Electrochemical reaction device and preparation method thereof

Abstract

The electrochemical reaction device comprises a plurality of electrochemical reaction units which are sequentially connected in series; the electrochemical reaction unit comprises a vertical cylindrical first reaction part and a U-shaped cylindrical second reaction part; the upper end and the lower end of each electrochemical reaction unit are provided with connecting pieces connected with the screen plate, and the connecting pieces are used for fixing the outer electrode and the inner electrode and are hermetically connected with the first reaction part and the second reaction part; an automatic exhaust valve is arranged above the second reaction part connected in each electrochemical reaction unit; gas in the electrolysis system is discharged out of the reaction system; attachments on the surface of the electrode are easy to clean and convenient to disassemble; installation is simple and fast; catalytic layers for electro-catalytic reaction are prepared on the inner wall of the outer electrode and the outer wall of the inner electrode of each electrochemical reaction unit; and catalyst layer materials on the surfaces of the positive and negative electrodes can be timely repaired.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical production devices, and in particular relates to an electrochemical reaction device and a preparation method thereof. Background Art

[0002] The electrochemical reaction device is the core device for organic electrochemical reaction synthesis. It consists of two electrodes and pipelines. This is the basic structural requirement of the electrochemical reaction device, which ensures that the electrochemical reaction can occur between the two electrodes.

[0003] Electrochemical reaction devices can be classified into two main types: one is an electrolytic reactor that uses external input electrical energy to promote electrochemical reactions at the interface of electrodes and electrolytes; the other is a chemical power reactor that spontaneously generates electrical energy through electrochemical reactions at the interface of electrodes and electrolytes.

[0004] The main process occurring in the reactor is electrochemical reaction, which includes four transfer processes: charge, mass, heat, and momentum, and is subject to the basic laws of electrochemical thermodynamics, electrode process kinetics, and transfer processes.

[0005] The electrochemical reaction device is a special chemical reactor that has the characteristics of developing the redox reaction process under the action of an electric field and designing and optimizing the electrochemical reaction device.

[0006] Electrochemical reaction is a special heterogeneous catalytic reaction that occurs at the interface between two types of conductors. The solid phase is the electrode, which has catalytic properties, but the catalytic properties are related to the electrode potential. This characteristic makes electrochemical reactions highly controllable and flexible.

[0007] Electrochemical reaction devices are widely used in the field of environmental protection. For example, electrochemical reactors are used in wastewater treatment. Electrochemical technology is effectively used for decolorization, sterilization, removal of heavy metal ions, removal of organic matter, and treatment of radioactive substances and other pollutants, showing its advantages of environmental friendliness and high water treatment efficiency.

[0008] The electrochemical reaction device is not only an efficient chemical reaction device, but also plays an important role in environmental protection and industrial applications. It has broad application prospects. However, during use, the electrodes often suffer from electrical corrosion and adhesion, which affects the efficiency of the chemical reaction. There is a need for an electrochemical reaction device that is easy to clean and adjust. Summary of the invention

[0009] In order to solve the above problems, the present invention discloses an electrochemical reaction device and a preparation method thereof.

[0010] To achieve the above object, the technical solution of the present invention is as follows: The present invention provides an electrochemical reaction device, comprising a plurality of electrochemical reaction units, which are sequentially connected in series; the electrochemical reaction unit comprises a vertical cylindrical first reaction part and a U-shaped cylindrical second reaction part; the first reaction part at the end is provided with a sealing cover, and a material port is provided on the sealing cover, and the material port is connected with an electrolyte cavity; the first reaction part comprises a shell, an outer electrode, and an inner electrode which are sequentially sleeved from the outside to the inside, a temperature control jacket is provided between the shell and the outer wall of the outer electrode, an electrolyte cavity is provided between the inner wall of the outer electrode and the outer wall of the inner electrode, and the first reaction part is connected to the second reaction part through a connector The first reaction part is provided with an external electrode connection hole, and a negative electrode terminal is provided in the external electrode connection hole to connect the external electrode. The second reaction part is provided with an internal electrode connection hole and an automatic exhaust valve, and a positive electrode terminal is provided in the internal electrode connection hole to connect the internal electrode. The internal structure of the second reaction part is the same as that of the first reaction part (the second reaction part also includes a shell, an external electrode, and an internal electrode which are sequentially sleeved from the outside to the inside, a temperature control jacket is provided between the shell and the outer wall of the external electrode, and an electrolyte cavity is provided between the inner wall of the external electrode and the outer wall of the inner electrode), and a filter part is also provided between the inner electrode and the outer electrode in the second reaction part.

[0011] Furthermore, a first groove is provided at the inner edge of the shell end, a second groove is provided at the outer edge of the outer electrode end, a third groove is provided at the inner edge of the outer electrode end, and a fourth groove is provided at the outer edge of the inner electrode end; the connecting member comprises an outer positioning plate, an outer connecting plate, and an inner connecting plate which are arranged in sequence from the outside to the inside, and a connecting mesh plate is fixedly arranged between the outer positioning plate, the outer connecting plate, and the inner connecting plate; a first flange matching the first groove is provided at the inner edge of the outer positioning plate, a second flange matching the second groove is provided at the outer edge of the outer connecting plate, a third flange matching the third groove is provided at the inner edge of the outer connecting plate, and a fourth flange matching the fourth groove is provided at the outer edge of the inner connecting plate; a first annular groove is provided in each of the first, second, third, and fourth grooves, and an O-ring is provided in each of the first annular grooves.

