A contact electrocatalytic method for preparing hydrogen peroxide based on Cu3(HHTP)2 metal-organic framework

Abstract

The application discloses a method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal organic framework, and belongs to the field of contact electrocatalysis materials. The method comprises the following steps: dispersing Cu3(HHTP)2 catalyst in ultrapure water, ultrasonic reaction under the conditions of avoiding light and 15-35 DEG C, taking a quantitative mixed solution from the reaction system every 10 min, centrifuging the mixed solution in a centrifugal tube, taking supernatant, mixing with KI solution and H 32 Mo7N6O 28 solution, avoiding light reaction, measuring absorbance at 350 nm and calculating hydrogen peroxide yield. The application drives water oxidation reaction and oxygen reduction reaction to be cooperatively performed by using Cu3(HHTP)2 catalyst through controlling contact electrocatalysis reaction conditions, realizes preparation of hydrogen peroxide in water environment at normal temperature and pressure, and the yield can reach 25.4 mmol.L ‑1 .g cat ‑1 .h ‑1 The reaction condition is mild, the operation is simple, and the method is green and environment-friendly.

Description

Technical Field

[0001] This invention belongs to the field of contact electrocatalytic materials, and in particular relates to a contact electrocatalytic method for preparing hydrogen peroxide based on Cu3(HHTP)2 metal-organic framework. Background Technology

[0002] Hydrogen peroxide (H2O2) is an important inorganic chemical raw material and fine chemical that combines practicality and environmental friendliness. Its reaction end products are only water and oxygen, with no secondary pollution, thus it is widely used in many fields such as chemical synthesis, pharmaceutical research and development, textile processing, wastewater treatment, and wet spinning of fibers. Currently, the industrial production of H2O2 still mainly relies on the technically mature anthraquinone oxidation method. However, this process not only has high production costs, but the organic waste it generates also poses a serious threat to the ecological environment. Therefore, developing a new technology that can produce H2O2 under mild conditions in a green, safe, and low-cost manner is of great significance.

[0003] Contact electrocatalysis, as a novel catalytic technology with great development potential, has been studied and applied in fields such as organic matter degradation and metal extraction. It has shown unique advantages in H2O2 preparation, providing a new technical route for the green and efficient synthesis of H2O2 under ambient temperature and pressure. However, in current practical applications, most catalysts are mainly fluoropolymers. Although these polymers possess inherent chemical inertness and stability, they also have inherent defects such as limited reaction pathways, rigid framework structures, and small interfacial areas, which limit their catalytic versatility.

[0004] Metal-organic frameworks (MOFs) possess ultra-large specific surface areas, flexible and diverse structural features, and precisely tunable electron-trapping capabilities, making them ideal candidate materials for promoting the efficient preparation of H2O2 through contact electrocatalysis. Currently, the π-d conjugated structure formed by the strong oxidizing aromatic ligand HHTP and transition metal ions such as Co, Ni, Cu, and Zn through coordination endows it with unique electronic properties, exhibiting extremely high Faradaic efficiency and selectivity for the two-electron oxygen reduction reaction (2e⁻ ORR). Simultaneously, its relatively moderate adsorption and desorption energies are also conducive to the efficient synthesis of hydrogen peroxide. These characteristics are extremely advantageous for the efficient preparation of H2O2. However, there are currently no reports on contact electrocatalysis methods for the preparation of hydrogen peroxide based on the Cu3(HHTP)2 metal-organic framework. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a contact electrocatalytic method for preparing hydrogen peroxide based on Cu3(HHTP)2 metal-organic framework. The process is simple, green and environmentally friendly, providing a new approach for the efficient preparation of hydrogen peroxide, and also broadening the application of metal-organic framework materials in the field of contact electrocatalysis.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A contact electrocatalytic method for preparing hydrogen peroxide based on a Cu3(HHTP)2 metal-organic framework includes the following steps:

[0008] (1) Disperse Cu3(HHTP)2 catalyst in ultrapure water and carry out ultrasonic reaction under light protection and 15-35 °C. Take a quantitative amount of the mixture from the reaction system every 10 min and place it in a centrifuge tube. Centrifuge and take the supernatant.

