Preparation method of acid-resistant and corrosion-resistant porous composite electrode, preparation method of electrolysis device and application method of electrolysis device

Abstract

The invention provides a preparation method of an acid-resistant and chlorine-corrosion-resistant porous composite electrode and a device constructed on the basis of the electrode and used for preparing hydrogen and chlorine by electrolyzing a sodium chloride solution, two cavities are provided, an acid or neutral saturated sodium chloride solution is filled in the cavities, the cavities are separated by a proton exchange membrane or a diaphragm, and the proton exchange membrane or the diaphragm is filled in the cavities. And in the electrolysis process, the cathode generates high-purity hydrogen, the anode generates high-purity chlorine, the chlorine is absorbed by sodium hydroxide in the gas collection bottle and generates sodium hypochlorite, or the chlorine is introduced into a sodium bromide / sodium iodide solution to replace bromine / iodine elementary substances, and the chlorine is discharged from the gas collection bottle. The sodium hypochlorite solution and the bromine / iodine water are used for disinfection and sterilization experiments. The corrosion-resistant porous composite electrode for electrolysis of an acidic or neutral saturated sodium chloride solution is prepared, the electrolysis voltage of the corrosion-resistant porous composite electrode is further reduced by loading a cathode / anode catalyst, and an acidic or neutral saturated sodium chloride solution electrolysis device constructed based on the electrode can be used for preparing high-purity hydrogen and chlorine.

Description

Technical Field

[0001] The present application belongs to the field of producing hydrogen and chlorine by electrolyzing sodium chloride, and in particular, relates to a method for preparing an acid-resistant and corrosion-resistant porous composite electrode, a method for preparing an electrolysis device, and an application method of the electrolysis device. Background Art

[0002] In recent years, with the continuous growth of the global population and the continuous consumption of fossil energy, the two major problems of energy shortage and environmental pollution have become increasingly serious. The development of green and sustainable clean energy has become an urgent problem to be solved. Hydrogen is considered to be one of the most ideal alternative clean energy sources to traditional fossil energy due to its high unit energy density and pollution-free characteristics, and water electrolysis is considered to be the most promising hydrogen production strategy driven by renewable energy. At present, water electrolysis technologies include alkaline water electrolysis, proton exchange membrane water electrolysis and anion exchange membrane water electrolysis. Among them, proton exchange membrane water electrolysis has the advantages of high working current density, fast system response, and high purity of hydrogen production. Conventional water electrolysis generally chooses distilled water as the electrolyte, which can avoid the influence of precipitation or oxides on the electrode during the electrolysis process, but fresh water resources are limited. If seawater or salt water, which is widely distributed in nature, is used as the electrolyte, it can not only avoid the consumption of fresh water resources, but also reduce costs, but the chloride ions in seawater or salt water and their electrolysis products chlorine, hypochlorite, etc. will corrode the electrode material and cause the performance of the electrolyzer to decay.

[0003] Sodium hypochlorite is an important chlorine-based disinfectant that can be used in drinking water purification, sewage treatment, organic bleaching and other fields. At present, there are two main methods for preparing sodium hypochlorite, namely the electrolysis of sodium chloride solution and the liquid alkali chlorination method. The electrolysis of sodium chloride solution refers to adding sodium chloride solution to the electrolytic cell, and through the action of electric current, the chloride ions in the salt solution undergo oxidation reaction to generate sodium hypochlorite, chlorine gas, chlorine dioxide, etc.; the liquid alkali chlorination method refers to passing chlorine gas into sodium hydroxide solution to produce sodium hypochlorite. The electrolysis method has the advantages of safe raw materials, high degree of self-control, and low comprehensive operating cost. It also avoids the safety risks of dangerous goods transportation and storage when using liquid chlorine. However, it also has disadvantages such as low product purity, high one-time investment and high power consumption. Summary of the invention

[0004] 1. In view of the problems and shortcomings of the above-mentioned prior art, the present invention provides an electrolysis device for preparing hydrogen and chlorine by electrolyzing acidic or neutral saturated sodium chloride solution and its application. The present invention is implemented by the following technical solutions.

[0005] 2. Here, an acid-resistant and corrosion-resistant porous composite electrode is designed, which can operate well in the electrolysis of concentrated brine. In order to reduce its voltage during the electrolysis process, the corresponding catalysts are loaded on the cathode and anode by electrodeposition and impregnation, respectively.

[0006] 3. In order to solve the above problems, a device for electrolyzing acidic or neutral saturated sodium chloride solution is also designed, and the processes of electrolytic hydrogen production, chlorine production and sodium hypochlorite production by liquid alkali chlorination are coupled, and the electrolytic cell device is separated into a cathode chamber and an anode chamber using a proton exchange membrane or a diaphragm, wherein the cathode chamber can obtain high-purity hydrogen, the anode chamber obtains high-purity chlorine, and the absorption liquid chamber connected to the anode chamber obtains a sodium hypochlorite solution. In addition, by replacing the sodium hydroxide in the absorption liquid chamber with sodium bromide or sodium iodide solution, bromine water or iodine water can be obtained. The obtained sodium hypochlorite / bromine water / iodine water is used for antibacterial experiments, and the minimum inhibitory concentration is determined by microdilution method, and the results show that it has a good bactericidal effect.