[0012] Furthermore, the inner electrode connecting hole passes through the shell, the outer electrode to the inner electrode, a thread is arranged in the inner electrode, a positive terminal is arranged in the inner electrode connecting hole, one end of the positive terminal is arranged with a thread, and the other end of the positive terminal is provided with a sealing end cover connected with the outer end bolt of the inner electrode connecting hole, and a plurality of second annular grooves are also arranged on the positive terminal, an O-ring is arranged in the second annular groove, the non-threaded end of the positive terminal is coated with a layer of insulating material, and the contact part between the sealing end cover and the inner electrode connecting hole is made of insulating material.

[0013] Furthermore, the external electrode connecting hole passes through the shell of the second reaction part to the external electrode, a thread is arranged inside the external electrode, a negative electrode terminal is arranged in the external electrode connecting hole, one end of the negative electrode connecting terminal is arranged with a thread, and the other end of the negative electrode terminal is provided with a sealing end cover connected with the outer end bolt of the external electrode connecting hole, and a plurality of third annular grooves are also arranged on the negative electrode terminal, an O-ring is arranged in the third annular groove, the non-threaded end of the negative electrode terminal is coated with a layer of insulating material, and the contact part between the sealing end cover and the external electrode connecting hole is made of insulating material.

[0014] The present invention also provides a method for preparing an electrochemical reaction device, comprising the following steps: S1: coating the inner wall of the outer electrode and the outer wall of the inner electrode with a coating for electrocatalytic reaction; S2: The shell, outer electrode and inner electrode of the first reaction part are sleeved in sequence, and the shell, outer electrode and inner electrode of the second reaction part are sleeved in sequence, a temperature control jacket is arranged between the shell and the outer electrode, the first reaction part is connected to the second reaction part through a connector, the outer electrode and the inner electrode are fixed, and bolts are used to connect them to obtain an electrochemical reaction unit; S3: connecting the plurality of electrochemical reaction units in series through connectors and connecting them with bolts; S4: The inner electrode terminal and the outer electrode terminal are respectively threadedly connected to the inner electrode connection hole and the outer electrode connection hole, the sealing cover at one end of the positive electrode terminal is bolted to the outer end of the inner electrode connection hole, and the sealing cover at one end of the negative electrode terminal is bolted to the outer end of the outer electrode connection hole; S5: introducing electrolyte into the electrolyte cavity through the material port; obtaining an electrochemical reaction device; the electrochemical reaction device is the electrochemical reaction device according to any one of claims 1-4.

[0015] Furthermore, in step S1, the coating preparation method of the outer wall of the inner electrode is: S1-1. Substrate surface treatment: polish the outer surface of the inner electrode; S1-2, preparation of the first coating: prepare a coating solution with a weight ratio of 30% yttrium chloride, 65% isopropanol, and 5% water, and after the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode, dry it at 105°C, place it in a muffle furnace, and heat it from 105°C to 550°C at a rate of 20-25°C per hour, and sinter it at a constant temperature for 30 minutes at this temperature, and then cool it to room temperature; the coating, drying, sintering, and cooling process are repeated 5-10 times; S1-3, preparation of the second coating: prepare a coating solution of 30% ruthenium chloride, 60% ethanol, and 10% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode coated with the first coating, dry it at 110°C, place it in a muffle furnace, heat it from 110°C to 650°C at a rate of 35-40°C per hour, and sinter it at a constant temperature for 30-40 minutes at this temperature, and then cool it to room temperature; the coating, drying, sintering, and cooling process are repeated 6-10 times; S1-4. Preparation of the third coating: prepare a coating solution with a weight ratio of 35% iridium chloride, 55% methanol and 10% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution on the outer surface of the inner electrode coated with the first and second coatings. After drying at 110°C, place it in a muffle furnace and heat it from 120°C to 850°C at a rate of 45°C per hour. Sinter it at this temperature for 60 minutes and then cool it to room temperature. Repeat the coating, drying, sintering and cooling process 6-10 times.

[0016] Furthermore, in step S1, the coating preparation method of the inner wall of the outer electrode is: S2-1. Substrate surface treatment: polish the inner surface of the outer electrode; S2-2, DC electroplating: by mass percentage, add 15% aminosulfonic acid, 35% carbonyl tris(triphenylphosphine) iridium hydride, 5% chloroplatinic acid, 25% methanol, 20% water, and 5% sulfuric acid into a container, stir at a stirring rate of 600 r / min for 5 min, and then heat to 60-70°C; put in an external electrode, use a DC power supply, set the voltage to 5V, electroplating time for 30 s, and continuously increase the voltage to 10V for large DC electroplating, large DC electroplating time for 200 min, and the total duration is 300 min; S2-3. Post-plating treatment: After electroplating, take out the outer electrode and immerse it in 20 g / L sodium carbonate solution for 1 min to neutralize the acid on the surface of the outer electrode, then rinse with clean water and dry.

[0017] The beneficial effects of the present invention are: The present invention discloses an electrochemical reaction device, comprising a plurality of electrochemical reaction units, which are sequentially connected in series; the electrochemical reaction unit comprises a vertical cylindrical first reaction part, a U-shaped cylindrical second reaction part, an S-shaped arrangement, a small overall size, a large driving force for material and energy transmission, a shortened diffusion distance of the fluid and a convection cycle, a reduced liquid mixing time, and greatly enhanced mass transfer capacity.

