A boron carbide coated platinum nickel nanoparticle electrocatalyst and its preparation method and application

Abstract

The invention discloses a boron carbide coated platinum nickel nanoparticle electrocatalyst and a preparation method and application thereof. The preparation method of the electrocatalyst comprises dissolving a boron source and a nickel-containing compound in an organic solvent, stirring to obtain a boron nickel emulsion; adding a carbon source, stirring again, heating to volatilize the organic solvent, and curing in a normal pressure oven to obtain a solidified product; grinding the obtained solidified product, taking a powdered product, adding a platinum source to mix evenly, roasting, and grinding after cooling to obtain the boron carbide coated platinum nickel nanoparticle electrocatalyst. The catalyst prepared by the invention is a rod-shaped coated material, the active substance is protected, has good stability, is used for electrolyzing water to prepare ozone, has high Faraday efficiency, and has low preparation cost. The electrolysis process is green and pollution-free, and is simple to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of electrocatalyst preparation, and specifically relates to a boron carbide-coated platinum-nickel nanoparticle electrocatalyst and a preparation method and application thereof. Background Art

[0002] Ozone has strong oxidizing and bactericidal abilities and is widely used in drinking water treatment, sewage treatment, chemical oxidation, medical and health care, aquaculture and other fields. It is a good "green and environmentally friendly disinfectant". At present, the main ways to produce ozone in industry are: high-voltage discharge method, ultraviolet method, electrochemical method, etc. In the process of ozone generation by high-voltage discharge method, the equipment is large, the investment cost is high, it is inconvenient to move, and the concentration of ozone produced is not high. Due to high-voltage ionization, the ozone mixture also contains a certain amount of carcinogens such as nitrogen oxides (NOx). The ultraviolet radiation method has low output, complex structure, and difficult to control wavelength. Compared with the first two methods, the preparation of ozone by electrochemical method has the advantages of small equipment size, simple operation, non-toxicity, and harmlessness, and the ozone concentration produced is high and there is no secondary pollution.

[0003] The key to the study of electrochemical ozone production lies in the preparation of suitable anode catalysts with high oxidation overpotential. Many electrode materials have been shown to inhibit the generation of oxygen and promote the generation of ozone. For example, the common precious metal platinum has been reported to have excellent performance in ozone production (Atmos, Chem, Phys, 2005, 8 (6), 13-16; J. Engery. Chem., 2015, 24 (2), 178-184). However, platinum is easily oxidized and lost, and is expensive, which is not conducive to large-scale production and application. Therefore, it is of great research significance to reduce the loading amount of precious metal platinum and improve the stability of platinum metal while ensuring the performance of ozone production.

[0004] Boron carbide has been gradually applied to the field of catalysis in recent years due to its low density, high strength, high temperature stability and good chemical stability (Small., 2021, 39, 2102814). Relevant literature has proved that the synergistic catalysis between boron and platinum is conducive to the production of ozone (ACS Catal., 2021, 11, 5438-5451). At present, there are no reports on the preparation of boron carbide coated with platinum nickel nanoparticles and their use in the electrolysis of water to produce ozone. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a boron carbide-coated platinum-nickel nanoparticle electrocatalyst and a preparation method and application thereof.

[0006] In order to achieve the above objectives, the following technical solutions are proposed:

[0007] A boron carbide coated platinum nickel nanoparticle electrocatalyst comprises boron carbide coated platinum nickel nanoparticles attached to the surface of a carrier, the loading amount of the platinum nanoparticles is 1-10% of the mass of the catalyst, and the carrier is a carbon source.

[0008] A method for preparing a boron carbide-coated platinum-nickel nanoparticle electrocatalyst comprises the following steps:

[0009] 1) dissolving a boron source and a nickel-containing compound in an organic solvent, stirring for 1-10 hours to obtain a boron-nickel emulsion; then adding a carbon source, stirring for 1-5 hours by ultrasonication, volatilizing the organic solvent at 50-90° C., and curing in a normal pressure oven at 100-150° C. for 2-6 hours to obtain a cured product;

[0010] 2) grinding the solidified product obtained in step 1), taking the powdered product, adding a platinum source and mixing evenly, calcining, cooling and grinding to obtain the boron carbide-coated platinum-nickel nanoparticle electrocatalyst;

[0011] The calcination step is: placing the uniformly mixed materials in a tubular furnace under ventilation conditions, heating the tubular furnace to 800-1200° C. at a heating rate of 2-10° C. / min, calcining for 2-6 hours, and cooling the obtained product to room temperature.