[0007] The present application provides a method for preparing an acid-resistant and corrosion-resistant porous composite electrode, the steps comprising:

[0008] Step 1: Preparation of cathode and anode corrosion-resistant porous composite electrodes

[0009] Take polymer materials such as polysulfone PSU or polyethersulfone PESf or polyphenylene sulfide PPS or polyetheretherketone PEEK or polybenzimidazole PBI, organic solvents such as N-methylpyrrolidone NMP or N,N-dimethylformamide DMF or dimethyl sulfoxide DMSO or dimethylacetamide DMAc or tetrahydrofuran THF, additives such as polyvinylpyrrolidone PVP or polyethylene glycol PEG, inorganic conductive materials such as carbon materials such as carbon fiber or graphite, or metal powders such as titanium or titanium alloy or stainless steel, and mix them by ball milling, and then use a casting coater to perform phase inversion casting to obtain a corrosion-resistant porous composite electrode; the electrode contains a support body to improve the mechanical properties of the electrode, and the support body is selected from a square or diamond lattice formed by nanofibers such as polyphenylene sulfide;

[0010] Step 2: Catalyst loading on cathode and anode electrodes

[0011] In order to improve the efficiency of hydrogen production during the electrolysis process and reduce the overpotential of hydrogen evolution, precious metal catalysts Pt, Pd, Ru, Rh or their alloys, or non-precious metal catalysts Fe, Cu, Ni or their alloys are selected, and the catalysts are loaded on the prepared electrode by electrodeposition, hot / cold spraying or ion sputtering; at the same time, in order to reduce the overpotential of the anode chlorine evolution reaction, precious metal oxide catalysts RuO2 or IrO2, or non-precious metal oxide catalysts MnO2, TiO2, PbO2 are selected, and the catalysts are loaded on the electrode by drip coating, spraying or dipping for later use.

[0012] The specific steps of step 1 are:

[0013] Step 1-1, adding PSU or PESf or PPS or PEEK, and PVP or PEG into an organic solvent NMP or DMF or DMAc, and ball milling for 2-4 hours to obtain, for example, a milky white polymer solution;

[0014] Step 1-2, adding carbon material carbon fiber or graphite, or metal powder titanium or stainless steel to the above polymer solution; ball milling for 24-48 hours to obtain a uniformly mixed slurry, and then vacuuming for 20-30 minutes to remove bubbles in the slurry;

[0015] Step 1-3, lay and fix a layer of commercial fiber mesh as a support on a cast-film coater; place the degassed slurry on the cast-film coater, and adjust the scraper height to control the thickness of the cast green body, the casting speed is 10-100 cm / min, and then transfer the cast green body to a water tank with a water depth of 20-40 cm for phase inversion process, take it out after standing for 12-24 hours, and then naturally dry it at room temperature or dry it at 100-200°C for 2-5 hours to obtain a corrosion-resistant porous composite electrode.

[0016] The specific steps of step 2 are:

[0017] Step 2-1: Prepare cathode catalyst by electrodeposition; one of the electrodeposition conditions: 5-50 g / L chloroplatinic acid or palladium chloride, 1 M HCl or ammonium chloride, current density 10-200 mA / cm 2 , the electrodeposition time is 1-10min, and the corrosion-resistant porous composite electrode prepared above is used as a carrier; a three-electrode system is adopted, in which a saturated calomel electrode is used as a reference electrode, a platinum sheet or a palladium sheet is used as a counter electrode, and a carrier is used as a working electrode; the experiment is carried out using a Cost electrochemical workstation, and after the electrodeposition is completed, the porous composite electrode loaded with Pt or Pd catalyst is stored or used after being ultrasonically or cleaned with ultrapure water; for Ni alloy, Fe alloy, Cu alloy catalyst, nickel sulfate, ferric chloride, copper nitrate, sodium chloride, boric acid, etc. are selected as the electrodeposition solution;

[0018] Step 2-2, prepare the anode catalyst by drip coating, spray coating or dipping; one of the drip coating / spray coating / dipping conditions: dissolve 20 mg RuO2 or RuCl3 and 2 mg conductive carbon black in a mixed solution of 2 ml ethanol or water and 0.1 ml Nafion solution (5 wt.%), stir magnetically for 4-12 hours, mix evenly, drip / spray the above catalyst slurry onto the surface of the porous composite carrier or immerse the carrier in the catalyst slurry, and repeat several times to obtain electrodes with different catalyst loadings; during the drip coating / spray coating / dipping process, after the loaded slurry is completely dried, the next drip coating / spray coating / dipping is carried out, wherein for the dipping method, heat treatment is carried out at 200-500°C and inert atmosphere such as Ar to obtain RuO2 with higher crystallinity; or Ru-doped MnO2 or TiO2 or PbO2 is selected as the preparation material of the anode catalyst.

[0019] The present application also provides a method for preparing an electrolytic device, comprising a corrosion-resistant electrode prepared by any of the above methods for preparing an acid-resistant and corrosion-resistant porous composite electrode;

[0020] The device adopts a proton exchange membrane or a diaphragm to separate an H-type electrolytic cell or a flow-type electrolytic cell into a cathode chamber and an anode chamber; the electrolyte in the cathode and anode chambers is acidic or neutral saturated sodium chloride, a gas collecting chamber is connected to the anode chamber, and 1M NaOH, NaBr or NaI is added into the collecting chamber as an absorption liquid; the cathode is located in the cathode chamber, wherein a porous composite electrode is electrodeposited with precious metals such as Pt, Pd, Ru, Rh or alloys thereof, or non-precious metals such as Ni alloy, Fe alloy or Cu alloy; the anode is located in the anode chamber, wherein the porous composite anode is impregnated with precious metal oxides such as RuO2 or IrO2, or non-precious metal oxides such as MnO2, TiO2 or PbO2.

[0021] The specific steps of the preparation method of the electrolytic device are:

[0022] Step 3-1, prepare an acidic or neutral saturated sodium chloride solution, that is, add sodium chloride to a 1M HCl solution or pure water until the sodium chloride is saturated, and prepare 30mL of a 1M NaOH or NaBr or NaI solution as a chlorine gas absorption liquid;

[0023] Step 3-2: Use a commercial proton exchange membrane or diaphragm to separate the cathode chamber and the anode chamber of the electrolytic cell. The cathode chamber and the anode chamber use the same acidic or neutral saturated sodium chloride electrolyte, and the volume of each is 30 mL.

