A photochemical synthesis method for producing H2O2 using benzyl compounds as a hydrogen source

Abstract

The photochemical synthesis method for producing H2O2 using benzyl compounds as the hydrogen source described in this invention uses oxygen or air as the oxygen source and ultraviolet light as the energy driving force. The process steps are as follows: (1) The benzyl compound is loaded into a reactor and oxygen or air is introduced to form a reaction system. The reaction system is irradiated with a light source containing ultraviolet light, and the reaction temperature is controlled at 20-60°C. The reaction time is at least 10 minutes. After the reaction is completed, an organic liquid containing H2O2 is obtained; (2) The organic liquid containing H2O2 obtained in step (1) is extracted with water as the extractant at the reaction temperature or room temperature. The H2O2 aqueous solution is obtained by phase separation. The above method can not only improve the synthesis rate and economy of H2O2, but also reduce energy consumption and production costs, eliminate safety hazards, and facilitate industrialization.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen peroxide (H2O2) preparation technology, and particularly relates to a method for photochemical gas-liquid two-phase synthesis of hydrogen peroxide (H2O2). Background Technology

[0002] Hydrogen peroxide (H₂O₂) is an important industrial raw material chemical with various synthesis methods, mainly including inorganic chemical reaction methods, isopropanol oxidation methods, electrolysis methods, anthraquinone methods, and direct synthesis methods using hydrogen and oxygen. Among these, the anthraquinone method accounts for over 95% of the total H₂O₂ production. The anthraquinone H₂O₂ production process mainly includes four steps: anthraquinone hydrogenation reduction, hydrogenated anthraquinone oxidation, hydrogen peroxide extraction and purification, and reaction solution recycling. The main problems are: the hydrogenation process involves the use of large amounts of hydrogen and precious metal catalysts, resulting in high costs and energy consumption; to achieve higher purity and concentration, H₂O₂ aqueous solution needs to be distilled to obtain a high-concentration H₂O₂ solution, and the extraction process introduces a large amount of organic matter (such as 2-ethylanthraquinone, trioctyl phosphate, etc.) into the aqueous phase; to minimize transportation costs, a large amount of energy is generally required to concentrate the H₂O₂ solution to a concentration as high as 70 wt%, and high-concentration H₂O₂, as a dangerous and highly oxidizing chemical substance, poses extremely high safety risks and significant safety hazards during transportation, handling, and storage.

[0003] Currently, photocatalytic production of H2O2 is a hot research topic [see Hou, H.; Zeng, X.; Zhang, X., Production of Hydrogen Peroxide by Photocatalytic Processes [J]. Angewandte Chemie International Edition 2020, 59(40), 17356-17376.]. However, the photocatalytic preparation of H2O2 faces several technical challenges: (1) low photocatalytic efficiency and difficulty in industrialization; (2) product separation and purification problems during hydrogen peroxide extraction and purification; and (3) problems of photocorrosion, light shielding, and product decomposition of catalysts.