[0012] Furthermore, in step 1), the boron source is boric acid, sodium borohydride, borax or boron powder; the nickel-containing compound is nickel nitrate, nickel chloride, nickel oxide, nickel sulfate or nickel hydroxide; the carbon source is carbon nanofibers, carbon nanotubes, graphene, carbon powder or fullerene; and the organic solvent is methanol, ethanol, isopropanol, dichloromethane or acetonitrile.

[0013] Furthermore, in step 1), the mass ratio of the boron source, the nickel-containing compound and the carbon source is 1-4:1-4:2-8.

[0014] Furthermore, in step 2), the gas is nitrogen, argon, helium or air.

[0015] The invention discloses an application of a boron carbide-coated platinum-nickel nanoparticle electrocatalyst in electrochemical production of ozone, comprising the following steps: using a constant current meter to control the voltage and current of a device, carrying out an electrochemical reaction in an integrated electrolytic cell, using a saturated potassium sulfate or saturated sodium sulfate aqueous solution as an electrolyte, coating the boron carbide-coated platinum-nickel nanoparticle catalyst uniformly on a carbon cloth as a working electrode, using a platinum sheet as a counter electrode, controlling the voltage of the reaction current cell, carrying out an electrocatalytic ozone production reaction, and obtaining an ozone product.

[0016] Furthermore, the reaction current is controlled at 50-200 mA; the cell voltage is controlled at 2-10 V.

[0017] The beneficial effects of the present invention are:

[0018] 1) The boron carbide-coated platinum-nickel nanoparticle electrocatalyst of the present invention is prepared in one step by a pyrolysis method using a boron source, a carbon source, a nickel-containing compound and a platinum source as raw materials, and the preparation steps are simple;

[0019] 2) In the preparation process of the boron carbide coated platinum nickel nanoparticle electrocatalyst of the present invention, a boron source, a carbon source and a nickel-containing compound are mixed in an organic solvent, and after evaporation to remove the volatile components, the obtained solid mixture is calcined at high temperature, and the platinum source and the boron source in the solid mixture are decomposed in sequence, and the active component platinum nanoparticles are coated in the boron carbide material, and the boron and platinum work synergistically to form abundant active sites, which are conducive to the generation of ozone;

[0020] 3) The boron carbide-coated platinum-nickel nanoparticle electrocatalyst of the present invention can protect the precious metal platinum from environmental influences, avoid aggregation and deactivation, and has excellent stability and reaction activity;

[0021] 4) The boron carbide-coated platinum-nickel nanoparticle electrocatalyst of the present invention significantly reduces the amount of precious metal platinum used compared to the commonly used precious metal catalysts in the prior art, which is beneficial to reducing costs. In addition, the boron carbide-coated platinum-nickel nanoparticle material catalyst of the present invention is used for electrocatalytic preparation of ozone, and the electrocatalytic reaction process conditions are mild, green and pollution-free, and the ozone production is relatively high;

[0022] 5) In the boron carbide-coated platinum-nickel nanoparticle electrocatalyst of the present invention, boron carbide protects the platinum nanoparticles, making the active components have good stability, providing basic application research for this type of material in the field of electrocatalysis, and having practical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1a This is a SEM image of the catalyst prepared in Example 1 at 1 μm;

[0024] Figure 1b This is the SEM image of the catalyst prepared in Example 1 at 500 nm;

[0025] Figure 2a This is the TEM image of the catalyst prepared in Example 1 at 50 nm;

[0026] Figure 2b This is a TEM image of the catalyst prepared in Example 1 at 10 nm;

[0027] Figure 2c This is a TEM image of the catalyst prepared in Example 1 at 5 nm;

[0028] Figure 3 This is a comparison chart of real-time detection of ozone concentration when the catalyst prepared in Example 1 and the commercial PbO2 catalyst in Example 7 are used for electrocatalytic production of ozone. DETAILED DESCRIPTION

[0029] The present invention is described in detail below through specific examples, but the use and purpose of these exemplary implementation modes are only used to illustrate the present invention, and do not constitute any form of limitation on the actual protection scope of the present invention, nor limit the protection scope of the present invention to them.

