Preparation method of novel electrode material for synthesizing medical grade hydrogen peroxide

Abstract

The invention relates to a preparation method of a novel electrode material for synthesizing medical grade hydrogen peroxide, which comprises the following steps: by taking litchi shell derived biomass charcoal as a substrate and metal acetate as a metal source, obtaining a composite precursor through complexation between glucose and metal; the heterogeneous carbon catalyst (CoNi-LC) with cobalt-nickel bimetal monatomic dispersion sites is prepared through calcination and acid pickling. CoNi-LC is dispensed on GDE to obtain a CoNi-LC / GDE modified electrode, under the action of a flow cell system and specific additional bias voltage, the yield of H2O2 synthesized by the catalyst in 10 h through electro-catalysis reaches up to 13.53 mol gcat <-1 >, the mass concentration is about 4.6%, and the concentration (3%) of medical H2O2 is achieved; the stable H2O2 yield and current response can still be kept after continuous catalytic reaction for 40 hours (the electrolyte solution is replaced once every 10 hours), and a green synthesis route and a sustainable technology are provided for H2O2 production. The method has the characteristics of simplicity, high efficiency and low cost, and can be applied to electro-catalytic synthesis of H2O2.

Description

Technical Field

[0001] The present invention belongs to the technical field of high value-added chemicals and catalyst production, and particularly relates to a method for preparing a novel electrode material (CoNi-LC) for synthesizing medical-grade hydrogen peroxide. Background Art

[0002] Hydrogen peroxide (H2O2), as an environmentally friendly oxidant, energy carrier, and wastewater treatment agent, has a wide range of applications in industrial synthesis, medicine, environmental remediation, food disinfection, fuel cell technology, and wastewater treatment. Currently, H2O2 is synthesized using methods such as the anthraquinone method, direct hydrogen-oxygen synthesis, electrochemical methods, and photocatalytic methods. The anthraquinone method is widely used in industry for large-scale H2O2 production, achieving concentrations exceeding 30%. High-concentration H2O2 is susceptible to violent decomposition and even explosion during transportation and storage due to its reaction with organic matter or metallic impurities, posing a significant risk. Furthermore, this method consumes excessive energy and produces a large number of toxic byproducts. Currently, the in situ electrochemical synthesis of H2O2 has attracted widespread interest.

[0003] The electrocatalytic oxygen reduction reaction (ORR) to synthesize H2O2 can be carried out at room temperature and has the advantages of low energy consumption, energy saving and environmental protection. Among them, the abundant O2 small molecule serves as the cathode reactant, obtains two electrons at the three-phase interface formed by the electrolyte and the electrode surface, and undergoes a reduction reaction to produce H2O2. This method has the characteristics of high yield and simple process, and the only by-product is H2O. However, the electrocatalytic generation of H2O2 is highly dependent on the electrocatalytic activity and selectivity of the two-electron ORR catalyst. Single-atom catalysts (SACs) based on transition metals with the highest atomic utilization have shown excellent electrocatalytic performance in electrochemical reactions. Compared with single-atom catalysts, double-single-atom catalysts (DACs) with two metal atoms as catalytic active centers not only inherit the advantages of single-atom catalysts, but also have enhanced interatomic synergy, thereby further stimulating their electronic and geometric effects, providing more opportunities for regulating the microenvironment of the active site and optimizing the interaction between the active site and the reactants, which is conducive to improving their electrocatalytic ability.

[0004] Carbon-based materials are often used as supports for the synthesis of single-atom catalysts due to their advantages such as good electrical conductivity, low cost, chemical resistance, porous structure and abundant anchoring sites. Biochar derived from lychee shells is rich in heteroatoms such as O, N, and P (derived from biomass components), which can form strong coordination with metal single atoms (such as M-N4, M-O4 structures), preventing migration and agglomeration, and is more suitable for use as a support for single-atom catalysts. The electrical conductivity (graphitized carbon layer) and surface functional groups of biochar can regulate the electronic state of metal single atoms (such as charge transfer) and optimize the adsorption energy of intermediates. At the same time, it has a multi-level pore structure and a large specific surface area, which promotes the diffusion of reactants / products and is particularly suitable for reactions involving gas. The raw material cost of lychee shells is extremely low, and the pyrolysis process is simple, making it suitable for industrial production. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a CoNi-LC electrocatalyst and a preparation method thereof.

[0006] A second object of the present invention is to provide a method for synthesizing medical-grade H2O2 using CoNi-LC electrocatalysis.