[0018] In the present invention, connectors for connecting mesh plates are arranged at the upper and lower ends of each electrochemical reaction unit, which are used to fix the outer electrode and the inner electrode and seal the first reaction part and the second reaction part.

[0019] The upper part of the second reaction part connected in each electrochemical reaction unit of the present invention is equipped with an automatic exhaust valve to exhaust the gas in the electrolysis system out of the reaction system.

[0020] The present invention adopts a continuous flow feeding method, which can accurately control the residence time of the material under the reaction conditions, improve the uniformity of the product, and reduce the generation of by-products.

[0021] The present invention can integrate multiple electrochemical reactors into a set of electrochemical reaction equipment by splicing, realize real-time monitoring and control of the electrochemical reactors, and is easy to disassemble and move, meeting the requirements of on-demand production.

[0022] The enlargement of the electrochemical reaction device of the structure of the present invention is achieved by increasing the number, avoiding the enlargement effect of traditional reactors, shortening the research and development time, and saving pilot equipment funds. The electrochemical reaction device has a small characteristic size, high heat and mass transfer efficiency, and the heat of the strong exothermic chemical reaction can be removed in time, avoiding the "flying temperature" phenomenon. Each reactor is relatively independent, reducing the danger. Since the reaction parameters can be accurately controlled, the consistency of the reaction results is guaranteed, and the product quality is stable.

[0023] The electrochemical reaction device of the present invention is easy to clean and disassemble the anode attachments; the installation is simple and quick. The inner wall of the outer electrode and the outer wall of the inner electrode of each electrochemical reaction unit are coated with a coating for electrocatalytic reaction; the coating material on the surface of the positive and negative electrodes can be repaired in time.

[0024] The present invention can replace inner electrodes and outer electrodes of different sizes according to needs to adjust the distance between the positive and negative electrodes.

[0025] Most of the DSA-coated titanium anode (Dimensionally Stable Anode, commonly known as dimensionally stable anode) electrodes use titanium metal as the substrate layer, and are mainly divided into titanium mesh and titanium sheet structures. DSA electrodes often use titanium as the substrate layer due to their good chemical stability. However, titanium is easily oxidized in the air, which requires certain pretreatment of the substrate. In order to increase the service life of the electrode, the titanium substrate is generally polished, degreased (alkali washed), and acid etched (pickled). In order to improve the electrocatalytic performance of the anode, the present invention improves the surface shape of the titanium substrate. The substrate pre-coating treatment used in the present invention uses a diamond suspension polishing method, and water is used as a suspending agent in the preparation process of the diamond suspension to evenly disperse the diamond powder in the liquid; hydroxypropyl methylcellulose is used as a thickener mainly to increase the viscosity of the liquid, so that the diamond powder can be better suspended in the liquid and is not easy to precipitate. The present invention uses polyacrylamide as a surfactant, which can reduce the surface tension of the liquid, promote the contact between the diamond powder and the polished object, and improve the polishing effect.

[0026] The substrate pretreatment method used in the present invention is conducive to increasing the roughness of the surface, increasing the adhesion area, forming a rough surface, having a better coating effect on the rough surface, and being conducive to the combination of the titanium substrate and the three-component catalytic elements of yttrium, ruthenium and iridium. In order to better protect the substrate from corrosion and improve the performance of the electrode, different intermediate layers are introduced to modify the DSA electrode, including an intermediate layer of yttrium and ruthenium oxide, to increase the corrosion resistance and electrocatalytic performance of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional schematic diagram of an electrochemical reaction device of the present invention; Figure 2 is a three-dimensional schematic diagram of an electrochemical reaction unit of the present invention; Figure 3 For the present invention Figure 2 A partial enlarged view of the connector; Figure 4 is a schematic cross-sectional view of an electrochemical reaction unit of the present invention; Figure 5 For the present invention Figure 4 A magnified view of the part A in the middle; Figure 6 is a cross-sectional view of a connecting piece of the present invention; Figure 7 For the present invention Figure 4 A magnified view of the part B in the middle; Figure 8 It is an efficient production device for the electrochemical reaction device of the present invention.

[0028] List of Figure Symbols: 1. Shell of the first reaction unit; 2. Shell of the second reaction unit; 3. Sealing cover; 4. External electrode connection hole; 5. Automatic exhaust valve; 6. Internal electrode connection hole; 7. External positioning plate; 8. First flange; 9. Second flange; 10. Third flange; 11. Fourth flange; 12. External electrode; 13. Internal electrode; 14. External connecting plate; 15. Internal connecting plate; 16. Electrolyte storage tank; 17. Electrolysis circulation pump; 18. Material inlet; 19. Temperature control jacket; 20. Electrolysis condenser; 21. Connection mesh plate; 22. Negative electrode terminal; 23. Sealing end cover. DETAILED DESCRIPTION