[0024] The invention discloses an application method of an electrolytic device for producing hydrogen and chlorine by electrolyzing an acidic or neutral saturated sodium chloride solution. The electrolytic device is prepared by the method described above, and the application method comprises: generating hydrogen at a cathode and generating chlorine at an anode, wherein the chlorine is absorbed by sodium hydroxide or sodium bromide / sodium iodide solution in a gas collection chamber and generates sodium hypochlorite or bromine / iodine water respectively; using the sodium hypochlorite, bromine water and iodine water disinfectants prepared above for antibacterial experiments, and selecting Staphylococcus aureus, Vibrio splendens, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio anguillarum and the like for determination of minimum inhibitory concentration by microdilution method.

[0025] The specific steps of the application method are:

[0026] Step 3-3: Turn on the electrolysis power supply, use the two-electrode method constant current charging mode, set the temperature to 20-95°C, the hydrogen system pressure to slightly positive pressure, the chlorine system pressure to slightly negative pressure, and the current density to 5-300mA / cm 2 , time 1-500h, effective electrode area 1cm 2The above; the protons in the acidic or neutral saturated sodium chloride solution in the cathode chamber undergo a reduction reaction on the electrode to generate hydrogen, and the lost protons are transmitted from the anode chamber through the proton exchange membrane to be replenished, and the generated hydrogen is stored in the gas storage tank; the chloride ions in the acidic or neutral saturated sodium chloride solution in the anode chamber undergo an oxidation reaction on the electrode to generate chlorine, and the generated chlorine enters the gas collection chamber or is absorbed by one of 1M NaOH / NaBr / NaI, and sodium hypochlorite / bromine water / iodine water is obtained at the same time;

[0027] Step 3-4, select Staphylococcus aureus, Vibrio splendens, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio anguillarum as the bacterial strains to be tested, perform gradient dilution in a 96-well plate, culture in a 37°C bacterial incubator for 24 hours, determine the linear relationship between the bacterial count and the OD600 absorbance value, and read the lowest disinfectant concentration at which no bacteria grow, which is the minimum inhibitory concentration of the bacteria for the disinfectant.

[0028] An electrolysis device for electrolyzing an acidic or neutral saturated sodium chloride solution to produce hydrogen and chlorine and its application, comprising the steps of:

[0029] Step 1: Preparation of porous composite electrodes

[0030] The electrodes were prepared by phase inversion casting.

[0031] Step 1-1, first add PSU or PESf and PVP to NMP or DMF, etc., and ball-mill for 2-4 hours to obtain, for example, a milky white polymer solution;

[0032] Step 1-2, adding carbon fiber or titanium powder to the above polymer solution; after ball milling for 24-48 hours, a uniformly mixed slurry is obtained, and then vacuuming for 20-30 minutes to remove bubbles in the slurry;

[0033] Step 1-3, first lay and fix a layer of commercial fiber (such as polypropylene / polyethylene / polyphenylene sulfide nanofiber, glass fiber, etc.) grid on the cast coating machine as a support; then place the degassed slurry on the cast coating machine, and adjust the scraper height to control the thickness of the cast green body, the casting speed is 10-100cm / min, and then quickly transfer it to a water tank with a water depth of 20-40cm or an ethanol-water solution of the same depth, let it stand for 12-24h and then take it out, and then dry it naturally at room temperature or dry it at 100-200℃ for 2-5h to obtain a corrosion-resistant porous composite electrode.

[0034] Step 2: Catalyst loading on cathode and anode electrodes

[0035] The cathode catalyst, such as precious metals such as Pt, Pd, Ru, Rh, or non-metals such as Ni, Cu, Fe, and their alloys, is loaded on the prepared electrode by methods such as electrodeposition, thermal spraying, cold spraying, or plasma spraying.

[0036] The anode catalyst, such as noble metal oxides such as RuO2, IrO2, or non-noble metal electrodes such as TiO2, PbO2, SnO2, is loaded on the prepared electrode by methods such as drop coating or dipping.

[0037] Step 2-1: Prepare cathode catalyst by electrodeposition. Electrodeposition conditions: 5-50 g / L chloroplatinic acid or palladium chloride, current density 10-200 mA / cm 2 , electroplating time 1-10min, using the corrosion-resistant porous composite electrode prepared above as a carrier; using a three-electrode system, in which a saturated calomel electrode is used as a reference electrode, a platinum sheet is used as a counter electrode, and a carrier is used as a working electrode. The experiment was carried out using a Coster electrochemical workstation. After the electrodeposition was completed, the porous composite electrode loaded with Pt catalyst was stored or used after ultrasonic or cleaning with ultrapure water. For Ni, Fe, Cu and their alloy catalysts, nickel sulfate, ferric chloride, copper nitrate, sodium chloride, boric acid, etc. were selected as the electrodeposition solution.

[0038] Step 2-2, prepare the anode catalyst by drip coating, spray coating or dipping method. One of the drip coating / spray coating / dipping conditions: dissolve 20mg RuO2 (or RuCl3) and 2mg conductive carbon black in a mixed solution of 2ml ethanol and 0.1ml Nafion solution (5wt.%), stir magnetically for 4-12h, mix evenly, drip or spray the above catalyst slurry onto the surface of the porous composite carrier or immerse the carrier in the catalyst slurry, and repeat several times to obtain electrodes with different catalyst loadings; during the drip coating / spray coating / dipping process, wait for the loaded slurry to dry completely before the next drip coating / spray coating / dipping, wherein for the dipping method, it is also necessary to heat treat at 200-500℃ and inert atmosphere such as Ar to obtain RuO2 with higher crystallinity. In addition, MnO2 or TiO2 or PbO2 or SnO2 doped with different metals (such as Ru, Ir, Ni, etc.) can also be selected as anode active catalysts.

