Method for preparing iodine pentafluoride through photocatalysis

Abstract

The invention provides a method for preparing iodine pentafluoride through photocatalysis, which comprises the following steps: mixing silver iodide and iodine pentafluoride in a reactor, introducing mixed gas of fluorine and protective gas, carrying out photocatalytic reaction under the irradiation of ultraviolet light, and separating to obtain the iodine pentafluoride. The reaction speed of silver iodide and fluorine is increased by utilizing the photosensitive characteristic of silver iodide, so that the reaction efficiency of iodine pentafluoride preparation is improved, and the iodide-based iodine pentafluoride production process is efficient, economical and feasible. The reaction speed is increased by adopting a photocatalysis method, the reaction completion time is only 5 hours, and the energy utilization efficiency and the production efficiency are high; and the iodine pentafluoride is produced by using the silver iodide as the raw material, and the byproduct is high-value silver fluoride, so that the value-added utilization of the raw material is realized, and the economic benefit is good. The method is simple in technological process, mild and controllable in reaction process, good in stability and more beneficial to industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of iodine pentafluoride preparation and relates to a method for preparing iodine pentafluoride by photocatalysis. Background Art

[0002] Iodine pentafluoride is an important raw material for the production of perfluoroiodoethane, IF7, NF3, SF4, C4F6 and other organic and inorganic fluorides. It can also be used in semiconductor etching and cleaning, lithium batteries and other fields. Therefore, it is of great significance to develop industrial preparation technology for iodine pentafluoride. In the prior art, the preparation methods of iodine pentafluoride mainly include the following two categories:

[0003] The first type is to react iodine pentafluoride with single substance I2 as raw material and single substance F2, wherein I2 single substance can participate in the reaction in gaseous state, solid state, melt state, or dissolved state, and its production process can be carried out by intermittent or continuous method. For example, Chinese invention patent (CN101528593) proposes that in the method for making iodine pentafluoride by reacting fluorine and iodine, iodine is supplied to the gas phase adjacent to the liquid of iodine pentafluoride containing iodine, and the liquid phase iodine pentafluoride generated is taken out from the reactor continuously or intermittently. Chinese invention patent (CN101920937A) proposes that solid iodine is placed above liquid iodine pentafluoride or iodine pentafluoride solution, fluorine gas is passed into liquid iodine pentafluoride or iodine pentafluoride solution, and the iodine pentafluoride generated by solid iodine and fluorine reaction flows into liquid iodine pentafluoride or iodine pentafluoride solution after dissolving part of iodine. The Chinese invention patent (CN104326443A) proposes a method for continuous production of iodine pentafluoride in a multi-reactor using iodine pentafluoride and molten iodine as raw materials. This method has high reaction efficiency, but the reaction process is difficult to control due to the intense heat release, and the sublimation of iodine blocks the reaction pipeline, resulting in a high production risk.

[0004] The second method is to use iodine-containing compounds to react with fluorine gas to generate iodine pentafluoride, wherein the iodine compound can be organic or inorganic. For example, US Pat. No. 6,239,319 B1 discloses a method for simultaneously preparing C2-C 10 The process of perfluoroalkane and IF5, the method uses perfluoroalkyl iodide to react with F2 in an inert solvent, and then prepares IF5 by distillation, but IF5 has low production capacity and high raw material prices. Chinese invention patent (CN105523522B) discloses a method of dissolving iodine alkali metal or iodine alkaline earth metal salt in iodine pentafluoride solution, and continuously passing fluorine gas to obtain iodine pentafluoride. The raw materials of this method are cheap and easy to obtain, and a large amount of heat release problems in the reaction process of elemental iodine and fluorine gas are avoided, but the reaction time is long (higher than 150h), and the production efficiency is low.

[0005] Therefore, how to provide a suitable iodine pentafluoride production process to solve the above-mentioned problems existing in the prior art has become one of the focuses of widespread attention of many forward-looking researchers in this field. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a method for preparing iodine pentafluoride by photocatalysis. The essence of the present invention is to utilize the photosensitivity of silver iodide to accelerate its reaction speed with fluorine gas to improve the efficiency of the preparation reaction of iodine pentafluoride, which is an efficient and economically feasible iodine pentafluoride production process based on iodide. Moreover, the preparation method has simple steps, mild conditions, good stability, strong controllability, and is more suitable for large-scale production promotion and application.

[0007] The present invention provides a method for preparing iodine pentafluoride by photocatalysis, comprising the following steps:

[0008] After silver iodide and iodine pentafluoride are mixed in a reactor, a mixed gas of fluorine and protective gas is introduced, and a photocatalytic reaction is carried out under the irradiation of ultraviolet light, and then iodine pentafluoride is obtained after separation.

