An apparatus for high flux electrocatalytic production of arsines and methods of use thereof

Abstract

This invention discloses a high-throughput electrocatalytic preparation apparatus for arsine and its usage method. The apparatus includes an anode electrolytic cell and cathode electrolytic cells on its left and right sides, respectively. Both the anode and cathode electrolytic cells are filled with acidic electrolyte and separated by a proton exchange membrane. The anode catalyst electrode in the anode electrolytic cell is connected to the positive terminal of a DC power supply; the cathode catalyst electrode in the cathode electrolytic cell is connected to the negative terminal of a DC power supply. An isolation valve and a cathode sludge receiving box are located at the lower end of the cathode electrolytic cell. This invention's equipment generates oxygen at the anode and arsine at the cathode through electrolysis. The principle is based on the reduction of elemental arsenic, which combines with hydrogen permeating through the proton exchange membrane to form arsine. This equipment has a simple structure and low cost. The design of dual cathode electrodes and their matching isolation valve and cathode sludge receiving box improves the efficiency of arsine production while reducing its cost, demonstrating significant application potential.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalysis technology, specifically relating to a high-throughput electrocatalytic preparation apparatus for arsine and its usage method. Background Technology

[0002] Arsine (AsH3) is a crucial basic material in the electronics industry and an important electronic specialty gas. In the semiconductor industry, it is mainly used for N-type doping of epitaxial silicon, N-type diffusion in silicon, ion implantation, growth of gallium arsenide (GaAs) and gallium arsenide phosphide (GaAsP), and the formation of semiconductor compounds with Group IIIA / VA elements. Currently, the preparation of arsine is primarily carried out through thermochemical methods, but the high emissions and difficulty in controlling the reaction process severely limit its widespread application. In recent years, electrochemical methods have developed rapidly due to their strong process controllability and ease of reaction control. Therefore, using electrochemical methods to prepare arsine can effectively solve the aforementioned problems. Currently, the main problem facing this reaction is that a large amount of elemental arsenic is generated during the reaction, forming "cathode sludge" at the bottom of the cathode tank. As the reaction time increases, the accumulation of "cathode sludge" severely affects the reaction efficiency and the yield of arsine. Therefore, solving this problem is particularly important. Summary of the Invention

[0003] In view of the technical problems existing in the prior art, the purpose of this invention is to provide a high-throughput electrocatalytic preparation device for arsine and its usage method. During the reaction, the generated "cathode sludge" will naturally settle and accumulate. This invention can separate the generated "cathode sludge" by setting up an isolation valve and a cathode sludge receiving box. Compared with previous processes, this equipment can improve equipment lifespan and reduce labor and economic costs. Furthermore, it can improve reaction performance by promptly removing the generated "cathode sludge," reducing mass transfer resistance during the reaction. During this reaction, the oxygen generated at the anode can be reused as an oxygen source. The equipment has a simple structure, low cost, and great application potential.

[0004] The technical solution adopted in this invention is as follows: A high-throughput electrocatalytic preparation apparatus for arsine includes an anode electrolyzer and cathode electrolyzers located on its left and right sides. Both the anode and cathode electrolyzers are filled with acidic electrolyte and separated by a proton exchange membrane. The anode electrolyzer contains an anode catalyst electrode with a conductive plate at its upper end and connected to the positive terminal of a DC power supply. The cathode electrolyzer contains a cathode catalyst electrode with a conductive plate at its upper end and connected to the negative terminal of a DC power supply. An isolation valve is located at the lower end of the cathode electrolyzer, and the bottom of the isolation valve is threadedly sealed to a cathode sludge receiving box. Elemental arsenic cathode sludge produced by the cathode catalyst electrode during the electrolytic reaction can settle through the isolation valve into the cathode sludge receiving box for collection.

[0005] Furthermore, the upper end of the anode electrolytic cell is provided with an anode exhaust port, and the upper end of the cathode electrolytic cell is provided with a cathode exhaust port. The anode exhaust port and the cathode exhaust port are respectively connected to a gas collection bag.

[0006] Furthermore, the anode catalyst electrode uses a titanium plate or titanium rod as the electrode substrate, and the surface of the electrode substrate is coated with an active component. The active component coating can be one of the following: platinum coating, iridium dioxide coating, or iridium-tantalum coating. The loading amount of the active component coating on the electrode substrate surface is 0.5-1.0 mg / cm³. 2 The iridium-tantalum coating is an IrO2-Ta2O5 composite oxide, and the molar ratio of Ir to Ta is 0.5-2.0:1, preferably 1:1.