[0039] Step 3: A corrosion-resistant porous composite electrode for electrolyzing acidic or neutral saturated sodium chloride solution to produce hydrogen and chlorine, and an electrolysis device and application thereof.

[0040] The H-type electrolytic cell or the flow-type electrolytic cell is separated into a cathode chamber and an anode chamber by a proton exchange membrane (such as Nafion117 membrane) or a composite diaphragm. The electrolytes in the cathode chamber and the anode chamber are both acidic (such as containing 1M HCl, other concentrations can also be used) or neutral saturated sodium chloride. A gas collection chamber is connected to the anode chamber, and 1M NaOH or NaBr or NaI is added to the collection chamber as an absorption liquid (other concentrations can also be used). The cathode is located in the cathode chamber, wherein a noble metal (such as Pt, Pd, Ru) or Ni, Fe, Cu and alloy catalysts thereof are electrodeposited on the porous composite electrode, and the anode is located in the anode chamber, wherein a noble metal oxide (such as RuO2, IrO2) or Ru, Ir, Ni and other doped MnO2, TiO2, SnO2, PbO2 and other catalysts are impregnated on the porous composite anode; hydrogen is generated at the cathode, and chlorine is generated at the anode. The chlorine is absorbed by the sodium hydroxide or sodium bromide / sodium iodide solution in the gas collection chamber and generates sodium hypochlorite or bromine / iodine water respectively. The sodium hypochlorite, bromine water and iodine water disinfectants prepared above were used in antibacterial experiments, and Staphylococcus aureus, Vibrio splendens, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio anguillarum and the like were selected for microdilution method minimum inhibitory concentration determination (bacterial growth detection OD600).

[0041] Step 3-1, prepare an acidic or neutral saturated sodium chloride solution, that is, add sodium chloride to a 1M HCl solution (other concentrations may also be used) or pure water until the sodium chloride is saturated, and prepare 30mL (other volumes may also be used) of a 1M NaOH or NaBr or NaI (other concentrations may also be used) solution as a chlorine gas absorption liquid;

[0042] Step 3-2, using a commercial proton exchange membrane (such as Nafion117 membrane) or a composite diaphragm to separate the cathode chamber and the anode chamber of the electrolytic cell, and using the same acidic or neutral saturated sodium chloride electrolyte in the cathode chamber and the anode chamber, with a volume of 30 mL (other concentrations may also be used);

[0043] Step 3-3, turn on the electrolysis power supply, adopt the two-electrode method constant current charging mode, set the temperature to 20-95°C, the hydrogen system pressure to slightly positive pressure (such as 49-98Pa), the chlorine system pressure to slightly negative pressure (such as -49--98Pa), and the current density to 5-300mA / cm 2 , time 1-500h, effective electrode area 1cm 2(Time, current, and electrode area can all be scaled up as needed). Protons in the acidic or neutral saturated sodium chloride solution in the cathode chamber undergo a reduction reaction on the electrode to generate hydrogen. The lost protons can be transferred from the anode chamber through the proton exchange membrane to be replenished, and the generated hydrogen is stored in the gas tank; chloride ions in the acidic or neutral saturated sodium chloride solution in the anode chamber undergo an oxidation reaction on the electrode to generate chlorine. The generated chlorine enters the gas collection chamber or is absorbed by one of 1M NaOH / NaBr / NaI (other concentrations can also be used). The reaction formula can be Cl2+2OH - =Cl - +ClO - +H2O、Cl2+2Br - =2Cl - +Br2 or Cl2 + 2I - =2Cl - + I2, sodium hypochlorite / bromine water / iodine water are obtained at the same time. In addition, the produced chlorine can also be used for other chlorination reactions (such as preparation of methyl chloride, hexachlorocyclohexane, etc.).

[0044] The beneficial effects of the present invention are:

[0045] (1) The method proposed in the present invention is a porous composite electrode and catalyst loading method and electrolysis device composed of materials such as carbon fiber or titanium metal and high molecular polymer with high resistance and strong corrosion resistance operating in acidic or neutral saturated sodium chloride solution, which has the advantages of simple electrode preparation method, easy operation, good catalyst loading effect, etc.

[0046] (2) The method proposed in the present invention can produce chlorine and its downstream products such as sodium hypochlorite, bromine / iodine water, and methyl chloride, and has the advantages of small equipment footprint, short process flow, easy operation, and environmental friendliness.

[0047] (3) The method proposed in the present invention can generate hydrogen by electrolysis in the cathode chamber, and generate chlorine and byproduct sodium hydroxide in the anode chamber. The present invention has the following advantages: First, the device is used to electrolyze sodium chloride solution to prepare hydrogen, using renewable electric energy as the driving force, using salt water that is widely present in nature as the electrolyte, and has the advantages of wide distribution of raw materials, low operating cost, good stability, high efficiency, and high product purity; Second, the product has high added value. In the process of electrolyzing sodium chloride solution, hydrogen and chlorine and their downstream products are obtained at the same time. Hydrogen is a sustainable and clean energy with no pollution. It is one of the current ways to solve the shortage of fossil energy and an important carrier for achieving green and low-carbon development. It is widely used in various fields such as petrochemicals, metallurgy, transportation, aerospace, etc. Chlorine and sodium hypochlorite are important disinfectants that can be used in sterilization, drinking water purification, sewage treatment, organic bleaching and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the device of the present invention.

[0049] The markings in the attached figure are as follows: 1-cathode electrolyte, 2-proton exchange membrane, 3-anolyte, 4-gas absorption liquid, 5-cathode, 6-anode.

[0050] Figure 2 It is a scanning electron microscope cross-sectional view of the carbon fiber-polyethersulfone composite electrode of the present invention.

[0051] Figure 3 It is a scanning electron microscope cross-sectional view of the metal titanium-polysulfone composite electrode of the present invention.