[0004] To overcome the problems existing in the anthraquinone method and photocatalytic method for preparing H2O2, ZL 202210662267.1 discloses a photosynthetic method for preparing H2O2. This method uses aromatic alcohol as hydrogen source, oxygen or air as oxygen source, and ultraviolet light as energy driving force. Under ultraviolet light irradiation, aromatic alcohol absorbs the energy of photons and undergoes homolytic cleavage to generate hydrogen free radicals. The hydrogen free radicals react with oxygen molecules to produce H2O2. This method avoids the high energy consumption and high pollution of the anthraquinone method for producing H2O2. Since the reaction system does not contain catalysts and sacrificial agents, it solves the problem of difficult separation and recovery of catalysts and sacrificial agents in the photocatalytic preparation of H2O2. It is also convenient to obtain H2O2 aqueous solutions of different concentrations by adjusting the volume ratio of extractant water to reaction liquid. However, the following problems exist: (1) Since the light absorption range of aromatic alcohols is limited to 200-300nm and its chemical structure determines that the reaction activity is low, even if sufficient energy is absorbed, it is difficult to further stimulate its participation in the reaction, so the photosynthesis rate is low; (2) Since aromatic alcohols contain hydroxyl groups, and organic compounds containing hydroxyl groups will increase the affinity with water molecules, there are hydrogen bonding or similar solubility between molecules, which leads to high solubility of aromatic alcohols in water, resulting in excessively high content of water-soluble organic matter (COD) in hydrogen peroxide products. If the content of organic matter is to be reduced, a separation and purification process needs to be introduced later, which increases the preparation cost; (3) After the aromatic alcohols are used to synthesize hydrogen peroxide, unsaturated aromatic aldehydes and ketones will be produced. The economic value of these products is far lower than that of the aromatic alcohols themselves. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a photochemical synthesis method for producing H2O2 using benzyl compounds as a hydrogen source, so as to improve the photosynthesis rate and economy, and reduce the content of water-soluble organic matter in hydrogen peroxide products.

[0006] The photochemical synthesis method for producing H2O2 using benzyl compounds as the hydrogen source described in this invention uses oxygen or air as the oxygen source and ultraviolet light as the energy driving force. The process steps are as follows:

[0007] (1) The benzyl compound is loaded into the reactor and oxygen or air is introduced to form a reaction system. The reaction system is irradiated with a light source containing ultraviolet light. The reaction temperature is controlled at 20-60℃ and the reaction time is at least 10 min. After the reaction is completed, an organic liquid containing H2O2 is obtained.

[0008] (2) Using water as the extractant, the organic liquid containing H2O2 obtained in step (1) is extracted at the reaction temperature or room temperature, and an aqueous solution of H2O2 is obtained by phase separation.

[0009] The reaction mechanism of the above method is as follows: under ultraviolet light irradiation, the benzyl compound absorbs the energy of photons and undergoes homolytic cleavage to generate hydrogen free radicals, which then reduce oxygen molecules to generate H2O2.

[0010] In the above method, the benzyl compound is a benzyl ether compound, a benzylamine compound, a benzyl alkane compound, a benzyl aldehyde compound, a benzyl acid compound, or a benzyl ketone compound. Benzyl ether compounds are preferably benzyl methyl ether, dibenzyl ether, or isochloromethane; benzylamine compounds are preferably benzylamine, phenethylamine, or N,N-dimethylbenzylamine; benzyl alkane compounds are preferably toluene, ethylbenzene, isopropylbenzene, styrene, or styrene; benzyl aldehyde compounds are preferably benzaldehyde or phenylacetaldehyde; benzyl acid compounds are preferably terephthalic acid; and benzyl ketone compounds are preferably benzylacetone or indene.

[0011] In the above method, the light source containing ultraviolet light is an artificial light source or natural light; the preferred artificial light source is a xenon lamp (λ = 300-1000nm) or a high-pressure mercury lamp (λ = 254-365nm).

[0012] In the above method, the air can be compressed air or natural air, with compressed air being preferred.

[0013] In the above method, the extractant water is deionized water, distilled water, ultrapure water or electronic grade water; during extraction, the extractant water can be determined according to the concentration of H2O2 aqueous solution, and the volume ratio of extractant water to organic liquid containing H2O2 is usually 1 to 5:1.

[0014] Compared with the prior art, the method described in this invention has the following beneficial technical effects:

[0015] (1) The method of the present invention loads a benzyl compound into a reactor and introduces oxygen or air to form a reaction system. Under the irradiation of a light source containing ultraviolet light, the benzyl compound absorbs the energy of photons and undergoes homolytic cleavage to generate hydrogen free radicals. The hydrogen free radicals reduce oxygen molecules to generate H2O2. Therefore, it solves the problems of high energy consumption and high pollution in the anthraquinone method for producing H2O2, and also solves the problems of using catalysts and sacrificial agents and the difficulty of their separation and recovery in the photocatalytic method for preparing H2O2.