[0030] Example 1: 3% Pt-Ni@B 13 Synthesis of C2 / CNF Catalyst and Its Electrocatalytic Ozone Production

[0031] 1) Dissolve 200 mg of boron powder and 200 mg of nickel chloride in 60 mL of acetonitrile and stir for 6 h to obtain a B-Ni emulsion; then add 400 mg of carbon nanofibers and stir for 5 h under ultrasonic conditions. After the solvent is evaporated to dryness at 70° C., the emulsion is placed in a normal pressure oven at 150° C. and cured for 2 h to obtain a cured product;

[0032] 2) Grinding the solidified product obtained in step 1), taking 100 mg of the powdered product, adding 6 mg of platinum source and mixing evenly, placing the material in a tubular furnace, introducing Ar gas, heating to 1100° C. at a heating rate of 5° C. / min, calcining for 6 hours, cooling and grinding to obtain the boron carbide-coated platinum-nickel nanoparticle electrocatalyst.

[0033] The 3% Pt-Ni@B obtained in this example 13 The platinum content of C2 / CNF was measured, and the results are shown in Table 1. It can be seen that the platinum content is about 3%. 13 C2 / CNF was observed by scanning electron microscopy. Figure 1a , Figure 1b , Figure 2a and Figure 2b .from Figure 1a and Figure 1b It can be seen that the 3% Pt-Ni@B prepared in Example 1 13 C2 is attached to the carbon nanofibers. Figure 2a It can be seen that the 3% Pt-Ni@B prepared in Example 1 13 The C2 catalyst is evenly dispersed on the carrier carbon nanofiber (the nanoparticles are platinum particles). Figure 2b and Figure 2c It can be seen that the 3% Pt-Ni@B prepared in Example 1 13 C2 / CNF catalyst is a coated structure.

[0034] The 3% Pt-Ni@B prepared in Example 1 13 The catalytic performance of C2 / CNF catalyst was tested, and the specific method is as follows:

[0035] Weigh 8 mg of the prepared 3% Pt-Ni@B 13 The C2 / CNF catalyst was placed in a 3 mL centrifuge tube, and 900 μL of ethanol and 100 μL of Nafion solution (Nafion solution mass concentration of 5%) were added at the same time, mixed evenly, and ultrasonicated in an ultrasonic tank for 30 min to completely disperse the catalyst in the mixture of ethanol and Nafion solution to obtain a uniform catalyst slurry. The treated carbon cloth was cut into a size of 2 cm × 2 cm, and the dispersed catalyst slurry was evenly dripped on the carbon cloth. After drying, it was used as a working electrode (i.e., 3% Pt-Ni@B 13 C2 / CNF catalyst coated on carbon cloth was used as the working electrode).

[0036] The voltage and current of the device are controlled by a constant current meter, and the electrochemical reaction is carried out in an integrated electrolytic cell. 13 C2 / CNF catalyst is coated on carbon cloth as working electrode; platinum sheet is used as counter electrode, and the electrolyte is saturated potassium sulfate aqueous solution. One end of the electrolytic cell is connected to an ozone detector to detect the generation of ozone in real time. During the electrocatalytic ozone production reaction, the current is controlled at 200mA and the cell voltage is controlled at 2-10V.

[0037] As the reaction proceeds, the real-time detection diagram of the ozone concentration produced by the electrocatalytic reaction is as follows: Figure 3 As shown, from Figure 3 It can be seen from the above that as the reaction proceeds, the ozone concentration gradually increases. When the reaction time reaches 2 hours, the ozone concentration can reach 6007 ppb, and the Faraday efficiency is 17.2%.

[0038] In order to verify the 3% Pt-Ni@B prepared in Example 1 13 C2 / CNF catalytic stability, after the above reaction once (total reaction time 2h), the working electrode was placed for one day, and then repeated electrocatalytic ozone preparation reaction experiments were carried out. In the second experiment of the working electrode reuse reaction, the ozone concentration after the reaction reached 2h could reach 5902ppb, and in the third experiment of the anode chamber working electrode reuse reaction, the ozone concentration after the reaction reached 2h could reach 5719ppb. During the repeated use of the working electrode, the electrocatalytic effect was basically not weakened, indicating that the 3% Pt@B prepared in Example 1 13 C2 / CNF has good stability.