[0007] Furthermore, the cathode catalyst electrode is made of arsenic rods or arsenic plates, preferably arsenic plates.

[0008] Furthermore, the two cathode mud receiving boxes are positioned at the same horizontal level.

[0009] Furthermore, a drain valve is provided at the bottom of the cathode sludge receiving box.

[0010] Furthermore, the cathode mud receiving box is equipped with an inverted conical guide pipe with a large opening at the top and a small opening at the bottom. The upper opening of the inverted conical guide pipe contacts the bottom of the isolation valve. When the isolation valve is open, the settled cathode mud can enter the bottom of the cathode mud receiving box through the isolation valve and the inverted conical guide pipe.

[0011] Furthermore, the acidic electrolyte is a 0.05-0.2M dilute sulfuric acid solution.

[0012] Furthermore, energize the anode and cathode catalyst electrodes, and adjust the isolation valve to the open state. The anode catalyst electrode undergoes an oxidation reaction to generate oxygen, while the cathode catalyst electrode undergoes a reduction reaction to generate arsine and elemental arsenic cathode sludge. The cathode sludge settles into the cathode sludge receiving box through the isolation valve. The isolation valve is closed periodically to drain the cathode sludge receiving box. Then, the lost electrolyte is replenished to the cathode electrolysis cell, and the isolation valve is reopened to allow the cathode sludge to settle and be collected again in the cathode sludge receiving box.

[0013] Furthermore, the voltage for the electrolysis reaction is 3-10V.

[0014] In this invention, the anodic and cathodic electrolytic cells are separated by a proton exchange membrane to prevent gas exchange. The device produces oxygen at the anode and arsine at the cathode through electrolysis. The principle involves reducing elemental arsenic, which then combines with hydrogen permeating through the proton exchange membrane to form arsine. This device has a simple structure and low cost. The design of dual cathode electrodes and their associated isolation valves and cathode sludge receiving box improves the efficiency of arsine production while reducing production costs, demonstrating significant application potential.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) By constructing a dual-cathode cell and using arsenic rods (elemental arsenic) as cathode electrodes, this invention can increase the amount of reactants involved and the reaction rate. On the other hand, the dual-cathode cell mode increases the yield of arsine. 2) By adding an isolation valve and a cathode sludge receiving box at the bottom of the cathode, the present invention can effectively remove the cathode sludge, improve the reaction efficiency, and increase the service life of the equipment by adding an isolation valve and a cathode sludge receiving box at the bottom of the cathode. As the reaction time increases during the reaction process, the cathode sludge will gradually increase, which will reduce the reaction efficiency and hinder the mass transfer process.

[0016] 3) The device for high-throughput electrocatalytic preparation of arsine obtained by the present invention improves the yield of arsine by improving the equipment. On the other hand, the oxygen generated at the anode can be used as an oxygen source for other reactions. Both electrodes are high-value-added products, and the device has great application potential. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of an apparatus for high-throughput electrocatalytic preparation of arsine according to the present invention; Figure 1 In the middle: 1. Cathode electrolytic cell; 2. Anode electrolytic cell; 3. Cathode catalyst electrode; 4. Anode catalyst electrode; 5. Proton exchange membrane; 6. Isolation valve; 7. Cathode sludge receiving box; 8. Positive terminal of DC power supply; 9. Negative terminal of DC power supply; Figure 2 The graph shows the current change over time at 6V for the electrolysis reaction of Example 1 and Comparative Examples 1-2. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings. However, the scope of protection of the present invention is not limited to the scope described herein, and also includes the preparation of all peroxide disinfectants using hydrogen peroxide as a reactant. The directional terms such as "upper" and "lower" in the present invention only represent relative positions in the figures and do not represent the absolute position of the product.

