Cathode and in-situ preparation of electronic grade high concentration hydrogen peroxide electro-synthesis equipment and method

Abstract

The application discloses a kind of cathode and in-situ preparation electronic grade high-concentration hydrogen peroxide electro-synthesis equipment and method, the cathode includes diffusion layer, catalytic layer and support layer, the diffusion layer and the catalytic layer are respectively arranged at the two sides of the support layer, wherein the diffusion layer and the catalytic layer are respectively by the mixture of polytetrafluoroethylene, salt and conductive carbon black is shaped in the two sides of the support layer and is prepared by heat treatment.The cathode and in-situ preparation electronic grade high-concentration hydrogen peroxide electro-synthesis equipment and method presented by the application, by optimizing cathode configuration, reaction vessel structure and operating parameter, various decomposition pathways of hydrogen peroxide are inhibited synergistically, so that high-concentration hydrogen peroxide is accumulated in-situ efficiently at high current density.

Description

Technical Field

[0001] This invention relates to the field of electrochemical synthesis technology, and in particular to an electrosynthesis apparatus and method for preparing high-concentration electronic-grade hydrogen peroxide in situ using a cathode. Background Technology

[0002] Electronic-grade hydrogen peroxide (high-purity hydrogen peroxide) is an indispensable key electronic chemical raw material in integrated circuit (IC) manufacturing processes. It is widely used in core processes such as RCA standard cleaning of silicon wafers (including SC-1 and SC-2 processes), photoresist stripping (SPM cleaning), metal layer etching, and cleaning after chemical mechanical polishing (CMP). As the linewidth of integrated circuits continues to shrink to the nanometer scale, extremely stringent requirements have been placed on the permissible content of impurities such as metal ions, particulate matter, and total organic carbon (TOC) in hydrogen peroxide. Relevant international standards (such as SEMI standards) clearly stipulate that the concentration of a single metal ion in electronic-grade hydrogen peroxide must be below trace (ppb) and ultra-trace (ppt) concentration levels, and the size and number of particulate matter must also be strictly controlled.

[0003] Currently, the mainstream industrial production method for hydrogen peroxide is the anthraquinone process. This process first uses anthraquinone (2-ethylanthraquinone or 2-pentylanthraquinone) as a hydrogen carrier, which is then mixed with an organic solvent (such as heavy aromatics and trioctyl phosphate) to form a working solution. This solution reacts with hydrogen in a hydrogenation tower under the action of a palladium-based or nickel-based catalyst to produce hydrogen anthraquinone. The reaction conditions are typically 40–70°C and 0.2–0.5 MPa. The hydrogenated solution is then transferred to an oxidation tower, where it reacts with oxygen or air to produce hydrogen peroxide. Finally, after extraction, purification, and concentration, products of different specifications are obtained. However, the anthraquinone process has many inherent drawbacks: anthraquinone itself is classified as a Group 2B carcinogen by the International Agency for Research on Cancer (IARC), and the process involves hydrogen and large amounts of flammable organic solvents, resulting in a long production process, complex equipment, and a high carbon footprint. Historically, explosions have occurred multiple times due to improper process control, negligence in raw material management, or operational errors. Furthermore, the subsequent purification and concentration steps consume enormous amounts of energy, further increasing production costs.

[0004] To overcome the aforementioned drawbacks of the anthraquinone method, electrocatalytic synthesis of hydrogen peroxide has attracted widespread attention in recent years. This technology uses oxygen and water as reactants, and at room temperature and pressure, it achieves hydrogen peroxide synthesis via a two-electron reduction reaction (2e⁻) at the cathode surface. -Electrocatalytic oxidation (ORR) directly generates hydrogen peroxide, offering significant advantages such as readily available raw materials (water and air), no organic solvents involved, mild reaction conditions, easy modular integration of production equipment, and the ability to utilize renewable energy. It is considered a green, safe, and low-carbon alternative. However, current electrocatalytic synthesis of hydrogen peroxide still faces a key bottleneck: low product concentration. This is because, during continuous electrolysis, the generated hydrogen peroxide is oxidized and decomposed at the anode, thermally decomposed due to increased electrolyte temperature, or further reduced to water at the cathode, resulting in low net accumulation efficiency. Therefore, conventional electrocatalytic systems struggle to achieve the hydrogen peroxide concentration required for commercial electronic products in a single electrolysis cycle (typically requiring a stock solution concentration of 30%–32%, while various process formulations significantly dilute it to 1%–8%). Subsequent steps such as evaporation and concentration to increase the concentration would substantially increase energy consumption and cost, weakening the economic viability of the electrosynthesis process.

[0005] Therefore, in order to gradually replace the traditional anthraquinone method and make electrocatalytic synthesis the mainstream green production method for electronic-grade hydrogen peroxide, it is necessary to develop electrosynthesis equipment and supporting technologies that can efficiently accumulate high concentrations of hydrogen peroxide in situ.

[0006] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes an electrosynthesis device and method for preparing high-concentration electronic-grade hydrogen peroxide in situ using a cathode. By optimizing the cathode configuration, reaction vessel structure, and operating parameters, various decomposition pathways of hydrogen peroxide (including chemical reduction, electrochemical reduction, thermal decomposition, and anodic oxidation) are synergistically suppressed, thereby achieving efficient in-situ accumulation of high-concentration hydrogen peroxide under high current density.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention discloses a cathode comprising a diffusion layer, a catalyst layer and a support layer, wherein the diffusion layer and the catalyst layer are respectively disposed on both sides of the support layer, and wherein the diffusion layer and the catalyst layer are respectively obtained by forming a mixture of polytetrafluoroethylene, salt and conductive carbon black on both sides of the support layer and then heat treating it.

[0009] Preferably, the thickness of the diffusion layer and / or the catalyst layer is 50 μm to 150 μm.

[0010] Preferably, both the diffusion layer and the catalyst layer are made of a mixture of polytetrafluoroethylene, salt, and conductive carbon black in a mass ratio of (0.5-2):(0.3-2):1.

[0011] Preferably, the cathode is prepared by the following method: a mixture of polytetrafluoroethylene, salt, and conductive carbon black is stirred to form a paste mixture, and the paste mixture is rolled onto both sides of the support layer; then the prepared electrode is washed, and then heated to 300℃ to 400℃ at a rate of 5℃ / min to 10℃ / min, calcined for 30min to 60min, and then cooled.