[0039] Example 2: 1% Pt-Ni@B 13 Synthesis of C2 / CNF Catalyst and Its Electrocatalytic Ozone Production

[0040] 1) Dissolve 300 mg of borax and 300 mg of nickel nitrate in 100 mL of isopropanol and stir for 1 hour to obtain a B-Ni emulsion; then add 1200 mg of carbon nanotubes and stir for 1 hour under ultrasonic conditions. After the solvent is evaporated to dryness at 80° C., the emulsion is placed in a normal pressure oven at 150° C. and cured for 6 hours to obtain a cured product;

[0041] 2) Grinding the solidified product obtained in step 1), taking 100 mg of the powdered product, adding 2 mg of platinum source and mixing evenly, placing the material in a tubular furnace, introducing N2 gas, heating the temperature to 1200°C at a heating rate of 2°C / min, and calcining for 5 hours. After cooling, grinding is performed to obtain the boron carbide-coated platinum-nickel nanoparticle electrocatalyst.

[0042] The 1% Pt-Ni@B prepared in Example 2 13 The catalytic performance of C2 / CNF catalyst was tested, and the specific method is as follows:

[0043] Weigh 8 mg of the prepared 1% Pt-Ni@B 13 The C2 / CNF catalyst was placed in a 3mL centrifuge tube, and 900μL of ethanol and 100μL of Nafion solution (Nafion solution mass concentration of 5%) were added at the same time, mixed evenly, and ultrasonicated in an ultrasonic tank for 30 minutes to completely disperse the catalyst in the mixture of ethanol and Nafion solution to obtain a uniform catalyst slurry. The treated carbon cloth was cut into a size of 2cm×2cm, and the dispersed catalyst slurry was evenly dripped on the carbon cloth. After drying, it was used as a working electrode (i.e., 1% Pt-Ni@B 13 C2 / CNF catalyst coated on carbon cloth was used as the working electrode).

[0044] The 1% Pt-Ni@B obtained in this example 13 The platinum content of C2 / CNF was measured, and the results are shown in Table 1. It can be seen that the platinum content is about 1%.

[0045] The voltage and current of the device are controlled by a constant current meter, and the electrochemical reaction is carried out in an integrated electrolytic cell. 13 C2 / CNF catalyst is coated on carbon cloth as working electrode; platinum sheet is used as counter electrode, electrolyte is saturated potassium sulfate aqueous solution, one end of the electrolytic cell is connected to ozone detector to detect ozone generation in real time. During the electrocatalytic ozone production reaction, the current is controlled at 200mA, the cell voltage is controlled between 2-10V, and the reaction time is 2 hours. As the reaction proceeds, the ozone concentration gradually increases. When the reaction time reaches 2 hours, the ozone concentration can reach 5211ppb, and the Faraday efficiency is 16%.

[0046] Example 3: 5% Pt-Ni@B13 Synthesis of C2 / CNF Catalyst and Its Electrocatalytic Ozone Production

[0047] 1) Dissolve 100 mg of boric acid and 200 mg of nickel oxide in 10 mL of ethanol and stir for 6 h to obtain a B-Ni emulsion; then add 300 mg of carbon powder and stir for 3 h under ultrasonic conditions. After the solvent is evaporated to dryness at 80° C., the emulsion is placed in a normal pressure oven at 150° C. and cured for 4 h to obtain a cured product;

[0048] 2) Grinding the solidified product obtained in step 1), taking 100 mg of the powdered product, adding 10 mg of a platinum source and mixing evenly, placing the material in a tubular furnace, introducing air, heating the material to 800° C. at a heating rate of 10° C. / min, and calcining the material for 6 hours. After cooling, the material is ground to obtain the boron carbide-coated platinum-nickel nanoparticle electrocatalyst.

[0049] The 5% Pt@B obtained in this example 13 The platinum content of C2 / CNF was measured, and the results are shown in Table 1. It can be seen that the platinum content is about 5%.