[0016] (2) The method of the present invention uses benzyl compounds as hydrogen sources. Since the absorption range of benzyl compounds (200nm to 400nm) is greater than that of the hydrogen source aromatic alcohol in ZL 202210662267.1 (200nm to 300nm), the benzyl compounds are more active when the reaction system is irradiated with a light source containing ultraviolet light, and more hydrogen free radicals are generated by homolytic cleavage. Therefore, compared with ZL202210662267.1, the synthesis rate of H2O2 is higher at the same reaction time (e.g., 4h) (see the examples of this application and ZL202210662267.1).

[0017] 3. The hydrogen source benzyl compound in the method of the present invention does not contain the hydroxyl structure of aromatic alcohols, so it has poor water solubility. Taking benzyl ether, toluene and ethylbenzene as examples, almost no organic matter was detected in the H2O2 product obtained by extraction, and the COD was extremely low (less than 20 ppm).

[0018] 4. The benzyl hydrogen source compound in the method of the present invention has high economic value after dehydrogenation, especially dibenzyl ether and isochromium. After dehydrogenation, dibenzyl ether will generate benzaldehyde, benzoic acid, benzyl benzoate, benzoin and other high-value organic compounds. After dehydrogenation, isochromium will generate isochromium, and the price of isochromium is 10 times higher than that of isochromium.

[0019] 5. The method described in this invention facilitates the small-scale or large-scale production of H2O2 aqueous solution. The raw materials are readily available, and the process and equipment are simple. Therefore, dilute H2O2 aqueous solution products can be produced directly at the place of use and used directly, avoiding the safety risks that exist in the transportation, handling and storage of high-concentration H2O2, eliminating safety hazards and reducing costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the reaction apparatus used in the embodiment. In the diagram, 1—artificial light source, 2—quartz glass cover, 3—reactor, 4—air inlet, 5—air outlet, 6—cooler, 7—water inlet, 8—water outlet, and 9—stirrer.

[0021] Figure 2 The graph shows the change in concentration of the H2O2 solution prepared in Example 1 over reaction time.

[0022] Figure 3 The graph shows the change in concentration of the H2O2 solution prepared in Example 2 over reaction time.

[0023] Figure 4 The graph shows the COD content in the H2O2 aqueous solutions prepared in Examples 1, 6, and 15. Detailed Implementation

[0024] The photochemical synthesis method for producing H2O2 using benzyl compounds as a hydrogen source, as described in this invention, will be further illustrated below with reference to the accompanying drawings and examples. Obviously, the described examples are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0025] In the following embodiments, except for Embodiment 11, all other embodiments use Figure 1The reaction apparatus shown includes an artificial light source 1, a quartz glass cover 2, a reactor 3, a condenser 6, and a stirrer 9. The stirrer 9 is a pedestal-type stirrer, mainly composed of a hollow base, a motor installed inside the base, and a stirring paddle connected to the motor's output shaft. The reactor 3 is a glass cylinder closed at the bottom and open at the top, with an air inlet 4 and an air outlet 5 respectively provided on its left and right side walls. The reactor 3 is placed on the top surface of the stirrer 9's base, and the stirring paddle of the stirrer 9 is located inside the reactor 3. The contact point between the stirring paddle and the bottom wall of the reactor 3 is sealed with sealant. The condenser 6 is used to control the reaction temperature of the reaction system. It is a jacketed structure and is arranged around the outer wall of the reactor 3. The condenser 6 has a water inlet 7 and a water outlet 8 respectively provided on its left and right side walls. The quartz glass cover 2 matches the reactor 3 and is used to cover the upper part of the reactor 3. The artificial light source 1 is fixed above the reactor 3. In use, the inlet 7 and outlet 8 of the cooler 6 are connected to the outlet and inlet of the constant temperature water bath device respectively through pipe fittings, and the inlet 4 of the reactor 3 is connected to the oxygen source through pipe fittings.

