A method for electrosynthesizing hydrogen peroxide using resin-filled materials, a reactor, and applications thereof

Abstract

The present invention relates to a method for electrosynthesizing hydrogen peroxide using a filled resin, a reactor, and an application thereof. By designing a reactor for electrosynthesizing hydrogen peroxide using a filled resin, a hydrogen peroxide solution is directly prepared using air and pure water. The electrochemical reactor comprises an anode and cathode, a liquid chamber, and a gas chamber. The liquid chamber between the anode and cathode is filled with a 732-type macroporous strong acid cation exchange resin. The anode is an iridium tantalum electrode, and the cathode is a gas diffusion cathode coated with an activated carbon black catalyst. Under direct current electrolysis, the cation exchange resin promotes the dissociation of pure water, and the oxygen in the air is reduced on the surface of the gas diffusion cathode and combines with the protons generated by the dissociation of water to form hydrogen peroxide. The present invention avoids the use of high-concentration electrolytes in the electrosynthesis of hydrogen peroxide, improves the concentration and current efficiency of the prepared hydrogen peroxide, has the advantages of low environmental pollution risk during the production process and high purity of the hydrogen peroxide product, and can be more conveniently applied to water treatment fields such as sterilization and pollutant removal.

Description

Technical Field

[0001] The present invention relates to the field of electrochemistry, and in particular to a method for electrosynthesizing high-purity hydrogen peroxide by using a filled resin, a reactor and an application thereof. Background Art

[0002] Hydrogen peroxide, commonly known as hydrogen peroxide, possesses strong oxidizing properties due to its unstable -1 oxygen atom, which is easily reduced to -2. Hydrogen peroxide is an environmentally friendly oxidant, producing water as its oxidation product without any toxic byproducts. Its oxidizing properties can damage the cell walls and membranes of bacteria and other microorganisms, leading to cytoplasmic exudation and cell death. Furthermore, by disrupting microbial enzymes and inhibiting bacterial DNA synthesis and metabolism, hydrogen peroxide can inhibit and kill bacteria. Therefore, hydrogen peroxide is widely used as a disinfectant and fungicide in public and household health and hygiene settings. Hydrogen peroxide also has extensive applications in industrial production processes. For example, as a highly efficient oxidant, hydrogen peroxide plays a key role in organic chemical synthesis, such as the oxidation of aromatic hydrocarbons and the ozonation ring-opening reaction of aromatic hydrocarbons. Its oxidizing properties cleave the conjugated double bonds of chromophores, initiating discoloration. Therefore, hydrogen peroxide is used as a bleaching agent in the papermaking and textile industries. Hydrogen peroxide can also be used to treat difficult-to-degrade pollutants in advanced oxidation technologies for water treatment. Through Fenton catalysts or coordinated ultraviolet light irradiation, the non-polar structure in the H2O2 molecule breaks, generating hydroxyl radicals (-OH) with a redox potential of up to 2.80 eV, which have a good oxidative decomposition effect on difficult-to-degrade pollutants.

[0003] Currently, industrial hydrogen peroxide is produced through the anthraquinone method, a chemical synthesis method with mature technology and low costs. However, this method can only be produced in a centralized manner and is not convenient for on-site preparation. The high-concentration hydrogen peroxide solution produced is transported to the user and then diluted according to the required scenario before use. High-concentration hydrogen peroxide solution is explosive. Its reaction with combustible materials can release large amounts of heat and oxygen, causing fire and explosion. It can also decompose when exposed to strong light, especially short-wave radiation, and can form explosive mixtures with various organic substances such as sugars, starches, and alcohols. It can explode under impact, heat, or electric sparks. Therefore, traditionally produced hydrogen peroxide poses safety risks during transportation and has disadvantages such as easy decomposition and reduced concentration during storage. The development of online hydrogen peroxide production technology is of great significance for ensuring its safe use and reducing risks.

[0004] Cathodic electrosynthesis is a method for preparing hydrogen peroxide online, which uses water and oxygen. Water is electrolyzed at the anode to produce H + , oxygen can obtain electrons under the action of cathode catalyst and react with water to generate HO2 -, H + Migrate to the cathode and react with HO2 - The combination of these two methods generates H2O2. The online electrosynthesis method for preparing hydrogen peroxide avoids the risks of storage and transportation, and is flexible and convenient to operate, making it a promising method for application.