[0012] Secondly, this invention discloses an electrosynthesis apparatus for in-situ preparation of electronic-grade high-concentration hydrogen peroxide, comprising a reaction vessel, a proton exchange membrane, an anode, a DC power supply, and the cathode described in the first aspect; wherein, The reaction vessel is used to contain the electrolyte, and the reaction vessel is divided into a cathode chamber and an anode chamber by the proton exchange membrane. The cathode is installed in the cathode chamber, the catalyst layer faces the electrolyte inside the cathode chamber, and the diffusion layer is exposed to air. The anode is installed in the anode chamber; The DC power supply is electrically connected to the cathode and the anode respectively, and is used to provide a constant current for the electrosynthesis reaction.

[0013] Preferably, the reaction vessel includes a first plate, a second plate, a third plate, and fasteners. The first plate, the second plate, and the third plate are fastened together by the fasteners. The first plate and the second plate are corresponding hollow structures. A groove is formed on the third plate at a position corresponding to the center of the hollow structure of the second plate. The cathode is sandwiched between the first plate and the second plate. The first plate is pressed against one side of the diffusion layer. A cathode chamber is formed at the center of the hollow structure of the second plate, and the second plate is pressed against one side of the catalyst layer. The proton exchange membrane is sandwiched between the second plate and the third plate by the fasteners. The groove on the third plate is formed on the side close to the proton exchange membrane to form the anode chamber for accommodating the anode.

[0014] Preferably, the reaction vessel further includes a first gasket and a second gasket, the first gasket and the second gasket being hollow structures corresponding to the hollow structure of the second plate, the first gasket being clamped and connected between the cathode and the second plate by the fastener, and the second gasket being clamped and connected between the proton exchange membrane and the third plate by the fastener.

[0015] Preferably, the electrosynthesis equipment further includes an electrolyte circulation unit, which includes a first storage container, a second storage container, a first peristaltic pump, and a second peristaltic pump. The first peristaltic pump is used to circulate the electrolyte in the cathode chamber and the first storage container, and the second peristaltic pump is used to circulate the electrolyte in the anode chamber and the second storage container.

[0016] Preferably, the anode and the cathode are arranged in parallel, and the distance between the anode and the cathode is 10mm to 20mm.

[0017] Thirdly, the present invention discloses a method for preparing electronic-grade high-concentration hydrogen peroxide using the electrosynthesis equipment described in the second aspect, characterized by comprising the following steps: injecting electrolyte into the cathode chamber and the anode chamber respectively, turning on the DC power supply, and applying a current density of 10–100 mA / cm². 2 During the electrolysis process, the electrolyte temperature is maintained below 35°C; electrolysis continues until the hydrogen peroxide concentration in the electrolyte in the cathode chamber reaches a predetermined value.

[0018] Compared with existing technologies, the advantages of this invention are as follows: By employing a cathode with a specific structure and composition, combined with optimized equipment configuration and operating parameters, this invention achieves in-situ, high-efficiency production of high-concentration hydrogen peroxide. The diffusion layer and catalytic layer of the cathode are respectively located on both sides of the support layer, formed by rolling and calcining a mixture of polytetrafluoroethylene, salt, and conductive carbon black in a specific ratio. This symmetrical structure balances the shrinkage stress on both sides of the support layer during calcination, preventing electrode warping and cracking, and improving the mechanical stability of the electrode. The diffusion layer has good hydrophobicity and oxygen diffusion channels, effectively preventing water from flooding the oxygen mass transfer channels and improving oxygen mass transfer efficiency. The catalytic layer has a moderate thickness, ensuring that the electric field repulsion pushes the produced hydrogen peroxide away from the cathode, preventing further reduction, while also balancing the oxygen mass transfer distance and the mechanical strength of the electrode. This structural design enables the cathode to efficiently produce hydrogen peroxide at high current densities and inhibit its further reduction. Applying the aforementioned cathode to the electrosynthesis equipment, along with a proton exchange membrane separating the cathode and anolyte, effectively prevents the oxidative decomposition of hydrogen peroxide at the anolyte. Controlling the electrolyte temperature slows down the thermal decomposition of hydrogen peroxide. Setting appropriate electrode spacing and electrolyte circulation helps disperse hydrogen peroxide into the solution, reducing its accumulation at the cathode interface. The synergistic effect of these technical features significantly suppresses the decomposition and side reaction losses of hydrogen peroxide during accumulation, enabling the equipment to operate at high current densities and directly produce high-concentration hydrogen peroxide. Ultimately, this achieves the direct electrosynthesis of high-concentration hydrogen peroxide at room temperature and pressure, avoiding the high pollution, high risk, and high energy consumption problems of the traditional anthraquinone method, and overcoming the shortcomings of low product concentration and large decomposition losses in ordinary electrocatalytic systems.

[0019] In a further embodiment, the present invention also has the following beneficial effects: (1) By controlling the thickness of the diffusion layer and / or catalyst layer within the range of 50μm to 150μm, sufficient oxygen mass transfer efficiency can be ensured, the mechanical strength of the electrode can be maintained, and the service life of the electrode can be extended.

[0020] (2) Both the diffusion layer and the catalyst layer are made of a mixture of polytetrafluoroethylene, salt and conductive carbon black in a specific mass ratio. This ratio ensures the balance of hydrophobicity, conductivity and catalytic activity of the cathode, which is beneficial to oxygen mass transfer and hydrogen peroxide generation.

[0021] (3) Through specific preparation methods, including rolling, washing and calcination, the electrode has a uniform material distribution and stable performance. Moreover, the process is simple, reproducible and suitable for large-scale production.

[0022] (4) By setting up an electrolyte circulation unit, the electrolyte in the cathode chamber and the anode chamber is circulated with the external storage container by a peristaltic pump. This not only effectively removes the heat of reaction and maintains the low temperature environment of the system, but also slows down the thermal decomposition of hydrogen peroxide. In addition, the flow of the solution disturbs the diffusion layer on the cathode surface, preventing the generated hydrogen peroxide from accumulating locally at the reaction interface, and further reducing the probability of its reduction. This not only helps to control the temperature, but also avoids excessively high local concentrations.

[0023] (5) The reaction vessel adopts a plate design and is assembled with fasteners, which facilitates disassembly and maintenance; the first gasket and the second gasket enhance the sealing performance and prevent electrolyte leakage.