[0052] Figure 4 The minimum inhibitory concentration test results of the absorption solution containing the product sodium hypochlorite / bromine water / iodine water and the reference solution 1M NaOH under the conditions of 300mA and 5h electrolysis of acidic saturated sodium chloride solution in Example 4 of the present invention, including the maximum multiples of dilution that can be performed for the absorption solution with obvious antibacterial effect on five different bacterial groups. DETAILED DESCRIPTION

[0053] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0054] Example 1

[0055] like Figure 1 As shown, the schematic diagram of the device for electrolyzing acidic saturated sodium chloride solution to produce hydrogen and chlorine, the proton exchange membrane separates the electrolytic cell into a cathode chamber and an anode chamber, the cathode electrolyte 1 in the left chamber of the H-type electrolytic cell is a mixed solution of 1M HCl and saturated sodium chloride; the anode electrolyte 3 in the right chamber is a mixed solution of 1M HCl and saturated sodium chloride; the cathode 5 is located in the left cathode chamber, the anode 6 is located in the right anode chamber, and the distance between the cathode and the anode is about 6cm. High-purity hydrogen is generated on the cathode 5, high-purity chlorine is generated on the anode, and a high-concentration sodium hypochlorite solution is generated in the gas absorption chamber.

[0056] The cathode 5 and the anode 6 are carbon fiber-polyethersulfone porous composite electrodes (such as Figure 2 As shown), the thickness is about 800 μm, and a commercial polypropylene fiber mesh is added as a support to improve the tensile strength; the proton exchange membrane 2 is DuPont proton exchange membrane model Nafion117, with a thickness of 183 μm and a conductivity of 0.083 S / cm;

[0057] The electrolysis device construction method for electrolyzing acidic saturated sodium chloride to produce hydrogen and chlorine (for producing sodium hypochlorite) and its sterilization application, the specific operation steps are as follows:

[0058] Step 1: Use a proton exchange membrane 2 to separate the H-type electrolytic cell into a cathode chamber and an anode chamber, and place a cathode 5 and an anode 6 in the cathode chamber and the anode chamber, respectively;

[0059] Step 2: Add sodium chloride to 1M HCl solution until saturated to prepare cathode electrolyte 1 and anode electrolyte 3; prepare 1M NaOH solution as gas absorption liquid 4;

[0060] Step 3, injecting the cathode electrolyte 1 and the anode electrolyte 3 into the cathode chamber and the anode chamber respectively, and injecting the gas absorption liquid 4 into the gas absorption chamber;

[0061] Step 4: At room temperature and pressure, connect the electrolysis power supply (such as Blue Electric D340A), charge at a constant current of 5mA for 50h, and the effective electrode area is 1cm 2 On the cathode 5, the protons in the acidic sodium chloride solution undergo an electro-reduction reaction to generate hydrogen, and the consumed protons are replenished from the anode chamber through the proton exchange membrane, and the generated hydrogen is stored in the gas storage tank; on the anode 6, the chloride ions in the acidic sodium chloride solution undergo an electro-oxidation reaction to generate chlorine, which is passed into the gas absorption chamber and reacts with the sodium hydroxide in the gas absorption liquid 4 to generate sodium hypochlorite.

[0062] The results of the 50-hour chronopotentiometry electrolysis experiment of acidic sodium chloride solution showed that the voltage was stable at 1.35V and the current density was 5mA / cm 2 The generated hydrogen and chlorine are stored in gas storage tanks respectively, and the sodium hypochlorite is collected in the gas absorption chamber. The purity of hydrogen and chlorine produced in this example is as high as 100%, the hydrogen yield is about 2.4mL / h, the Faraday efficiency of hydrogen / chlorine evolution reaction is 100%, and the generated sodium hypochlorite has a stable bactericidal effect, with low voltage consumption and low energy consumption.

[0063] Example 2

[0064] like Figure 1 As shown, the schematic diagram of the device for preparing hydrogen and chlorine by electrolyzing acidic saturated sodium chloride solution, the proton exchange membrane separates the electrolytic cell into a cathode chamber and an anode chamber, the cathode electrolyte 1 in the left chamber of the H-type electrolytic cell is a mixed solution of 1M HCl and saturated sodium chloride; the anode electrolyte 3 in the right chamber is a mixed solution of 1M HCl and saturated sodium chloride; the cathode 5 is located in the cathode chamber, the anode 6 is located in the anode chamber, and the distance between the cathode and the anode is 4cm. High-purity hydrogen is generated on the cathode 5, high-purity chlorine is generated on the anode, and a high-concentration bromine aqueous solution is generated in the gas absorption chamber.

[0065] The cathode 5 and the anode 6 are titanium-polysulfone porous composite electrodes (such as Figure 3As shown), the thickness is about 800 μm, and a commercial polyethylene fiber mesh is added as a support to improve the tensile strength; the proton exchange membrane 2 is DuPont chlor-alkali membrane model Nafion N2060;

[0066] The electrolysis device construction method for electrolyzing acidic saturated sodium chloride to produce hydrogen and chlorine (for producing bromine water) and its sterilization application, the specific operation steps are as follows:

[0067] Step 1: Use a proton exchange membrane 2 to separate the H-type electrolytic cell into a cathode chamber and an anode chamber, and place a cathode 5 and an anode 6 in the cathode chamber and the anode chamber, respectively;

[0068] Step 2: Add sodium chloride to 1M HCl solution until saturated to prepare cathode electrolyte 1 and anode electrolyte 3; prepare 1M NaBr solution as gas absorption liquid 4;

[0069] Step 3, injecting the cathode electrolyte 1 and the anode electrolyte 3 into the cathode chamber and the anode chamber respectively, and injecting the gas absorption liquid 4 into the gas absorption chamber;

[0070] Step 4: At room temperature and pressure, connect the electrolysis power supply (such as Blue Electric D340A), charge at a constant current of 25mA for 5h, and the effective electrode area is 1cm 2 On the cathode 5, the protons in the acidic sodium chloride solution undergo an electro-reduction reaction to generate hydrogen, and the consumed protons are replenished from the anode chamber through the proton exchange membrane, and the generated hydrogen is stored in the gas storage tank; on the anode 6, the chloride ions in the acidic sodium chloride solution undergo an electro-oxidation reaction to generate chlorine, and the chlorine is passed into the gas absorption chamber and reacts with the sodium bromide in the gas absorption liquid 4 to generate bromine water.