[0026] In the following examples, benzyl methyl ether, dibenzyl ether, isochloromethane, benzylamine, phenethylamine, N,N-dimethylbenzylamine, toluene, ethylbenzene, isopropylbenzene, styrene, styrene, benzaldehyde, phenylacetaldehyde, terephthalic acid, benzyl acetone, and indene were of analytical grade and purchased commercially.

[0027] Example 1

[0028] This embodiment uses oxygen as the oxygen source, benzyl methyl ether as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0029] (1) 5 mL of benzyl methyl ether was added to reactor 3, and oxygen was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. A 300 W xenon lamp with a light power density of 500 mW / cm² was used. 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 1 hour. During the entire reaction process, oxygen was kept flowing in and the gas outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction time was up, an organic liquid containing H2O2 was obtained.

[0030] (2) Using deionized water as the extractant, the volume ratio of the extractant to the H2O2-containing organic liquid obtained in step (1) was 5:1. The organic liquid containing H2O2 obtained in step (1) was extracted at room temperature. After phase separation, an aqueous H2O2 solution and an organic phase were obtained. The concentration of H2O2 in the aqueous H2O2 solution obtained after 1 hour of reaction was measured. See [reference needed]. Figure 2 ;

[0031] (3) The H2O2 aqueous solution and organic phase obtained from phase separation in step (2) are added to reactor 3. Oxygen is introduced into the reactor at a flow rate of 12 mL / min. The reaction is carried out at 20°C for 1 h under the irradiation and stirring of the xenon lamp. Extraction is completed during the reaction. Then, the liquid in the reactor is subjected to phase separation to obtain the H2O2 aqueous solution and organic phase. The concentration of H2O2 in the obtained H2O2 aqueous solution after 2 h of reaction is measured. See Figure 2 ;

[0032] (4) The H2O2 aqueous solution and organic phase obtained from phase separation in step (3) are added to reactor 3. Oxygen is introduced into the reactor at a flow rate of 12 mL / min. The reaction is carried out at 20°C for 1 h under the irradiation and stirring of the xenon lamp. Extraction is completed during the reaction. Then, the liquid in the reactor is subjected to phase separation to obtain the H2O2 aqueous solution and organic phase. The concentration of H2O2 in the obtained H2O2 aqueous solution after 3 h of reaction is measured. See Figure 2 ;

[0033] (5) The H2O2 aqueous solution and organic phase obtained from phase separation in step (4) are added to reactor 3. Oxygen is introduced into the reactor at a flow rate of 12 mL / min. The reaction is carried out at 20°C for 1 h under the irradiation and stirring of the xenon lamp. Extraction is completed during the reaction. Then, the liquid in the reactor is subjected to phase separation to obtain the H2O2 aqueous solution and organic phase. The concentration of H2O2 in the obtained H2O2 aqueous solution after 4 h of reaction is measured. See Figure 2 .

[0034] (6) The COD content of the obtained H2O2 aqueous solution was tested, and it was found to be very low, only 18 ppm. See [reference needed]. Figure 4 .

[0035] from Figure 2 It can be seen that as the reaction time increases, the concentration of H2O2 in the resulting H2O2 aqueous solution increases. After reacting at 20℃ for 4 hours, the concentration of H2O2 in the H2O2 aqueous solution is 406.22 mM.