[0024] (6) By controlling the distance between the anode and cathode to 10mm to 20mm, the electric field distribution and material transport efficiency were optimized, and the current efficiency was improved.

[0025] (7) The method for preparing high-concentration hydrogen peroxide further optimizes the yield and concentration of hydrogen peroxide by controlling the current density, electrolyte temperature and circulation conditions.

[0026] Other beneficial effects of the embodiments of the present invention will be further described below. Attached Figure Description

[0027] Figure 1 This is the method for preparing the cathode according to Embodiment 1 of the present invention.

[0028] Figure 2 This is a schematic diagram of the electrosynthesis equipment for in-situ preparation of electronic-grade high-concentration hydrogen peroxide according to Embodiment 2 of the present invention; Figure 3 yes Figure 2 Exploded structural diagram of the electrosynthesis equipment; Figure 4 yes Figure 2 Schematic diagram of the operation of the electrosynthesis equipment; Figure 5 This is a comparison diagram of the effects of the electrode of the present invention and the electrode without salt in preparing hydrogen peroxide in a specific embodiment of the present invention; Figure 6 This is a performance diagram of the electrocatalytic hydrogen peroxide synthesis equipment in specific embodiment two of the present invention when a proton exchange membrane is not used; Figure 7 This is a performance diagram of the electrocatalytic hydrogen peroxide synthesis equipment in specific embodiment three of the present invention when using a proton exchange membrane. Detailed Implementation

[0029] 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.

[0030] 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 both fixing and circuit / signal connectivity.

[0031] 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.

[0032] 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.

[0033] Embodiment 1 of the present invention discloses a cathode, comprising a diffusion layer, a catalyst layer and a support layer, wherein the diffusion layer and the catalyst layer are respectively disposed on both sides of the support layer, wherein the diffusion layer and the catalyst layer are respectively formed by molding a mixture of polytetrafluoroethylene, salt and conductive carbon black on both sides of the support layer and then heat-treating them.

[0034] In a further embodiment, the thickness of the diffusion layer and / or catalyst layer is 50 μm to 150 μm. Both the diffusion layer and the catalyst layer are made of a mixture of polytetrafluoroethylene, salt, and conductive carbon black in a mass ratio of (0.5–2):(0.3–2):1. Specifically, as... Figure 1 As shown, the specific preparation process of the cathode is as follows: 0.5-2 parts by mass of polytetrafluoroethylene, 0.3-2 parts by mass of salt, and 1 part by mass of conductive carbon black are mixed and stirred to form a paste mixture. The paste mixture is then extruded into a film using a roller press and rolled onto both sides of the support layer. After rolling, the prepared electrode is thoroughly washed for 10-24 hours, then placed in a muffle furnace and heated to 300-400℃ at a rate of 5-10℃ / min, calcined for 30-60 minutes, and then cooled. During the thorough washing process, a conductivity meter is used to monitor the washing water until the conductivity remains constant to ensure complete removal of salt. The salt can be, for example, sodium sulfate or sodium chloride, and more specifically, anhydrous sodium sulfate with a particle size of 50-200 μm can be used as a pore-forming agent. The support layer can be, for example, stainless steel mesh, titanium mesh, or nickel mesh, which provides a framework for catalyst adhesion and helps improve the mechanical strength of the electrode. Conductive carbon black, for example, is acetylene black that has been acid-treated to increase oxygen-containing functional groups.

[0035] The cathode in Embodiment 1 of this invention is an air self-diffusion cathode, composed of a catalytic layer, a support layer, and a diffusion layer. From the perspective of electrode symmetry, during calcination, shrinkage stress causes the electrode to warp towards the side carrying the catalytic material, making it prone to cracking and peeling during assembly. However, by setting the catalytic layer and diffusion layer on both sides of the support layer respectively, the stress on both sides of the support layer cancels each other out. In this balanced state, the mechanical stability of the electrode is maximized. Furthermore, the diffusion layer is made of a mixture of polytetrafluoroethylene, salt, and conductive carbon black with a mass ratio of (0.5-2):(0.3-2):1. After thorough washing and calcination, it has more oxygen diffusion channels and maintains strong hydrophobic properties, with a surface contact angle greater than 150°. This effectively prevents water from flooding the oxygen diffusion and mass transfer channels, thereby further improving the oxygen mass transfer efficiency. In addition, the thickness of the catalyst layer on the cathode is 50-150 µm. If it is too thick, the oxygen transport channel will become longer, resulting in insufficient oxygen supply rate at the catalytic reaction interface, which will affect the electrode efficiency. If it is too thin, the mechanical strength of the electrode will decrease, making it prone to structural collapse and affecting the electrode life. Therefore, this invention sets the thickness of the catalyst layer appropriately (50-150 µm). On the one hand, it ensures the high efficiency of the electric field repulsion in pushing the produced hydrogen peroxide away from the cathode, thereby avoiding further reduction of the produced hydrogen peroxide by the cathode during diffusion into the solution. On the other hand, it balances the oxygen mass transfer distance and the mechanical strength of the electrode, achieving higher oxygen mass transfer efficiency and pressure resistance.

[0036] In summary, this invention employs an innovative air self-diffusion cathode preparation and structure: the air self-diffusion cathode is prepared using polytetrafluoroethylene, salt, and carbon black as raw materials through a rolling-washing-calcination method (raw material mass ratio (0.5-2):(0.3-2):1, rolled onto both sides of a stainless steel mesh, titanium mesh, or nickel mesh, thoroughly washed for 10-24 hours, and calcined at 300-400℃ for 30-60 minutes). This cathode can actively capture oxygen from ambient air, undergoing a two-electron oxygen reduction reaction to generate hydrogen peroxide, requiring no external gas supply device (such as an oxygen cylinder or air compressor), and only needs electricity to drive the equipment to operate efficiently.