[0007] The technical solution adopted in the present invention is:

[0008] A novel electrode material CoNi-LC, the preparation method of which comprises the following steps:

[0009] 1) Preparation of litchi shell-derived biochar (LC): Litchi shells were washed three times with water, dried in an oven at 80°C, and ground into powder using a grinder. The litchi shell powder was then spread evenly on a porcelain boat and transferred to a tube furnace for calcination. After calcination, 500 mg of the calcined litchi shell powder was added to a round-bottom flask containing 100 mL of nitric acid solution and refluxed. The mixture was then cooled to room temperature and washed with water and anhydrous ethanol multiple times until neutral. The resulting solid powder was dried at 60°C and ground to obtain LC.

[0010] 2) Preparation of the novel electrode material CoNi-LC: 300 mg of LC, 100 mg of ZnCl2·6H2O, 249 mg of Co(Ac)2·4H2O, and 0.248 mg of Ni(Ac)2·4H2O were weighed and added to 40 mL of water and stirred for 30 min. Then, 6 g of glucose was added and stirred for another 2 h. The solid obtained by centrifugation was dried in an oven at 60°C to obtain a composite precursor. The resulting composite precursor was evenly ground and spread on a quartz boat, then transferred to a tube furnace and calcined. After calcination, the mixture was cooled to room temperature to obtain the catalyst M@CoNi-LC, which contains coexisting metal particles and single-atom sites. 500 mg of M@CoNi-LC was weighed and added to a round-bottom flask containing 100 mL of nitric acid solution. After reflux, the mixture was cooled to room temperature and washed multiple times with water and anhydrous ethanol until neutral. The resulting solid powder was dried at 60°C and ground to obtain CoNi-LC.

[0011] Furthermore, in the preparation method of the novel electrode material CoNi-LC, in step 1), the calcination conditions are: in a nitrogen atmosphere, at 5°C min -1 The temperature was raised to 900 °C and maintained for 2 h.

[0012] Furthermore, in the preparation method of the above-mentioned novel electrode material CoNi-LC, in step 1), the concentration of the nitric acid solution is 3M.

[0013] Furthermore, in the preparation method of the novel electrode material CoNi-LC, in step 1), the reflux condition is: reflux at 80° C. for 8 h.

[0014] Furthermore, in the preparation method of the novel electrode material CoNi-LC, in step 2), the calcination conditions are: in a nitrogen atmosphere, at 5°C min -1 The temperature was raised to 900 °C and maintained for 2 h.

[0015] Furthermore, in the above-mentioned method for preparing the novel electrode material CoNi-LC, in step 2), the concentration of the nitric acid solution is 3M.

[0016] Furthermore, in the preparation method of the novel electrode material CoNi-LC, in step 2), the reflux condition is: reflux at 80° C. for 8 h.

[0017] Application of the novel electrode material CoNi-LC described in any one of the above in the electrocatalytic synthesis of medical-grade hydrogen peroxide.

[0018] Furthermore, the above application method includes the following steps:

[0019] 1) Preparation of CoNi-LC / CF / PTFE: 1 mg of CoNi-LC was dispersed in 500 μL of aqueous ethanol and ultrasonically dispersed to form a uniform dispersion. The dispersion was dropwise applied to carbon felt and dried at room temperature to obtain CoNi-LC / CF. 2% PTFE was then sprayed onto the CoNi-LC / CF, dried at room temperature, and calcined in a tube furnace to obtain the hydrophobic CoNi-LC / CF / PTFE electrode.

[0020] 2) Electrocatalytic synthesis of H2O2 by CoNi-LC / CF / PTFE: A standard three-electrode system was used in an H-type reactor with a proton exchange membrane as the diaphragm, with CoNi-LC / CF / PTFE as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. The electrolytic cell solution was 20 mL of a 0.1 M O2-saturated KOH solution, and O2 was continuously introduced during the reaction. Before the reaction, the electrolytic solution was quenched with 100 mV s -1 The CV scan was performed for 30 cycles in the potential range of 0-1.0 V vs. RHE until a stable solid / liquid interface was obtained; the catalytic reaction was driven by a potential of 0.3 V vs. RHE.

[0021] Furthermore, in the above application method, the volume ratio of ethanol to water in the ethanol aqueous solution is 1 / 4.

[0022] Furthermore, in the above application method, the calcination conditions are: calcination at 350° C. for 30 minutes under nitrogen atmosphere.