[0005] However, this method still has some shortcomings. It requires the preparation of a high concentration of electrolyte solution in the preparation of hydrogen peroxide to ensure high conductivity of the aqueous solution and reduce H + Migration and solution resistance, reducing operating energy consumption. The anolyte is generally H2SO4 or sodium sulfate, and the catholyte is KOH, NaOH or sodium sulfate. For example, a Chinese invention patent application with publication number CN118345404A discloses a device and method for producing hydrogen peroxide by two-electron electrochemical oxygen reduction. In the electrochemical in-situ synthesis of hydrogen peroxide, the electrolyte solution is a mixed solution of sodium sulfate and sulfuric acid, the sodium sulfate concentration is 0.05~0.2mol / L, and the sulfuric acid concentration is 0.01~0.02mol / L. For another example, a Chinese invention patent application with publication number CN118835270A discloses a bimetallic CoPb catalyst for electrosynthesis of hydrogen peroxide, a preparation method, and a method for electrosynthesis of hydrogen peroxide, wherein the test solution is a 0.1mol / L KOH solution.

[0006] However, high concentrations of electrolytes increase the cost of preparing hydrogen peroxide, and strong acid or alkaline electrolytes have high requirements for electrode materials and reaction equipment. The hydrogen peroxide solution finally prepared contains a large amount of acid and base inorganic salts, which may cause sulfate, acid and base corrosion and pollution during use. In addition, even if a pH-neutral cathode solution such as sodium sulfate solution is used, H + If the supply is insufficient, the pH value of the prepared hydrogen peroxide solution will increase. Alkaline solution is not conducive to the preservation of hydrogen peroxide. For specific applications such as Fenton oxidation treatment, additional acid adjustment is required, which increases subsequent operating costs.

[0007] It can be seen that the current electrosynthesis of hydrogen peroxide involves the addition of a large amount of electrolyte, which causes corrosion and pollution problems. The hydrogen peroxide solution prepared thereby also has a limited scope of use due to the high concentration of electrolyte. Summary of the Invention

[0008] The object of the present invention is to provide a method, a reactor and its application for preparing a high-purity hydrogen peroxide solution by electrosynthesis using pure water as a raw material by filling a solution chamber with an ion exchange resin, thereby providing at least a useful solution or option for solving one or more technical problems existing in the prior art.

[0009] To achieve the above objectives, the present invention adopts the following technical solutions.

[0010] A method for electrosynthesizing hydrogen peroxide with resin filling, the technical concept of which is to design an electrosynthesizing hydrogen peroxide reactor filled with 732 cation exchange resin, using pure water and an oxygen source as electrosynthesizing raw materials; when electrosynthesizing hydrogen peroxide, a regulated DC power supply is connected to the electrosynthesizing hydrogen peroxide reactor, and pure water is electrolyzed at the anode of the electrosynthesizing hydrogen peroxide reactor to produce H + , 732 cation exchange resin promotes the dissociation of pure water, oxygen is reduced on the gas diffusion cathode surface of the electrosynthetic hydrogen peroxide reactor, and combines with the protons generated by the dissociation of pure water to form hydrogen peroxide.

[0011] The electrosynthetic hydrogen peroxide reactor includes an anode, a liquid chamber, a gas diffusion cathode, and a gas chamber, which are arranged in sequence. The 732 cation exchange resin is arranged in the liquid chamber, pure water is circulated in the liquid chamber, and flowing oxygen is arranged in the gas chamber. Clamps are respectively arranged on the outside of the anode and the gas chamber, and gaskets are respectively arranged between the clamps and the gas chamber, between the gas chamber and the gas diffusion cathode, between the gas diffusion cathode and the liquid chamber, between the liquid chamber and the anode, and between the anode and the corresponding clamps.

[0012] More preferably, the pure water in the liquid chamber forms a circulation flow with the pure water storage tank through a peristaltic pump, and the flow rate of the pure water is controlled at 10-20 mL / min.

[0013] More preferably, the current density of the electrosynthetic hydrogen peroxide reactor is maintained at 10-80 mA / cm 2 .