[0037] like Figures 2 to 4 As shown in Embodiment 2 of the present invention, an electrosynthesis device for in-situ preparation of electronic-grade high-concentration hydrogen peroxide is disclosed, comprising a reaction vessel 10, a proton exchange membrane 20, a cathode 30, an anode 40, an electrolyte circulation unit 50, and a DC power supply 60. The reaction vessel 10 is used to contain the electrolyte, and the reaction vessel 10 is divided into a cathode chamber and an anode chamber by the proton exchange membrane 20. The cathode 30 is installed in the cathode chamber, and the cathode 30 is the cathode used in Embodiment 1, wherein the catalyst layer faces the electrolyte in the cathode chamber, and the diffusion layer is exposed to air. The anode 40 is installed in the anode chamber. The electrolyte circulation unit 50 is used to circulate the electrolyte in the cathode chamber and the anode chamber respectively. The DC power supply 60 is connected to the cathode 30 and the anode 40 respectively, and is used to provide a constant current for the electrosynthesis reaction.

[0038] The anode 40 can be, for example, a commercially available ruthenium-iridium-titanium plate electrode, arranged parallel to the cathode at a spacing of 10–20 mm and connected to the positive terminal of the DC power supply 60. The anode is immersed in an electrolyte, which is sodium sulfate, prepared at a concentration of 0.5–1.5 M, to ensure that the solution temperature is maintained below 35°C during continuous electrolysis, preferably between 10°C and 30°C. Furthermore, a proton exchange membrane can be added to the anode chamber, or a more stable anode material such as lead- or boron-doped diamond (BDD) can be used to suppress the dissolution and migration of metal ions.

[0039] The proton exchange membrane 20 can separate the electrolyte in the cathode chamber and the anode chamber, and simultaneously provide hydrogen ions (H+). + It provides a channel for the migration and transport of hydrogen peroxide, which can avoid the oxidative decomposition of hydrogen peroxide by the anode and increase the yield of hydrogen peroxide.

[0040] The reaction vessel 10 includes a first plate 11, a second plate 12, a third plate 13, and a fastener 14. The first plate 11, the second plate 12, and the third plate 13 are fastened together by the fastener 14. The first plate 11 and the second plate 12 are corresponding hollow structures (or can also be called annular structures). A groove is formed on the third plate 13 at a position corresponding to the center of the hollow structure of the second plate 12. A hole is formed on the top of the second plate 12 to connect to the center of the hollow structure. An opening is formed on the top of the third plate 13 to connect to the groove. The cathode 30 is sandwiched between the first plate 11 and the second plate 12. The first plate 11 is pressed against one side of the diffusion layer. The center of the hollow structure of the second plate 12 forms a cathode chamber, and the second plate 12 is pressed against one side of the catalyst layer. The proton exchange membrane 20 is sandwiched between the second plate 12 and the third plate 13 by the fastener 14. A groove is formed on the third plate 13 near the proton exchange membrane to form an anode chamber for accommodating the anode 40. Furthermore, the reaction vessel 10 also includes a first gasket 15 and a second gasket 16. The first gasket 15 and the second gasket 16 are hollow structures corresponding to the hollow structure of the second plate 12. The first gasket 15 is clamped and connected between the cathode 30 and the second plate 12 by fasteners 14 to fill the gap and block the permeation path of the electrolyte in the cathode chamber. The second gasket 16 is clamped and connected between the proton exchange membrane 20 and the third plate 13 by fasteners 14 to fill the gap and block the permeation path of the electrolyte in the anode chamber.

[0041] In this embodiment, the first plate 11 is designed to be hollow with no opening at the top; the second plate 12 is designed to be hollow with an opening at the top; the third plate 13 is not hollow but has a groove (facing the proton exchange membrane 20), and an opening conforming to the size of the anode 40 is provided at the top. The hollow designs of the first plate 11 and the second plate 12 refer to a through-type structure, which can be understood as a "hui"-shaped plate with thickness. The "mouth" inside is the hollow part, while the third plate 13 is a solid plate structure, but a groove is provided on the side facing the proton exchange membrane 20. The hollow part of the second plate 12 forms the accommodation cavity for the electrolyte in the cathode chamber, and the opening at the top is for installing the pipeline of the electrolyte circulation unit. The groove of the third plate 13 forms the accommodation cavity for the electrolyte in the anode chamber, and the opening at the top is for installing the pipeline of the electrolyte circulation unit. Among them, the hollow parts of the first plate 11 and the second plate 12 are connected to the groove of the third plate 13 (or it can be understood that the projections of the hollow parts of the first plate 11 and the second plate 12 and the groove of the third plate 13 on the same cross-section at least partially overlap). Through the hollow part of the first plate 11, the diffusion layer of the cathode 30 can be exposed to air, and the oxygen in the air is the reactant in the electrolysis process. The anode 40 can be inserted into the groove through the opening at the top of the third plate 14. In a specific embodiment, the fastener 14 adopts a combination screw, and is assembled in the order of the first plate 11, the cathode 30, the first gasket 15, the second plate 12, the proton exchange membrane 20, the second gasket 16, the anode 40 and the third plate 13 through the combination screw; the total length of the reaction vessel is 60 - 65 mm, the total width is 35 - 40 mm, the height is 60 - 65 mm, and the volume of the electrolyte that can be accommodated is 15 - 25 mL; among them, the areas of the cathode 30 and the anode 40 in contact with the electrolyte are both 10 - 15 cm 2 , the cathode 30 is in single-sided contact, and the anode 40 is immersed. Further, the first plate 11, the second plate 12 and the third plate 13 can adopt transparent plates. The reaction vessel in this embodiment essentially constitutes an electrolytic cell with a sandwich structure, which is in turn: an air diffusion plate (the first plate 11) - the cathode 30 - the cathode chamber (the hollow part of the second plate 12) - the proton exchange membrane - the anode chamber (the groove of the third plate 13) - the anode.

[0042] The electrolyte circulation unit 50 includes a first storage container 51, a second storage container 52, a first peristaltic pump 53, and a second peristaltic pump 54. The first and second storage containers 51 and 52 can be used to temporarily store electrolytes in the cathode chamber and anode chamber that exceed the capacity of the reaction vessel 10, respectively. The first peristaltic pump 53 is used to circulate the electrolyte between the cathode chamber and the first storage container 51, and the second peristaltic pump 54 is used to circulate the electrolyte between the anode chamber and the second storage container 52. Each peristaltic pump is equipped with two flexible tubes to achieve linkage between the electrolytes in the reaction vessel and the storage container. The flexible tubes are inserted through the openings at the top of the second plate 12 or the third plate 13. The circulation speed of the electrolyte can be controlled by adjusting the pump speed of each peristaltic pump.