[0023] Furthermore, the above application method includes the following steps:

[0024] 1) Preparation of CoNi-LC / GDE: 1 mg of CoNi-LC was dispersed in 500 μL of ethanol-water solution, 5 μL of 5% Nafion solution was added, and ultrasonic dispersion was performed to form a uniform dispersion. The dispersion was dropwise applied to a gas diffusion electrode and dried at room temperature to obtain the gas diffusion electrode CoNi-LC / GDE.

[0025] 2) Electrocatalytic synthesis of H2O2 by CoNi-LC / GDE: A standard three-electrode system was used in an H-type flow cell with a proton exchange membrane as the diaphragm, with CoNi-LC / GDE as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. The electrolytic cell solution was 20 mL of 0.1 M O2-saturated KOH solution, and O2 was continuously introduced during the reaction. Before the reaction, the electrolytic solution was quenched with 100 mV s -1 The CV scan was performed for 30 cycles in the potential range of 0-1.0 V vs. RHE until a stable solid / liquid interface was obtained; the catalytic reaction was driven by a potential of 0.3 V vs. RHE.

[0026] Furthermore, in the above application method, the volume ratio of ethanol to water in the ethanol aqueous solution is 1 / 4.

[0027] The beneficial effects of the present invention are:

[0028] 1. This invention uses litchi shell-derived biochar as a carrier and synthesizes a CoNi-LC electrocatalyst with high atomic utilization through a series of simple chemical manipulations. This achieves resource recycling, a simple preparation process, and a low-carbon, environmentally friendly approach, in line with the principles of green chemistry. The synthesized catalyst possesses uniformly dispersed dual single-atom active sites, and the biochar carrier is rich in surface functional groups and has a micro- and mesoporous structure, resulting in excellent two-electron ORR catalytic activity and selectivity.

[0029] 2. The present invention is simple, efficient, low-cost, highly selective, and requires low voltage for electrocatalysis. Using the method of the present invention, under the action of a flow cell system and a specific additional bias voltage, the catalyst can electrocatalytically synthesize H2O2 at a yield of up to 13.53 mol g within 10 hours. cat -1 , the mass concentration is about 4.6%, reaching the concentration of medical H2O2 (3%); the continuous catalytic reaction is carried out for 40 hours (the electrolyte solution is replaced every 10 hours), and the stable H2O2 production and current response can still be maintained, providing a green synthesis route and sustainable technology for the production of H2O2. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The scanning electron microscope (SEM) image (a), transmission electron microscope (TEM) image (b) and spherical aberration corrected transmission electron microscope (HAADF-STEM) image (c) of CoNi-LC.

[0031] Figure 2 are the X-ray diffraction (XRD) spectra of M@CoNi-LC, LC, Ni-LC, Co-LC, and CoNi-LC.

[0032] Figure 3 Rotating ring disk electrode (RRDE) curves (a) and selectivity and electron transfer number curves (b) of CoNi-LC, Co-LC, Ni-LC and LC.

[0033] Figure 4 This is a graph showing the change in H2O2 yield over time during electrocatalytic synthesis of CoNi-LC, Co-LC, Ni-LC and LC at a potential of 0.3 V vs RHE.

[0034] Figure 5The linear scan curve (LSV) diagram of CoNi-LC in the H-type electrolytic cell and flow cell (a) and the electrocatalytic synthesis of H2O2 yield and current response diagram of the flow cell system (b). DETAILED DESCRIPTION

[0035] Example 1 Preparation of CoNi-LC electrocatalyst

[0036] (1) Preparation of litchi shell-derived biochar (LC)

[0037] The lychee shells were washed with water for 3 times, dried in an oven at 80°C and crushed into powder using a grinder. The lychee shell powder was then spread on a porcelain boat and transferred to a tube furnace. The mixture was heated at 5°C min-1 under a nitrogen atmosphere. -1 The temperature was raised to 900°C at a rate of 100°C and maintained for 2 hours. After calcination, the mixture was cooled to room temperature. 500 mg of the calcined litchi shell powder was weighed and added to a round-bottom flask containing 100 mL of 3M nitric acid solution. The mixture was refluxed at 80°C for 8 hours and then cooled to room temperature. The mixture was washed with water and anhydrous ethanol multiple times until neutral. The resulting solid powder was dried at 60°C and ground to obtain LC.