[0014] More preferably, oxygen or air is introduced into the gas chamber. When the intake gas is air, the intake gas flow rate is 400-600 mL / min.

[0015] On the other hand, the present invention also provides a resin-filled reactor for electrosynthesis of hydrogen peroxide, characterized in that it includes an anode, a liquid chamber, a gas diffusion cathode and a gas chamber arranged in sequence, the spacing between the anode and the gas diffusion cathode is 3-7 mm, 732 cation exchange resin is provided in the liquid chamber, and the filling amount is 0.8 g / mL; pure water is provided in circulation in the liquid chamber, and oxygen is provided in the gas chamber; clamping plates are respectively provided on the outside of the anode and the gas chamber, and gaskets are respectively provided between the clamping plates and the gas chamber, between the gas chamber and the gas diffusion cathode, between the gas diffusion cathode and the liquid chamber, between the liquid chamber and the anode, and between the anode and the corresponding clamping plates.

[0016] More preferably, a water inlet and a water outlet are provided on the liquid chamber, the water inlet is located at the bottom of the liquid chamber, the water outlet is located at the top of the liquid chamber, and the water inlet and the water outlet are coaxial; an air inlet and an air outlet are provided on the gas chamber, the air inlet and the air outlet are coaxially arranged and located in the middle of the side where the plate surface of the gas chamber is located; the axis of the water inlet and the water outlet is perpendicular to the axis of the air inlet and the air outlet.

[0017] More preferably, the anode electrode is a titanium-based iridium-tantalum electrode, and the gas diffusion cathode is an activated carbon black gas diffusion cathode.

[0018] More preferably, the activated carbon black gas diffusion cathode is prepared by the following preparation steps: first, acetylene black and PTFE emulsion are evenly mixed with anhydrous ethanol in a mass ratio of 3:1~10, and then rolled to one side of a stainless steel mesh with a roller press, and calcined in a muffle furnace to obtain a diffusion layer; a certain mass of conductive carbon black is evenly mixed with an appropriate amount of anhydrous ethanol in a mass ratio of 0.01~0.05, and then mixed with PTFE emulsion in a mass ratio of 3:1~10 of total solids. After the remaining anhydrous ethanol is completely volatilized, it is rolled to the other side of the stainless steel mesh to obtain a catalytic layer; thus, an air diffusion cathode is obtained.

[0019] On the other hand, the present invention also provides use of the above-mentioned resin-filled reactor for electrosynthesis of hydrogen peroxide in the preparation of high-purity hydrogen peroxide.

[0020] The present invention adopts the above technical solution to have at least the following beneficial effects.

[0021] This invention aims to solve the problem of the need to add electrolytes during the current electrosynthetic hydrogen peroxide production process, and to realize the electrosynthetic preparation of high-purity hydrogen peroxide solution using pure water as raw material; to avoid the risk of corrosion of equipment and environmental pollution caused by inorganic salts and acids and alkalis in the solution, and to expand the application range of the prepared hydrogen peroxide. The present invention has developed a resin-filled electrosynthetic hydrogen peroxide reactor and a construction method thereof, which can achieve the production of high-efficiency and high-concentration hydrogen peroxide without the need for the addition of electrolytes, and realize the process of preparing H2O2 from pure water. High-purity hydrogen peroxide can be used in fields such as environmental disinfection, chemical synthesis, and the treatment of difficult-to-degrade pollutants, and can be widely used in practice.

[0022] Because the electrosynthesis reactor of the present invention does not require the addition of electrolytes during the preparation process and only consumes pure water, compared with other electrosynthesis methods, it not only reduces the risks of acid-base corrosion caused by the use of inorganic electrolytes, but also the prepared hydrogen peroxide contains extremely low impurities and can be directly used for water treatment, chemical synthesis, such as Fenton advanced oxidation, disinfection, etc.; this is especially true for industries with high requirements for hydrogen peroxide solutions, such as the integrated circuit industry (T / ICMTIA 2-2019), which requires the concentration of inorganic salts such as sulfates and chlorides in the hydrogen peroxide solution to be less than 10 μg / L. The hydrogen peroxide solution prepared by conventional electrosynthesis must be desalted and purified, while the hydrogen peroxide solution prepared by the present invention effectively reduces the pretreatment steps in the application. Therefore, the present invention is beneficial to the practical application of hydrogen peroxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0024] Figure 1 Shown is a schematic structural diagram of the reactor for preparing hydrogen peroxide by electrosynthesis in Example 1.

