Nickel monatomic modified boron-nitrogen doped carbon catalyst as well as preparation method and application thereof
By loading nickel single atoms on the surface of the boron-nitrogen doped carbon catalyst, the adsorption energy of the oxygen intermediate is regulated, and the problems of low selectivity of hydrogen peroxide and high reaction overpotential in the prior art are solved, and high selectivity electrocatalytic synthesis of hydrogen peroxide at room temperature is achieved, and pure solution is synthesized in a solid electrolyte reaction cell.
Patent Information
- Application Number
- CN202510210554.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2025-05-30
AI Technical Summary
The prior art When electrocatalyzing a two-electron oxygen reduction reaction to synthesize hydrogen peroxide at room temperature, there are problems of low selectivity and high reaction overpotentials, and the preparation technology of carbon materials is complex and difficult to produce on a large scale.
A boron-nitrogen-doped carbon catalyst modified with nickel single atoms is used. This catalyst regulates the adsorption energy of oxygen intermediates by supporting nickel single atoms on the boron-nitrogen-doped carbon surface, reduces the reaction overpotential, and improves the selectivity of hydrogen peroxide.
It has achieved high selective electrocatalyzed two electron oxygen reduction reactions at room temperature to synthesize hydrogen peroxide, lowered the reaction overpotential, and synthesized pure hydrogen peroxide solution in a solid electrolyte reaction cell, which is of great practical significance.
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Figure CN120060891A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of energy catalysis, and particularly relates to a nickel single-atom modified boron and nitrogen co-doped carbon catalyst, a preparation method thereof, and an application thereof. Background Art
[0002] As an environmentally friendly and widely functional oxidant, hydrogen peroxide is applied in multiple fields such as first aid, pulp and textile bleaching, pollution treatment, and chemical synthesis. Hydrogen peroxide is listed as one of the important disinfectants for COVID-19, and it is expected that the market demand for hydrogen peroxide will reach 5.7 million metric tons in 2027. Currently, hydrogen peroxide is mainly synthesized through the anthraquinone process, which is based on the hydrogenation of some anthraquinone derivatives (usually 2-ethylanthraquinone) under hydrogen conditions, followed by oxidation in an oxygen-containing organic solvent. The hydrogenation process uses noble metal hydrogen peroxide-based catalysts. The anthraquinone process consumes a large amount of hydrogen, generates a large amount of organic waste liquid, and requires subsequent purification procedures to obtain a pure hydrogen peroxide solution, which is then transported to the destination. This process not only consumes energy but also causes environmental pollution. In addition, hydrogen peroxide can also be directly synthesized from hydrogen and oxygen, which can avoid the use of organic substances and the long-distance transportation of hydrogen peroxide. However, due to the extremely high explosion risk of the hydrogen / oxygen mixture, the yield of hydrogen peroxide is very low. Therefore, a safe, environmentally friendly, and low-energy-consuming method for synthesizing hydrogen peroxide is needed.
[0003] Electrocatalytic two-electron oxygen reduction reaction for synthesizing hydrogen peroxide at room temperature can solve the above problems. The raw materials used in this method are water and oxygen, combined with sustainable electrical energy, providing an efficient, safe, environmentally friendly, and energy-saving synthesis method. However, in the oxygen reduction process, thermodynamically, it is more inclined to generate water through four-electron oxygen reduction, thereby inhibiting the selectivity of hydrogen peroxide. In terms of catalyst selection, carbon materials have been widely studied due to their advantages such as easy structure regulation, large specific surface area, rich surface defects, and low price. The catalytic performance of carbon materials is mainly regulated by means of oxygen-containing functional group modification, heteroatom doping, and loading of metal single atoms. Among them, carbon materials modified with oxygen-containing functional groups have high selectivity for hydrogen peroxide, but they require a large overpotential at high current densities, which limits their industrial applications; carbon materials loaded with metal single atoms have problems such as complex preparation technology, difficulty in large-scale production, and difficulty in synthesizing carbon precursors. Summary of the Invention
[0004] Aiming at the problems existing in the process of electrocatalytic two-electron oxygen reduction reaction for synthesizing hydrogen peroxide at room temperature by traditional carbon materials, the present invention provides a nickel single-atom modified boron and nitrogen co-doped carbon catalyst, a preparation method thereof, and an application thereof, realizing high selectivity for electrocatalytic two-electron oxygen reduction reaction for synthesizing hydrogen peroxide at room temperature, while reducing the reaction overpotential, and synthesizing a pure hydrogen peroxide solution in a solid electrolyte reaction cell, which is of great significance in practical applications.