[0009] Preferably, the mass ratio of silver iodide to iodine pentafluoride is (0.003-0.02):1.

[0010] Preferably, the mixing temperature is 20 to 40°C;

[0011] The protective gas includes an inert gas.

[0012] Preferably, the volume ratio of fluorine gas in the mixed gas is 10% to 25%;

[0013] The molar ratio of fluorine gas to silver iodide in the mixed gas is (10-30):1;

[0014] The pressure of the mixed gas is 0.5-3 MPa.

[0015] Preferably, the temperature of the photocatalytic reaction is 50-70°C;

[0016] The photocatalytic reaction time is 5 to 20 hours.

[0017] Preferably, the photocatalytic reaction is specifically carried out under stirring conditions;

[0018] The stirring speed is 150 to 300 rpm.

[0019] Preferably, the wavelength of the ultraviolet light is 200-400 nm.

[0020] Preferably, the photocatalytic reaction further includes a cooling step;

[0021] The temperature after cooling is 10-20°C.

[0022] Preferably, the separation is solid-liquid separation;

[0023] The separated liquid phase is the product, and the solid phase is silver fluoride.

[0024] Preferably, the separation further includes a step of distilling the liquid phase.

[0025] The present invention provides a method for preparing iodine pentafluoride by photocatalysis, comprising the following steps: mixing silver iodide and iodine pentafluoride in a reactor, introducing a mixed gas of fluorine and protective gas, performing a photocatalytic reaction under the irradiation of ultraviolet light, and then obtaining iodine pentafluoride after separation. Compared with the prior art, the present invention particularly designs a method for preparing iodine pentafluoride by photocatalysis, the essence of which is to use the photosensitivity of silver iodide to accelerate its reaction speed with fluorine gas to improve the efficiency of iodine pentafluoride preparation reaction, and is an efficient and economically feasible iodine pentafluoride production process based on iodide.

[0026] The invention adopts a photocatalytic method to increase the reaction speed, the reaction completion time is only 5 hours, and the energy utilization efficiency and production efficiency are high; and iodine pentafluoride is produced by using silver iodide as a raw material, and high-value silver fluoride is produced as a by-product, thereby realizing the value-added utilization of raw materials and having good economic benefits. The invention has a simple process flow, a mild and controllable reaction process, good stability, and is more conducive to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the process flow of the photocatalytic preparation of iodine pentafluoride provided by the present invention;

[0028] Figure 2 A graph showing the concentration variation of silver iodide, a reactant in the photocatalytic reaction process provided by the present invention;

[0029] Figure 3 is the ultraviolet absorption spectrum of silver iodide;

[0030] Figure 4 This is a scanning electron microscope-energy spectrum diagram of the silver fluoride reaction product prepared by the present invention. DETAILED DESCRIPTION

[0031] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0032] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0033] The raw materials used in the present invention have no particular limitation on their purity. The present invention preferably uses analytical purity or conventional purity in the field of iodine pentafluoride preparation.

[0034] The brands and abbreviations of all raw materials of the present invention are conventional brands and abbreviations in the art. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the brands, abbreviations and corresponding uses.

[0035] The abbreviations of all processes of the present invention are conventional abbreviations in the field, and each abbreviation is clear and unambiguous in the field of its related use. Those skilled in the art can understand its conventional process steps based on the abbreviations.

[0036] The present invention provides a method for preparing iodine pentafluoride by photocatalysis, comprising the following steps:

[0037] After silver iodide and iodine pentafluoride are mixed in a reactor, a mixed gas of fluorine and protective gas is introduced, and a photocatalytic reaction is carried out under the irradiation of ultraviolet light, and then iodine pentafluoride is obtained after separation.

[0038] In the present invention, the mass ratio of silver iodide to iodine pentafluoride is preferably (0.003-0.02):1, more preferably (0.007-0.016):1, and more preferably (0.011-0.012):1.

[0039] In the present invention, the mixing temperature is preferably 20 to 40°C, more preferably 24 to 36°C, and more preferably 28 to 32°C.

[0040] In the present invention, the protective gas preferably includes an inert gas.

[0041] In the present invention, the volume ratio of fluorine gas is preferably 10% to 25%, more preferably 13% to 22%, and even more preferably 16% to 19%.

[0042] In the present invention, the molar ratio of fluorine gas to silver iodide in the mixed gas is preferably (10-30):1, more preferably (17-28):1, more preferably (15-25):1, and more preferably (17-23):1.

[0043] In the present invention, the pressure of the mixed gas is preferably 0.5 to 3 MPa, more preferably 1.0 to 2.5 MPa, and even more preferably 1.5 to 2.0 MPa.