[0043] The operation mode of the electrosynthesis equipment is as follows: Figure 4 As shown, the hollow portion of the second plate 12 serves as the electrolyte storage space (i.e., the cathode chamber) directly in contact with the cathode, and the groove of the third plate 13 serves as the electrolyte storage space (i.e., the anode chamber) directly in contact with the anode. An external storage container (first storage container 51) for the cathode chamber and an external storage container (second storage container 52) for the anode chamber are added. The first storage container 51 is linked to the cathode chamber via a first peristaltic pump 53 and two corresponding flexible hoses, while the second storage container 52 is linked to the anode chamber via a second peristaltic pump 54 and two corresponding flexible hoses. This continuous circulation not only helps to further reduce the solution temperature but also agitates the solution, preventing the hydrogen peroxide produced by the cathode 30 from locally accumulating at the two-electron oxygen reduction reaction interface, thus effectively mitigating the further reduction of hydrogen peroxide to water. Furthermore, the first and second storage containers 51 and 52 also facilitate increasing the solution volume according to usage requirements. It should be noted that the ports of the hoses responsible for outputting the solution are all fixed at the liquid surface, while the ports of the hoses responsible for inputting the solution are all fixed at the bottom, achieving a bottom-in, top-out effect. This not only helps stabilize the liquid level inside the reaction vessel but also helps to expel bubbles generated during the reaction, preventing bubble accumulation from negatively impacting the reaction. The cathode 30 and anode 40 are connected to the negative and positive terminals of the DC power supply 60 respectively via power output clamps. The reaction current of the equipment is controlled by adjusting the constant current of the DC power supply 60.

[0044] In Embodiment 2 of the present invention, the oxygen required for the production of hydrogen peroxide comes directly from the air. The catalyst layer of the cathode consumes oxygen to synthesize hydrogen peroxide. The three-phase interface of the reaction forms a partial pressure difference with the oxygen in the atmosphere. The cathode utilizes the self-breathing function driven by the oxygen partial pressure to continuously replenish the oxygen consumed in the reaction through the diffusion layer of the air self-diffusion cathode, thus breaking through the limitations of oxygen source and mass transfer, thereby achieving higher hydrogen peroxide production efficiency and concentration.

[0045] The electrosynthesis device of Embodiment 2 of this invention can achieve high-concentration hydrogen peroxide accumulation under high current density: the device can effectively suppress the decomposition and side reaction losses of hydrogen peroxide during continuous electrolysis, and can withstand up to 100 mA / cm². 2 By applying a specific current density, hydrogen peroxide with a concentration of approximately 10 wt% is directly produced. Compared to the operating system without a proton exchange membrane, the highest production concentration is increased by approximately 21 times, a significantly better result than existing reported or derivable electrocatalytic synthesis technologies. The electrosynthesis equipment features a simple structure and convenient disassembly and maintenance: the reaction vessel is assembled from three transparent plates and two sealing gaskets using combination screws, making disassembly and assembly of each component easy, facilitating daily inspection, maintenance, and electrode replacement. Furthermore, the core components possess excellent scalability: the commercially available ruthenium-iridium-titanium anode, proton exchange membrane, and self-made air self-diffusion cathode (mechanically rolled) used in this invention are all easily scalable. Therefore, the overall size of the equipment and the hydrogen peroxide production are highly adjustable, allowing for large-scale expansion according to actual needs.

[0046] Embodiment 3 of this invention discloses a method for preparing electronic-grade high-concentration hydrogen peroxide, using the electrosynthesis equipment described in Embodiment 2, comprising the following steps: injecting electrolyte into the cathode chamber and anode chamber respectively, and starting the electrolyte circulation unit; turning on the DC power supply, applying a current density of 10–100 mA / cm². 2 During the electrolysis process, maintain the electrolyte temperature below 35°C; continue electrolysis until the hydrogen peroxide concentration in the electrolyte in the cathode chamber reaches the predetermined value.

[0047] In a further embodiment, the specific steps include: (1) Assembling the reaction vessel according to the assembly sequence described in Embodiment 2, and installing the cathode, anode, proton exchange membrane, and gasket for sealing, and tightening the screws. (2) Preparing a 0.5-1.5 M sodium sulfate aqueous solution as the electrolyte, adding a portion of the electrolyte to the cathode chamber and anode chamber respectively (the liquid levels in both chambers are equal), and adding the remaining electrolyte to the two storage containers respectively. (3) Connecting the hoses corresponding to the peristaltic pumps, starting the two peristaltic pumps, and setting an appropriate pump speed (e.g., 2-40 mL / min) to circulate the electrolyte between the reaction vessel and the storage container. (4) Connecting the cathode to the negative terminal of the DC power supply and the anode to the positive terminal. Turning on the DC power supply and setting a constant current value (e.g., calculated based on the electrode area, the current density range is 10-100 mA / cm²). 2 (5) During electrolysis, a two-electron oxygen reduction reaction occurs in the cathode chamber: O2 + 2H+ + + 2e - → H2O2, producing hydrogen peroxide; Oxygen evolution reaction occurs in the anode chamber: 2H2O → O2 + 4H + + 4e- The generated hydrogen ions migrate to the cathode chamber through the proton exchange membrane, maintaining charge balance. Since the cathode adopts an air self-diffusion structure, no additional oxygen is required. (6) Control the electrolyte temperature to always be below 35°C (this can be achieved by reducing the current density, increasing the circulation speed, or using a circulating water bath for auxiliary cooling). Continue electrolysis for a certain period of time (e.g., 4 to 12 hours), and periodically sample and test the hydrogen peroxide concentration in the cathode solution until the concentration reaches about 10 wt%. (7) Stop electrolysis and collect the electrolyte in the cathode chamber. This solution is the crude hydrogen peroxide product with a concentration of about 10 wt%.

[0048] Embodiment 4 of the present invention discloses a method for preparing electronic-grade hydrogen peroxide. The method for preparing high-concentration electronic-grade hydrogen peroxide in Embodiment 3 is used to obtain a crude hydrogen peroxide product with a hydrogen peroxide concentration reaching a predetermined value. The crude hydrogen peroxide product is purified by passing it through a reverse osmosis membrane filtration device to obtain electronic-grade hydrogen peroxide.