[0009] (2) The supernatant is mixed with KI solution and H2O solution. 32 Mo7N6O 28 The solutions were mixed in proportion and reacted in the dark. The absorbance was measured at 350 nm and the hydrogen peroxide yield was calculated.

[0010] Preferably, in step (1), the mass-to-volume ratio of the Cu3(HHTP)2 catalyst to ultrapure water is 0.5-3:2 (mg / mL).

[0011] Preferably, in step (1), the conditions for the ultrasonic reaction include an ultrasonic power of 240-1200W, an ultrasonic frequency of 40-120kHz, and an ultrasonic time of 30-60 min.

[0012] More preferably, in step (1), the mass-to-volume ratio of the Cu3(HHTP)2 catalyst to the ultrapure water is 1:2 (mg / mL), and the conditions for the ultrasonic reaction include an ultrasonic power of 240W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 60 min.

[0013] Preferably, in step (1), the centrifugation conditions include centrifugation at a centrifugal force of 12000 RCF for 10 min.

[0014] Preferably, in step (2), the concentration of the KI solution is 0.1 mol / L, and the H+ concentration is... 32 Mo7N6O 28 The concentration of the solution is 0.01 mol / L, and the supernatant, KI solution, and H+... 32 Mo7N6O 28 The volume ratio of the solutions is 10:40:1.

[0015] Preferably, in step (2), the reaction time in the dark is 10 min.

[0016] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0017] (1) This invention utilizes Cu3(HHTP)2 metal-organic framework as a catalyst, controlling the contact electrocatalytic reaction conditions (temperature, catalyst dosage, experimental atmosphere, and ultrasonic conditions), and leverages its unique π-d conjugated structure and solid-liquid contact electrochemical effect to drive the synergistic water oxidation reaction (WOR) and oxygen reduction reaction (ORR), thereby achieving the preparation of hydrogen peroxide (H2O2) in an aqueous environment under ambient temperature and pressure. Under optimal reaction conditions, the hydrogen peroxide yield can reach 25.4 mmol·L⁻¹. -1 .g cat - 1 .h -1 Its catalytic performance is superior to some piezoelectric catalytic materials, and its catalytic stability is excellent. Even after multiple ultrasonic cycles, it still maintains high catalytic activity and good stability.

[0018] (2) In the contact electrocatalytic preparation of hydrogen peroxide based on Cu3(HHTP)2 metal-organic framework of the present invention, the reaction raw materials are only water and oxygen in the air. The reaction conditions are mild, the operation is simple, green and environmentally friendly, and there is no secondary pollution. It provides a new way for the efficient preparation of hydrogen peroxide and also broadens the application scope of metal-organic framework materials in the field of contact electrocatalysis. Attached Figure Description

[0019] Figure 1 The diagram shows the reaction mechanism of the Cu3(HHTP)2 catalyst generating H2O2 via contact electrocatalysis in the examples.

[0020] Figure 2 The absorbance of 10 mg Cu3(HHTP)2 catalyst at 350 nm wavelength after sonication for 60 min in the example is shown.

[0021] Figure 3 The yield of hydrogen peroxide produced by Cu3(HHTP)2 catalysis after different numbers of cyclic ultrasonic experiments is shown in the example. Detailed Implementation

[0022] To more fully understand and demonstrate the technical solutions, objectives, and advantages of the present invention, the technical effects produced by the present invention will be further described in detail and completely below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. It should be noted that other embodiments obtained by those skilled in the art without departing from the concept of the present invention are all within the protection scope of the present invention.

[0023] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0024] The following examples present a contact electrocatalytic method for preparing hydrogen peroxide based on the Cu3(HHTP)2 metal-organic framework. The reaction mechanism of the Cu3(HHTP)2 catalyst generating H2O2 through contact electrocatalysis is as follows: Figure 1 As shown, Cu3(HHTP)2 has a relatively negative triboelectric polarity and a unique π-d conjugated structure. Under ultrasonic action, the solid-liquid contact electrostatic effect drives WOR and ORR to proceed synergistically, achieving efficient preparation of hydrogen peroxide.