[0029] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. Example 1

[0030] An electrochemical reaction device such as Figure 1-6As shown, it includes a plurality of electrochemical reaction units, which are sequentially connected in series; the electrochemical reaction unit includes a vertical cylindrical first reaction part and a U-shaped cylindrical second reaction part; the first reaction part at the end is provided with a sealing cover 3, and a material port 18 is provided on the sealing cover 3, and the material port 18 is connected to the electrolyte cavity; the first reaction part includes a shell, an outer electrode 12, and an inner electrode 13 which are sequentially sleeved from the outside to the inside, a temperature control jacket 19 is provided between the shell and the outer wall of the outer electrode 12, an electrolyte cavity is provided between the inner wall of the outer electrode 12 and the outer wall of the inner electrode 13, the first reaction part is connected to the second reaction part through a connector, and the first reaction part is provided with There is an external electrode connecting hole 4, and a negative electrode terminal 22 is arranged in the external electrode connecting hole 4 to connect the external electrode 12. The second reaction part is provided with an internal electrode connecting hole 6 and an automatic exhaust valve 5. A positive electrode terminal is arranged in the internal electrode connecting hole 6 to connect the internal electrode 13. The internal structure of the second reaction part is the same as that of the first reaction part. The second reaction part also includes a shell, an external electrode 12, and an internal electrode 13 which are sequentially sleeved from the outside to the inside. A temperature control jacket 19 is arranged between the shell and the outer wall of the external electrode 12, an electrolyte cavity is arranged between the inner wall of the external electrode 12 and the outer wall of the inner electrode 13, and a filter part is also arranged between the inner electrode 13 and the outer electrode 12 in the second reaction part.

[0031] A first groove is provided at the inner edge of the end of the shell, a second groove is provided at the outer edge of the end of the outer electrode 12, a third groove is provided at the inner edge of the end of the outer electrode 12, a fourth groove is provided at the outer edge of the end of the inner electrode 13, and the connecting member comprises an outer positioning plate 7, an outer connecting plate 14, and an inner connecting plate 15 which are arranged in sequence from the outside to the inside, and a connecting mesh plate 21 is fixedly arranged between the outer positioning plate 7, the outer connecting plate 14, and the inner connecting plate 15; a first flange 8 matching the first groove is provided at the inner edge of the outer positioning plate 7, a second flange 9 matching the second groove is provided at the outer edge of the outer connecting plate 14, a third flange 10 matching the third groove is provided at the inner edge of the outer connecting plate 14, and a fourth flange 11 matching the fourth groove is provided at the outer edge of the inner connecting plate 15; a first annular groove is provided in each of the first, second, third, and fourth grooves, and an O-ring is provided in each of the first annular grooves.

[0032] The inner electrode connection hole 6 passes through the shell, the outer electrode 12 to the inner electrode 13, a thread is arranged in the inner electrode 13, a positive terminal is arranged in the inner electrode connection hole 6, one end of the positive terminal is arranged with a thread, and a sealing end cover 23 is arranged at the other end of the positive terminal to be connected with the outer end bolt of the inner electrode connection hole 6, a plurality of second annular grooves are also arranged on the positive terminal, an O-ring is arranged in the second annular groove, a non-threaded end of the positive terminal is coated with a layer of insulating material, and the contact part of the sealing end cover 23 and the inner electrode connection hole 6 is made of insulating material.

[0033] The outer electrode connection hole 4 passes through the shell 2 of the second reaction part to the outer electrode 12, and a thread is arranged inside the outer electrode 12. A negative electrode terminal 22 is arranged in the outer electrode connection hole 4, and one end of the negative electrode terminal is arranged with a thread. The other end of the negative electrode terminal 22 is provided with a sealing end cover 23 connected with the outer end bolt of the outer electrode connection hole 4. A plurality of third annular grooves are also arranged on the negative electrode terminal 22, and an O-ring is arranged in the third annular groove. The non-threaded end of the negative electrode terminal 22 is coated with a layer of insulating material, and the contact part of the sealing end cover 23 and the outer electrode connection hole 4 is made of insulating material.

[0034] As a specific embodiment of the present invention: The dimensions of the housing 1 of the first reaction part are: length 100cm-500cm, diameter 10-50cm; Shell 2 of the second reaction part; radius 10-50cm; Sealing cover 3; diameter 10-50cm, height 5-20cm; Inner electrode connection hole 6; diameter 3-10cm; Automatic exhaust valve 5, diameter 1-10cm; External electrode connection hole 4, diameter 3-10 cm; Connector; diameter 12-52cm; The first flange 8 has a height of 3-5 cm; The second flange 9 has a height of 3-5 cm; Third flange 10; height 3-5 cm; Fourth flange 11; height 3-5 cm; External electrode 12; length 100cm-500cm, diameter 2-10cm; Inner electrode 13; length 100cm-500cm, diameter 1-9cm. Example 2

[0035] A method for preparing an electrochemical reaction device comprises the following steps: S1: coating the inner wall of the outer electrode 12 and the outer wall of the inner electrode 13 with a coating for electrocatalytic reaction; S2: The shell 1, the outer electrode 12, and the inner electrode 13 of the first reaction part are sleeved in sequence, and the shell 2, the outer electrode 12, and the inner electrode 13 of the second reaction part are sleeved in sequence, a temperature control jacket 19 is provided between the shell and the outer electrode 12, the first reaction part is connected to the second reaction part through a connector, the outer electrode 12 and the inner electrode 13 are fixed, and bolts are used to connect to obtain an electrochemical reaction unit; S3: connecting the plurality of electrochemical reaction units in series through connectors and connecting them with bolts; S4: The inner electrode 13 terminal and the outer electrode 12 terminal are respectively threadedly connected to the inner electrode connection hole 6 and the outer electrode connection hole 4, the sealed end cover 23 at one end of the positive terminal is bolted to the outer end of the inner electrode connection hole 6, and the sealed end cover 23 at one end of the negative terminal 22 is bolted to the outer end of the outer electrode connection hole 4; the gap between the positive and negative electrodes is 1-20mm.