[0050] The 5% Pt-Ni@B prepared in Example 3 13 The catalytic performance of C2 / CNF catalyst was tested as follows: 8 mg of the prepared 5% Pt-Ni@B 13 The C2 / CNF catalyst was placed in a 3mL centrifuge tube, and 900μL of ethanol and 100μL of Nafion solution (Nafion solution mass concentration of 5%) were added at the same time, mixed evenly, and ultrasonicated in an ultrasonic tank for 30 minutes to completely disperse the catalyst in the mixture of ethanol and Nafion solution to obtain a uniform catalyst slurry. The treated carbon cloth was cut into a size of 2cm×2cm, and the dispersed catalyst slurry was evenly dripped on the carbon cloth. After drying, it was used as a working electrode (i.e., 5% Pt@B 13 C2 / CNF catalyst coated on carbon cloth was used as the working electrode).

[0051] The voltage and current of the device are controlled by a constant current meter, and the electrochemical reaction is carried out in an integrated electrolytic cell. 13 C2 / CNF catalyst is coated on carbon cloth as working electrode; platinum sheet is used as counter electrode, and the electrolyte is saturated potassium sulfate aqueous solution. An ozone detector is connected to one end of the electrolytic cell to detect the generation of ozone in real time. During the electrocatalytic ozone production reaction, the current is controlled at 200mA, the cell voltage is controlled between 2-10V, and the reaction time is 2 hours. As the reaction proceeds, the ozone concentration gradually increases. When the reaction time reaches 2 hours, the ozone concentration can reach 4991ppb, and the Faraday efficiency is 15.6%.

[0052] Example 4: 7% Pt-Ni@B 13 Synthesis of C2 / CNF Catalyst and Its Electrocatalytic Ozone Production

[0053] 1) Dissolve 200 mg of sodium borohydride and 100 mg of nickel hydroxide in 60 mL of dichloromethane and stir for 2 h to obtain a B-Ni emulsion; then add 200 mg of graphene and stir for 5 h under ultrasonic conditions. After the solvent is evaporated to dryness at 50° C., the mixture is placed in a normal pressure oven at 100° C. and cured for 5 h to obtain a cured product;

[0054] 2) Grinding the solidified product obtained in step 1), taking 100 mg of the powdered product, adding 14 mg of a platinum source and mixing evenly, placing the material in a tubular furnace, introducing helium gas, heating the temperature to 800° C. at a heating rate of 5° C. / min, and calcining for 2 h. After cooling, grinding is performed to obtain the boron carbide-coated platinum-nickel nanoparticle electrocatalyst.

[0055] The 7% Pt-Ni@B prepared in Example 4 13 The catalytic performance of C2 / CNF catalyst was tested, and the specific method is as follows:

[0056] Weigh 8 mg of the prepared 7% Pt-Ni@B 13 The C2 / CNF catalyst was placed in a 3mL centrifuge tube, and 900μL of ethanol and 100μL of Nafion solution (Nafion solution mass concentration of 5%) were added at the same time, mixed evenly, and ultrasonicated in an ultrasonic tank for 30 minutes to completely disperse the catalyst in the mixture of ethanol and Nafion solution to obtain a uniform catalyst slurry. The treated carbon cloth was cut to a size of 2cm×2cm, and the dispersed catalyst slurry was evenly dripped on the carbon cloth. After drying, it was used as a working electrode (i.e., 7% Pt-Ni@B 13 C2 / CNF catalyst coated on carbon cloth was used as the working electrode).

[0057] The 7% Pt-Ni@B obtained in this example 13 The platinum content of C2 / CNF was measured, and the results are shown in Table 1. It can be seen that the platinum content is about 7%.

[0058] The voltage and current of the device are controlled by a constant current meter, and the electrochemical reaction is carried out in an integrated electrolytic cell. 13C2 / CNF catalyst is coated on carbon cloth as working electrode; platinum sheet is used as counter electrode, and the electrolyte is saturated potassium sulfate aqueous solution. An ozone detector is connected to one end of the electrolytic cell to detect the generation of ozone in real time. During the electrocatalytic ozone production reaction, the current is controlled at 200mA, the cell voltage is controlled between 2-10V, and the reaction time is 2 hours. As the reaction proceeds, the ozone concentration gradually increases. When the reaction time reaches 2 hours, the ozone concentration can reach 3518ppb, and the Faraday efficiency is 12.1%.