[0005] The technical solution adopted by the present invention is as follows:
[0006] A nickel single-atom modified boron and nitrogen co-doped carbon catalyst, comprising boron and nitrogen co-doped carbon in a tubular structure, and nickel single atoms supported on the surface of the boron and nitrogen co-doped carbon; wherein, a boron-nitrogen bond is formed between the boron atoms and the nitrogen atoms.
[0007] Furthermore, the doping mass fraction of the nickel single atoms is 0.5 to 0.8 wt%.
[0008] A preparation method of a nickel single-atom modified boron and nitrogen co-doped carbon catalyst comprises the following steps:
[0009] Step 1: Ultrasonically dissolve urea, polyethylene glycol, boric acid and nickel nitrate hexahydrate in deionized water to obtain a mixed solution A;
[0010] Step 2: Carry out condensation reflux on the mixed solution A under stirring to obtain a mixed solution B;
[0011] Step 3: Evaporate the mixed solution B to dryness by rotary evaporation to obtain a white solid C;
[0012] Step 4: Pyrolyze the white solid C under an argon atmosphere to obtain a nickel single-atom modified boron and nitrogen co-doped carbon catalyst.
[0013] Furthermore, in Step 1, the mass ratio of urea, polyethylene glycol, boric acid and nickel nitrate hexahydrate is 15 to 25: 1.5 to 2.0: 0.6 to 1.5: 0.02 to 0.0774.
[0014] Furthermore, the concentration of nickel nitrate hexahydrate in the mixed solution A is 0.2 to 0.3 mg / mL.
[0015] Furthermore, in Step 2, the temperature of the condensation reflux is 100 to 130 °C, the duration is 10 to 16 h, and the stirring speed is 400 to 600 rpm.
[0016] Furthermore, in Step 3, the temperature of the rotary evaporation is 40 to 50 °C, the duration is 1.5 to 2 h, and the rotation speed is 40 to 50 rpm.
[0017] Furthermore, in Step 4, the temperature of the pyrolysis is 800 to 1000 °C, the duration is 5 to 7 h, and the flow rate of argon is 80 to 100 sccm.
[0018] The present invention also provides an application of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst according to any one of the above technical solutions or the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained by the preparation method according to any one of the above technical solutions in the two-electron oxygen reduction reaction for preparing hydrogen peroxide.
[0019] A device for preparing hydrogen peroxide by two - electron oxygen reduction uses a conductive substrate loaded with a nickel single - atom modified boron - nitrogen doped carbon catalyst as the working electrode, where the loading amount of the nickel single - atom modified boron - nitrogen doped carbon catalyst is 0.2 - 0.5 mg / cm 2 .
[0020] Further, the device for preparing hydrogen peroxide by two - electron oxygen reduction is tested in a constant - current mode, and the current density range is - 10 - - 500 mA / cm 2 .
[0021] Further, when the device for preparing hydrogen peroxide by two - electron oxygen reduction is realized based on a flow - through cell reactor, the flow rate of the electrolyte used is 90 - 150 mL / h.
[0022] Further, when the device for preparing hydrogen peroxide by two - electron oxygen reduction is realized based on a solid - state electrolyte reactor, it is used to prepare a pure hydrogen peroxide solution. Deionized water is introduced into the middle layer of the device, and the flow rate is 36 - 60 mL / h.