[0049] In a further embodiment, the specific steps include: processing the aforementioned 10 wt% crude hydrogen peroxide product through a reverse osmosis membrane filtration device. The reverse osmosis membrane is a commercially available spiral or flat-sheet reverse osmosis membrane (such as a polyamide composite membrane) with oxidation resistance and high desalination rate, and the operating pressure is typically 0.5–2.0 MPa. After one or more reverse osmosis filtrations, metal ions, particulate matter, and other impurity ions in the hydrogen peroxide can be effectively removed, resulting in 10 wt% electronic-grade hydrogen peroxide with a purity meeting SEMI standards (e.g., metal ion content below 0.1 ppb, particle count meeting the corresponding grade).

[0050] This post-processing purification technique is simple and efficient: at 100 mA / cm 2 The high-concentration hydrogen peroxide (containing sodium sulfate electrolyte) produced after 10 hours of operation can be filtered through a reverse osmosis membrane to obtain electronic-grade product. The reverse osmosis membrane uses a commercially available spiral-wound or flat-sheet reverse osmosis membrane (such as a polyamide composite membrane) with oxidation resistance and high desalination rate, operating at a pressure of 0.5–2.0 MPa. One or more filtrations effectively remove metal ions, particulate matter, and other impurities, yielding 10 wt% electronic-grade hydrogen peroxide with a purity meeting SEMI standards (e.g., metal ion content below 0.1 ppb, particle count meeting the corresponding grade). This post-treatment method avoids the energy-intensive distillation and concentration steps of the traditional anthraquinone process, significantly reducing purification costs.

[0051] Using the aforementioned equipment and method, this invention achieves the direct electrosynthesis of high-concentration (10 wt%) hydrogen peroxide at room temperature and pressure, avoiding the high pollution, high risk, and high energy consumption problems of the traditional anthraquinone method, and overcoming the shortcomings of low product concentration and large decomposition loss in ordinary electrocatalytic systems. Combined with reverse osmosis membrane purification, electronic-grade hydrogen peroxide can be obtained in a green, safe, and low-cost manner, suitable for cleaning, etching, and other processes in integrated circuit manufacturing.

[0052] In summary, this invention employs an innovative air-diffusion cathode electrosynthesis technology for hydrogen peroxide, coupled with optimized equipment components and operating parameters, which significantly suppresses the decomposition and side reaction losses of hydrogen peroxide during its accumulation process. This technical solution allows for the direct one-step preparation of approximately 10 wt% hydrogen peroxide in the electrosynthesis equipment, achieving efficient in-situ production of high-concentration hydrogen peroxide. Subsequently, this 10 wt% hydrogen peroxide is filtered through a reverse osmosis membrane to obtain 10 wt% electronic-grade hydrogen peroxide with purity meeting electronic-grade standards (such as the SEMI standard's limits on impurities like metal ions and particulate matter).

[0053] The cathode, electrosynthesis equipment and method for in-situ preparation of electronic-grade high-concentration hydrogen peroxide disclosed in the above embodiments of the present invention will be further described in detail below with reference to specific embodiments. Specific Implementation Example 1: In this specific embodiment, electrode 1, prepared with a salt-free formula (i.e., using polytetrafluoroethylene and conductive carbon black as raw materials), and electrode 2, used in Embodiment 1 of the present invention, are respectively used as cathodes in the reaction system for preparing hydrogen peroxide. The concentration of hydrogen peroxide produced is compared when electrode 1 and electrode 2 are used as cathodes in the reaction system for preparing hydrogen peroxide.

[0055] In this specific embodiment, the reaction system uses a common hydrogen peroxide preparation system apparatus, which includes a reaction vessel, a DC power supply and electrode clamps, a magnetic stirrer, a cathode, an anode, and rubber gaskets. In one set of experiments, the cathode is electrode 1, prepared using a salt-free formula (i.e., using polytetrafluoroethylene and conductive carbon black as raw materials), while in the other set of experiments, the cathode is electrode 2 as described in Embodiment 1 of this invention. The reaction vessel is a common cuboid structure with a cavity, where the distance between the anode and cathode is 15 mm. During the reaction, the magnetic stirrer rotates at 800 rpm / min, and the electrolyte is 110 mL of 0.25 M sodium sulfate solution. In the reaction vessel, the cathode and anode are opposite each other, each with an area of ​​7 cm². 2 The cathode is fixed to the side of the reaction vessel by washers and stainless steel screws, and the anode is fixed by electrode clamps.

[0056] Using 0.25 M sodium sulfate as the electrolyte, the electrodes were operated by a DC power supply at a current density of 100 mA / cm². 2 A constant current was applied, without using a proton exchange membrane, and the total solution volume was 110 mL. The test was conducted continuously for 5 hours, with the concentration of hydrogen peroxide measured every 1 hour. Figure 5As shown, electrode 1 reached its peak concentration of 739.49 mg / L at the first hour, while electrode 2 reached 1982.76 mg / L at the first hour, which was 2.68 times that of electrode 1. Electrode 2 reached its peak concentration of 2191.55 mg / L at the third hour, while electrode 1, after reaching its peak concentration at the first hour, decreased to 211.52 mg / L at the third hour. At this point, the hydrogen peroxide production concentration of electrode 2 was 10.36 times that of electrode 1. Comparing the peak concentrations of the two, electrode 2 was 2.96 times that of electrode 1. The above results indicate that the hydrogen peroxide production performance of the cathode prepared by the salt-containing formulation in Example 1 of this invention is significantly improved. Specifically, this is because the cathode in Example 1 of this invention forms more oxygen diffusion channels and has more stable strong hydrophobic properties. Specific Implementation Example 2: In this specific embodiment, a reaction system without a proton exchange membrane is used. The second plate 12 and the proton exchange membrane 20 of the electrosynthesis equipment in Example 2 are disassembled, leaving only a gasket, a peristaltic pump, and an external storage container. The groove of the third plate 13 serves as the electrolyte space that is in direct contact with both the anode and cathode. The cathode 30 is fixed by the first plate 11 and the third plate 13 as clamps on the diffusion layer side and the catalyst layer side, respectively. The remaining setup is consistent with the reaction system using a proton exchange membrane in Example 2.