[0019] An apparatus for high-throughput electrocatalytic preparation of arsine, reference Figure 1 The system includes an anode electrolytic cell 2 and cathode electrolytic cells 1 located on its left and right sides, respectively. Both the anode and cathode electrolytic cells are filled with acidic electrolyte and separated by a proton exchange membrane 5. The anode electrolytic cell 2 contains an anode catalyst electrode 4, with a conductive plate at its upper end and connected to the positive terminal 8 of a DC power supply. The cathode electrolytic cell 1 contains a cathode catalyst electrode 3, with a conductive plate at its upper end and connected to the negative terminal 9 of a DC power supply. An isolation valve 6 is located at the lower end of the cathode electrolytic cell 1, and the bottom of the isolation valve 6 is threadedly sealed to a cathode sludge receiving box 7. During the electrolysis reaction, the elemental arsenic cathode sludge produced by the cathode catalyst electrode can settle through the isolation valve 6 into the cathode sludge receiving box 7 for collection. A drain valve is located at the bottom of the cathode sludge receiving box 7.

[0020] The anode electrolytic cell 2 is equipped with an anode exhaust port at its upper end, and the cathode electrolytic cell 1 is equipped with a cathode exhaust port at its upper end. The anode exhaust port and the cathode exhaust port are respectively connected to a gas collection bag. The anode electrolytic cell 2 and the cathode electrolytic cell 1 are also respectively equipped with feed inlets at their upper ends.

[0021] The cathode mud receiving box 7 is equipped with an inverted conical guide tube with a large opening at the top and a small opening at the bottom. The upper opening of the inverted conical guide tube contacts the bottom of the isolation valve 6. When the isolation valve 6 is open, the settled cathode mud can enter the bottom of the cathode mud receiving box 7 through the isolation valve 6 and the inverted conical guide tube.

[0022] The device of this invention has a symmetrical structure, with the two cathode mud receiving boxes 7 positioned at the same horizontal height.

[0023] In this embodiment, the anode is an iridium-plated titanium plate; the cathode is an arsenic plate.

[0024] The apparatus of this application can operate according to the following procedure: Electricity is applied to the anode catalyst electrode 4 and the cathode catalyst electrode 3, and the isolation valve 6 is adjusted to the open state. An oxidation reaction occurs at the anode catalyst electrode to generate oxygen, while a reduction reaction occurs at the cathode catalyst electrode to generate arsine and elemental arsenic cathode sludge. The cathode sludge settles into the cathode sludge receiving box 7 through the isolation valve 6. The isolation valve 6 is periodically closed, and the cathode sludge receiving box 7 is drained. For example: the isolation valve 6 is closed, the cathode sludge receiving box 7 is removed, the mixture in the cathode sludge receiving box 7 is filtered, and the filtrate is added back into the cathode electrolysis cell through the feed inlet. The filter residue is collected, the cathode sludge receiving box 7 is reinstalled at the lower end of the isolation valve 6, the isolation valve 6 is opened, and the collected cathode sludge continues.

[0025] Example 1: A high-throughput electrocatalytic preparation apparatus for arsine and its application Adopting such Figure 1 The device structure shown uses an iridium-tantalum plated titanium plate (IrO2-Ta2O5 / Ti, with dimensions of 10 cm × 5 cm × 0.2 cm and a surface area of ​​50 cm² on one side). 2 The Ir and Ta molar ratio is 1:1, and the total loading of IrO2-Ta2O5 on both sides of the titanium plate is 30 mg, meaning the loading of IrO2-Ta2O5 on one side of the titanium plate is 0.6 mg / cm³. 2 The anode is placed inside the anolyte, which measures 20 cm × 10 cm × 5 cm. An O-ring seal is used at the upper conductive plate to prevent gas leakage from the anode. There are two holes at the upper end of the anolyte: one for feeding and one for venting. =1cm), with a drain hole at the lower end ( =2 cm), and a drain valve is installed at the drain hole.

[0026] A proton exchange membrane is installed on each of the left and right sides of the anodic electrolytic cell, selectively allowing protons to pass through during the reaction while separating the reaction products. A cathode electrolytic cell, measuring 18 cm × 10 cm × 2 cm, is located on the other side of the membrane. Both cathode cells have polytetrafluoroethylene (PTFE) gaskets at their contact points with the membranes to prevent leakage of solution and gas during the reaction. Inside the cathode electrolytic cell, an arsenic plate (10 cm × 5 cm × 0.2 cm) serves as the cathode catalyst electrode. A sealing ring is installed between the upper end of the arsenic plate and the cathode electrolytic cell. An exhaust port is located at the upper end of the cathode electrolytic cell. =0.8 cm) and inlet ( =1 cm).