[0036] Example 2

[0037] This embodiment uses compressed air as the oxygen source, benzyl methyl ether as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0038] (1) 5 mL of benzyl methyl ether was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 1 hour. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0039] (2) Using deionized water as the extractant, the volume ratio of the extractant to the H2O2-containing organic liquid obtained in step (1) was 5:1. The organic liquid containing H2O2 obtained in step (1) was extracted at room temperature. After phase separation, an aqueous H2O2 solution and an organic phase were obtained. The concentration of H2O2 in the aqueous H2O2 solution obtained after 1 hour of reaction was measured. See [reference needed]. Figure 3 ;

[0040] (3) The H2O2 aqueous solution and organic phase obtained from phase separation in step (2) are added to reactor 3. Compressed air is introduced into the reactor at a flow rate of 12 mL / min. The reaction is carried out at 20°C for 1 h under the irradiation and stirring of the xenon lamp. Extraction is completed during the reaction. Then, the liquid in the reactor is subjected to phase separation to obtain the H2O2 aqueous solution and organic phase. The concentration of H2O2 in the obtained H2O2 aqueous solution after 2 h of reaction is measured. See Figure 3 ;

[0041] (4) The H2O2 aqueous solution and organic phase obtained from phase separation in step (3) are added to reactor 3. Compressed air is introduced into the reactor at a flow rate of 12 mL / min. The reaction is carried out at 20°C for 1 h under the irradiation and stirring of the xenon lamp. Extraction is completed during the reaction. Then, the liquid in the reactor is subjected to phase separation to obtain the H2O2 aqueous solution and organic phase. The concentration of H2O2 in the obtained H2O2 aqueous solution after 3 h of reaction is measured. See Figure 3 ;

[0042] (5) The H2O2 aqueous solution and organic phase obtained from phase separation in step (4) are added to reactor 3. Compressed air is introduced into the reactor at a flow rate of 12 mL / min. The reaction is carried out at 20°C for 1 h under the irradiation and stirring of the xenon lamp. Extraction is completed during the reaction. Then, the liquid in the reactor is subjected to phase separation to obtain the H2O2 aqueous solution and organic phase. The concentration of H2O2 in the obtained H2O2 aqueous solution after 4 h of reaction is measured. See Figure 3 .

[0043] from Figure 3 It can be seen that as the reaction time increases, the concentration of H2O2 in the resulting H2O2 aqueous solution increases. After reacting at 20℃ for 4 hours, the concentration of H2O2 in the H2O2 aqueous solution is 400.08 mM.

[0044] Example 3

[0045] This embodiment uses compressed air as the oxygen source, a different colored lamp as the hydrogen source, and a xenon lamp as the light source containing ultraviolet light. Figure 1 The reaction apparatus shown follows the steps below:

[0046] (1) Fill reactor 3 with 5 mL of the different colored material and introduce compressed air into the reactor at a flow rate of 6 mL / min to form a reaction system. Use a 300W xenon lamp with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0047] (2) Using deionized water as the extractant, the volume ratio of the extractant to the H2O2-containing reaction solution obtained in step (1) was 5:1. The organic liquid containing H2O2 obtained in step (1) was extracted at room temperature. After phase separation, an aqueous H2O2 solution and an organic phase were obtained. The concentration of the obtained aqueous H2O2 solution was tested, and the concentration of H2O2 was 390.96 mM. The structure of the organic phase was confirmed. By nuclear magnetic resonance and high-resolution mass spectrometry analysis, the organic phase contained the dehydrogenated compound isochorium.

[0048] Example 4

[0049] This embodiment uses compressed air as the oxygen source, N,N-dimethylbenzylamine as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0050] (1) 5 mL of N,N-dimethylbenzylamine was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 18 mL / min to form a reaction system. A 300W xenon lamp with a light power density of 500 mW / cm² was used. 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0051] (2) Using deionized water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 5:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 400.14 mM.

[0052] Example 5

[0053] This embodiment uses compressed air as the oxygen source, a different colored lamp as the hydrogen source, and a xenon lamp as the light source containing ultraviolet light. Figure 1 The reaction apparatus shown follows the steps below:

[0054] (1) Fill reactor 3 with 5 mL of the different colored material and introduce compressed air into the reactor at a flow rate of 12 mL / min to form a reaction system. Use a 300W xenon lamp with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0055] (2) Using deionized water as the extractant, the volume ratio of the extractant to the H2O2-containing organic liquid obtained in step (1) was 5:1. The organic liquid containing H2O2 obtained in step (1) was extracted at room temperature. After phase separation, an aqueous H2O2 solution and an organic phase were obtained. The concentration of the obtained aqueous H2O2 solution was tested, and the concentration of H2O2 was 122.56 mM. The structure of the organic phase was confirmed. By nuclear magnetic resonance and high-resolution mass spectrometry analysis, the organic phase contained the dehydrogenated compound isochorium.