[0058] Using 1 M sodium sulfate as the electrolyte, the electrodes were subjected to a DC power supply at current densities of 30 mA / cm². 2 50 mA / cm 2 and 100 mA / cm 2 A constant current was applied, without using a proton exchange membrane. The total solution volume was 30 mL, with 20 mL in the reaction vessel and 10 mL in the external storage container. The equipment was continuously tested for 10 hours, and the concentration of hydrogen peroxide was measured every hour. Figure 6 As shown, the peak concentration of hydrogen peroxide is positively correlated with the current density, especially at a current density of 30 mA / cm². 2 The concentration peaked at 9 hours, with a peak concentration of 1.59 wt% for hydrogen peroxide at a current density of 50 mA / cm². 2 The concentration peaked at 8 hours, with a peak concentration of 2.42 wt% for hydrogen peroxide at a current density of 100 mA / cm². 2 At that time, the concentration peaked at 4 hours, with a peak concentration of 2.84 wt%. Specific Implementation Example 3: This specific embodiment employs a reaction system using a proton exchange membrane, specifically the electrosynthesis equipment described in Example 2, with 1 M sodium sulfate as the electrolyte. A DC power supply is used to apply currents of 30 mA / cm² to the electrodes. 2 50mA / cm 2 and 100 mA / cm 2 A constant current was applied, and a proton exchange membrane was used. The solution volume in both the cathode and anode chambers of the reaction vessel was 10 mL, while the corresponding solution volumes in the first and second external storage containers were 5 mL each. The equipment was continuously tested for 10 hours, and the concentration of hydrogen peroxide was measured every hour. Figure 7 As shown, the peak concentration of hydrogen peroxide is positively correlated with the current density, especially at a current density of 30 mA / cm². 2 The concentration peaked at 9 hours, with a peak concentration of 4.84 wt% for hydrogen peroxide at a current density of 50 mA / cm². 2 The concentration peaked at 9 hours, with a peak concentration of 5.82 wt% for hydrogen peroxide at a current density of 100 mA / cm². 2 The concentration peaked at 10 h, reaching 9.88 wt%. This result demonstrates that the provided equipment and technology can effectively and continuously accumulate the produced hydrogen peroxide, and the resulting concentration surpasses that achieved or derived from existing related technologies. (At 100 mA / cm²) 2 The high-concentration hydrogen peroxide (containing sodium sulfate electrolyte) produced after 10 hours of operation only needs to pass through a reverse osmosis membrane filtration device (using an oxidation-resistant, high-desalination-rate commercial spiral or flat reverse osmosis membrane, operating pressure 0.5–2.0 MPa, one or multiple filtrations) to remove sodium sulfate and other impurity ions. This effectively removes metal ions, particulate matter, and residual impurities, resulting in 10 wt% electronic-grade hydrogen peroxide with a purity that meets SEMI standards (e.g., metal ion content below 0.1 ppb, particle count meeting the corresponding grade).

[0059] In summary, it can be seen that the present invention, combining the specific cathode in Example 1 and the reaction system using a proton exchange membrane in Example 2, achieves the following: Firstly, the use of a proton exchange membrane to separate the electrolytes of the cathode and anode avoids the oxidative decomposition of hydrogen peroxide by the anode. Secondly, controlling the temperature of the reaction solution below 35°C slows down the self-decomposition of hydrogen peroxide. Furthermore, maintaining the solution in a flowing and mixed state and setting the electrode spacing (width of the cathode chamber) appropriately helps to disperse hydrogen peroxide into the solution, reducing its accumulation at the cathode catalyst layer interface and preventing further reduction of hydrogen peroxide to water. Therefore, this specific Example 3, through the synergistic cooperation of the proton exchange membrane, the specific electrode spacing (10-20 mm), temperature control (<35°C), and the circulation system with a specific cathode structure capable of withstanding high current density, can achieve a maximum cumulative hydrogen peroxide concentration of 10 wt% in 10 hours.

[0060] The cathode and the electrosynthesis equipment and method for in-situ preparation of electronic-grade high-concentration hydrogen peroxide disclosed in this invention have the following advantages: (1) Innovative electrode configuration, high efficiency and low cost: This invention uses an air self-diffusion cathode to synthesize hydrogen peroxide through a two-electron oxygen reduction reaction. Compared with conventional immersion cathodes, it does not rely on dissolved oxygen in the solution, thus avoiding the decrease in reaction rate caused by limited oxygen mass transfer. Compared with gas diffusion electrodes that require external pressurized oxygen flow, the diffusion layer and catalyst layer structure of the cathode in this invention are optimized (rolling-calcination method, specific ratio of PTFE, salt and conductive carbon black), so that oxygen in the air can actively and stably diffuse to the catalyst layer interface to participate in the reaction, without the need for additional oxygen source or pressurization equipment, thereby reducing the complexity of equipment integration and operating costs.

[0061] (2) Effectively suppressing hydrogen peroxide loss and achieving high concentration accumulation: Supported by excellent cathode performance, a reasonable reaction vessel structure (cathode-anode spacing of 10–20 mm, proton exchange membrane isolation, and circulating cooling control temperature <35℃), and optimized operating parameters (constant current mode), this invention can significantly reduce the loss of hydrogen peroxide during continuous electrolysis caused by anodic oxidation, thermal decomposition, and cathode re-reduction. Experimental results show that at 100 mA / cm²... 2 Operating at a specific current density, hydrogen peroxide with a concentration of approximately 10 wt% can be directly accumulated. Compared to the operating system without a proton exchange membrane, the highest yield concentration increased by approximately 21 times. This concentration is sufficient to meet the requirements for working solution concentration in some cleaning and etching processes in integrated circuit manufacturing (e.g., after dilution). Furthermore, the yield concentration can be flexibly controlled by adjusting the applied current density.

[0062] (3) The equipment is easy to assemble and supports in-situ production: The equipment of this invention has a compact structure and standardized components (transparent plates, gaskets, and screws). It can operate simply by connecting to a DC power supply, realizing the in-situ electrosynthesis of hydrogen peroxide. Compared with the traditional anthraquinone method, which requires large-scale centralized production facilities and long-distance transportation and storage, and some electrosynthesis equipment requires additional gas cylinders or gas circuit devices, this invention has greater flexibility of use and can be deployed near integrated circuit production lines as needed, avoiding the risks of chemical transportation and supply delays.