[0036] S5: introducing electrolyte into the electrolyte chamber through the material port 18; obtaining an electrochemical reaction device; the electrochemical reaction device is the electrochemical reaction device described in Example 1.

[0037] The coating preparation method of the outer wall of the inner electrode 13 is: There are four stages: pre-coating treatment, first layer preparation, second layer preparation and third layer preparation.

[0038] Substrate pretreatment: Before the titanium substrate material coating is prepared, surface pretreatment is required to increase the roughness of its surface. Add 15% nano-quartz sand (1-10nm, content ≥98%), 35% diamond nanoparticles (1-10nm, content ≥98%), 20% water, 5% wax powder, 10% terrazzo (200-500nm), 10% polyacrylamide, and 5% hydroxypropyl methylcellulose by weight in a stirring container. Stir at a stirring rate of 650 r / min for 5 min to form a uniform suspension. Put the titanium substrate in the container, stir and polish at a stirring rate of 850 r / min for 3 hours, and then rinse with pure water several times to form a rough surface. The rough surface has a better coating effect, which is conducive to the combination of the titanium substrate and the three-component catalytic elements of yttrium, iridium, and ruthenium.

[0039] Among them, suspending agent: suspending agent is mainly a substance that can evenly disperse diamond powder in liquid. Commonly used suspending agents include water. Thickener: thickener is mainly used to increase the viscosity of the liquid, so that the diamond powder can be better suspended in the liquid and not easy to precipitate. Commonly used thickeners include polyvinyl alcohol, hydroxypropyl methylcellulose, etc. Surfactant: Surfactant can reduce the surface tension of the liquid, promote the contact between diamond powder and the object to be polished, and improve the polishing effect. Commonly used surfactants include polyacrylamide.

[0040] Preparation of the first coating: Prepare a coating solution with a weight ratio of 30% yttrium chloride, 65% isopropanol, and 5% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode 13, dry it at 105°C, place it in a muffle furnace, heat it from 105°C to 550°C at a rate of 25°C per hour, and sinter it at a constant temperature for 30 minutes at this temperature, and then cool it to room temperature. Repeat the coating, drying, sintering, and cooling process 5 times.

[0041] Preparation of the second coating: Prepare a coating solution with a weight ratio of 30% ruthenium chloride, 60% ethanol, and 10% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode 13 coated with the second coating, dry it at 110°C, place it in a muffle furnace, heat it from 110°C to 650°C at a rate of 35°C per hour, and sinter it at this temperature for 30 minutes, and then cool it to room temperature. Repeat the coating, drying, sintering, and cooling process 8 times.

[0042] (4) Preparation of the third coating: prepare a coating solution with a weight ratio of 35% iridium chloride, 55% methanol, and 10% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode 13 coated with the first and second coatings. After drying at 110°C, place it in a muffle furnace and heat it from 120°C to 850°C at a rate of 45°C per hour. Sinter it at this temperature for 60 minutes, and then cool it to room temperature. Repeat the coating, drying, sintering, and cooling process 10 times. The three-coat layer on the inner wall of the outer electrode 12 is completed. A three-component catalytic layer of yttrium, ruthenium, and iridium is fired on the surface of the titanium substrate. The inner wall method of the outer electrode 12 is: Electroplating is mainly divided into three stages: pre-plating treatment, electroplating and post-plating treatment.

[0043] (1) Pre-plating treatment: Before the electroplating of the stainless steel substrate material, surface pretreatment is required to increase the roughness of its surface. Place the container in a constant temperature heating stirrer and add 10% polyvinyl alcohol, 35% diamond nanoparticles (1-10nm, content ≥98%), 35% methanol, and 20% water by weight to the container. Stir at a stirring rate of 650 r / min for 5 min to form a uniform suspension, then heat to 35-40°C, place the outer electrode 12 stainless steel substrate material in the container, stir at a stirring rate of 850 r / min for 25 min, then put it in an ultrasonic bath for 3 hours, and then rinse with pure water several times to form a rough surface. The difference in surface morphology has a great influence on the effect of electroplating (electrocatalytic performance), and has a better effect on a rough surface. On the surface of the rough stainless steel substrate material, there are many tiny grain boundaries, which are conducive to the combination of the stainless steel substrate material with the three groups of elements of platinum, iridium, and phosphorus.

[0044] (2) DC electroplating: Place the container in a constant temperature heating stirrer, add 15% aminosulfonic acid, 30% carbonyl tris(triphenylphosphine) iridium hydride, 5% chloroplatinic acid, 25% methanol, 20% water, and 5% sulfuric acid by weight into the container. Stir at a stirring rate of 600 r / min for 5 min until it is uniform, then heat to 60-70°C, place the electroplating positive electrode stainless steel substrate and the electroplating negative electrode platinum electrode into the container, use a DC power supply, manually set the voltage and time, and perform DC electroplating. Set the voltage to 5V and the electroplating time to 30 s, mainly to remove the oxide layer on the surface of the stainless steel substrate material and activate the surface of the substrate material. Then gradually increase the voltage to enter the small DC electroplating stage. The electroplating time is 100 min, and the voltage is continuously increased to 10V for large DC electroplating. The large DC electroplating time is 200 min, and the total time is 300 min.

