Coal-based active coke, structure directional regulation method and application

Abstract

The application provides a coal-based active coke, a structure directional regulation and control method and application. The application uses low-cost shaped coal-based active coke as raw material, reduces the oxygen content of the reduced active coke powder through particle size refinement and reduction treatment, and then controls the multi-scale structure of the reduced active coke powder through ball milling treatment in an air atmosphere, an argon atmosphere or a carbon dioxide atmosphere. The regulation and control method can obtain a high-performance carbon-based electrocatalyst with reduced amorphous carbon lattice size, rich edge defects, different oxygen doping concentrations and developed mesoporous structure. The overall process flow is simple to operate, no waste gas and waste liquid are generated, and the method has the potential for large-scale production and wide commercialization. In addition, the raw material used in the application is coal-derived shaped active coke, and active cokes developed from different types of coal can be used as raw materials, so that the material source is relatively wide and the cost is extremely low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon-based electrocatalysts, in particular to a coal-based activated coke, a structure directional regulation method and application. BACKGROUND

[0002] H2O2 is one of the most important 100 chemicals in the world as an energy carrier in fuel cells, a green oxidant in chemical production and environmental remediation. Compared with the high-energy and high-pollution anthraquinone process, the two-electron path oxygen reduction reaction (ORR) for preparing H2O2 can realize in-situ production and utilization, which is an important technical choice for synthesizing H2O2. Since there are two paths (two-electron / four-electron) in the ORR process, developing high-performance electrocatalysts to strengthen the two-electron path is the key to the selective synthesis of H2O2.

[0003] Carbon materials have been widely concerned due to their low cost, easy to control of doped or defect structure, etc. The structural characteristics of the high-performance carbon-based catalysts developed so far are summarized. The carbon materials for strengthening the selective generation of H2O2 usually have the following characteristics: (1) Defect sites on the molecular atomic scale regulate the electronic structure characteristics of the carbon surface, such as oxygen-containing functional groups and edge defects; (2) Developed mesoporous structure on the nanoscale for strengthening the diffusion and migration of reactant species inside the material. Therefore, reasonable regulation of the multi-scale structure of carbon materials is an important starting point for developing high-performance carbon-based catalysts.

[0004] At present, coal is an important energy material and a natural carbon source in nature. By controlling the carbonization temperature, the aromatic macromolecules in raw coal can evolve into amorphous carbon structure. Coal-based activated coke, as a low-cost amorphous carbon material after preliminary carbonization and activation of raw coal and molding, has derived a large number of non-sp2 carbon structures (five-membered rings, edge defects, chemical functional groups, etc.) and its pore structure has also been preliminarily developed. The multi-scale structure of coal-based activated coke preliminarily developed by mechanical and chemical methods can be further regulated for the electrocatalytic synthesis of H2O2.

[0005] Therefore, in view of the structural requirements of carbon materials for the electrocatalytic synthesis of H2O2, it is an urgent technical problem for those skilled in the art to develop low-cost and high-performance amorphous carbon-based electrocatalysts based on the mechanical and chemical regulation of the multi-scale structure (defect-pore-carbon microcrystal) of coal-based activated coke. SUMMARY

[0006] The present application aims to at least partially solve one of the technical problems in the related art.

[0007] To this end, the purpose of the present application is to propose a coal-based activated coke, a structure directional regulation method and application. The method is a method for directional regulation of amorphous carbon multi-scale structure by regulating the multi-scale structure of coal-based activated coke through a mechanochemical method. A low-cost, high-performance carbon-based electrocatalyst is obtained to realize the electrocatalytic synthesis of H2O2.

[0008] To achieve the above-mentioned purpose, according to the first aspect of the present application, a method for directional regulation of the structure of coal-based activated coke is proposed, comprising the steps of:

[0009] The shaped coal-based activated coke is crushed, ground and sieved to obtain activated coke powder with a particle size of hundreds of nanometers;

[0010] The activated coke powder is placed in a reducing atmosphere formed by mixing hydrogen and argon at 800-1200℃ and is kept for 0.5-5h to perform reduction treatment, and then is lowered to room temperature to obtain reduced activated coke powder;

[0011] The reduced activated coke powder is placed in an air atmosphere, an argon atmosphere or a carbon dioxide atmosphere and is ball milled to obtain a ball milling product; wherein the rotation speed during ball milling is 300r / min-1000r / min, and the time is 12-24h;

[0012] The ball milling product is sequentially subjected to acid washing and water washing and is dried to obtain a carbon-based electrocatalyst.

[0013] In some embodiments, the material of the ball milling tank during ball milling of the reduced activated coke powder is stainless steel, agate or corundum.

[0014] In some embodiments, the argon atmosphere during ball milling of the reduced activated coke powder is directly introducing argon into the ball milling tank.

[0015] In some embodiments, the carbon dioxide atmosphere during ball milling of the reduced activated coke powder is directly introducing dry ice into the ball milling tank, wherein the mass ratio of the dry ice to the reduced activated coke powder is 1:0.1-10.

[0016] In some embodiments, when the activated coke powder is heated in the reducing atmosphere, the heating rate is 0.1-10℃min -1 The temperature is raised to 800-1200℃ at a temperature rising rate; based on the reducing atmosphere, the volume percentage of hydrogen is 5%, and the volume percentage of argon is 95%.

[0017] In some embodiments, the method for acid washing of the ball milling product is using dilute hydrochloric acid or nitric acid with a concentration of 0.1-2mol / L for cleaning 2-3 times.