[0056] Example 6

[0057] This embodiment uses compressed air as the oxygen source, toluene as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0058] (1) 5 mL of toluene was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 400 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0059] (2) Using ultrapure water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 5:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 360.34 mM.

[0060] (3) The COD content of the H2O2 aqueous solution was tested and found to be very low, only 16 ppm. See [reference needed]. Figure 4 .

[0061] Example 7

[0062] This embodiment uses compressed air as the oxygen source, benzylacetone as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0063] (1) 5 mL of benzylacetone was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 300 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0064] (2) Using ultrapure water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 5:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 260.65mM.

[0065] Example 8

[0066] This embodiment uses compressed air as the oxygen source, styrene as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0067] (1) 5 mL of styrene was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0068] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 1223.83 mM.

[0069] Example 9

[0070] This embodiment uses compressed air as the oxygen source, benzyl methyl ether as the hydrogen source, and a high-pressure mercury lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0071] (1) 5 mL of benzyl methyl ether was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. A 300W high-pressure mercury lamp with a light power density of 300 mW / cm² was used. 2 Under the irradiation and stirring of the high-pressure mercury lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0072] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 5:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 360.2 mM.

[0073] Example 10

[0074] This embodiment uses compressed air as the oxygen source, indene as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0075] (1) 5 mL of indene was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 12 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 40°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0076] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 5:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 884.1 mM.

[0077] Example 11

[0078] This embodiment uses air as the oxygen source, benzyl methyl ether as the hydrogen source, natural light as the ultraviolet light source, and a shallow pool-type photoreactor (petition dish) as the reaction apparatus. The steps are as follows:

[0079] (1) 5 mL of benzyl methyl ether was placed in a shallow pool photoreactor and left to stand in the air. The reaction was carried out for 4 hours under sunlight and stirring (the reaction temperature was about 30°C). After the reaction time was over, an organic liquid containing H2O2 was obtained.

[0080] (2) Using deionized water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 5:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 77.78 mM.

[0081] Example 12

[0082] This embodiment uses oxygen as the oxygen source, dibenzyl ether as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0083] (1) 5 mL of dibenzyl ether was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0084] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) was 1:1. The organic liquid containing H2O2 obtained in step (1) was extracted at room temperature. After phase separation, an aqueous H2O2 solution and an organic phase were obtained. The concentration of the obtained aqueous H2O2 solution was tested, and the concentration of H2O2 was 1423.89 mM. The structure of the organic phase was confirmed by nuclear magnetic resonance and high-resolution mass spectrometry analysis. The organic phase contained benzaldehyde (a dehydrogenated dibenzyl ether), benzoic acid, benzyl benzoate, and benzoin.

[0085] Example 13

[0086] This embodiment uses oxygen as the oxygen source, benzoylamine as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0087] (1) 5 mL of aniline was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0088] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 423.87 mM.

[0089] Example 14

[0090] This embodiment uses oxygen as the oxygen source, phenylethylamine as the hydrogen source, and a xenon lamp as the light source containing ultraviolet light. Figure 1 The reaction apparatus shown follows the steps below:

[0091] (1) 5 mL of phenylethylamine was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0092] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 523.82 mM.

[0093] Example 15

[0094] This embodiment uses oxygen as the oxygen source, ethylbenzene as the hydrogen source, and a xenon lamp as the light source containing ultraviolet light. Figure 1 The reaction apparatus shown follows the steps below:

[0095] (1) 5 mL of ethylbenzene was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0096] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 123.83 mM.