[0038] (2) Preparation of Cobalt-Nickel Double Single Atom Catalyst (CoNi-LC)

[0039] 300 mg of LC, 100 mg of ZnCl2·6H2O, 249 mg of Co(Ac)2·4H2O, and 0.248 mg of Ni(Ac)2·4H2O were weighed and added to 40 mL of water and stirred for 30 min. Then, 6 g of glucose was added to the above solution and stirred for 2 h. The solid was obtained by centrifugation and dried in an oven at 60 ° C to obtain a composite precursor. The obtained composite precursor was evenly ground and spread on a quartz boat, transferred to a tube furnace, and heated at 5 ° C min under a nitrogen atmosphere. -1 The temperature was raised to 900°C at a rate of 100°C and held for 2 hours. After calcination, the catalyst was cooled to room temperature to obtain a catalyst containing coexisting metal particles and single-atom sites (M@CoNi-LC). 500mg of M@CoNi-LC was weighed and added to a round-bottom flask containing 100mL of 3M nitric acid solution. The solution was refluxed at 80°C for 8 hours and then cooled to room temperature. The solution was washed with water and anhydrous ethanol multiple times until neutral. The resulting solid powder was dried at 60°C and ground to obtain CoNi-LC.

[0040] For comparison, Ni-LC and Co-LC were prepared according to the above method without adding Co(Ac)2·4H2O and Ni(Ac)2·4H2O, respectively.

[0041] Figure 1 The SEM image (a), TEM image (b) and HAADF-STEM image (c) of CoNi-LC. Figure 1 As can be seen in a, CoNi-LC presents a three-dimensional porous structure with a rough surface; Figure 1 b shows that CoNi-LC has an obvious mesoporous structure; Figure 1 The randomly distributed white bright spots (circled in red dashed circles) shown in c confirm that Co and Ni atoms exist in the LC in the form of single atoms without obvious clusters or nanoparticles.

[0042] Figure 2 The XRD spectra of M@CoNi-LC, CoNi-LC, Ni-LC, Co-LC and LC are shown in Figure 2. Figure 2 It can be seen that M@CoNi-LC has obvious peaks of metal Co and Ni; while the XRD spectra of CoNi-LC, Ni-LC, Co-LC and LC are similar, with only the diffraction peak of graphite carbon, indicating that metal Co and Ni may be dispersed in atomic form.

[0043] Example 2 Electrocatalytic Selectivity Test

[0044] 2 mg of CoNi-LC electrocatalyst was weighed and added to 800 μL of ethanol / water mixed solution (v / v, 15 / 1) containing 1% Nafion, and ultrasonic dispersion was performed to obtain a uniform dispersion. 8 μL of the dispersion was dropped onto the surface of a rotating disk electrode (RRDE) (ring electrode area: 0.1866 cm 2 , disk electrode area: 0.2475cm 2 ), and then naturally dried to form a uniform film to obtain CoNi-LC modified RRDE.

[0045] Selectivity testing was performed using a CHI760E electrochemical workstation in a standard three-electrode system. A CoNi-LC-modified RRDE was used as the working electrode, an Ag / AgCl electrode as the reference electrode, and a Pt sheet as the counter electrode. The electrolyte solution was a 0.1 M O2-saturated KOH solution, with O2 continuously flowing throughout the reaction. Linear sweep voltammetry (LSV) curves were obtained with a scanning potential range of 0–1.0 V vs. RHE, a ring electrode potential of 1.2 V vs. RHE, and a scan rate of 5 mV s. -1 , the rotation speed is 1600rpm. According to formula (1), the working potential (vs.Ag / AgCl) (E Ag / AgCl ) is converted to the potential relative to the standard hydrogen electrode (vs. RHE) (E RHE ).

[0046] E RHE = E Ag / AgCl + 0.0592pH + 0.1976 (1)

[0047] The formula for calculating the selectivity of H2O2 and the number of transferred electrons is as follows:

[0048]

[0049] Among them, I ring is the ring electrode current density, I disk is the disk electrode current density, N is the collection efficiency, and is 0.37.

[0050] Depend on Figure 3 It can be seen that compared with Ni-LC, Co-LC, and LC, CoNi-LC has a comparable disk current density but the highest ring current density, indicating that it has the best two-electron oxygen reduction reaction (ORR) activity. The selectivity (%) and electron transfer number (n) calculated according to formulas (2) and (3) show that the two-electron ORR selectivity of CoNi-LC is between 80% and 99% in the potential range of 0.1 to 0.7 V vs. RHE, and the number of transferred electrons is approximately 2.3, which is more conducive to the synthesis of H2O2 through two-electron ORR.