[0027] An isolation valve 6 is installed at the lower end of the cathode electrolysis cell 1. The bottom of the isolation valve 6 is then threaded and sealed to a cathode sludge receiving box 7 (the cathode sludge receiving box 7 measures 2.3 cm × 10 cm × 2 cm). A drain valve is installed at the bottom of the cathode sludge receiving box 7. The isolation valve separates the generated "cathode sludge" from the cathode electrolysis cell, ensuring the continuous operation of the reaction.

[0028] The operating steps during the electrolysis reaction are as follows: energize the anode catalyst electrode 4 and the cathode catalyst electrode 3, adjust the isolation valve 6 to the open state, the anode catalyst electrode undergoes an oxidation reaction to generate oxygen, and the cathode catalyst electrode undergoes a reduction reaction to generate arsine and elemental arsenic cathode sludge. The cathode sludge settles into the cathode sludge receiving box 7 through the isolation valve 6. The isolation valve 6 is closed periodically to drain the cathode sludge receiving box 7. Then, the lost electrolyte is replenished into the cathode electrolysis cell, and the isolation valve 6 is opened again to allow the cathode sludge to settle and be collected in the cathode sludge receiving box 7.

[0029] The specific reaction conditions were as follows: the reaction voltage was controlled at 3, 6 and 9 V, and the electrolyte in both the anode and cathode electrolytic cells was a dilute sulfuric acid (0.1 M) solution. The cathode sludge formed under different voltages was treated. As the reaction voltage and time increased, the oxygen / arsine yield at different times was shown in Table 1, and the amount of cathode sludge accumulated at different times was shown in Table 2.

[0030] Table 1. Oxygen / arsenic yield under different currents .

[0031] The results in Table 1 show that the present invention has excellent oxygen production performance and arsine production capacity, and has good application potential. The yield of arsine increases with the increase of current and reaction time. At the same time, the generated "cathode sludge" is removed during the reaction process to avoid the reduction of reaction rate due to the accumulation of "cathode sludge".

[0032] Table 2. Cathode slime production under different currents .

[0033] The results in Table 2 show that the amount of cathode mud increases with the increase of reaction time and voltage, and gradually increases with the extension of reaction time. This is mainly because the surface of arsenic is in a dense state at the beginning of the reaction. As the reaction "etches", the dense arsenic will become a loose and porous surface, which is easier to detach.

[0034] Comparative Example 1: An apparatus for the electrocatalytic preparation of arsine and its application (single cathode cell) The apparatus of Comparative Example 1 was repeated in Example 1, except that the number of "cathode electrolytic cells" was only one, and the other conditions remained the same. The specific reaction conditions were that the reaction current was controlled at 3, 6 and 9 V, and the electrolyte was a dilute sulfuric acid (0.1 M) solution.

[0035] The test was conducted by adjusting the reaction conditions, and the results are shown in Table 3.

[0036] Table 3. Oxygen / arsenic yield under different currents .

[0037] The results in Table 3 show that removing one of the cathode cells in this invention does not significantly increase the yield of anolyte oxygen, but it does reduce the yield of the cathode product arsine. The main reason for this result is that the design of the dual cathode cells can accelerate the proton transfer rate, increase the reaction efficiency, and obtain more product (arsine) per unit time.

[0038] Comparative Example 2: A high-throughput electrocatalytic apparatus for the preparation of arsine (without isolation valve and cathode slime receiving box). The apparatus of Comparative Example 2 is the same as that of Example 1, except for the following two points: 1) The lower end of the cathode electrolysis cell 1 in Comparative Example 2 is not equipped with an isolation valve 6 and a cathode mud receiving box 7; 2) In the electrolysis reaction operation, Comparative Example 2 does not perform sewage discharge treatment at the lower end of the cathode electrolysis cell 1, and the other conditions remain unchanged.

[0039] The specific reaction conditions are as follows: the reaction current is controlled at 3, 6 and 9 V, and the electrolyte is a dilute sulfuric acid (0.1 M) solution.

[0040] The test was conducted by adjusting the reaction conditions, and the results are shown in Table 4.

[0041] Table 4. Oxygen / arsenic yield under different currents .

