Add 2 mmol of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 1 mmol of nickel nitrate hexahydrate (Ni(NO3)2·6H2O), 10 mmol of urea and 6 mmol of ammonium fluoride to 30 mL of deionized water and stir magnetically for 0.5 hours to obtain a pink transparent solution; (3) Transfer the titanium mesh treated in step (1) and the solution obtained in step (2) to a high-pressure reactor and perform a hydrothermal reaction at 120°C for 12 hours. Then, after cooling to room temperature, use water and anhydrous ethanol to ultrasonically clean away impurities that have not grown on the surface of the titanium mesh, and dry it in a vacuum oven at 60°C to obtain the precursor CoNi-LDH (CoNi layered double hydroxide); (4) Add 1 mmol of selenium powder and 1 mmol of sodium borohydride to 30 mL of deionized water. (5) The titanium mesh with CoNi-LDH grown in step (3) and the solution obtained in step (4) were transferred to a high-pressure reactor and hydrothermally reacted at 180°C for 4 hours. After cooling to room temperature, the impurities not grown on the surface of the titanium mesh were ultrasonically cleaned with water and anhydrous ethanol. The mixture was dried at 60°C in a vacuum oven to obtain a cobalt-nickel bimetallic selenide (Co2NiSe4) with a morphology of nanoneedle array grown on the titanium mesh.

[0057] In this example, after the hydrogen evolution catalyst or chlorine evolution catalyst is grown in situ on the titanium mesh, the gap between the titanium mesh wires is in the range of 1 micrometer to 5 micrometers; both the anode conductive plate 61 and the cathode conductive plate 51 have electrical connection extensions A to connect to an external electrochemical workstation and provide a stable current to the electrodes.

[0058] The first permeable baffle 1 includes a first baffle body 11 with a window, a first permeable membrane 12, and a first permeable membrane fixing member 13. The first baffle body 11 has a first through hole 111. The first permeable membrane fixing member 13 detachably fixes the first permeable membrane 12 to cover the window 112 of the first baffle body 11. The first permeable membrane fixing member 13 has a first hydrogen outlet 131 communicating with the first permeable membrane 12. The shape and structure of the second permeable baffle 2 are the same as those of the first permeable baffle 1, and will not be described again. The positions of the electrolyte inlet 31, the first through hole 111 on the first baffle body, the penetrating cathode 52, the second through hole 211 on the second permeable baffle 2, the penetrating anode 62, and the solution outlet 41 correspond to each other and are all on the unidirectional flow path of the electrolyte.

[0059] In this example, the first housing 3 and the second housing 4 are made of acrylic plastic. The inlet pipe 10 and the outlet pipe 20 are silicone hoses, and the thickness of the first ventilated baffle 1 and the second ventilated baffle 2 is 0.5-2 cm. The baffle body and the ventilated membrane fastener are made of epoxy resin, and the ventilated membrane is made of hydrophobic polytetrafluoroethylene (PTFE).

[0060] Example 2

[0061] This embodiment provides a method for producing hydrogen and chlorine through sequential electrofiltration and seawater electrolysis, which includes the following steps:

[0062] S1. Apply voltage to the through-hole anode unit and through-hole cathode unit of the through-hole reactor of Example 1;

[0063] S2. Using seawater or simulated seawater as the electrolyte, the peristaltic pump 7 is controlled to operate, so that the electrolyte is pumped into the electrolyte inlet at a set flow rate, sequentially passing through the first ventilated baffle, the through-type cathode unit, the second ventilated baffle, and the through-type anode unit, and flowing out from the solution outlet. Hydrogen gas is generated in the through-type cathode unit, and the hydrogen gas is discharged through the ventilated membrane of the ventilated baffle via the hydrogen gas outlet (in the experiment of this invention, no bubbles were observed to be discharged at the solution outlet 41, indicating that the hydrogen gas had been completely discharged from the ventilated membrane). A solution containing active chlorine is generated in the through-type anode unit, and the solution containing active chlorine is discharged from the solution outlet 41.

[0064] In some embodiments, the flow rate of the electrolyte in step S2 is controlled to be greater than 0 mL / min and up to 10 mL / min. More preferably, the flow rate of the electrolyte is controlled to be 6 mL / min.

[0065] In this example, the peristaltic pump was turned on and the flow rate was set to 6 mL / min, driving the electrolyte to flow continuously and unidirectionally through the permeation reactor. The electrolyte permeated the cathode and anode sequentially. The electrochemical workstation was then started to conduct electrocatalytic activity and long-term stability tests, such as... Figure 4 and Figure 5 As shown.

[0066] like Figure 4 As shown, the electrocatalytic effect: using natural seawater as the electrolyte, linear sweep voltammetry (LSV) tests were performed on both the through-flow reactor of Example 1 and a commercial H-type electrolyzer (100-100 mL) (except for the reactor structure, all other conditions were kept consistent, such as electrode area, electrolyte volume, catalyst, etc.). It was found that at 3.5 V, the current density in the through-flow reactor of this example was 45.4 mA cm⁻¹. -2 Compared to a conventional H-type electrolyzer (17.0 mA cm⁻¹), -2 The test result was 28.4 mA cm. -2 .