[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0024] 1. The present invention proposes a nickel single - atom modified boron - nitrogen doped carbon catalyst and its preparation method and application. On the one hand, introducing nitrogen elements into carbon can improve the stability of boron doping, and the formed boron - nitrogen bond serves as the active site for the two - electron oxygen reduction reaction to prepare hydrogen peroxide, which can effectively improve the reaction activity. On the other hand, loading nickel single atoms on the surface of boron - nitrogen doped carbon helps to regulate the adsorption energy of oxygen intermediates, reduce the reaction over - potential, and further improve the hydrogen peroxide selectivity, thereby realizing highly selective electrocatalytic two - electron oxygen reduction reaction to synthesize hydrogen peroxide at room temperature, low over - potential, and large current density.
[0025] 2. More importantly, the nickel single - atom modified boron - nitrogen doped carbon catalyst prepared by the present invention can synthesize a pure hydrogen peroxide solution in a solid - state electrolyte reaction cell, and by adjusting the flow rate of deionized water, pure hydrogen peroxide solutions with different concentrations can be obtained, which is of great significance in practical applications.
[0026] 3. The preparation method of the present invention is novel, simple and controllable, easy to implement, and suitable for large - scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0028] Figure 1 It is the transmission electron microscope image of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention;
[0029] Figure 2 It is the high-angle annular dark-field image of the scanning transmission electron microscope of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention;
[0030] Figure 3 It is the X-ray diffraction pattern of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1;
[0031] Figure 4 It is the X-ray absorption fine structure spectrum of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention;
[0032] Figure 5 It is the structural schematic diagram of the flow cell reactor used in Example 2 of the present invention;
[0033] Figure 6 It is the Faraday efficiency of hydrogen peroxide at different current densities for the two-electron oxygen reduction reaction to prepare hydrogen peroxide in the flow cell reactor using the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1;
[0034] Figure 7 It is the partial current density of hydrogen peroxide at different potentials for the two-electron oxygen reduction reaction to prepare hydrogen peroxide in the flow cell reactor using the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1;
[0035] Figure 8 It is the structural schematic diagram of the solid electrolyte reactor used in Example 3 of the present invention;
[0036] Figure 9 It is the Faraday efficiency of hydrogen peroxide at different current densities for the two-electron oxygen reduction reaction to prepare pure hydrogen peroxide solution in the solid electrolyte reactor using the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention;
[0037] Figure 10 It is the total current density and the partial current density of hydrogen peroxide at different full cell voltages for the two-electron oxygen reduction reaction to prepare pure hydrogen peroxide solution in the solid electrolyte reactor using the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 of the present invention. Detailed implementation manners
[0038] To further understand the present invention, the preferred embodiments of the present invention will be described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.
[0039] For all raw materials of the present invention, there are no special restrictions on their sources, and they can be purchased on the market or prepared by conventional methods well-known to those skilled in the art.
[0040] For all raw materials of the present invention, there are no special restrictions on their purity. The present invention preferably adopts analytical pure or the conventional purity requirements in the field of atomic layer deposition.
[0041] For all raw materials and process procedures of the present invention, their trade names or abbreviations all belong to the conventional trade names or abbreviations in the field. Each trade name or abbreviation is clear and definite in the field of its related uses. Those skilled in the art can purchase them from the market or prepare them by conventional methods according to the trade name, abbreviation and corresponding uses, or implement them with corresponding equipment.
[0042] The present invention will be further described in detail below in conjunction with examples:
[0043] Example 1
[0044] In this example, a nickel single-atom modified boron and nitrogen co-doped carbon catalyst was prepared, which specifically included the following steps:
[0045] Step 1: Weigh 20 g of urea, 2 g of polyethylene glycol, 1.2 g of boric acid, and 25.8 mg of nickel nitrate hexahydrate, add them together to a 500 mL round-bottom flask, then add 120 mL of deionized water, and ultrasonicate for 15 min until completely dissolved to obtain a mixed solution A;
[0046] Step 2: Stir the mixed solution A with a magnetic stirrer at a rotation speed of 500 rpm, carry out condensation reflux in an oil bath, the reaction temperature is 120 °C, and the reaction duration is 12 h to obtain a mixed solution B;
[0047] Step 3: Use a rotary evaporator to evaporate the mixed solution B to dryness, the evaporation temperature is 50 °C, the duration is 1.5 h, and the rotation speed is 50 rpm to obtain a white solid C;
[0048] Step 4: Put the white solid C into a crucible, pyrolyze it at 900 °C for 6 h under an argon atmosphere to obtain the nickel single-atom modified boron and nitrogen co-doped carbon catalyst.