[0059] Example 5: B 13 Synthesis of C2 / CNF Catalyst and Its Electrocatalytic Ozone Production

[0060] 1) Dissolve 200 mg of boric acid and 200 mg of nickel sulfate in 60 mL of methanol and stir for 10 h to obtain a B-Ni emulsion; then add 400 mg of fullerene and stir for 4 h under ultrasonic conditions. After the solvent is evaporated to dryness at 90° C. and the organic solvent is completely evaporated, place the mixture in a normal pressure oven at 150° C. and cure for 2 h to obtain a cured product;

[0061] 2) Grinding the solidified product obtained in step 1), taking 100 mg of the powdered product, placing the material in a tubular furnace, introducing Ar gas, heating to 1000° C. at a heating rate of 7° C. / min, calcining for 5 h, cooling and grinding to obtain the boron carbide-coated nickel nanoparticle electrocatalyst.

[0062] The Ni@B obtained in this example 13 The platinum content of C2 / CNF was measured, and the results are shown in Table 1. It can be seen that the platinum content is almost zero.

[0063] Table 1 Summary of the results of determination of platinum content of each catalyst

[0064]

[0065] The Ni@B prepared in Example 5 13 The catalytic performance of C2 / CNF catalyst was tested as follows: 8 mg of the prepared Ni@B 13 The C2 / CNF catalyst was placed in a 3 mL centrifuge tube, and 900 μL of ethanol and 100 μL of Nafion solution (Nafion solution mass concentration was 5%) were added at the same time, mixed evenly, and ultrasonicated in an ultrasonic tank for 30 min to completely disperse the catalyst in the mixture of ethanol and Nafion solution to obtain a uniform catalyst slurry. The treated carbon cloth was cut into a size of 2 cm × 2 cm, and the dispersed catalyst slurry was evenly dripped on the carbon cloth. After drying, it was used as a working electrode (i.e., B 13 C2 / CNF catalyst coated on carbon cloth was used as the working electrode).

[0066] The voltage and current of the device are controlled by a constant current meter, and the electrochemical reaction is carried out in an integrated electrolytic cell. 13 C2 / CNF catalyst is coated on carbon cloth as working electrode; platinum sheet is used as counter electrode, and the electrolyte is saturated potassium sulfate aqueous solution. An ozone detector is connected to one end of the electrolytic cell to detect the generation of ozone in real time. During the electrocatalytic ozone production reaction, the current is controlled at 200mA, the cell voltage is controlled between 2-10V, and the reaction time is 2 hours. As the reaction proceeds, the ozone concentration gradually increases. When the reaction time reaches 2 hours, the ozone concentration can reach 2121ppb, and the Faraday efficiency is 8.0%.

[0067] Example 6: Electrocatalytic production of ozone using commercial PbO2 catalyst

[0068] Weigh 8 mg of commercial PbO2 catalyst (purchased from Aladdin Reagent Network), mix with 900 μL ethanol and 100 μL Nafion solution (Nafion solution mass concentration is 5%), and ultrasonicate for 30 minutes to completely disperse the catalyst in the mixture of ethanol and Nafion solution to obtain a uniform catalyst slurry. Cut the carbon cloth into a size of about 2 cm × 2 cm, and evenly drip the dispersed catalyst slurry on the carbon cloth. After drying, use it as a working electrode (i.e., the material coated with PbO2 catalyst on the carbon cloth is used as the working electrode).

[0069] The voltage and current of the device are controlled by a constant current meter, and the electrochemical reaction is carried out in an integrated electrolytic cell. The PbO2 catalyst is coated on a carbon cloth as a working electrode; the platinum sheet is used as a counter electrode, and the electrolyte is a saturated potassium sulfate aqueous solution. An ozone detector is connected to one end of the electrolytic cell to detect the generation of ozone in real time. During the electrocatalytic ozone production reaction, the current is controlled at 200mA, the cell voltage is controlled between 2-10V, and the reaction time is 2 hours. As the reaction proceeds, the real-time detection diagram of the ozone concentration produced by the electrocatalytic reaction is as shown in the figure below. Figure 3 As shown, from Figure 3 It can be seen from the above that as the reaction proceeds, the ozone concentration gradually increases, and the ozone concentration can reach 2549 ppb when the reaction time reaches 2 hours.