[0067] like Figure 5 As shown, long-term stability effect: To accelerate the testing of the permeation reactor's resistance to chloride corrosion and stability during seawater electrolysis, simulated seawater with a concentration of 1M NaCl (approximately twice that of natural seawater) was used. This high-concentration corrosive chloride ion electrolyte simulated extreme conditions that might be encountered during long-term operation, such as electrode corrosion and catalyst deactivation, in a short time, thereby efficiently evaluating the durability of the catalyst and the device. In the simulated concentrated seawater with 1M NaCl, 10 mA cm⁻¹ -2 A chronopotentiometry (CP) test was conducted for 240 hours at a current density. The CP curve of the reactor in this embodiment showed almost no voltage increase compared to the H-type electrolyzer, remaining in a relatively stable state. This indicates that in a high-chlorine environment, the present invention can effectively extend the service life of the electrodes through the unidirectional flow of the electrolyte.

[0068] The embodiments of the present invention also tested LSV curves at different flow rates, such as Figure 6As shown, the electrocatalytic performance significantly improved as the flow rate increased from 0 mL / min to 6 mL / min, indicating that the mass transfer limitation was gradually overcome during the reaction. When the flow rate increased from 6 mL / min to 10 mL / min, the improvement in catalytic activity shown in the LSV curve slowed down, indicating that the reaction rate was no longer controlled by mass transfer but instead by the intrinsic catalytic kinetics of the electrode surface. This suggests that further increasing the flow rate beyond 6 mL / min does not significantly improve performance, but increases system energy consumption and the risk of mechanical erosion. Therefore, 6 mL / min represents the optimal balance between high efficiency and stable operation.

[0069] In this invention, the flow path of the electrolyte must be the entire working area of ​​the penetrating electrode, passing through the front of the electrode rather than just its surface. This is the physical basis for achieving "sequential electrofiltration" and enhancing mass transfer. During electrolysis, the reactor is completely filled with electrolyte at all times, forming a continuous, ion-conducting liquid medium. Both the cathode and anode are spatially immersed in this electrolyte, ensuring that: at any moment during electrolysis, a complete ion-conducting circuit is formed between the cathode and anode through the continuous electrolyte medium, guaranteeing that the current circuit will not be interrupted; simultaneously, the continuously flowing electrolyte: (a) continuously provides fresh seawater to the cathode for the hydrogen evolution reaction; (b) due to the low current density of this invention (e.g., 10 mA cm⁻¹), -2 The generated hydroxide ions are dispersed in a large amount of seawater (e.g., at a flow rate of 6 mL / min). When transported to the anode, the pH value of the seawater is not significantly higher than that of normal seawater. Furthermore, the chlorine evolution catalyst used in this embodiment of the invention has high selectivity, minimal side reactions, and the byproduct oxygen is a harmless byproduct that is easily treated; therefore, it has almost no impact on the product active chlorine. Thus, this invention utilizes a continuously flowing electrolyte to ensure the instantaneous continuity of the ion circuit, while simultaneously using a directional fluid path to isolate and optimize the reaction environment, thereby achieving the goal of efficient hydrogen production and controllable co-production of active chlorine.

[0070] In other embodiments, centrifugal pumps, metering pumps, etc., may also be used to provide fluid power.

[0071] In the above embodiments, the through-hole anode and through-hole cathode are mesh-like (including titanium mesh and catalyst grown in situ on the titanium mesh). In other embodiments, they can also be in the form of foam, particle-filled bed, etc., as long as the electrolyte can effectively penetrate.

[0072] In Example 1, the reactor body is assembled by stacking the shell, anode, cathode, partition, etc. In other examples, the reactor can also be designed as a concentric cylindrical shape, with the electrolyte penetrating radially from the inside to the outside (or from the outside to the inside), as long as the electrolyte flows unidirectionally from the cathode to the anode.

[0073] The reactor of this invention can be used in the process of "direct electrolysis of seawater to produce hydrogen and concurrent production of active chlorine".

[0074] To address the reverse corrosion problem in existing technologies, this invention employs a "penetrating electrode" and a "unidirectional electrolyte flow" design. A peristaltic pump drives the electrolyte to form a forced, unidirectional flow from inlet to outlet within the reactor. This flow pattern establishes a positive "fluid flushing" effect in fluid dynamics, acting as a fluid barrier to continuously carry the active chlorine products generated at the anode away from the reaction zone and out of the system, fundamentally cutting off their reverse diffusion path to the cathode. Therefore, the cathode is always in a relatively "clean" environment, avoiding corrosion by active chlorine, thereby greatly extending the service life of the electrode and the entire device, and ensuring long-term operational stability.