[0051] Example 3 Static electrocatalytic production of H2O2

[0052] (1) Preparation of CoNi-LC / CF / PTFE:

[0053] 1 mg of CoNi-LC was dispersed in 500 μL of ethanol / water (1 / 4 by volume) and ultrasonically dispersed to form a uniform dispersion. The dispersion was then drop-coated onto carbon felt (CF, 2 cm × 2 cm × 0.2 cm) and dried at room temperature to produce CoNi-LC / CF. 2% PTFE was then sprayed onto the CoNi-LC / CF, dried at room temperature, and calcined in a tube furnace at 350°C under a nitrogen atmosphere for 30 minutes to obtain the hydrophobic CoNi-LC / CF / PTFE electrode.

[0054] (2) Electrocatalytic synthesis of H2O2 by CoNi-LC / CF / PTFE:

[0055] A standard three-electrode system was used in an H-type reactor with a proton exchange membrane as the diaphragm, with CoNi-LC / CF / PTFE as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. The electrolytic cell solution was 20 mL of a 0.1 M O2-saturated KOH solution, and O2 was continuously introduced during the reaction. Before the test, the voltage was set at 100 mV s -1 CV scans were performed at a rate of 30 cycles in the potential range of 0-1.0 V vs. RHE until a stable solid / liquid interface was obtained. During the catalytic reaction driven by a potential of 0.3 V vs. RHE, 0.5 mL of the solution was removed every 30 minutes and the H2O2 production was measured using the potassium titanium oxalate colorimetric method.

[0056] In the static catalytic synthesis system H2O2, CoNi-LC / CF / PTFE electrode was used to catalyze ORR to synthesize H2O2. The results are as follows Figure 4 As shown in Figure 2, the H2O2 production first increased and then stabilized with time. After 5 h of catalytic reaction on the CoNi-LC / CF / PTFE electrode, the maximum value reached 38.39 M g cat -1 , which are all higher than the H2O2 yields synthesized by Ni-LC, Co-LC and LC.

[0057] Example 4 Dynamic electrocatalytic production of H2O2

[0058] (1) Preparation of CoNi-LC / GDE:

[0059] Weigh 1 mg of CoNi-LC and disperse it in 500 μL of ethanol solution (volume ratio is 1 / 4), add 5 μL of 5% Nafion solution, and disperse it by ultrasonic to form a uniform dispersion. 2 ) and dried at room temperature to obtain the gas diffusion electrode CoNi-LC / GDE.

[0060] (2) Electrocatalytic synthesis of H2O2 by CoNi-LC / GDE:

[0061] A standard three-electrode system was used in an H-type flow cell with a proton exchange membrane as the diaphragm, with CoNi-LC / GDE as the working electrode, Ag / AgCl as the reference electrode, and Pt sheet as the counter electrode. The electrolytic cell solution was 20 mL of 0.1 M O2-saturated KOH solution, and O2 was continuously introduced during the reaction. Before the test, the voltage was set at 100 mV s -1 CV scans were performed at a rate of 30 cycles in the potential range of 0-1.0 V vs. RHE until a stable solid / liquid interface was obtained. During the catalytic reaction driven by a potential of 0.3 V vs. RHE, 0.5 mL of the solution was removed every 30 minutes and the H2O2 production was measured using the potassium titanium oxalate colorimetric method.

[0062] In the dynamic catalytic synthesis system H2O2, CoNi-LC / GDE electrode was used to catalyze ORR to synthesize H2O2. Figure 5 As shown. Figure 5 a It can be found that the current density of ORR catalyzed by the flow cell system is significantly greater than that in the static H-type electrolytic cell; Figure 5 As can be seen in b, the H2O2 production increases with time, and the production reaches 13.53 mol g after 10 h of catalytic reaction. cat -1, the mass concentration was about 4.6%, reaching the concentration of medical H2O2 (3%); the continuous catalytic reaction was carried out for 40 hours (the electrolyte solution was replaced every 10 hours), and the stable H2O2 production and current response were still maintained.

