CN118374814A - A device for preparing arsine by double-anode electrocatalysis and its application - Google Patents

Abstract

The present application discloses a device and application for preparing arsine by dual anode electrocatalysis. The device of the present application comprises a cathode electrolyzer and two anode electrolyzers arranged on both sides of the cathode electrolyzer. The cathode electrolyzer and the anode electrolyzer are separated by a diaphragm, and an anode catalyst is tightly fitted on one side of the diaphragm facing the anode electrolyzer; a cathode electrode is inserted into the cathode electrolyzer, and the cathode electrode is connected to the negative electrode of the power supply through a wire, and two anode catalysts on opposite sides of the two diaphragms are connected to the positive electrode of the power supply in parallel through a wire. The present invention directly improves the current density of the reaction by designing a "dual-channel" anode electrolyzer structure and regulating the ability of the reaction to transfer protons by increasing the number of anode electrolyzers and anode catalysts, thereby increasing the rate of oxygen generation at the anode on the one hand and accelerating the generation of arsine at the cathode on the other hand.

Description

A device for preparing arsine by double-anode electrocatalysis and its application

Technical Field

The invention belongs to the technical field of electrocatalysis, and in particular relates to a device for preparing arsine by double-anode electrocatalysis and its application.

Background technique

With the continuous advancement of science and technology, the development of semiconductor chips and liquid crystal panel industries has occupied an important position, and the demand for electronic chemicals has also increased year by year. The production of semiconductor chips and liquid crystal panels involves nearly 300 kinds of electronic chemicals, but the development of electronic chemicals is not optimistic. Due to the harsh conditions of the production process of electronic chemicals, there are very large safety hazards in the production process, which leads to huge production costs and seriously affects its production process.

As a common electronic chemical, electronic special gases are widely used in film forming processes, dry etching, chemical cleaning, etc., especially in integrated circuits, flat panel display devices and semiconductors. It is an indispensable material. At present, the preparation method of arsine mainly relies on thermochemical methods, through the formation of arsenic compounds, and further through the reaction with acid to form arsine. However, in this process, the cost is high due to the impure gas, the process is cumbersome, and the reaction process has the safety hazard of explosion. However, the electrocatalytic preparation of arsine has attracted the attention of many researchers with its unique advantages. The electrocatalytic process can accurately control the reaction through electric current and catalysts to achieve controllable preparation of arsine. However, there is still relatively little research on electrocatalytic reactors, and the development of efficient and safe electroreactors has become an urgent need.

Summary of the invention

In view of the problems existing in the prior art, the purpose of the present invention is to provide a device for preparing arsine by dual-anode electrocatalysis. By designing a dual-anode electrolyzer, rapid transmission of dual-channel ions is achieved, the rate of catalytic reaction is increased, and the yield of arsine is increased. The anode electrolyzer and the cathode electrolyzer are separated by a diaphragm to achieve absolute separation of oxidizing gas and strongly reducing gas arsine, thereby forming a safe preparation of arsine. Compared with previous equipment, the reactor is simple in equipment, fast in reaction rate, and increases the yield of the product.

The device for preparing arsine by dual-anode electrocatalysis comprises a cathode electrolyzer and two anode electrolyzers arranged on the left and right sides of the cathode electrolyzer, wherein the cathode electrolyzer and the two anode electrolyzers on both sides thereof are separated by diaphragms, and the rapid transmission of ions is achieved through the diaphragms, and an anode catalyst is tightly fitted on one side of the diaphragm facing the anode electrolyzer; the bottom and top of the anode electrolyzer are respectively provided with an anode liquid inlet and an anode liquid discharge and exhaust port, and the bottom and top of the cathode electrolyzer are respectively provided with a cathode liquid inlet and a cathode liquid discharge and exhaust port, and a cathode electrode is inserted into the cathode electrolyzer, and the cathode electrode is connected to the negative pole of the power supply through a wire, and two anode catalysts on opposite sides of the two diaphragms are connected in parallel with the positive pole of the power supply through a wire. Oxygen generated by electrolysis is discharged from the anode liquid discharge and exhaust port, and arsine is discharged from the cathode liquid discharge and exhaust port. A cathode electrode is provided in the cathode electrolyzer, and the cathode electrode is made of arsenic single substance material.