[0049] Comparative Example 1
[0050] In this comparative example, a boron and nitrogen co-doped carbon catalyst was prepared. The difference in the preparation process compared with Example 1 is only that: in Step 1, the raw material nickel nitrate hexahydrate is not added; the remaining steps remain unchanged.
[0051] The nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1 were characterized below.
[0052] Figure 1 and Figure 2 are the transmission electron microscope image and the scanning transmission electron microscope high-angle annular dark field image of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1, respectively. It can be seen that the synthesized nickel single-atom modified boron and nitrogen co-doped carbon catalyst is overall in a tubular structure, and the tube diameter is between 65 and 75 nm. Among them, the circled nickel does not aggregate, and the nickel is specifically uniformly loaded on the surface of the boron and nitrogen co-doped carbon in the form of single atoms.
[0053] Figure 3 are the X-ray diffraction patterns of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1. It can be seen that the diffraction peaks of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1 are basically the same, indicating that the introduction of nickel single atoms does not affect the structure of the boron and nitrogen co-doped carbon catalyst.
[0054] Figure 4 are the X-ray absorption fine structure spectra of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1. According to the marked bonding species, it can be known that there is a boron-nitrogen (B-N) bond as an active site in the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1.
[0055] Example 2
[0056] Using a flow cell reactor, the two-electron oxygen reduction to prepare hydrogen peroxide reaction tests were carried out on the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1, respectively.
[0057] In this example, a flow cell reactor with a structure as Figure 5 shown was specifically used. The carbon gas diffusion layer loaded with the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 or the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1 was used as the cathode (working electrode), nickel foam was used as the anode (counter electrode), a mercury / mercuric oxide electrode was used as the reference electrode, the diaphragm was a proton exchange membrane, the cathode electrolyte and the anode electrolyte were both 1 mol / L potassium hydroxide solution, the flow rate of the cathode electrolyte was 108 mL / h, the flow rate of the anode electrolyte was 300 mL / h, and the flow rate of oxygen was 50 sccm. The test was carried out by the constant current method, and the applied current density range was -10 to -500 mA / cm 2 . The obtained product was colored with titanium sulfate and detected by ultraviolet absorption spectroscopy to calculate the product concentration. Combining with the data of the electrochemical workstation, the Faraday efficiency of the product was obtained.
[0058] Figure 6 For the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1, the Faraday efficiency of hydrogen peroxide in the catalytic two-electron oxygen reduction reaction to prepare hydrogen peroxide in a flow cell reactor was tested at different current densities, specifically at -10, -20, -30, -50, -100, -150, -200, -250, -300, -400, -500 mA / cm 2 At these 11 current densities, the Faraday efficiency of hydrogen peroxide of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 was higher than that of the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1, and a hydrogen peroxide selectivity higher than 80% was achieved, indicating that the preparation method of Example 1 can improve the activity and selectivity of hydrogen peroxide.
[0059] Figure 7 For the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 and the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1, the partial current density of hydrogen peroxide at different potentials in the catalytic two-electron oxygen reduction reaction to prepare hydrogen peroxide in a flow cell reactor was tested, specifically at -10, -20, -30, -50, -100, -150, -200, -250, -300, -400, -500 mA / cm 2 At these 11 current densities, it can be seen that the potential of the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 was only 0.58 volts (compared to the reversible hydrogen electrode) at -500 mA / cm 2 and a partial current density of hydrogen peroxide higher than 410 mA / cm 2 could be obtained at most. Compared with the boron and nitrogen co-doped carbon catalyst obtained in Comparative Example 1, the reaction potential at the same current density was more negative, that is, a larger reaction overpotential was required, indicating that the preparation method of Example 1 can reduce the reaction overpotential.