[0025] Figure 2 Shown is the change in the concentration of hydrogen peroxide produced by the electrosynthesis reactor filled with different ion exchange resins over time.

[0026] Figure 3 Shown is the change in current efficiency during the production of hydrogen peroxide in electrosynthesis reactors filled with different ion exchange resins.

[0027] Figure 4 Shown are the results of the cathode linear sweep voltammetry curves of the electrosynthesis reactor filled with different ion exchange resins.

[0028] Figure 5 Shown are the results of electrochemical impedance spectroscopy measurements of electrosynthesis reactors filled with different ion exchange resins.

[0029] Figure 6 The figure shows the effect of the distance between the cathode and anode on the production of hydrogen peroxide and the current efficiency in an electrosynthesis reactor filled with 732 cation exchange resin.

[0030] Figure 7 The graph shows the change in the concentration of hydrogen peroxide produced at different current densities over time in an electrosynthesis reactor filled with 732 cation exchange resin.

[0031] Figure 8 The figure shows the change of current efficiency and energy consumption over time at different current densities in the electrosynthesis reactor filled with 732 cation exchange resin.

[0032] Figure 9 The figure shows the effect of different sodium sulfate solution concentrations on the electrosynthetic H2O2 product concentration and current efficiency under unfilled resin conditions.

[0033] Figure 10 The figure shows the effect of different sodium sulfate solution concentrations on the electrosynthetic H2O2 product concentration and current efficiency under resin filling conditions.

[0034] Description of the accompanying drawings.

[0035] 1: Clamp, 2: Silicone gasket, 3: Anode, 4: Liquid chamber, 5: Gas diffusion cathode, 6: Gas chamber, 7: Ion exchange resin. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the essence of the present invention, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] Reference Figure 1 As shown, a resin-filled electrosynthetic hydrogen peroxide reactor comprises a titanium-based iridium-tantalum anode electrode 3, a liquid chamber 4, a gas diffusion cathode 5 and a gas chamber 6 arranged in sequence, an ion exchange resin 7 is provided in the liquid chamber 4, a water inlet and a water outlet are provided on the liquid chamber 4, the water inlet is located at the bottom of the liquid chamber 4, the water outlet is located at the top of the liquid chamber 4, and the water inlet and the water outlet are coaxial; an air inlet and an air outlet are provided on the gas chamber 6, the air inlet and the air outlet are coaxially arranged and located on the gas chamber 6. The middle part of the side where the plate surface of the chamber 6 is located; the axes of the water inlet and the water outlet are perpendicular to the axes of the gas inlet and the gas outlet; a clamping plate 1 is respectively provided on the outside of the titanium-based iridium tantalum anode electrode 3 and the gas chamber 6, and a gasket 2 is respectively provided between the clamping plate 1 and the gas chamber 6, between the gas chamber 6 and the gas diffusion cathode 5, between the gas diffusion cathode 5 and the liquid chamber 4, between the liquid chamber 4 and the titanium-based iridium tantalum anode electrode 3, and between the titanium-based iridium tantalum anode electrode 3 and the corresponding clamping plate 1.

[0039] In this embodiment, the liquid chamber 4, the gas chamber 6 and the clamping plate 1 are preferably all made of organic glass. The titanium-based iridium-tantalum anode electrode 3 is purchased from Baoji Changli Special Metal Co., Ltd., with a size of 3 cm × 3 cm and an effective area of ​​7 cm 2 .

[0040] The gas diffusion cathode 5 is prepared by the following steps: First, acetylene black and PTFE (polytetrafluoroethylene) emulsion are uniformly mixed with anhydrous ethanol at a mass ratio of 3:1-10, then rolled onto one side of a stainless steel mesh using a roller press and calcined in a muffle furnace to form a diffusion layer. Conductive carbon black is uniformly mixed with anhydrous ethanol at a mass ratio of 0.01-0.05, then mixed at a mass ratio of total solids to PTFE emulsion of 3:1-10. After the remaining anhydrous ethanol has completely evaporated, the mixture is rolled onto the other side of the stainless steel mesh to form a catalytic layer. This completes the air diffusion cathode. In this embodiment, the conductive carbon black is selected from Cabot XC-72R, a US-based brand. Obviously, the purchase and use of this brand of conductive carbon black is not limited to that of Cabot.