[0097] (3) The COD content of the obtained H2O2 aqueous solution was tested, and it was found to be very low, only 19 ppm. See [reference needed]. Figure 4 .

[0098] Example 16

[0099] This embodiment uses oxygen as the oxygen source, isopropylbenzene as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0100] (1) 5 mL of isopropylbenzene was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0101] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 223.13 mM.

[0102] Example 17

[0103] This embodiment uses oxygen as the oxygen source, styrene as the hydrogen source, and a xenon lamp as the light source containing ultraviolet light. Figure 1 The reaction apparatus shown follows the steps below:

[0104] (1) 5 mL of styrene was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0105] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 103.87 mM.

[0106] Example 18

[0107] This embodiment uses oxygen as the oxygen source, styrene as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0108] (1) 5 mL of styrene-propylene is added to reactor 3, and compressed air is introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp is 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0109] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 201.33 mM.

[0110] Example 19

[0111] This embodiment uses oxygen as the oxygen source, benzaldehyde as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0112] (1) 5 mL of benzaldehyde was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0113] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 91.53 mM.

[0114] Example 20

[0115] This embodiment uses oxygen as the oxygen source, phenylacetaldehyde as the hydrogen source, and a xenon lamp as the light source containing ultraviolet light. Figure 1 The reaction apparatus shown follows the steps below:

[0116] (1) 5 mL of phenylacetaldehyde was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0117] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 191.03 mM.

[0118] Example 21

[0119] This embodiment uses oxygen as the oxygen source, terephthalic acid as the hydrogen source, and a xenon lamp as the ultraviolet light source. Figure 1 The reaction apparatus shown follows the steps below:

[0120] (1) 5 mL of terephthalic acid was added to reactor 3, and compressed air was introduced into the reactor at a flow rate of 10 mL / min to form a reaction system. The xenon lamp was 300 W with a light power density of 500 mW / cm². 2 Under the irradiation and stirring of the xenon lamp, the reaction was carried out at 20°C for 4 hours. During the entire reaction process, compressed air was kept in the air supply and the air outlet 5 set on the side wall of the reactor 3 was kept open. After the reaction was completed, an organic liquid containing H2O2 was obtained.

[0121] (2) Using distilled water as the extractant, the volume ratio of the extractant to the organic liquid containing H2O2 obtained in step (1) is 1:1. The organic liquid containing H2O2 obtained in step (1) is extracted at room temperature. After phase separation, an aqueous solution of H2O2 and an organic phase are obtained. The concentration of the obtained aqueous solution of H2O2 is tested, and the concentration of H2O2 is 71.42 mM.

Claims

1. A photochemical synthesis method for producing H202 using a benzyl compound as a hydrogen source, characterized by The process steps are as follows: (1) The benzyl compound is loaded into the reactor and oxygen or air is introduced to form a reaction system. The reaction system is irradiated with a light source containing ultraviolet light. The reaction temperature is controlled at 20~60℃ and the reaction time is at least 10min. After the reaction is completed, an organic liquid containing H2O2 is obtained. The benzyl compound is benzyl methyl ether, dibenzyl ether, isochloromethane, benzylamine, phenethylamine, N,N-dimethylbenzylamine, toluene, ethylbenzene, isopropylbenzene, styrene, styrene, benzaldehyde, phenylacetaldehyde, benzyl acetone or indene. (2) Using water as the extractant, the organic liquid containing H2O2 obtained in step (1) is extracted at the reaction temperature or room temperature, and an aqueous solution of H2O2 is obtained by phase separation.

2. The photochemical synthesis method for producing H2O2 using benzyl compounds as a hydrogen source according to claim 1, characterized in that... The light source containing ultraviolet light is either artificial or natural light.

3. The photochemical synthesis method for producing H2O2 using a benzyl compound as a hydrogen source according to claim 1 or 2, characterized in that... The extractant water is deionized water, distilled water, ultrapure water, or electronic grade water.

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