[0063] (4) Simple composition and easy to scale up: The equipment of this invention has a simple composition, and the core components all have mature scale-up potential. The large-area preparation technology of commercial ruthenium-iridium-titanium electrodes and proton exchange membranes is quite mature. The self-made air self-diffusion cathode adopts a mechanical roll forming process, which has significant advantages over traditional preparation methods such as manual brushing in terms of material uniformity, electrode mechanical strength, batch reproducibility, and large-scale production. Therefore, the technical solution of this invention is easy to scale up the size and number of reaction vessels according to the actual demand for hydrogen peroxide.

[0064] (5) Low post-processing purification cost, directly yielding electronic-grade products: The 10 wt% crude hydrogen peroxide product obtained by electrosynthesis in this invention only needs to be filtered through a reverse osmosis membrane filtration device (using commercial spiral or flat reverse osmosis membranes with oxidation resistance and high desalination rate, operating pressure 0.5-2.0 MPa, one or multiple filtrations) to effectively remove metal ions, particulate matter, and other impurity ions, obtaining 10 wt% electronic-grade hydrogen peroxide with purity meeting SEMI standards (e.g., metal ion content below 0.1 ppb, particle count meeting the corresponding grade). Compared with the anthraquinone method requiring high-energy-consuming distillation and concentration steps, and the dilemma of needing to significantly concentrate low-concentration products from conventional electrosynthesis, this invention directly produces 10 wt% concentration, requiring only membrane filtration purification afterward, greatly reducing post-processing energy consumption and cost, and realizing green and efficient preparation of electronic-grade hydrogen peroxide.

[0065] (6) Clean raw materials, simplified process, and high safety: This invention prepares hydrogen peroxide based on electrocatalytic synthesis, using oxygen and water as reactants. It completely avoids anthraquinone (a Group 2B carcinogen), organic solvents, and hydrogen, eliminating carcinogenic risks, flammability and explosion hazards, and high carbon footprint from the source. In terms of process, it eliminates the need for the complex hydrogenation, oxidation, extraction, and concentration steps of the anthraquinone method, and can directly produce high-concentration hydrogen peroxide in a one-step electrosynthesis method, significantly reducing process complexity and safety risks.

[0066] The background section of this invention may include background information about the problems or circumstances surrounding the invention, rather than a description of prior art by others. Therefore, the content included in the background section is not an admission of prior art by the applicant.

[0067] 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. Furthermore, those skilled in the art can combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification without contradiction. 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 defined by the appended claims.

Claims

1. A cathode, characterized in that, It includes a diffusion layer, a catalyst layer, and a support layer. The diffusion layer and the catalyst layer are respectively disposed on both sides of the support layer. The diffusion layer and the catalyst layer are respectively obtained by forming a mixture of polytetrafluoroethylene, salt, and conductive carbon black on both sides of the support layer and then heat treating it.

2. The cathode according to claim 1, characterized in that, The thickness of the diffusion layer and / or the catalyst layer is 50 μm to 150 μm.

3. The cathode according to claim 1, characterized in that, Both the diffusion layer and the catalyst layer are made of a mixture of polytetrafluoroethylene, salt, and conductive carbon black in a mass ratio of (0.5-2):(0.3-2):

1.

4. The cathode according to claim 1, characterized in that, The electrode is prepared by the following method: a mixture of polytetrafluoroethylene, salt and conductive carbon black is stirred to form a paste mixture, and the paste mixture is rolled onto both sides of the support layer; then the prepared electrode is washed, and then heated to 300℃~400℃ at a rate of 5℃ / min~10℃ / min, calcined for 30min~60min and then cooled.

5. An electrosynthesis apparatus for in-situ preparation of electronic-grade high-concentration hydrogen peroxide, characterized in that, It includes a reaction vessel, a proton exchange membrane, an anode, a DC power supply, and a cathode as described in any one of claims 1 to 4; wherein, The reaction vessel is used to contain the electrolyte, and the reaction vessel is divided into a cathode chamber and an anode chamber by the proton exchange membrane. The cathode is installed in the cathode chamber, the catalyst layer faces the electrolyte inside the cathode chamber, and the diffusion layer is exposed to air. The anode is installed in the anode chamber; The DC power supply is electrically connected to the cathode and the anode respectively, and is used to provide a constant current for the electrosynthesis reaction.

6. The electrosynthesis apparatus according to claim 5, characterized in that, The reaction vessel includes a first plate, a second plate, a third plate, and fasteners. The first plate, the second plate, and the third plate are fastened together by the fasteners. The first plate and the second plate are corresponding hollow structures. A groove is formed on the third plate at a position corresponding to the center of the hollow structure of the second plate. The cathode is sandwiched between the first plate and the second plate. The first plate is pressed against one side of the diffusion layer. A cathode chamber is formed at the center of the hollow structure of the second plate, and the second plate is pressed against one side of the catalyst layer. The proton exchange membrane is sandwiched between the second plate and the third plate by the fasteners. The groove on the third plate is formed on the side close to the proton exchange membrane to form the anode chamber for accommodating the anode.

7. The electrosynthesis apparatus according to claim 6, characterized in that, The reaction vessel further includes a first gasket and a second gasket, which are hollow structures corresponding to the hollow structure of the second plate. The first gasket is clamped and connected between the cathode and the second plate by the fastener, and the second gasket is clamped and connected between the proton exchange membrane and the third plate by the fastener.

8. The electrosynthesis apparatus according to claim 5, characterized in that, It also includes an electrolyte circulation unit, which includes a first storage container, a second storage container, a first peristaltic pump, and a second peristaltic pump. The first peristaltic pump is used to circulate the electrolyte in the cathode chamber and the first storage container, and the second peristaltic pump is used to circulate the electrolyte in the anode chamber and the second storage container.

9. The electrosynthesis apparatus according to claim 5, characterized in that, The anode and the cathode are arranged in parallel, and the distance between the anode and the cathode is 10mm to 20mm.

10. A method for preparing electronic-grade high-concentration hydrogen peroxide using the electrosynthesis equipment according to any one of claims 5 to 9, characterized in that, Includes the following steps: Electrolyte is injected into the cathode chamber and the anode chamber respectively, and the DC power supply is turned on, with an applied current density of 10–100 mA / cm². 2 During the electrolysis process, the electrolyte temperature is maintained below 35°C; electrolysis continues until the hydrogen peroxide concentration in the electrolyte in the cathode chamber reaches a predetermined value.

Images