[0041] In this embodiment, the ion exchange resin is preferably 732 cation exchange resin, and the pretreatment method is as follows: weigh an appropriate amount of resin, add anhydrous ethanol until the liquid surface covers the resin, stir for 1 hour, and then rinse with deionized water; then pour in a 5wt% hydrochloric acid solution, stir for 1 hour, and then rinse with deionized water until the effluent is neutral; pour in a 5wt% sodium hydroxide solution, stir for 1 hour, and then rinse with deionized water until the effluent is neutral; finally, pour in a 5wt% hydrochloric acid solution and repeat the above steps, rinse with deionized water and set aside. The pretreated resin is filled into the liquid chamber 4 with a filling amount of 3.7g, a filling volume ratio of 0.8L / L, a distance between the anode and the cathode of 5mm, and the liquid chamber 4 is connected to an external liquid reservoir. The effective volume of pure water is 15mL.

[0042] The method for preparing high-purity hydrogen peroxide in the resin-filled electrosynthetic hydrogen peroxide reactor of this embodiment is as follows: the solution in the liquid reservoir and the liquid chamber 4 is circulated by a peristaltic pump at a flow rate of 15 mL / min. The anode and cathode are connected to a DC regulated power supply, and the power supply voltage is adjusted so that the current density of the electrosynthetic reactor is maintained at 80 mA / cm 2 The gas chamber 6 is connected to an external air pump, and the inlet gas is air at an inlet flow rate of 500 mL / min. In some embodiments, the air can be replaced by pure oxygen (99.2%).

[0043] Comparative Example 1.

[0044] This comparative example provides a resin-filled electrosynthesis hydrogen peroxide reactor, the structure of which is substantially the same as that of Example 1, except that the filled ion exchange resin is Amberlyst 15 ion exchange resin.

[0045] Comparative Example 2.

[0046] This comparative example provides a resin-filled electrosynthesis hydrogen peroxide reactor, which has a structure substantially the same as that of Example 1, except that the liquid chamber 4 is not filled with ion exchange resin, and sodium sulfate solution is used as the electrolyte solution of the electrosynthesis device to prepare hydrogen peroxide.

[0047] Comparative Example 3.

[0048] This comparative example provides a filled resin electrosynthesis hydrogen peroxide reactor, the structure of which is basically the same as that of Example 1, except that sodium sulfate solution is used instead of pure water as the inlet water of the filled resin electrosynthesis hydrogen peroxide reactor.

[0049] Performance testing trials.

[0050] Experiment 1: Effect of different ion exchange resins on reactor performance.

[0051] Hydrogen peroxide was prepared using the reactors of Example 1 and Comparative Example 1.

[0052] The concentration of hydrogen peroxide and the current efficiency change with time as shown in the following figure: Figure 2 、 Figure 3 As shown. Figure 2 、 Figure 3 As can be seen, the H₂O₂ product concentration in the reactor filled with 732 cation exchange resin is higher than that in the reactor filled with Amberlyst-15 ion exchange resin. The former produces a product concentration of 7319.2 mg / L, while the latter produces a product concentration of 4957.1 mg / L, only 67.7% of the former. Furthermore, the current efficiency of the reactor filled with 732 cation exchange resin reaches 61.8%, 20% higher than that of the reactor filled with Amberlyst-15 ion exchange resin.

[0053] The results of the cathode linear sweep voltammetry curve and the electrochemical impedance spectroscopy are as follows: Figure 4 、 Figure 5 As shown. Figure 4 It can be seen that under the same applied voltage conditions, the response current value of the reactor filled with 732 cation exchange resin is higher. When the applied voltage is -5V, the response current value of the reactor filled with 732 cation exchange resin is -383.6 mA, while the response current value of the reactor filled with Amberlyst-15 particle exchange resin is only -36.4 mA, which is only 1 / 10 of the former.