[0042] Table 4 shows that, compared to the device in this invention, the production of oxygen and arsine is significantly reduced under high current conditions in the device without an isolation valve and cathode sludge receiving box. During the reaction, it was observed that a large number of black arsenic particles were generated in the cathode tank with increasing reaction time, forming "cathode sludge" at the bottom of the tank. Furthermore, the "cathode sludge" accumulated with prolonged reaction time, severely affecting the mass transfer process and leading to a decrease in the yield of the anode product oxygen and the cathode product arsine in the later stages of the reaction.

[0043] The current (voltage of 6V) during the electrolysis process of Example 1 and Comparative Examples 1-2 was recorded and compared. Figure 2As shown, it can be observed that the current in Example 1 and Comparative Example 1 of the high-throughput electrocatalytic preparation apparatus of the present invention did not change significantly within the test range, while the current in Comparative Example 2 gradually decreased with the increase of reaction time. This indicates that the resistance of the reaction system increased during the process. The main reason for this phenomenon is the enrichment of elemental arsenic (cathode mud) during the reaction, which hinders the mass transfer process of the reaction, resulting in a decrease in the efficiency of the current and a decrease in the yield of the product arsine.

Claims

1. An apparatus for high-throughput electrocatalytic preparation of arsine, characterized in that... The system includes an anode electrolytic cell (2) and cathode electrolytic cells (1) set on its left and right sides respectively. Both the anode electrolytic cell and the cathode electrolytic cell are filled with acidic electrolyte and are separated by a proton exchange membrane (5). The anode electrolytic cell (2) is equipped with an anode catalyst electrode (4), which has a conductive plate at its upper end and is connected to the positive terminal (8) of a DC power supply. The cathode electrolytic cell (1) is equipped with a cathode catalyst electrode (3), which has a conductive plate at its upper end and is connected to the negative terminal (9) of a DC power supply. An isolation valve (6) is set at the lower end of the cathode electrolytic cell (1), and the bottom of the isolation valve (6) is threaded and sealed to a cathode mud receiving box (7). When the electrolysis reaction is carried out, the elemental arsenic cathode mud produced by the cathode catalyst electrode can settle into the cathode mud receiving box (7) through the isolation valve (6) for collection.

2. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The anode electrolytic cell (2) is provided with an anode exhaust port at the upper end, and the cathode electrolytic cell (1) is provided with a cathode exhaust port at the upper end. The anode exhaust port and the cathode exhaust port are respectively connected to a gas collection bag.

3. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The anode catalyst electrode (4) shall be selected from one of the following: a titanium plate or rod with platinum coating, a titanium plate or rod with iridium dioxide coating, or a titanium plate or rod with iridium-tantalum coating.

4. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The cathode catalyst electrode (3) is made of arsenic rod or arsenic plate, preferably arsenic plate.

5. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The two cathode mud receiving boxes (7) are at the same horizontal height.

6. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The bottom of the cathode mud receiving box (7) is equipped with a drain valve.

7. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The cathode mud receiving box (7) is equipped with an inverted conical guide tube with a large opening at the top and a small opening at the bottom. The upper opening of the inverted conical guide tube is in contact with the bottom of the isolation valve (6). When the isolation valve (6) is open, the settled cathode mud can enter the bottom of the cathode mud receiving box (7) through the isolation valve (6) and the inverted conical guide tube.

8. The apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... The acidic electrolyte is a 0.05-0.2M dilute sulfuric acid solution.

9. The method of using the apparatus for high-throughput electrocatalytic preparation of arsine according to claim 1, characterized in that... When the anode catalyst electrode (4) and the cathode catalyst electrode (3) are energized, the isolation valve (6) is adjusted to be in the open state. The anode catalyst electrode undergoes an oxidation reaction to generate oxygen, and the cathode catalyst electrode undergoes a reduction reaction to generate arsine and elemental arsenic cathode sludge. The cathode sludge settles into the cathode sludge receiving box (7) through the isolation valve (6). The isolation valve (6) is closed periodically to drain the cathode sludge receiving box (7). Then, the lost electrolyte is replenished into the cathode electrolysis cell. The isolation valve (6) is opened again to allow the cathode sludge to settle and be collected in the cathode sludge receiving box (7).

10. A method of using the apparatus for high-throughput electrocatalytic preparation of arsine according to claim 9, characterized in that... The voltage for the electrolysis reaction is 3-10V.

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