Furthermore, the present invention also stipulates that the anode electrolytic cell and the cathode electrolytic cell are made of organic materials, such as PTFE, PE and PVC, etc., preferably PE.

Furthermore, the present invention also defines that there is a diaphragm between the anode tank and the cathode tank, and the diaphragm is a ceramic membrane, an anion membrane or a proton membrane, and Nafion 115 (proton membrane) is preferably used.

Furthermore, the present invention also defines that there is a group (two) of anode electrolytic cells, which are respectively located on the left and right sides of the cathode electrolytic cell and are arranged in parallel, and gaskets are used to seal the junction between the cathode electrolytic cell and the diaphragm, and the junction between the diaphragm and the anode electrolytic cell.

Furthermore, the present invention also defines that a circular opening is provided in the middle of the side of the cathode electrolytic cell, which is the cathode electrode opening. The cathode electrode is laterally inserted into the cathode electrolytic cell from the cathode electrode opening, and a sealing device is provided at the junction of the cathode electrode and the cathode electrode opening. The cathode electrode is made of arsenic single-element material and has a round rod structure.

The present invention also provides an application of the dual-anode electrocatalytic preparation of arsine device, and the application process is as follows: electrolytes are respectively introduced into the cathode electrolytic cell and the two anode electrolytic cells, the electrolyte adopts a 0.5-3M KOH aqueous solution, and an electrolytic reaction is carried out under power, the reaction current is 400-600mA, and the cathode product arsine gas is discharged from the cathode liquid exhaust port of the cathode electrolytic cell for collection.

Furthermore, the anode catalyst is a titanium anode with an iridium coating, with a titanium sheet as the electrode substrate, the iridium coating is iridium dioxide, and the loading amount of the iridium coating on the electrode substrate is 0.2-2 mg/ ^cm2 ; the anode product during the electrolysis reaction is oxygen, which is discharged from the anode liquid exhaust port at the top of the anode electrolyzer for collection.

Furthermore, the present invention also defines that all the sealing gaskets in the present invention can be polytetrafluoroethylene gaskets, expanded polytetrafluoroethylene gaskets, etc., preferably expanded polytetrafluoroethylene gaskets.

Compared with the prior art, the present invention has the following beneficial effects:

1) The present invention realizes the rapid transmission of protons by designing a "dual-channel" anode electrolyzer structure, which improves the rate of oxygen generation at the anode and accelerates the generation of arsine at the cathode. The design of the present invention realizes the preparation of arsine with high yield and improves the utilization efficiency of protons.

2) The present invention improves the transmission of H ⁺ formed after the anode reaction by placing the anode catalyst in close contact with the diaphragm, shortens the distance between the electrode and the membrane, reduces the reaction resistance, effectively improves the stability of the catalyst material, and avoids the reduction of catalytic efficiency due to excessive resistance heating.

3) The dual-anode electrocatalytic preparation of arsine device of the present invention regulates the ability of the reaction to transfer protons by increasing the number of anode electrolytic cells and anode catalysts, directly increases the current density of the reaction, indirectly increases the probability of the As ^3- generated by reduction at the cathode and H ⁺ combining, improves the mass transfer capacity of the reaction, and thus achieves an increase in the yield of arsine. The device of the present invention has a simple structure, low cost, high efficiency, and great application potential.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall structure of a device for preparing arsine by dual-anode electrocatalysis according to the present invention;

FIG. 2 is a schematic diagram of the structure of the cathode electrolytic cell of the present invention.

FIG. 3 is a schematic diagram of the overall structure of a comparative example of the present invention.