[0054] from Figure 5It can be seen that the internal resistance of the reactor filled with 732 cation exchange resin is 6.86 Ω, which is much lower than the 37.37 Ω of the reactor filled with Amberlyst-15 particle exchange resin. The charge transfer impedance Rct of the former is 0.99 Ω, while that of the latter is as high as 36.32 Ω, which is 35 times higher.

[0055] By comparing the results of Example 1 and Comparative Example 1, it can be clearly seen that the addition of different ion exchange resins has a significant effect on the performance of the electrosynthesis reactor, and the concentrations of the generated hydrogen peroxide vary greatly.

[0056] Experiment 2: Effect of the distance between anode and cathode on hydrogen peroxide production and current efficiency.

[0057] Hydrogen peroxide was prepared according to the method of Example 1, and the current efficiency was tested when the electrode spacing was 7 mm, 5 mm, 3 mm, and 2 mm. The results are as follows: Figure 6 shown.

[0058] from Figure 6 It can be seen that when the electrode spacing is 7mm, 5mm, 3mm, and 2mm, the H2O2 product concentrations produced after the reactor runs for 30 minutes are 7252.6 mg / L, 7319.2 mg / L, 6321.1 mg / L, and 5422.8 mg / L, respectively, and the corresponding current efficiencies are 61.3%, 61.8%, 53.4%, and 45.8%, respectively. This is because reducing the electrode spacing can effectively reduce the internal resistance of the reactor, but reducing the electrode spacing also reduces the total amount of resin filled in the reactor, which can be used to transfer H + The total amount of sulfonic acid groups decreases, resulting in a decrease in the concentration of H2O2 products produced by electrosynthesis. Therefore, the optimal electrode spacing is between 3-7 mm.

[0059] Experiment 3: Effect of different current densities on the preparation of hydrogen peroxide.

[0060] Hydrogen peroxide was prepared according to the method of preparing hydrogen peroxide in Example 1, and the current density was tested at 10 mA / cm 2 , 20mA / cm 2 、30mA / cm 2 , 40mA / cm 2 , 50mA / cm 2 、60mA / cm 2 , 70mA / cm 2 , 80mA / cm 2 , 90mA / cm 2 The hydrogen peroxide concentration, current efficiency and energy consumption change with time. Figure 7 、 Figure 8 shown.

[0061] from Figure 7 and Figure 8 Yes, the current density is 10 mA / cm 2 Up to 80 mA / cm 2 When the current density continued to increase to 90 mA / cm 2 When the current density is between 10 and 80 mA / cm 2 When the current density increased to 90 mA / cm 2 When the applied current density increases from 10 mA / cm 2 Up to 90 mA / cm 2 When the battery is heated, the energy consumption increases from 6.53 kWh / kg to 21.93 kWh / kg.

[0062] This indicates that current density significantly influences hydrogen peroxide production in a 732 cation exchange resin reactor. The concentration, current efficiency, and energy consumption of hydrogen peroxide produced vary significantly at different current densities. A high current density is recommended when high-concentration hydrogen peroxide production is desired, while a low current density is recommended when lower energy consumption is desired.

[0063] Experiment 4: Effect of different sodium sulfate solution concentrations on the electrosynthetic H2O2 product concentration and current efficiency under unfilled resin conditions.

[0064] Hydrogen peroxide was prepared according to the method of preparing hydrogen peroxide in Comparative Example 2, and the H2O2 product concentration and current efficiency (30 min) were tested when the electrolyte solution concentration was 0.01 mol / L, 0.02 mol / L, 0.04 mol / L, 0.06 mol / L, 0.08 mol / L and 0.10 mol / L. The results are as follows: Figure 9 shown.

[0065] from Figure 9It can be seen that, without resin filling, after 30 minutes of reactor operation, when the sodium sulfate concentration increased from 0.01 mol / L to 0.1 mol / L, the H₂O₂ product concentration increased from 385.9 mg / L to 658.7 mg / L, a 70.7% increase; the current efficiency also increased from 26.1% to 44.5%, an 18.4% increase. However, the current efficiency of the electrosynthesis reactor with sodium sulfate as the electrolyte was lower than that of the reactor filled with 732 cation exchange resin, and the maximum hydrogen peroxide concentration achieved was also lower than that of the reactor filled with 732 cation exchange resin. This demonstrates that the proposed electrosynthesis hydrogen peroxide reactor filled with 732 cation exchange resin can significantly improve the efficiency of existing electrosynthesis hydrogen peroxide.