[0071] The results of the 5-hour chronopotentiometry electrolysis experiment of acidic sodium chloride solution showed that the voltage was stable at 1.75V and the current density was 25mA / cm 2 The generated hydrogen and chlorine are stored in gas storage tanks, and the bromine water is collected in a gas absorption chamber. The purity of hydrogen and chlorine produced in this example is as high as 100%, the hydrogen yield is about 11.7mL / h, the Faraday efficiency of hydrogen / chlorine evolution reaction is 100%, and the generated bromine water has a stable bactericidal effect, with low voltage consumption and low energy consumption.

[0072] Example 3

[0073] like Figure 1As shown, the schematic diagram of the device for preparing hydrogen and chlorine by electrolyzing acidic saturated sodium chloride solution, the proton exchange membrane separates the electrolytic cell into a cathode chamber and an anode chamber, the cathode electrolyte 1 in the left chamber of the H-type electrolytic cell is a mixed solution of 1M HCl and saturated sodium chloride; the anode electrolyte 3 in the right chamber is a mixed solution of 1M HCl and saturated sodium chloride; the cathode 5 is located in the cathode chamber, the anode 6 is located in the anode chamber, and the distance between the cathode and the anode is 2cm. High-purity hydrogen is generated on the cathode 5, high-purity chlorine is generated on the anode, and a high-concentration iodine aqueous solution is generated in the gas absorption chamber.

[0074] The cathode 5 and the anode 6 are graphite-polyetheretherketone porous composite electrodes prepared and loaded with catalysts, with a thickness of about 200 μm, and a commercial glass fiber mesh is added as a support to improve the tensile strength; the proton exchange membrane 2 is a DuPont chlor-alkali membrane model Nafion N2060;

[0075] The electrolysis device construction method for electrolyzing acidic saturated sodium chloride to produce hydrogen and chlorine (for producing iodine water) and its sterilization application, the specific operation steps are as follows:

[0076] Step 1: Use a proton exchange membrane 2 to separate the H-type electrolytic cell into a cathode chamber and an anode chamber, and place a cathode 5 and an anode 6 in the cathode chamber and the anode chamber, respectively;

[0077] Step 2: Add sodium chloride to 1M HCl solution until saturated to prepare cathode electrolyte 1 and anode electrolyte 3; prepare 1M NaI solution as gas absorption liquid 4;

[0078] Step 3, injecting the cathode electrolyte 1 and the anode electrolyte 3 into the cathode chamber and the anode chamber respectively, and injecting the gas absorption liquid 4 into the gas absorption chamber;

[0079] Step 4: At room temperature and pressure, connect the electrolysis power supply (such as Blue Electric D340A), charge at a constant current of 10mA for 500h, and the effective electrode area is 5cm 2 On the cathode 5, the protons in the acidic sodium chloride solution undergo an electro-reduction reaction to generate hydrogen, and the consumed protons are replenished from the anode chamber through the proton exchange membrane, and the generated hydrogen is stored in the gas storage tank; on the anode 6, the chloride ions in the acidic sodium chloride solution undergo an electro-oxidation reaction to generate chlorine, and the chlorine is passed into the gas absorption chamber and reacts with the sodium iodide in the gas absorption liquid 4 to generate iodine water.

[0080] The results of the 500-hour chronopotentiometry electrolysis experiment of acidic sodium chloride solution showed that the voltage was stable at 1.48V and the current density was 10mA / cm 2The generated hydrogen and chlorine are stored in gas storage tanks, and the iodine water is collected in the gas absorption chamber. The purity of hydrogen and chlorine produced in this example is as high as 100%, the hydrogen yield is about 4.77mL / h, the Faraday efficiency of hydrogen / chlorine evolution reaction is 100%, and the generated iodine water has a stable bactericidal effect, with low voltage consumption and low energy consumption.

[0081] Example 4

[0082] like Figure 1 As shown, the schematic diagram of the device for electrolyzing acidic saturated sodium chloride solution to produce hydrogen and chlorine is shown. The proton exchange membrane separates the electrolytic cell into a cathode chamber and an anode chamber. The cathode electrolyte 1 in the left chamber of the flow-type electrolytic cell is a mixed solution of 1M HCl and saturated sodium chloride; the anode electrolyte 3 in the right chamber is a mixed solution of 1M HCl and saturated sodium chloride; the cathode 5 is located in the cathode chamber, the anode 6 is located in the anode chamber, and the cathode and the anode are located on both sides of the proton exchange membrane, which is a zero-spacing design. High-purity hydrogen is generated on the cathode 5, high-purity chlorine is generated on the anode, and a high-concentration sodium hypochlorite solution is generated in the gas absorption chamber.