In Figure 1: 1. anode electrolytic cell; 2. cathode electrolytic cell; 3. anode electrode; 4. anode catalyst; 5. proton exchange membrane; 6. cathode electrode; 7. positive electrode of DC power supply; 8. negative electrode of DC power supply; 9. anode liquid outlet; 10. anode liquid inlet.

In Figure 2: 11. cathode liquid outlet; 12. cathode liquid inlet.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

As shown in FIG1 , a device for preparing arsine by dual-anode electrocatalysis of the present invention comprises a cathode electrolytic cell 2 and two anode electrolytic cells 1 arranged on the left and right sides of the cathode electrolytic cell 2. The cathode electrolytic cell 2 and the two anode electrolytic cells 1 on both sides thereof are separated by diaphragms 5, respectively, and the rapid transmission of ions is achieved through the diaphragms 5. In order to prevent the cathode electrolytic cell 2 and the anode electrolytic cell 1 from being directly connected and leaking without passing through the diaphragm 5, gaskets are arranged on both sides of the diaphragm 5 to play a sealing role. That is to say, the junction between the cathode electrolytic cell 2 and the diaphragm 5 and the junction between the diaphragm 5 and the anode electrolytic cell 1 are both sealed with gaskets.

The top of the anode electrolyzer 1 is provided with an anode liquid discharge vent 9, which is connected to the anode product collector using an external polytetrafluoroethylene adapter, and the bottom is provided with an anode liquid inlet 10, which is also connected to the feed tank using an external polytetrafluoroethylene adapter. Each anode electrolyzer 1 is provided with an anode catalyst electrode 3, which is tightly fitted with the diaphragm 5. In the two anode electrolyzers 1, the two anode catalysts 4 on the opposite sides of the two diaphragms 5 are connected in parallel to the positive electrode 7 of the power supply through a wire, and the generated oxygen is discharged from the anode liquid discharge vent 9.

As shown in FIG2 , the cathode electrolyzer of the present invention is provided with a cathode liquid discharge and exhaust port 11 at the top, which is connected to the cathode product collector using an external polytetrafluoroethylene adapter, and a cathode liquid inlet 12 is provided at the bottom, which is also connected to the feed tank using an external polytetrafluoroethylene adapter. A circular opening is provided in the middle of the side of the cathode electrolyzer, which is the cathode electrode opening 6. The cathode electrode is laterally inserted into the cathode electrolyzer 2 from the cathode electrode opening 6, and a sealing gasket is provided at the junction of the cathode electrode and the cathode electrode opening 6. The cathode electrode is connected to the negative electrode 8 of the power supply through a wire, and the product arsine is discharged from the cathode liquid discharge and exhaust port 11.

To further illustrate, further in the present invention, the anode electrolyzer 1 and the cathode electrolyzer 2 of the present invention are made of organic materials, such as PTFE, PE and PVC, etc., preferably PE. There is a diaphragm 5 between the anode electrolyzer 1 and the cathode electrolyzer 2, and the diaphragm is made of ceramic membrane, anion membrane and proton membrane, etc., preferably Nafion 115 (proton membrane). The anode catalyst 4 can be made of platinum-plated titanium or nickel, iridium-plated titanium or nickel, etc., preferably iridium-plated titanium. The connection between the power supply and the electrode is made of copper, aluminum and their alloy materials, preferably copper, and is treated by hot tinning. All sealing gaskets can be made of polytetrafluoroethylene gaskets, expanded polytetrafluoroethylene gaskets, preferably expanded polytetrafluoroethylene gaskets.