[0066] Experiment 5: Effect of different sodium sulfate solution concentrations on the electrosynthetic H2O2 product concentration and current efficiency under resin filling conditions.

[0067] Hydrogen peroxide was prepared according to the method of preparing hydrogen peroxide in Comparative Example 3, and the H2O2 product concentration and current efficiency (30 min) were tested when the electrolyte solution concentration was 0 mol / L, 0.01 mol / L, 0.02 mol / L, 0.04 mol / L, 0.06 mol / L, 0.08 mol / L and 0.10 mol / L. The results are as follows: Figure 10 shown.

[0068] from Figure 10 It can be seen that when filled with 732 cation exchange resin, when the sodium sulfate concentration increased from 0 to 0.1 mol / L, the H2O2 product concentration decreased from 911.6 mg / L to 678.7 mg / L, a 25.5% decrease in H2O2 product concentration; the current efficiency also decreased from 61.6% to 45.9%. Compared with Comparative Example 2, when the resin was filled, the H2O2 yields at sodium sulfate solution concentrations of 0.01 mol / L, 0.02 mol / L, 0.04 mol / L, 0.06 mol / L, and 0.08 mol / L were 125.9%, 106.9%, 60.0%, 41.2%, and 31.2% higher than when sodium sulfate solution of the same concentration was used as the electrolyte alone. Compared with Example 1, the current efficiency of the electrosynthesis reactor in Comparative Example 3, when filled with resin and sodium sulfate electrolyte, was lower than that of the 732 cation exchange resin, and the maximum hydrogen peroxide concentration achieved was also lower than that of the latter.

[0069] The analysis shows that 732 cation exchange resin contains sulfonic acid group -SO3H, which is easy to dissociate into H + , so it is strongly acidic. Under the action of the external electric field, the H + Migrate to the cathode, and in the anode reaction of cathode electrosynthesis of H2O2, , the obtained H+ Combined with the negatively charged group of the resin, the sulfonic acid group is regenerated. Therefore, when deionized water is passed through the reactor filled with resin, H + While meeting the needs of resin regeneration; but when there is sodium sulfate solution, Na + H produced by the anode reaction + The competition with the negatively charged groups of the resin leads to the + The transfer capacity is greatly reduced, so as the concentration of the sodium sulfate solution increases, the concentration of the product obtained by the reaction continues to decrease. When the concentration of the sodium sulfate solution is higher than 0.04 mol / L, the H on the surface of the sulfonic acid group of the resin filled in the reactor is completely replaced by Na, and the resin's ion transfer capacity is completely ineffective, so the product concentration will not continue to decrease.

[0070] Based on Comparative Examples 1 to 3, the present invention can achieve efficient preparation of hydrogen peroxide with pure water, and improve the effect of conventional electrosynthesis of hydrogen peroxide by adding electrolyte.

[0071] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art could make numerous modifications and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention. Any portions not described in the specific embodiments represent prior art or common knowledge.

[0073] It should also be noted that, in the description of the present invention, the detailed description of the preferred embodiment of the present invention and the included embodiments can more easily understand the content of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In the event of a conflict, the definitions in this specification shall prevail.

[0074] As used herein, the term "prepared from" is used synonymously with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0075] In the present invention, when amount, concentration or other value or parameter is expressed as a range, preferred range or a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including a range of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When a numerical range is described in the present invention, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0076] In addition, the indefinite articles "a" and "an" before the elements or components of the present invention do not limit the quantity requirement (i.e., the number of times the elements or components appear). Therefore, "a" or "an" should be interpreted as including one or at least one, and elements or components in the singular also include plural forms, unless the number is obviously intended to be singular.