[0044] In the present invention, the temperature of the photocatalytic reaction is preferably 50-70°C, more preferably 53-68°C, and more preferably 55-65°C.

[0045] In the present invention, the photocatalytic reaction time is preferably 5 to 20 hours, more preferably 8 to 17 hours, and more preferably 11 to 14 hours.

[0046] In the present invention, the photocatalytic reaction is preferably carried out under stirring conditions.

[0047] In the present invention, the stirring speed is preferably 150 to 300 rpm, more preferably 180 to 270 rpm, and more preferably 210 to 240 rpm.

[0048] In the present invention, the wavelength of the ultraviolet light is preferably 200 to 400 nm, more preferably 250 to 390 nm, more preferably 280 to 380 nm, and most preferably 300 to 370 nm.

[0049] In the present invention, the photocatalytic reaction preferably further includes a cooling step.

[0050] In the present invention, the temperature after cooling is preferably 10 to 20°C, more preferably 12 to 18°C, and more preferably 14 to 16°C.

[0051] In the present invention, the separation is preferably solid-liquid separation.

[0052] In the present invention, the separated liquid phase is preferably the product, and the solid phase is preferably silver fluoride.

[0053] In the present invention, the separation preferably further includes a step of rectifying the liquid phase.

[0054] The present invention is to complete and refine the overall technical solution, better ensure the characteristics and structure of the product iodine pentafluoride, and further improve the reaction efficiency of the iodine pentafluoride preparation process. The above-mentioned method for preparing iodine pentafluoride by photocatalysis may specifically include the following contents:

[0055] The preparation process of the present invention is specifically as follows:

[0056] (1) mixing silver iodide and iodine pentafluoride in a reactor, controlling the mass ratio of silver iodide to iodine pentafluoride to be 0.003-0.02:1, and controlling the temperature in the reactor to be 20-40° C.;

[0057] (2) introducing a mixed gas of fluorine and an inert gas into the reactor, wherein the inert gas is one of argon and helium, the volume ratio of fluorine gas is 10-25%, the molar ratio of fluorine gas to silver iodide in the mixed gas is 10-30:1, the reaction pressure is controlled to be 0.5-3MPa, the temperature is 50-70°C, the stirring speed is controlled to be 150-300 rpm, ultraviolet light with a wavelength of 200-400nm is provided to the reaction system, and the preferred parameter is 300-370nm, and the reaction time is controlled to be 5-20h;

[0058] (3) After the reaction is completed, the reaction is cooled to 10-20° C. for solid-liquid separation. The solid is the silver fluoride product, and the liquid is distilled to produce the iodine pentafluoride product.

[0059] See also Figure 1 , Figure 1 The present invention provides a schematic diagram of the process flow of the method for preparing iodine pentafluoride by photocatalysis.

[0060] The above content of the present invention provides a method for preparing iodine pentafluoride by photocatalysis. The method for preparing iodine pentafluoride by photocatalysis designed by the present invention is essentially to utilize the photosensitivity of silver iodide to accelerate its reaction speed with fluorine gas to improve the efficiency of iodine pentafluoride preparation reaction, and is an efficient and economically feasible iodine pentafluoride production process based on iodide.

[0061] The invention adopts a photocatalytic method to increase the reaction speed, the reaction completion time is only 5 hours, and the energy utilization efficiency and production efficiency are high; and iodine pentafluoride is produced by using silver iodide as a raw material, and high-value silver fluoride is produced as a by-product, thereby realizing the value-added utilization of raw materials and having good economic benefits. The invention has a simple process flow, a mild and controllable reaction process, good stability, and is more conducive to industrial production.

[0062] In order to further illustrate the present invention, a photocatalytic method for preparing iodine pentafluoride provided by the present invention is described in detail below in conjunction with examples. However, it should be understood that these examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are given only to further illustrate the characteristics and advantages of the present invention, rather than to limit the claims of the present invention. The protection scope of the present invention is not limited to the following examples.

[0063] Example 1

[0064] 1000g of iodine pentafluoride was loaded into the reactor, and silver iodide was added. The mass ratio of silver iodide to iodine pentafluoride was controlled to be 0.005:1, and the temperature in the reactor was controlled to be 20°C. Fluorine-argon mixed gas was introduced into the reaction raw materials, the volume ratio of fluorine gas was 10%, the molar ratio of fluorine gas to silver iodide was controlled to be 30:1, the reaction pressure was 3Mpa, the reaction temperature was 70°C, the stirring speed was controlled to be 150 rpm, the wavelength of ultraviolet light irradiation was controlled to be 300-370nm, the reaction time was controlled to be 5h, and the silver iodide content in the reaction system changed as follows: Figure 2 shown. Figure 2 This is a graph showing the concentration variation of silver iodide, a reactant in the photocatalytic reaction process provided by the present invention.