Example 1: A dual-anode electrocatalytic device for preparing arsenic

The device structure is shown in Figure 1-2. The cathode electrolyzer is located between the two anode electrolyzers. A Nafion 115 membrane is provided between the cathode electrolyzers, which selectively transmits ions in the reaction process and has the function of separating the products of the cathode and cathode electrolyzers, thereby achieving absolute separation of explosive gases and realizing safe arsine production. An iridium-plated titanium anode (the titanium anode is a titanium sheet of 3cm*3cm in size, and the iridium-plated layer is iridium dioxide with a loading of 1mg/ ^cm2 ) is closely arranged on the side of the Nafion 115 membrane facing the anode electrolyzer, so that the two Nafion 115 membranes are respectively provided with an iridium-plated titanium anode. An anode liquid discharge outlet is provided at the top of the anode electrolyzer for oxygen generation and discharge, and an anode liquid inlet is provided at the bottom for the entry of electrolyte. A cylindrical arsenic single substance catalyst electrode is provided in the middle of the cathode electrolyzer, and an o-type expanded polytetrafluoroethylene gasket is provided between the arsenic single substance catalyst electrode and the cathode electrolyzer. The specific reaction conditions are as follows: the reaction current is controlled to be 400, 500 and 600 mA, the electrolyte in the cathode electrolytic cell and the two anode electrolytic cells is 1M KOH solution, the anode catalyst area is 9 cm ² , and the cathode catalyst area is 9.42 cm ² .

The reaction conditions were changed for testing, and the results are shown in Table 1.

Table 1. Oxygen/Arsine production at different currents

The results in Table 1 show that the present invention has both excellent oxygen preparation performance and arsine production capacity, and has good application potential.

Example 2: A dual-anode electrocatalytic device for preparing arsine

The structure of the electrolysis device in Example 2 is the same as that in Example 1. The specific reaction conditions are that the current controlling the reaction is 500 mA, the electrolyte in the cathode electrolytic cell and the two anode electrolytic cells is KOH solution, the anode catalyst area is 9 cm ² , and the cathode catalyst area is 9.42 cm ² .

The reaction conditions were changed for testing, and the results are shown in Table 2.

Table 2. Oxygen/arsine production at different electrolyte concentrations

The results in Table 2 show that the present invention can achieve the optimal condition screening for arsine production by adjusting the electrolyte concentration. When the electrolyte concentration is 1 M, the production of oxygen and arsine is the highest. As the electrolyte concentration increases, the production decreases, which may be due to the influence of the hydrogen evolution reaction.

Comparative Example 1: Single anode electrocatalytic preparation of arsenic

The device structure is shown in Figure 3. The cathode electrolyzer is located on the right side of the anode electrolyzer. A Nafion 115 membrane is provided between the cathode electrolyzer and the anode electrolyzer. It selectively transmits ions in the reaction process and has the function of separating the products of the cathode and cathode electrolyzers, achieving absolute separation of explosive gases and realizing safe arsine production. A titanium anode with an iridium coating is closely arranged on the side of the Nafion 115 membrane facing the anode electrolyzer (the titanium anode is a titanium sheet with a size of 3cm*3cm, and the iridium coating is iridium dioxide with a loading of 1mg/ ^cm2 ). An anode liquid discharge outlet is provided at the top of the anode electrolyzer for oxygen generation and discharge, and an anode liquid inlet is provided at the bottom for the entry of electrolyte. A cylindrical arsenic single substance catalyst electrode is provided in the middle of the cathode electrolyzer, and an o-type expanded polytetrafluoroethylene gasket is provided between the arsenic single substance catalyst electrode and the cathode electrolyzer. The specific reaction conditions are as follows: the reaction current is controlled to be 500 mA, the electrolyte in the cathode electrolytic cell and the anode electrolytic cell are both 1M KOH solution, the anode catalyst area is 9 cm ² , and the cathode catalyst area is 9.42 cm ² .

The reaction conditions were changed for testing, and the results are shown in Table 3.

Table 3. Oxygen/Arsine production at different currents

The results in Table 3 show that the effect of preparing arsine is best when the current is 500mA/ ^cm2 . However, compared with the dual-anode electrocatalytic arsine preparation device, the effect of arsine production is reduced by 50%-60%. This result is mainly due to the parallel structure of the dual anodes, which improves the oxygen evolution capacity of the anode. Compared with the single electrode, the amount of oxygen produced is increased by about one time. This process improves the mass transfer capacity of the reaction process, greatly increases the transmission speed and amount of H ⁺ to the cathode, and further increases the production rate of arsine.