[0083] The cathode 5 and the anode 6 are carbon fiber-polyphenylene sulfide porous composite electrodes prepared and loaded with catalysts, with a thickness of about 200 μm, and a commercial aramid fiber grid is added as a support to improve the tensile strength; the proton exchange membrane 2 is a DuPont chlor-alkali membrane model Nafion N982;

[0084] The electrolysis device construction method for electrolyzing acidic saturated sodium chloride to produce hydrogen and chlorine (for producing sodium hypochlorite) and its sterilization application, the specific operation steps are as follows:

[0085] Step 1: Use a proton exchange membrane 2 to separate the flow-type electrolytic cell into a cathode chamber and an anode chamber, and place a cathode 5 and an anode 6 in the cathode chamber and the anode chamber, respectively;

[0086] Step 2: Add sodium chloride to 1M HCl solution until saturated to prepare cathode electrolyte 1 and anode electrolyte 3; prepare 1M NaOH solution as gas absorption liquid 4;

[0087] Step 3, injecting the cathode electrolyte 1 and the anode electrolyte 3 into the cathode chamber and the anode chamber respectively, and injecting the gas absorption liquid 4 into the gas absorption chamber;

[0088] Step 4: At room temperature and pressure, connect the electrolysis power supply (such as Blue Electric D340A), charge at a constant current of 300mA for 5h, and the effective electrode area is 1cm 2On the cathode 5, the protons in the acidic sodium chloride solution undergo an electro-reduction reaction to generate hydrogen, and the consumed protons are replenished from the anode chamber through the proton exchange membrane, and the generated hydrogen is stored in the gas storage tank; on the anode 6, the chloride ions in the acidic sodium chloride solution undergo an electro-oxidation reaction to generate chlorine, which is passed into the gas absorption chamber and reacts with the sodium hydroxide in the gas absorption liquid 4 to generate sodium hypochlorite.

[0089] The results of the 5-hour chronopotentiometry electrolysis experiment of acidic sodium chloride solution showed that the voltage was stable at 5.25V and the current density was 300mA / cm 2 The generated hydrogen and chlorine are stored in gas storage tanks respectively, and the sodium hypochlorite solution is collected in the gas absorption chamber. The purity of hydrogen and chlorine produced in this example is as high as 100%, the hydrogen yield is 125.4mL / h, the Faraday efficiency of hydrogen / chlorine evolution reaction is 100%, and the generated sodium hypochlorite has a stable bactericidal effect, with low voltage consumption and low energy consumption.

[0090] Figure 4 The graph shows the growth status of five bacterial groups in an absorption solution containing sodium hypochlorite (electrolyzed acidic saturated sodium chloride solution conditions: 300mA, 5h); number ① is Vibrio splendidus, number ② is Vibrio parahaemolyticus, number ③ is Vibrio harveyi, number ④ is Staphylococcus aureus, number ⑤ is Vibrio anguillarum; there are 12 columns in different numbers, each column in different numbers represents the same dilution multiple, from left to right are 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096; the first row of each number is the growth rate of the bacteria at 1M The first row shows bacteria growing in an environment of NaOH, the second row shows bacteria growing in an absorption solution containing the product sodium hypochlorite, and the third row is a blank cell; high turbidity represents high bacterial concentration and good growth, while clearness and transparency represent no bacterial growth; experiments show that the absorption solution containing the product sodium hypochlorite has a good inhibitory effect on the growth of these five bacteria, and bacterial growth will only be found when the absorption solution containing the product sodium hypochlorite is diluted at least 256 times.

Claims

1. A method for preparing an acid-resistant and corrosion-resistant porous composite electrode, characterized in that the steps include: Step 1: Preparation of cathode and anode corrosion-resistant porous composite electrodes Take polymer materials such as polysulfone PSU or polyethersulfone PESf or polyphenylene sulfide PPS or polyetheretherketone PEEK or polybenzimidazole PBI, organic solvents such as N-methylpyrrolidone NMP or N,N-dimethylformamide DMF or dimethyl sulfoxide DMSO or dimethylacetamide DMAc or tetrahydrofuran THF, additives such as polyvinylpyrrolidone PVP or polyethylene glycol PEG, inorganic conductive materials such as carbon materials such as carbon fiber or graphite, or metal powders such as titanium or titanium alloy or stainless steel, and mix them by ball milling, and then use a casting coater to perform phase inversion casting to obtain a corrosion-resistant porous composite electrode; the electrode contains a support body to improve the mechanical properties of the electrode, and the support body is selected from a square or diamond lattice formed by nanofibers such as polyphenylene sulfide; Step 2: Catalyst loading on cathode and anode electrodes In order to improve the efficiency of hydrogen production during the electrolysis process and reduce the overpotential of hydrogen evolution, precious metal catalysts Pt, Pd, Ru, Rh or their alloys, or non-precious metal catalysts Fe, Cu, Ni or their alloys are selected, and the catalysts are loaded on the prepared electrode by electrodeposition, hot / cold spraying or ion sputtering; at the same time, in order to reduce the overpotential of the anode chlorine evolution reaction, precious metal oxide catalysts RuO2 or IrO2, or non-precious metal oxide catalysts MnO2, TiO2, PbO2 are selected, and the catalysts are loaded on the electrode by drip coating, spraying or dipping for later use.

2. The method for preparing the acid-resistant and corrosion-resistant porous composite electrode according to claim 1, characterized in that: The specific steps of step 1 are: Step 1-1, adding PSU or PESf or PPS or PEEK, and PVP or PEG into an organic solvent NMP or DMF or DMAc, and ball milling for 2-4 hours to obtain, for example, a milky white polymer solution; Step 1-2, adding carbon material carbon fiber or graphite, or metal powder titanium or stainless steel to the above polymer solution; ball milling for 24-48 hours to obtain a uniformly mixed slurry, and then vacuuming for 20-30 minutes to remove bubbles in the slurry; Step 1-3, lay and fix a layer of commercial fiber mesh as a support on a cast-film coater; place the degassed slurry on the cast-film coater, and adjust the scraper height to control the thickness of the cast green body, the casting speed is 10-100 cm / min, and then transfer the cast green body to a water tank with a water depth of 20-40 cm for phase inversion process, take it out after standing for 12-24 hours, and then naturally dry it at room temperature or dry it at 100-200°C for 2-5 hours to obtain a corrosion-resistant porous composite electrode.