Claims

1. A new electrode material CoNi-LC, characterized in that: The preparation method comprises the following steps: 1) Preparation of litchi shell-derived biochar (LC): Litchi shells were washed three times with water, dried in an oven at 80°C, and ground into powder using a grinder. The litchi shell powder was then spread evenly on a porcelain boat and transferred to a tube furnace for calcination. After calcination, 500 mg of the calcined litchi shell powder was added to a round-bottom flask containing 100 mL of nitric acid solution and refluxed. The mixture was then cooled to room temperature and washed with water and anhydrous ethanol multiple times until neutral. The resulting solid powder was dried at 60°C and ground to obtain LC. 2) Preparation of the novel electrode material CoNi-LC: 300 mg of LC, 100 mg of ZnCl2·6H2O, 249 mg of Co(Ac)2·4H2O, and 0.248 mg of Ni(Ac)2·4H2O were weighed and added to 40 mL of water and stirred for 30 min. Then, 6 g of glucose was added and stirred for another 2 h. The solid obtained by centrifugation was dried in an oven at 60°C to obtain a composite precursor. The resulting composite precursor was evenly ground and spread on a quartz boat, then transferred to a tube furnace and calcined. After calcination, the mixture was cooled to room temperature to obtain the catalyst M@CoNi-LC, which contains coexisting metal particles and single-atom sites. 500 mg of M@CoNi-LC was weighed and added to a round-bottom flask containing 100 mL of nitric acid solution. After reflux, the mixture was cooled to room temperature and washed multiple times with water and anhydrous ethanol until neutral. The resulting solid powder was dried at 60°C and ground to obtain CoNi-LC.

2. A novel electrode material CoNi-LC according to claim 1, characterized in that: In step 1) and step 2), the calcination conditions are: under nitrogen atmosphere, at 5°C min -1 The temperature was raised to 900 °C and maintained for 2 h.

3. The novel electrode material CoNi-LC according to claim 1, characterized in that: In step 1) and step 2), the concentration of the nitric acid solution is 3M.

4. The novel electrode material CoNi-LC according to claim 1, characterized in that: In step 1) and step 2), the reflux condition is: reflux at 80° C. for 8 h.

5. Use of the novel electrode material CoNi-LC according to any one of claims 1 to 4 in the electrocatalytic synthesis of medical-grade hydrogen peroxide.

6. The use according to claim 5, characterized in that The method comprises the following steps: 1) Preparation of CoNi-LC / CF / PTFE: 1 mg of CoNi-LC was dispersed in 500 μL of aqueous ethanol and ultrasonically dispersed to form a uniform dispersion. The dispersion was dropwise applied to carbon felt and dried at room temperature to obtain CoNi-LC / CF. 2% PTFE was then sprayed onto the CoNi-LC / CF, dried at room temperature, and calcined in a tube furnace to obtain the hydrophobic CoNi-LC / CF / PTFE electrode. 2) Electrocatalytic synthesis of H2O2 by CoNi-LC / CF / PTFE: A standard three-electrode system was used in an H-type reactor with a proton exchange membrane as the diaphragm, with CoNi-LC / CF / PTFE as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. The electrolytic cell solution was 20 mL of a 0.1 M O2-saturated KOH solution, and O2 was continuously introduced during the reaction. Before the reaction, a 100 mVs -1 The CV scan was performed for 30 cycles in the potential range of 0-1.0 V vs. RHE until a stable solid / liquid interface was obtained; the catalytic reaction was driven by a potential of 0.3 V vs. RHE.

7. The use according to claim 5, characterized in that The method comprises the following steps: 1) Preparation of CoNi-LC / GDE: 1 mg of CoNi-LC was dispersed in 500 μL of ethanol-water solution, 5 μL of 5% Nafion solution was added, and ultrasonic dispersion was performed to form a uniform dispersion. The dispersion was dropwise applied to a gas diffusion electrode and dried at room temperature to obtain the gas diffusion electrode CoNi-LC / GDE. 2) Electrocatalytic synthesis of H2O2 by CoNi-LC / GDE: A standard three-electrode system was used in an H-type flow cell with a proton exchange membrane as the diaphragm, with CoNi-LC / GDE as the working electrode, Ag / AgCl as the reference electrode, and a Pt sheet as the counter electrode. The electrolytic cell solution was 20 mL of 0.1 M O2-saturated KOH solution, and O2 was continuously introduced during the reaction. Before the reaction, the electrolytic solution was quenched with 100 mV s -1 The CV scan was performed for 30 cycles in the potential range of 0-1.0 V vs. RHE until a stable solid / liquid interface was obtained; the catalytic reaction was driven by a potential of 0.3 V vs. RHE.

8. The use according to claim 6 or 7, characterized in that The volume ratio of ethanol to water in the ethanol aqueous solution is 1 / 4.

9. The use according to claim 6, characterized in that The calcination conditions are: calcination at 350° C. for 30 min under nitrogen atmosphere.

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