[0025] The Cu3(HHTP)2 catalyst used in the following examples can be prepared using methods known in the prior art. Specific exemplary preparation steps are as follows:

[0026] Hexahydroxytriphenyl was weighed and dissolved in a mixed solution of deionized water and DMF at a volume ratio of 1:1. After stirring evenly, copper acetate powder was added. The mixed solution was then sonicated to obtain a dark blue solution. The mixed solution was placed in an 85°C oven for 24 h and allowed to cool naturally to room temperature. The product was washed repeatedly with deionized water and acetone, centrifuged, and collected. The product was then dried in a 70°C vacuum drying oven for 12 h to obtain black Cu3(HHTP)2.

[0027] Example 1

[0028] 30 mg of Cu3(HHTP)2 catalyst was dispersed in 20 mL of ultrapure water and sonicated at 240 W (ultrasound machine power adjusted to 100%) and 40 kHz, maintained at 20-25℃ and protected from light throughout the process. Starting from the start of sonication, samples were taken every 10 min until the sonication time reached 60 min. Each time, 2 mL of the mixed solution was centrifuged at 12000 RCF for 10 min. After centrifugation, 500 μL of the supernatant was taken and successively reacted with 50 μL of 0.01 mol / L H2O. 32 Mo7N6O 28 The solution was mixed with 2 mL of 0.1 mol / L KI solution and reacted in the dark for 10 min. The absorbance of the mixture at a wavelength of 350 nm was measured by UV-Vis spectrophotometer, and the H2O2 yield after 60 min of sonication was calculated.

[0029] Example 2

[0030] Weigh 25 mg of Cu3(HHTP)2 catalyst and disperse it in 20 mL of ultrapure water. Sonicate the solution at 240 W (ultrasonic machine power set to 100%) and 40 kHz, maintaining a temperature of 20-25℃ and avoiding light throughout the process. Starting from the start of sonication, sample every 10 min until the sonication time reaches 60 min. Each time, take 2 mL of the mixed solution using a dropper and centrifuge at 12000 RCF for 10 min. After centrifugation, take 500 μL of the supernatant and sequentially react it with 50 μL of 0.01 mol / L H2O. 32 Mo7N6O 28 The solution was mixed with 2 mL of 0.1 mol / L KI solution and reacted in the dark for 10 min. The absorbance of the mixture at a wavelength of 350 nm was measured by UV-Vis spectrophotometer, and the H2O2 yield after 60 min of sonication was calculated.

[0031] Example 3

[0032] Weigh 25 mg of Cu3(HHTP)2 catalyst and disperse it in 20 mL of ultrapure water. Sonicate the solution at 480 W (ultrasound machine power set to 100%) and 80 kHz, maintaining a temperature of 20-25℃ and avoiding light throughout the process. Starting from the start of sonication, sample every 10 min until the sonication time reaches 60 min. For each sample, take 2 mL of the mixture using a dropper and centrifuge at 12000 RCF for 10 min. After centrifugation, take 500 μL of the supernatant and sequentially react it with 50 μL of 0.01 mol / L H2O. 32 Mo7N6O 28 The solution was mixed with 2 mL of 0.1 mol / L KI solution and reacted in the dark for 10 min. The absorbance of the mixture at a wavelength of 350 nm was measured by UV-Vis spectrophotometer, and the H2O2 yield after 60 min of sonication was calculated.

[0033] Example 4

[0034] Weigh 15 mg of Cu3(HHTP)2 catalyst and disperse it in 20 mL of ultrapure water. Sonicate the solution at 240 W (ultrasound machine power set to 100%) and 40 kHz, maintaining a temperature of 20-25℃ and avoiding light throughout the process. Starting from the start of sonication, sample every 10 min until the sonication time reaches 60 min. Each time, take 2 mL of the mixed solution using a dropper and centrifuge at 12000 RCF for 10 min. After centrifugation, take 500 μL of the supernatant and sequentially react it with 50 μL of 0.01 mol / L H2O. 32Mo7N6O 28 The solution was mixed with 2 mL of 0.1 mol / L KI solution and reacted in the dark for 10 min. The absorbance of the mixture at a wavelength of 350 nm was measured by UV-Vis spectrophotometer, and the H2O2 yield after 60 min of sonication was calculated.