[0070] from Figure 3 It can be seen that when applied to the electrocatalytic ozone production reaction, the 3% Pt@B 13 The catalytic reaction rate and catalytic effect of C2 / CNF catalyst are better than those of commercial PbO2 catalyst, with a Faradaic efficiency of 12.8%.

[0071] The experimental results of Examples 1-6 are shown in Table 2:

[0072] Table 2 Comparison of ozone concentration and Faraday efficiency of each catalyst

[0073]

[0074]

[0075] Note: From Table 2, it can be concluded that the boron carbide-coated platinum-nickel nanoparticle electrocatalyst in Example 1 of the present invention has the strongest ozone production capacity and the highest Faraday efficiency. This may be attributed to the fact that the encapsulated platinum atoms can transfer charges to the boron or carbon in its "armor" layer, activating it and facilitating the adsorption of oxygen; platinum and boron synergistically catalyze to form abundant active sites, which is conducive to the further conversion of the enriched intermediates into ozone, greatly improving the catalytic efficiency and having good stability.

[0076] The above description is only part of the embodiments of the present invention and is not intended to limit the present invention. All equivalent changes and modifications made according to the content of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing a boron carbide-coated platinum-nickel nanoparticle electrocatalyst, characterized in that The following steps are involved: 1) dissolving a boron source and a nickel-containing compound in an organic solvent, stirring for 1-10 hours to obtain a boron-nickel emulsion; then adding a carbon source, stirring for 1-5 hours by ultrasonication, volatilizing the organic solvent at 50-90° C., and curing in a normal pressure oven at 100-150° C. for 2-6 hours to obtain a cured product; 2) grinding the solidified product obtained in step 1), taking the powdered product, adding a platinum source and mixing evenly, calcining, cooling and grinding to obtain the boron carbide-coated platinum-nickel nanoparticle electrocatalyst; The calcination step comprises: placing the uniformly mixed materials in a tube furnace under ventilation conditions, heating the tube furnace to 800-1200° C. at a heating rate of 2-10° C. / min, calcining for 2-6 hours, and cooling the obtained product to room temperature; The catalyst is composed of boron carbide-coated platinum-nickel nanoparticles attached to the surface of a carbon source, and the loading amount of the platinum nanoparticles is 1-10% of the mass of the catalyst.

2. The method for preparing a boron carbide-coated platinum-nickel nanoparticle electrocatalyst according to claim 1, characterized in that In step 1), the boron source is boric acid, sodium borohydride, borax or boron powder; the nickel-containing compound is nickel nitrate, nickel chloride, nickel oxide, nickel sulfate or nickel hydroxide; the carbon source is carbon nanofibers, carbon nanotubes, graphene, carbon powder or fullerene; and the organic solvent is methanol, ethanol, isopropanol, dichloromethane or acetonitrile.

3. The method for preparing a boron carbide-coated platinum-nickel nanoparticle electrocatalyst according to claim 1, characterized in that In step 1), the mass ratio of the boron source, the nickel-containing compound and the carbon source is 1-4:1-4:2-8.

4. The method for preparing a boron carbide-coated platinum-nickel nanoparticle electrocatalyst according to claim 1, characterized in that In step 2), the gas is nitrogen, argon, helium or air.

5. Use of the boron carbide-coated platinum-nickel nanoparticle electrocatalyst prepared by the preparation method according to claim 1 in electrochemical production of ozone.

6. The use according to claim 5, characterized in that The following steps are involved: A constant current meter is used to control the voltage and current of the device, and an electrochemical reaction is carried out in an integrated electrolytic cell. Saturated potassium sulfate or saturated sodium sulfate aqueous solution is used as the electrolyte, and a boron carbide-coated platinum-nickel nanoparticle catalyst is evenly coated on a carbon cloth as a working electrode. A platinum sheet is used as a counter electrode. The voltage of the reaction current cell is controlled to carry out an electrocatalytic ozone production reaction to obtain an ozone product.

7. The use according to claim 6, characterized in that The reaction current is controlled at 50-200mA; the cell voltage is controlled at 2-10V.

Images