[0065] See also Figure 3 , Figure 3 This is the ultraviolet absorption spectrum of silver iodide.

[0066] After the reaction is completed, the mixture is cooled to 20°C and solid-liquid separation is performed. The solid product is silver fluoride. The electron microscopy and energy spectrum analysis of the product are as follows: Figure 4 shown.

[0067] See also Figure 4 , Figure 4 This is a scanning electron microscope-energy spectrum diagram of the silver fluoride reaction product prepared by the present invention.

[0068] The content of silver iodide in the reaction liquid is shown in Table 1. After the liquid is distilled, an iodine pentafluoride product is produced. Table 1 shows the conversion rate of the reactants in the examples of the present invention.

[0069] Table 1

[0070] Example Reaction time / h Silver iodide content / g / ml 1 5 0.0003 2 10 0.0005 3 20 0.0011

[0071] Example 2

[0072] 1000g of iodine pentafluoride was loaded into the reactor, silver iodide was added, the mass ratio of silver iodide to iodine pentafluoride was controlled to be 0.01:1, and the temperature in the reactor was controlled to be 30°C; fluorine-helium mixed gas was introduced into the reactants, the volume ratio of fluorine gas was 25%, the molar ratio of fluorine gas to silver iodide was controlled to be 20:1, the reaction pressure was controlled to be 2Mpa, the reaction temperature was 60°C, the stirring speed was controlled to be 200 rpm, the wavelength of ultraviolet light irradiation was controlled to be 250-350nm, and the reaction time was controlled to be 10h. After the reaction was completed, it was cooled to 15°C, solid-liquid separation was performed, the solid product was silver fluoride, and the iodine pentafluoride product was produced after liquid distillation. The silver iodide content after the reaction was completed is shown in Table 1.

[0073] Example 3

[0074] 1000g of iodine pentafluoride was loaded into the reactor, silver iodide was added, the mass ratio of silver iodide to iodine pentafluoride was controlled to be 0.02:1, and the temperature in the reactor was controlled to be 40°C; fluorine-argon mixed gas was introduced into the reactant, the volume ratio of fluorine gas was 15%, the molar ratio of fluorine gas to silver iodide was 10:1, the reaction pressure was controlled to be 0.5Mpa, the reaction temperature was controlled to be 50°C, the stirring speed was controlled to be 300 rpm, the wavelength of ultraviolet light irradiation was controlled to be 200-400nm, and the reaction time was controlled to be 20h. After the reaction was completed, it was cooled to 10°C, and solid-liquid separation was performed. The solid product was silver fluoride, and the content of silver iodide in the reaction liquid was shown in Table 1. The iodine pentafluoride product was produced after liquid distillation.

[0075] The above is a detailed introduction to a photocatalytic method for preparing iodine pentafluoride provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and its core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing iodine pentafluoride by photocatalysis, characterized in that: The following steps are involved: After silver iodide and iodine pentafluoride are mixed in a reactor, a mixed gas of fluorine and protective gas is introduced, and a photocatalytic reaction is carried out under the irradiation of ultraviolet light, and then iodine pentafluoride is obtained after separation.

2. The method according to claim 1, characterized in that The mass ratio of the silver iodide to iodine pentafluoride is (0.003-0.02):

1.

3. The method according to claim 1, characterized in that The mixing temperature is 20 to 40°C; The protective gas includes an inert gas.

4. The method according to claim 1, characterized in that: In the mixed gas, the volume ratio of fluorine gas is 10% to 25%; The molar ratio of fluorine gas to silver iodide in the mixed gas is (10-30):1; The pressure of the mixed gas is 0.5-3 MPa.

5. The method according to claim 1, characterized in that The temperature of the photocatalytic reaction is 50-70°C; The photocatalytic reaction time is 5 to 20 hours.

6. The method according to claim 1, characterized in that The photocatalytic reaction is specifically carried out under stirring conditions; The stirring speed is 150 to 300 rpm.

7. The method according to claim 1, characterized in that The wavelength of the ultraviolet light is 200-400nm.

8. The method according to claim 1, characterized in that The photocatalytic reaction further includes a cooling step; The temperature after cooling is 10-20°C.

9. The method according to claim 1, characterized in that: The separation is specifically solid-liquid separation; The separated liquid phase is the product, and the solid phase is silver fluoride.

10. The method according to claim 1, characterized in that The separation further includes a step of rectifying the liquid phase.

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