[0060] Example 3
[0061] Using a solid electrolyte reactor, a test for the two-electron oxygen reduction to prepare a pure hydrogen peroxide solution was carried out on the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1.
[0062] In this example, a structure as Figure 8The solid-state electrolyte reactor shown uses a carbon gas diffusion layer loaded with the nickel single-atom modified boron and nitrogen co-doped carbon catalyst (i.e., the cathode catalyst) obtained in Example 1 as the cathode (working electrode), places it on the cathode plate, and the anion exchange membrane is closely attached to the cathode catalyst; then places the intermediate layer filled with the solid electrolyte, and then sequentially assembles the proton exchange membrane, the anode catalyst iridium oxide, and the anode plate; finally, gaskets and silicone washers are added on both sides to ensure tightness. During the test, oxygen with a flow rate of 30 sccm is introduced into the cathode, deionized water with a flow rate of 50.4 mL / h is introduced into the intermediate layer, and the anode electrolyte uses a 1 mol / L sulfuric acid solution with a flow rate of 300 mL / h. The test is carried out by the constant current method, and the applied current density range is -10 to -500 mA / cm 2 . The obtained product is colored with titanium sulfate and detected by ultraviolet absorption spectroscopy, the product concentration is calculated, and combined with the data of the electrochemical workstation, the Faraday efficiency of the product is obtained.
[0063] Figure 9 For the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 to catalyze the two-electron oxygen reduction to prepare a pure hydrogen peroxide solution in a solid-state electrolyte reactor, the Faraday efficiency of hydrogen peroxide at different full cell voltages, specifically tested -10, -20, -30, -50, -100, -200, -300, -400, -500 mA / cm 2 These 9 current densities can achieve a hydrogen peroxide Faraday efficiency of more than 90% at low current densities. Although the efficiency decreases with the increase of the current density, a hydrogen peroxide Faraday efficiency of more than 70% is still achieved.
[0064] Figure 10 For the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 to catalyze the two-electron oxygen reduction to prepare a pure hydrogen peroxide solution in a solid-state electrolyte reactor, the total current density and the hydrogen peroxide partial current density at different full cell voltages, specifically tested -10, -20, -30, -50, -100, -200, -300, -400, -500 mA / cm 2 These 9 current densities, the full cell voltage at 500 mA / cm 2 is only 4.4 V, indicating that the nickel single-atom modified boron and nitrogen co-doped carbon catalyst obtained in Example 1 has a low reaction overpotential.
[0065] Example 4
[0066] In this example, a nickel single-atom modified boron and nitrogen co-doped carbon catalyst was prepared. Compared with Example 1 in the preparation process, the only differences are: adjusting the addition amount of nickel nitrate hexahydrate in step 1 to 77.4 mg, and adjusting the pyrolysis temperature in step 4 to 1000 °C and the duration to 5 h; the rest of the steps remain unchanged.
[0067] Example 5
[0068] In this example, a nickel single-atom modified boron and nitrogen co-doped carbon catalyst was prepared. The difference in the preparation process compared with Example 1 is only that: the addition amount of boric acid in Step 1 was adjusted to 0.2 g, and the pyrolysis temperature in Step 4 was adjusted to 800 °C with a duration of 7 h; the remaining steps remained unchanged.
[0069] Example 6
[0070] In this example, a nickel single-atom modified boron and nitrogen co-doped carbon catalyst was prepared. The difference in the preparation process compared with Example 1 is only that: the addition amount of nickel nitrate hexahydrate in Step 1 was adjusted to 20 mg; the remaining steps remained unchanged.
[0071] Example 7
[0072] In this example, a nickel single-atom modified boron and nitrogen co-doped carbon catalyst was prepared. The difference in the preparation process compared with Example 1 is only that: the evaporation temperature in Step 3 was adjusted to 40 °C with a duration of 2 h; the remaining steps remained unchanged.