[0045] (3) Post-plating treatment: After electroplating, the stainless steel outer electrode 12 is taken out and immersed in a 20 g / L sodium carbonate solution for 1 min to neutralize the acid on the surface of the stainless steel outer electrode 12. Then, it is rinsed with clean water and dried to prevent corrosion of the coating.

[0046] The deposition of platinum and iridium-phosphorus elements is achieved on a non-catalytic stainless steel substrate material. A galvanic cell is formed using a platinum electrode and a stainless steel substrate material. Platinum is first deposited on the surface of the stainless steel substrate material through a galvanic cell reaction, and the electroplating reducing agent in the solution reduces the platinum ions in the solution on the platinum nucleus with self-catalytic properties. Carbonyl tris(triphenylphosphine) iridium hydride is used as a reducing agent and a platinum sheet is used as a counter electrode. The deposited product contains not only platinum but also iridium-phosphorus elements, and a platinum-iridium-phosphorus three-component catalytic layer is deposited on the stainless steel surface. Example 3

[0047] The present invention provides an efficient production method of electrosynthesized succinic acid, using an electrochemical reaction device of the above embodiment 2 to efficiently produce the equipment such as Figure 1-7 As shown, the following steps are included: S1: Before the reaction, the gap between the positive electrode and the negative electrode in the assembled electrochemical reaction device is 1-5 mm. The assembled electrochemical reaction device is nitrogen-substituted three times. After the nitrogen substitution is completed, the electrolyte is prepared in the electrolyte storage tank 16 (16). The electrolyte ratio is: water, electrolyte 1 mol / L sulfuric acid, and raw material 1.5 mol / L maleic acid.

[0048] S2: The prepared electrolyte is transferred into the electrochemical reaction device through the electrolysis circulation pump 17 and the feed port 18, and then the feed flow rate is controlled to be 3m³ / h by the feed speed of the electrolysis circulation pump 17, and the temperature in the electrochemical reaction device is controlled at 60~70℃ by the temperature control jacket 19, and the electrochemical reaction pressure is normal pressure.

[0049] S3: The oxygen generated by the electrosynthesis of succinic acid in the electrochemical reaction device is discharged from the system through the automatic exhaust valve 5, so that the pressure in the electrochemical reaction device is kept at normal pressure.

[0050] S4: After the electrolysis is completed, maleic acid undergoes an electroreduction hydrogenation reaction on the cathode to produce succinic acid. After the electrolyte flowing out of the electrochemical reaction device is cooled to room temperature, succinic acid crystals are precipitated, and then the product is obtained by filtering and drying. The yield of succinic acid is greater than 80.5%.

[0051] Further, the S3 specifically includes: connecting to the negative electrode of the DC power supply through the outer electrode connection hole 4, connecting to the positive electrode of the DC power supply through the inner electrode connection hole 6, gradually controlling the flow rate to 0.5m³ / h and the temperature to 65°C, and after the flow rate and temperature are stable, slowly increasing the electrolysis voltage of the DC power supply in the constant voltage mode, and stopping the voltage increase when the current density reaches 1500A / ㎡, at which time the electrochemical synthesis reaction of succinic acid is continued. Example 4

[0052] 116 kg of raw material maleic acid, 54.35 L of electrolyte sulfuric acid and 784.5 kg of solvent water were added to the electrolyte storage tank 16 (16), stirred evenly, and then introduced into the electrochemical reaction device through the electrolysis circulation pump 17 (17). The gap between the positive electrode and the negative electrode was 15 mm, and the temperature was pre-controlled at 30°C. Before feeding, the electrochemical reaction device was replaced with nitrogen three times to replace the air with nitrogen. When the flow rate temperature was 0.1 m³ / h, the DC power supply was turned on to carry out the electrochemical synthesis reaction, and the electrolysis reaction temperature was gradually controlled to 6 5℃, the current density gradually increased to 1500A / ㎡, and a continuous electrosynthesis reaction of succinic acid was carried out. The oxygen produced by electrolysis was condensed by the electrolytic condenser 20 and discharged from the system. A small amount of condensed liquid was regularly discharged to the electrolyte storage tank 16 for circulation. The temperature of the electrolytic condenser 20 was controlled at -20~10℃. After 10 hours of electrolysis, the electrolyte flowing out of the electrochemical reaction device was cooled to room temperature to precipitate succinic acid crystals. After filtration and drying, 96.5kg of product succinic acid was obtained, and the molar yield calculated based on maleic acid was 81.8%. Example 5

[0053] 120kg of raw material maleic acid, 55L of electrolyte sulfuric acid and 778.8 / kg of solvent water were added to the electrolyte storage tank 16. After stirring evenly, they were passed into the electrochemical reaction device through the electrolysis circulation pump 17. The gap between the positive electrode and the negative electrode was 12mm. The temperature was pre-controlled at 35°C. Before feeding, the electrochemical reaction device was replaced by nitrogen three times to replace the air with nitrogen. When the flow temperature was 0.15m³ / h, the DC power supply was turned on for electrochemical synthesis reaction, and the electrolysis reaction temperature was gradually controlled to 68°C. The current The density gradually rises to 1500A / ㎡, and the electrosynthesis reaction of succinic acid is carried out continuously. The oxygen produced by electrolysis is condensed through the electrolytic condenser 20 and discharged from the system. A small amount of condensed liquid is regularly discharged to the electrolyte storage tank 16 for circulation. The temperature of the electrolytic condenser 20 is controlled at -20~10℃. After 6.7 hours of electrolysis, the electrolyte flowing out of the electrochemical reaction device is cooled to room temperature to precipitate succinic acid crystals. After filtering and drying, 97.8kg of product succinic acid is obtained, and the molar yield calculated based on maleic acid is 80.2%. Example 6