The contents described in this specification are merely an enumeration of implementation forms of the inventive concept, and the protection scope of the present invention should not be regarded as being limited to the specific forms described in the embodiments.

Claims (8)

1. A device for preparing arsine by dual-anode electrocatalysis, characterized in that it comprises a cathode electrolytic cell (2) and two anode electrolytic cells (1) arranged on the left and right sides of the cathode electrolytic cell (2), the cathode electrolytic cell (2) and the two anode electrolytic cells (1) on both sides thereof are separated by a diaphragm (5), and the diaphragm (5) is used to realize the rapid transmission of ions, and an anode catalyst (4) is tightly attached to the side surface of the diaphragm (5) facing the anode electrolytic cell (1); the bottom and top of the anode electrolytic cell (1) are respectively provided with An anode liquid inlet (10) and an anode liquid discharge and exhaust port (9), a cathode liquid inlet (12) and a cathode liquid discharge and exhaust port (11) are respectively provided at the bottom and top of the cathode electrolytic cell (2), a cathode electrode is inserted into the cathode electrolytic cell (2), and the cathode electrode is connected to the negative electrode (8) of the power supply through a wire, and two anode catalysts (4) on opposite sides of the two diaphragms (5) are connected in parallel to the positive electrode (7) of the power supply through a wire; a cathode electrode is provided in the cathode electrolytic cell (2), and the cathode electrode is selected from arsenic single substance material. 2. A dual-anode electrocatalytic device for preparing arsine as described in claim 1, characterized in that both the cathode electrolytic cell (2) and the anode electrolytic cell (1) are made of organic materials, and the organic material is PTFE, PE or PVC, preferably PE. 3. A dual-anode electrocatalytic device for preparing arsine as described in claim 1, characterized in that the diaphragm (5) is a ceramic membrane, an anion membrane or a proton membrane, preferably a proton membrane Nafion 115. 4. A dual-anode electrocatalytic device for preparing arsine as described in claim 1, characterized in that the anode catalyst (4) is selected from one of the following: platinum-coated titanium or nickel, iridium-coated titanium or nickel, preferably iridium-coated titanium. 5. A dual-anode electrocatalytic device for preparing arsine as described in claim 1, characterized in that the two anode electrolytic cells (1) on the left and right sides of the cathode electrolytic cell (2) are arranged in parallel, and gaskets are used to seal the junction between the cathode electrolytic cell (2) and the diaphragm (5) and the junction between the diaphragm (5) and the anode electrolytic cell (1). 6. A dual-anode electrocatalytic device for preparing arsine as described in claim 1, characterized in that a circular opening is provided in the middle of the side of the cathode electrolytic cell (2), which is the cathode electrode opening (6), the cathode electrode is laterally inserted into the cathode electrolytic cell (2) from the cathode electrode opening (6), and a sealing device is provided at the junction of the cathode electrode and the cathode electrode opening (6), and the cathode electrode is a round rod structure. 7. The use of a dual-anode electrocatalytic preparation of arsine device as described in claim 1, characterized in that the application process is as follows: electrolytes are respectively introduced into the cathode electrolytic cell (2) and the two anode electrolytic cells (1), the electrolyte is a 0.5-3M KOH aqueous solution, and an electrolytic reaction is carried out under power, the reaction current is 400-600mA, and the cathode product arsine gas is discharged from the cathode liquid exhaust port (11) of the cathode electrolytic cell (2) for collection. 8. The use as claimed in claim 7, characterized in that the anode catalyst (4) is a titanium anode with an iridium coating, with a titanium sheet as the electrode substrate, the iridium coating is iridium dioxide, and the loading amount of the iridium coating on the electrode substrate is 0.2-2 mg/ ^cm2 ; the anode product during the electrolysis reaction is oxygen, which is discharged from the anode liquid exhaust port (9) at the top of the anode electrolyzer (1) for collection.