[0073] The above is a detailed introduction to a nickel single-atom modified boron and nitrogen co-doped carbon catalyst and its preparation method and application proposed by the present invention. Specific examples were used herein to elaborate on the principle and implementation manner of the present invention. The description of the above examples is only used to help understand the method and its core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of the present invention patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the literal description of the claims, or if they include equivalent structural elements that have no substantial difference from the literal description of the claims, then these other embodiments should also be included within the scope of the claims.
Claims
1. A boron-nitrogen-doped carbon catalyst modified with a nickel single atom, characterized in that: It includes boron-nitrogen doped carbon with a tubular structure, and single nickel atoms supported on the surface of the boron-nitrogen doped carbon; wherein a boron-nitrogen bond is formed between the boron atom and the nitrogen atom.
2. The boron-nitrogen-doped carbon catalyst modified with nickel single atoms according to claim 1, characterized in that: The doping mass fraction of the nickel single atom is 0.5-0.8 wt %.
3. A method for preparing a boron-nitrogen-doped carbon catalyst modified with a nickel single atom, characterized in that: The following steps are involved: Step 1, dissolving urea, polyethylene glycol, boric acid and nickel nitrate hexahydrate in deionized water by ultrasonication to obtain a mixed solution A; Step 2, condensing and refluxing the mixed solution A in a stirred state to obtain a mixed solution B; Step 3, evaporating the mixed solution B by rotary evaporation to obtain a white solid C; Step 4: Pyrolyze the white solid C under an argon atmosphere to obtain a boron-nitrogen-doped carbon catalyst modified with a nickel single atom.
4. The method for preparing the boron-nitrogen-doped carbon catalyst modified with nickel single atoms according to claim 3, characterized in that: In step 1, the mass ratio of urea, polyethylene glycol, boric acid and nickel nitrate hexahydrate is 15-25:1.5-2.0:0.6-1.5:0.02-0.0774, and the concentration of nickel nitrate hexahydrate in the mixed solution A is 0.2-0.3 mg / mL.
5. The method for preparing the boron-nitrogen-doped carbon catalyst modified with nickel single atom according to claim 3, characterized in that: In step 2, the condensation reflux temperature is 100-130° C., the duration is 10-16 h, and the stirring speed is 400-600 rpm.
6. The method for preparing the boron-nitrogen-doped carbon catalyst modified with nickel single atoms according to claim 3, characterized in that: In step 3, the temperature of rotary evaporation is 40-50° C., the duration is 1.5-2 h, and the rotation speed is 40-50 rpm.
7. The method for preparing the boron-nitrogen-doped carbon catalyst modified with nickel single atoms according to claim 3, characterized in that: In step 4, the pyrolysis temperature is 800-1000° C., the duration is 5-7 hours, and the flow rate of argon is 80-100 sccm.
8. Use of the boron-nitrogen-doped carbon catalyst modified with a nickel single atom obtained by the method of any one of claims 3 to 7 in the reaction of preparing hydrogen peroxide by two-electron oxygen reduction.
9. A two-electron oxygen reduction device for preparing hydrogen peroxide, characterized in that: A conductive substrate loaded with a boron-nitrogen-doped carbon catalyst modified with a single nickel atom obtained by the method of any one of claims 3 to 7 is used as a working electrode, wherein the loading amount of the boron-nitrogen-doped carbon catalyst modified with a single nickel atom is 0.2 to 0.5 mg / cm 2 .
10. The two-electron oxygen reduction device for preparing hydrogen peroxide according to claim 9, characterized in that: It is realized based on a flow cell reactor or a solid electrolyte reaction cell; when it is realized based on a flow cell reactor, the flow rate of the electrolyte used is 90 to 150 mL / h; when it is realized based on a solid electrolyte reactor, it is used to prepare a pure hydrogen peroxide solution, and deionized water is introduced into the middle layer of the device at a flow rate of 36 to 60 mL / h.