3. The method for preparing the acid-resistant and corrosion-resistant porous composite electrode according to claim 1, characterized in that: The specific steps of step 2 are: Step 2-1: Prepare cathode catalyst by electrodeposition; one of the electrodeposition conditions: 5-50 g / L chloroplatinic acid or palladium chloride, 1 M HCl or ammonium chloride, current density 10-200 mA / cm 2 , the electrodeposition time is 1-10min, and the corrosion-resistant porous composite electrode prepared above is used as a carrier; a three-electrode system is adopted, in which a saturated calomel electrode is used as a reference electrode, a platinum sheet or a palladium sheet is used as a counter electrode, and a carrier is used as a working electrode; the experiment is carried out using a Cost electrochemical workstation, and after the electrodeposition is completed, the porous composite electrode loaded with Pt or Pd catalyst is stored or used after being ultrasonically or cleaned with ultrapure water; for Ni alloy, Fe alloy, Cu alloy catalyst, nickel sulfate, ferric chloride, copper nitrate, sodium chloride, boric acid, etc. are selected as the electrodeposition solution; Step 2-2, preparing the anode catalyst by drip coating, spray coating or dipping method; one of the drip coating / spray coating / dipping conditions: dissolving 20 mg RuO2 or RuCl3 and 2 mg conductive carbon black in a mixed solution of 2 ml ethanol or water and 0.1 ml Nafion solution (5 wt.%), stirring by magnetic force for 4-12 hours, and after mixing evenly, drip coating / spraying the above catalyst slurry onto the surface of the porous composite support or immersing the support into the catalyst slurry, and repeating the process multiple times to obtain electrodes with different catalyst loadings; during the drip coating / spray coating / dipping process, after the loaded slurry is completely dried, the next drip coating / spray coating / dipping is performed, wherein for the dipping method, heat treatment is performed at 200-500° C. and in an inert atmosphere such as Ar to obtain RuO2 with higher crystallinity. 2； Or select Ru-doped MnO2 or TiO2 or PbO2 as the preparation material of the anode catalyst.

4. A method for preparing an electrolytic device, characterized in that: A corrosion-resistant electrode prepared by the method for preparing an acid-resistant and corrosion-resistant porous composite electrode according to any one of claims 1 to 3; The device adopts a proton exchange membrane or a diaphragm to separate an H-type electrolytic cell or a flow-type electrolytic cell into a cathode chamber and an anode chamber; the electrolyte in the cathode and anode chambers is acidic or neutral saturated sodium chloride, a gas collecting chamber is connected to the anode chamber, and 1M NaOH, NaBr or NaI is added into the collecting chamber as an absorption liquid; the cathode is located in the cathode chamber, wherein precious metals Pt, Pd, Ru, Rh or their alloys, or non-precious metals Ni, Fe, Cu or their alloys are electrodeposited on the porous composite electrode, and the anode is located in the anode chamber, wherein precious metal oxides RuO2 or IrO2, or non-precious metal oxides MnO2, TiO2 or PbO2 are impregnated on the porous composite anode.

5. The method for preparing an electrolytic device according to claim 4, characterized in that: The specific steps are: Step 3-1, prepare an acidic or neutral saturated sodium chloride solution, that is, add sodium chloride to a 1M HCl solution or pure water until the sodium chloride is saturated, and prepare 30mL of 1M NaOH or NaBr or NaI solution as a chlorine gas absorption liquid; Step 3-2: Use a commercial proton exchange membrane or diaphragm to separate the cathode chamber and the anode chamber of the electrolytic cell. The cathode chamber and the anode chamber use the same acidic or neutral saturated sodium chloride electrolyte, and the volume of each is 30 mL.

6. An application method of an electrolysis device for producing hydrogen and chlorine by electrolyzing acidic or neutral saturated sodium chloride solution, characterized in that: The electrolysis device is prepared by the method described in claims 4-5, and the application method comprises: generating hydrogen at the cathode and generating chlorine at the anode, the chlorine is absorbed by the sodium hydroxide or sodium bromide / sodium iodide solution in the gas collection chamber and generates sodium hypochlorite or bromine / iodine water respectively; the prepared sodium hypochlorite, bromine water and iodine water disinfectants are used in antibacterial experiments, and Staphylococcus aureus, Vibrio splendens, Vibrio parahaemolyticus, Vibrio harveyi, Vibrio anguillarum and the like are selected for microdilution method minimum inhibitory concentration determination.

7. The application method of the electrolysis device for producing hydrogen and chlorine by electrolyzing acidic or neutral saturated sodium chloride solution according to claim 6, characterized in that: The application method specifically includes: Step 3-3: Turn on the electrolysis power supply, use the two-electrode method constant current charging mode, set the temperature to 20-95°C, the hydrogen system pressure to slightly positive pressure, the chlorine system pressure to slightly negative pressure, and the current density to 5-300mA / cm 2 , time 1-500h, effective electrode area 1cm 2 The above; the protons in the acidic or neutral saturated sodium chloride solution in the cathode chamber undergo a reduction reaction on the electrode to generate hydrogen, and the lost protons are transmitted from the anode chamber through the proton exchange membrane or the diaphragm to be replenished, and the generated hydrogen is stored in the gas storage tank; the chloride ions in the acidic or neutral saturated sodium chloride solution in the anode chamber undergo an oxidation reaction on the electrode to generate chlorine, and the generated chlorine enters the gas collection chamber or is absorbed by one of 1M NaOH / NaBr / NaI, and sodium hypochlorite / bromine water / iodine water is obtained; Step 3-4, select Staphylococcus aureus, Vibrio splendens, Vibrio parahaemolyticus, Vibrio harveyi, and Vibrio anguillarum as the bacterial strains to be tested, perform gradient dilution in a 96-well plate, culture in a 37°C bacterial incubator for 24 hours, determine the linear relationship between the bacterial count and the OD600 absorbance value, and read the lowest disinfectant concentration at which no bacteria grow, which is the minimum inhibitory concentration of the bacteria for the disinfectant.

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