[0054] 116 kg of raw material maleic acid, 54.35 L of electrolyte sulfuric acid and 784.5 kg of solvent water were added to the electrolyte storage tank 16, and after being stirred evenly, they were passed into the electrochemical reaction device through the electrolysis circulation pump 17. The gap between the positive electrode and the negative electrode was 8 mm, and the temperature was pre-controlled at 40°C. Before feeding, the electrochemical reaction device was replaced with nitrogen three times to replace the air with nitrogen. When the flow temperature was 0.05 m³ / h, the DC power supply was turned on for electrochemical synthesis reaction, and the electrolysis reaction temperature was gradually controlled to 70°C. The current density gradually increased to 1500A / ㎡, and the electrosynthesis of succinic acid was carried out continuously. The oxygen produced by electrolysis was condensed through the electrolytic condenser 20 and discharged from the system. A small amount of condensed liquid was regularly discharged to the electrolyte storage tank 16 for circulation. The temperature of the electrolytic condenser 20 was controlled at -20~10℃. After 20 hours of electrolysis, the electrolyte flowing out of the electrochemical reaction device was cooled to room temperature to precipitate succinic acid crystals. After filtering and drying, 98kg of product succinic acid was obtained, and the molar yield calculated based on maleic acid was 83.9%. Example 7

[0055] 125kg of raw material maleic acid, 55L of electrolyte sulfuric acid and 786.5kg of solvent water were added to the electrolyte storage tank 16, and after being stirred evenly, they were passed into the electrochemical reaction device through the electrolysis circulation pump 17. The gap between the positive electrode and the negative electrode was 6.5mm, and the temperature was pre-controlled at 40°C. Before feeding, the electrochemical reaction device was replaced by nitrogen three times to replace the air with nitrogen. When the flow temperature was 0.05m³ / h, the DC power supply was turned on for electrochemical synthesis reaction, and the electrolysis reaction temperature was gradually controlled to 70°C. The current The density gradually rises to 1500A / ㎡, and the electrosynthesis reaction of succinic acid is carried out continuously. The oxygen produced by electrolysis is condensed through the electrolytic condenser 20 and discharged from the system. A small amount of condensed liquid is regularly discharged to the electrolyte storage tank 16 for circulation. The temperature of the electrolytic condenser 20 is controlled at -20~10℃. After 20 hours of electrolysis, the electrolyte flowing out of the electrochemical reaction device is cooled to room temperature to precipitate succinic acid crystals. After filtering and drying, 106.9kg of product succinic acid is obtained, and the molar yield calculated based on maleic acid is 84.1%. Example 8

[0056] 120kg of raw material maleic acid, 55L of electrolyte sulfuric acid and 778.8 / kg of solvent water were added to the electrolyte storage tank 16, and after being stirred evenly, they were passed into the electrochemical reaction device through the electrolysis circulation pump 17. The gap between the positive electrode and the negative electrode was 5mm, and the temperature was pre-controlled at 35°C. Before feeding, the electrochemical reaction device was replaced by nitrogen three times to replace the air with nitrogen. When the flow temperature was 0.15m³ / h, the DC power supply was turned on for electrochemical synthesis reaction, and the electrolysis reaction temperature was gradually controlled to 68°C. The current density was The temperature of the electrolytic condenser 20 is controlled at -20 to 10°C. After 6.7 hours of electrolysis, the electrolyte flowing out of the electrochemical reaction device is cooled to room temperature to precipitate succinic acid crystals. After filtration and drying, 102.8 kg of product succinic acid is obtained, and the molar yield calculated based on maleic acid is 84.3%.

[0057] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. An electrochemical reaction device, characterized in that: It comprises a plurality of electrochemical reaction units, which are sequentially connected in series; the electrochemical reaction unit comprises a vertical cylindrical first reaction part and a U-shaped cylindrical second reaction part; the first reaction part at the end is provided with a sealing cover, the sealing cover is provided with a material port, and the material port is connected with an electrolyte chamber; the first reaction part comprises a shell, an outer electrode, and an inner electrode which are sequentially sleeved from the outside to the inside, a temperature control jacket is provided between the shell and the outer wall of the outer electrode, an electrolyte chamber is provided between the inner wall of the outer electrode and the outer wall of the inner electrode, the first reaction part is connected with the second reaction part through a connecting piece, an outer electrode connecting hole is provided on the first reaction part, a negative electrode terminal is provided in the outer electrode connecting hole to connect the outer electrode, an inner electrode connecting hole and an automatic exhaust valve are provided on the second reaction part, a positive electrode terminal is provided in the inner electrode connecting hole to connect the inner electrode, the internal structure of the second reaction part is the same as that of the first reaction part, and a filter part is also provided between the inner electrode and the outer electrode in the second reaction part.