[0035] Example 5

[0036] Weigh 10 mg of Cu3(HHTP)2 catalyst and disperse it in 20 mL of ultrapure water. Sonicate the solution at 240 W (ultrasound machine power set to 100%) and 40 kHz, maintaining a temperature of 20-25 °C and avoiding light throughout the process. Starting from the start of sonication, sample every 10 min until the sonication time reaches 60 min. Each time, take 2 mL of the mixed solution using a dropper and centrifuge at 12000 RCF for 10 min. After centrifugation, take 500 μL of the supernatant and sequentially react it with 50 μL of 0.01 mol / L H2O. 32 Mo7N6O 28 The solution was mixed with 2 mL of 0.1 mol / L KI solution and reacted in the dark for 10 min. The absorbance of the mixture at a wavelength of 350 nm was measured by UV-Vis spectrophotometer, and the H2O2 yield after 60 min of sonication was calculated.

[0037] Testing showed that the reaction conditions in Example 5 were the optimal conditions, and the absorbance after 60 minutes of sonication was as follows: Figure 2 As shown, the H2O2 yield after 60 min of sonication was 25.4 mmol·L⁻¹. -1 .g cat -1 .h -1 The yield after five cycles of catalysis is as follows: Figure 3 As shown, the Cu3(HHTP)2 catalyst exhibits superior catalytic performance compared to some piezoelectric catalytic materials, demonstrates excellent catalytic stability, and maintains high catalytic activity even after multiple ultrasonic cycles.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A contact electrocatalytic method for preparing hydrogen peroxide based on a Cu3(HHTP)2 metal-organic framework, characterized in that, Includes the following steps: (1) Disperse Cu3(HHTP)2 catalyst in ultrapure water and carry out ultrasonic reaction under light protection and 15-35 ℃. Take a quantitative amount of the mixture from the reaction system every 10 min and place it in a centrifuge tube. Centrifuge and take the supernatant. (2) The supernatant is mixed with KI solution and H2O solution. 32 Mo7N6O 28 The solutions were mixed in proportion and reacted in the dark. The absorbance was measured at 350 nm and the hydrogen peroxide yield was calculated.

2. The method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal-organic framework according to claim 1, characterized in that, In step (1), the mass-to-volume ratio of the Cu3(HHTP)2 catalyst to ultrapure water is 0.5-3:2 (mg / mL).

3. The method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal-organic framework according to claim 1, characterized in that, In step (1), the conditions for the ultrasonic response include an ultrasonic power of 240-1200W, an ultrasonic frequency of 40-120kHz, and an ultrasonic time of 30-60 min.

4. The method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal-organic framework according to claim 1, characterized in that, In step (1), the mass-to-volume ratio of the Cu3(HHTP)2 catalyst to ultrapure water is 1:2 (mg / mL), and the conditions for the ultrasonic reaction include an ultrasonic power of 240W, an ultrasonic frequency of 40kHz, and an ultrasonic time of 60 min.

5. The method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal-organic framework according to claim 1, characterized in that, In step (1), the centrifugation conditions include centrifugation at a centrifugal force of 12000 RCF for 10 min.

6. The method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal-organic framework according to claim 1, characterized in that, In step (2), the concentration of the KI solution is 0.1 mol / L, and the H+ concentration is... 32 Mo7N6O 28 The concentration of the solution is 0.01 mol / L, and the supernatant, KI solution, and H+... 32 Mo7N6O 28 The volume ratio of the solutions is 10:40:

1.

7. The method for preparing hydrogen peroxide by contact electrocatalysis based on Cu3(HHTP)2 metal-organic framework according to claim 1, characterized in that, In step (2), the reaction time in the dark is 10 min.

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