Claims

1. A method for electrosynthesizing hydrogen peroxide by filling resin, characterized in that: An electrosynthetic hydrogen peroxide reactor filled with 732 cation exchange resin is designed, using pure water and oxygen source as electrosynthetic raw materials. During electrosynthesis of hydrogen peroxide, a regulated DC power supply is connected to the electrosynthetic hydrogen peroxide reactor, and pure water is electrolyzed at the anode of the electrosynthetic hydrogen peroxide reactor to produce H + , 732 cation exchange resin promotes the dissociation of pure water, oxygen is reduced on the surface of the gas diffusion cathode of the electrosynthetic hydrogen peroxide reactor, and combines with the protons generated by the dissociation of pure water to form hydrogen peroxide; The electrosynthetic hydrogen peroxide reactor includes an anode, a liquid chamber, a gas diffusion cathode, and a gas chamber, which are arranged in sequence. The 732 cation exchange resin is arranged in the liquid chamber, pure water is circulated in the liquid chamber, and flowing oxygen is arranged in the gas chamber. Clamps are respectively arranged on the outside of the anode and the gas chamber, and gaskets are respectively arranged between the clamps and the gas chamber, between the gas chamber and the gas diffusion cathode, between the gas diffusion cathode and the liquid chamber, between the liquid chamber and the anode, and between the anode and the corresponding clamps.

2. The method for electrosynthesizing hydrogen peroxide by filling resin according to claim 1, characterized in that: The pure water in the liquid chamber forms a circulation flow with the pure water storage tank through a peristaltic pump, and the flow rate of the pure water is controlled at 10-20 mL / min.

3. The method for electrosynthesizing hydrogen peroxide by filling resin according to claim 1, characterized in that: The current density of the electrosynthetic hydrogen peroxide reactor is maintained at 10-80 mA / cm 2 .

4. The method for electrosynthesizing hydrogen peroxide by filling resin according to claim 1, characterized in that: Oxygen or air is introduced into the gas chamber. When the intake gas is air, the intake gas flow rate is 400-600 mL / min.

5. A reactor for electrosynthesis of hydrogen peroxide by resin filling, characterized in that: The invention comprises an anode, a liquid chamber, a gas diffusion cathode and a gas chamber arranged in sequence, wherein the spacing between the anode and the gas diffusion cathode is 3-7 mm, and a 732 cation exchange resin with a filling amount of 0.8 g / mL is provided in the liquid chamber; pure water is circulated in the liquid chamber, and oxygen is provided in the gas chamber; a clamping plate is provided on the outside of the anode and the gas chamber respectively, and a gasket is provided between the clamping plate and the gas chamber, between the gas chamber and the gas diffusion cathode, between the gas diffusion cathode and the liquid chamber, between the liquid chamber and the anode, and between the anode and the corresponding clamping plate.

6. The resin-filled reactor for electrosynthesis of hydrogen peroxide according to claim 5, characterized in that: A water inlet and a water outlet are provided on the liquid chamber, the water inlet is located at the bottom of the liquid chamber, the water outlet is located at the top of the liquid chamber, and the water inlet and the water outlet are coaxial; an air inlet and an air outlet are provided on the gas chamber, the air inlet and the air outlet are coaxially arranged and located in the middle of the side where the plate surface of the gas chamber is located; the axis of the water inlet and the water outlet is perpendicular to the axis of the air inlet and the air outlet.

7. The resin-filled reactor for electrosynthesis of hydrogen peroxide according to claim 5, characterized in that: The anode electrode is a titanium-based iridium-tantalum electrode, and the gas diffusion cathode is an activated carbon black gas diffusion cathode.

8. The resin-filled reactor for electrosynthesis of hydrogen peroxide according to claim 7, characterized in that: The activated carbon black gas diffusion cathode is prepared by the following preparation steps: first, acetylene black and PTFE emulsion are mixed uniformly with anhydrous ethanol at a mass ratio of 3:1-10, then rolled onto one side of a stainless steel mesh using a roller press, and calcined in a muffle furnace to obtain a diffusion layer; a certain mass of conductive carbon black is mixed uniformly with an appropriate amount of anhydrous ethanol at a mass ratio of 0.01-0.05, then mixed with the PTFE emulsion at a mass ratio of 3:1-10 for total solids, and after the remaining anhydrous ethanol is completely volatilized, rolled onto the other side of the stainless steel mesh to obtain a catalytic layer; thus, an air diffusion cathode is obtained.

9. Use of the resin-filled reactor for electrosynthesis of hydrogen peroxide according to any one of claims 5 to 8 in the preparation of high-purity hydrogen peroxide.

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