2. An electrochemical reaction device according to claim 1, characterized in that: The inner edge of the shell end is provided with a first groove, the outer edge of the outer electrode end is provided with a second groove, the inner edge of the outer electrode end is provided with a third groove, and the outer edge of the inner electrode end is provided with a fourth groove. The connecting part includes an outer positioning plate, an outer connecting plate, and an inner connecting plate which are arranged in sequence from the outside to the inside, and a connecting mesh plate is fixedly arranged between the outer positioning plate, the outer connecting plate, and the inner connecting plate; the inner edge of the outer positioning plate is provided with a first flange matching the first groove, the outer edge of the outer connecting plate is provided with a second flange matching the second groove, the inner edge of the outer connecting plate is provided with a third flange matching the third groove, and the outer edge of the inner connecting plate is provided with a fourth flange matching the fourth groove; the first groove, the second groove, the third groove, and the fourth groove are all provided with a first annular groove, and the first annular groove is provided with an O-ring.

3. An electrochemical reaction device according to claim 2, characterized in that: The inner electrode connection hole passes through the shell of the second reaction part, the outer electrode to the inner electrode, a thread is arranged in the inner electrode, a positive electrode terminal is arranged in the inner electrode connection hole, one end of the positive electrode terminal is arranged with a thread, and a sealing end cover is arranged at the other end of the positive electrode terminal and is connected with the outer end bolt of the inner electrode connection hole. A plurality of second annular grooves are also arranged on the positive electrode terminal, and an O-ring is arranged in the second annular groove.

4. An electrochemical reaction device according to claim 1, characterized in that: The outer electrode connection hole passes through the shell of the first reaction part to the outer electrode, a thread is arranged in the outer electrode, a negative electrode terminal is arranged in the outer electrode connection hole, one end of the negative electrode terminal is arranged with a thread, and a sealing end cover is arranged at the other end of the negative electrode terminal and is connected with the outer end bolt of the outer electrode connection hole, and a plurality of third annular grooves are also arranged on the negative electrode terminal, and an O-ring is arranged in the third annular groove.

5. A method for preparing an electrochemical reaction device, characterized in that: The following steps are involved: S1: coating the inner wall of the outer electrode and the outer wall of the inner electrode with a coating for electrocatalytic reaction; S2: The shell, outer electrode and inner electrode of the first reaction part are sleeved in sequence, and the shell, outer electrode and inner electrode of the second reaction part are sleeved in sequence, a temperature control jacket is provided between the shell and the outer electrode, the first reaction part is connected to the second reaction part through a connector, the outer electrode and the inner electrode are fixed, and bolts are used to connect to obtain an electrochemical reaction unit; S3: connecting the plurality of electrochemical reaction units in series through connectors and connecting them with bolts; S4: The inner electrode terminal and the outer electrode terminal are respectively threadedly connected to the inner electrode connection hole and the outer electrode connection hole, the sealing cover at one end of the positive electrode terminal is bolted to the outer end of the inner electrode connection hole, and the sealing cover at one end of the negative electrode terminal is bolted to the outer end of the outer electrode connection hole; S5: introducing electrolyte into the electrolyte cavity through the material port; obtaining an electrochemical reaction device; the electrochemical reaction device is the electrochemical reaction device according to any one of claims 1-4.

6. The method for preparing an electrochemical reaction device according to claim 5, characterized in that: In step S1, the coating preparation method of the outer wall of the inner electrode is: S1-1. Substrate surface treatment: polish the outer surface of the inner electrode; S1-2, preparation of the first coating: prepare a coating solution with a weight ratio of 30% yttrium chloride, 65% isopropanol, and 5% water, and after the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode, dry it at 105°C, place it in a muffle furnace, and heat it from 105°C to 550°C at a rate of 20-25°C per hour, and sinter it at a constant temperature for 30 minutes at this temperature, and then cool it to room temperature; the coating, drying, sintering, and cooling process are repeated 5-10 times; S1-3, preparation of the second coating: prepare a coating solution of 30% ruthenium chloride, 60% ethanol, and 10% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution to the outer surface of the inner electrode coated with the first coating, dry it at 110°C, place it in a muffle furnace, heat it from 110°C to 650°C at a rate of 35-40°C per hour, and sinter it at a constant temperature for 30-40 minutes at this temperature, and then cool it to room temperature; the coating, drying, sintering, and cooling process are repeated 6-10 times; S1-4. Preparation of the third coating: prepare a coating solution with a weight ratio of 35% iridium chloride, 55% methanol and 10% water. After the components in the coating solution are fully dissolved, evenly apply the coating solution on the outer surface of the inner electrode coated with the first and second coatings. After drying at 110°C, place it in a muffle furnace and heat it from 120°C to 850°C at a rate of 45°C per hour. Sinter it at this temperature for 60 minutes and then cool it to room temperature. Repeat the coating, drying, sintering and cooling process 6-10 times.

7. The method for preparing an electrochemical reaction device according to claim 5, characterized in that: In step S1, the method for preparing the inner wall of the outer electrode is: S2-1. Substrate surface treatment: polish the inner surface of the outer electrode; S2-2, DC electroplating: by mass percentage, add 15% aminosulfonic acid, 35% carbonyl tris(triphenylphosphine) iridium hydride, 5% chloroplatinic acid, 25% methanol, 20% water, and 5% sulfuric acid into a container, stir at a stirring rate of 600 r / min for 5 min, and then heat to 60-70°C; put in an external electrode, use a DC power supply, set the voltage to 5V, electroplating time for 30 s, and continuously increase the voltage to 10V for large DC electroplating, large DC electroplating time for 200 min, and the total duration is 300 min; S2-3. Post-plating treatment: After electroplating, take out the outer electrode and immerse it in 20 g / L sodium carbonate solution for 1 min to neutralize the acid on the surface of the outer electrode, then rinse with clean water and dry.

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