[0075] To address existing mass transfer limitations and reaction efficiency issues, the electrolyte of this invention flows sequentially through the penetrating electrode in a unidirectional flow mode, achieving "sequential electrocatalysis" and forced convection. This reduces the mass transfer boundary layer and allows for timely replenishment of reactants and removal of products.

[0076] The above description provides a further detailed explanation of the present invention in conjunction with specific / preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the concept of the present invention, and all such substitutions or modifications should be considered within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "an embodiment," "some embodiments," "preferred embodiment," "example," "specific example," or "some examples," etc., indicates that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples. Although the embodiments of the present invention and their advantages have been described in detail, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the scope of protection of the patent application.

Claims

1. A reactor for sequential electrofiltration and seawater electrolysis to produce hydrogen and chlorine, characterized in that, It includes a housing, a first ventilated baffle, a penetrating cathode unit, a second ventilated baffle, a penetrating anode unit, and a drive device; The interior of the outer shell has a sealed reaction chamber, and is provided with an electrolyte inlet and a solution outlet communicating with the reaction chamber; The first ventilated baffle, the penetrating cathode unit, the second ventilated baffle, and the penetrating anode unit are all disposed within the reaction chamber; The through-hole cathode unit includes a through-hole cathode, which includes a titanium mesh and a hydrogen evolution catalyst grown in situ on the titanium mesh; the through-hole anode unit includes a through-hole anode, which includes a titanium mesh and a chlorine evolution catalyst grown in situ on the titanium mesh. The first and second ventilated baffles are respectively disposed on both sides of the penetrating cathode unit, with the second ventilated baffle located between the penetrating cathode unit and the penetrating anode unit. The first and second ventilated baffles allow hydrogen gas generated by the penetrating cathode unit to escape while preventing leakage of liquid electrolyte. The first ventilated baffle includes a first baffle body with a window, a first ventilated membrane, and a first ventilated membrane fixing member. The first baffle body has a first through hole, and the first ventilated membrane fixing member secures the first ventilated membrane to cover the first baffle body. The first ventilated membrane fixing member has a first hydrogen outlet communicating with the first ventilated membrane; the second ventilated partition includes a second partition body with a window, a second ventilated membrane, and a second ventilated membrane fixing member. The second partition body has a second through hole, and the second ventilated membrane fixing member fixes the second ventilated membrane to cover the window of the second partition body. The second ventilated membrane fixing member has a second hydrogen outlet communicating with the second ventilated membrane; the positions of the electrolyte inlet, the first through hole, the second through hole, the penetrating cathode, the penetrating anode, and the solution outlet correspond to each other. The driving device is connected to the electrolyte inlet and is used to pump electrolyte into the reaction chamber and drive the electrolyte to form a unidirectional flow that sequentially penetrates the first venting baffle, the penetrating cathode unit, the second venting baffle, and the penetrating anode unit and flows out of the solution outlet.

2. The reactor as described in claim 1, characterized in that: The penetrating cathode unit includes a cathode conductive plate and the penetrating cathode disposed on the cathode conductive plate. The penetrating anode unit includes an anode conductive plate and the penetrating anode disposed on the anode conductive plate.

3. The reactor as described in claim 2, characterized in that: The anode conductive plate has a third through hole, and the penetrating anode completely covers the third through hole; the cathode conductive plate has a fourth through hole, and the penetrating cathode completely covers the fourth through hole.

4. The reactor as described in claim 1, characterized in that: The outer casing includes a first casing and a second casing. The electrolyte inlet is disposed on the first casing, and the solution outlet is disposed on the second casing. The first casing, the first ventilated baffle, the penetrating cathode unit, the second ventilated baffle, the penetrating anode unit, and the second casing are stacked and assembled.

5. The reactor as described in claim 1, characterized in that: The reactor also includes an electrolyte storage device, a solution collection device containing active chlorine, an inlet pipe, and an outlet pipe. The electrolyte storage device is connected to the electrolyte inlet through the drive device and the inlet pipe, and the solution outlet is connected to the solution collection device containing active chlorine through the outlet pipe.

6. The reactor as described in claim 1, characterized in that: The housing is secured and sealed by insulating fasteners and seals; the drive device is a peristaltic pump.

7. A method for producing hydrogen and chlorine from seawater by sequential electrofiltration and electrolysis using the reactor described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Apply voltage to the penetrating anode unit and the penetrating cathode unit of the reactor; S2. Using seawater or simulated seawater as the electrolyte, the drive device is controlled to operate, so that the electrolyte is pumped in from the electrolyte inlet at a set flow rate, and flows through the first ventilated baffle, the through-type cathode unit, the second ventilated baffle and the through-type anode unit in sequence, and flows out from the solution outlet. Hydrogen gas is generated in the through-type cathode unit and a solution containing active chlorine is generated in the through-type anode unit.

8. The method for producing hydrogen and chlorine from seawater by sequential electrofiltration and electrolysis as described in claim 7, characterized in that, In step S2, the flow rate of the electrolyte is controlled at 6 mL / min.

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