[0018] In some embodiments, the ball milling product is washed with water for 2-5 times, and is subjected to drying treatment at 60℃-100℃ for 12-24h to obtain the carbon-based electrocatalyst.

[0019] According to a second aspect of the present application, a carbon-based electrocatalyst based on coal-based activated coke structure directional regulation is provided, the carbon-based electrocatalyst is amorphous carbon and the lattice size is sub-nanometer; at the same time, it is rich in edge defects, different oxygen doping concentrations, and the mesopore ratio is greater than 50%.

[0020] In some embodiments, the carbon-based electrocatalyst is an alkaline system catalyst, the initial potential of which is 0.83V and the selectivity of which is greater than 90%.

[0021] According to a third aspect of the present application, the carbon-based electrocatalyst based on coal-based activated coke structure directional regulation in any of the above embodiments is applied in catalytic synthesis of H2O2, and the carbon-based electrocatalyst catalyzes the synthesis of H2O2.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The present application uses low-cost shaped coal-based activated coke as raw material, obtains reduced-oxygen reduced activated coke powder through particle size refinement and reduction treatment, and then performs ball milling treatment in an air atmosphere, an argon atmosphere or a carbon dioxide atmosphere to regulate the multi-scale structure of the reduced activated coke powder. Compared with the top-down material synthesis means such as etching, oxidation, corrosion and grinding in the related art, the regulation method of the present application can obtain high-performance carbon-based electrocatalyst with reduced amorphous carbon lattice size, rich edge defects, different oxygen doping concentrations and developed mesopore structure. The overall process flow is simple to operate, no waste gas and waste liquid are generated, and it has the potential for large-scale production and broad commercialization prospects. In addition, the raw material used in the present application is coal-derived shaped activated coke, and activated coke developed from different types of coal can be used as raw material, so the material source is relatively extensive and the cost is extremely low.

[0024] At the same time, the mechanical and chemical effects induced by the ball milling process in the structural directional regulation method of the coal-based activated coke in the present application can tailor the crystallite structure of the reduced activated coke powder, such as regulating the amorphous carbon lattice size of the activated coke and the pore distribution of the material by adjusting the ball milling time and the ball milling speed; and regulating the types and contents of oxygen-containing functional groups on the carbon-based surface by adjusting the ball milling atmosphere and concentration. Therefore, by reasonably adjusting the ball milling process parameters, the multi-scale structure of the carbon material can be deeply regulated, and the obtained carbon-based electrocatalyst exhibits high activity (initial potential of 0.83V), high selectivity (greater than 90%) and stability in an alkaline system, and can be applied in catalytic synthesis of H2O2.

[0025] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above mentioned and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a flow chart of the structural directional regulation method of the coal-based active coke proposed in the present application;

[0028] Figure 2 is a SEM image of the coal-based active coke obtained in Example 1 of the present application;

[0029] Figure 3 is a TEM image of the coal-based active coke obtained in Example 1 of the present application;

[0030] Figure 4 is an XPS spectrum of the coal-based active coke obtained in Example 1 of the present application;

[0031] Figure 5 is a cyclic voltammetry test curve of the coal-based active coke obtained in Example 1 of the present application as an electrocatalyst;

[0032] Figure 6 is a rotating ring-disk test curve of the coal-based active coke obtained in Example 1 of the present application as an electrocatalyst;

[0033] Figure 7 is a rotating disk test curve of the coal-based active coke obtained in Example 1 of the present application as an electrocatalyst;

[0034] Figure 8 is a stability test curve of the coal-based active coke obtained in Example 1 of the present application as an electrocatalyst;

[0035] Figure 9 is a SEM image of the coal-based active coke obtained in Comparative Example 1 of the present application;

[0036] Figure 10 is a TEM image of the coal-based active coke obtained in Comparative Example 1 of the present application;

[0037] Figure 11 is an XPS spectrum of the coal-based active coke obtained in Comparative Example 1 of the present application;

[0038] Figure 12 is a cyclic voltammetry test curve of the coal-based active coke obtained in Comparative Example 1 of the present application as an electrocatalyst;

[0039] Figure 13 is a rotating ring-disk test curve of the coal-based active coke obtained in Comparative Example 1 of the present application as an electrocatalyst;

[0040] Figure 14 is an XPS spectrum of the coal-based active coke obtained in Comparative Example 2 of the present application;

[0041] Figure 15 is a cyclic voltammetry test curve of the coal-based activated coke obtained in Comparative Example 2 of the present application as an electrocatalyst;

[0042] Figure 16 is a rotating ring-disk test curve of the coal-based activated coke obtained in Comparative Example 2 of the present application as an electrocatalyst;

[0043] Figure 17 is a SEM image of the coal-based activated coke obtained in Comparative Example 3 of the present application;

[0044] Figure 18 is a TEM image of the coal-based activated coke obtained in Comparative Example 3 of the present application;

[0045] Figure 19 is an XPS spectrum of the coal-based activated coke obtained in Comparative Example 3 of the present application;

[0046] Figure 20 is a rotating ring-disk test curve of the coal-based activated coke obtained in Comparative Example 3 of the present application as an electrocatalyst;

[0047] Figure 21 is a nitrogen adsorption isotherm graph of the coal-based activated coke prepared in the present application. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below with reference to the accompanying drawings, in which the same or similar components are denoted by the same or similar reference numerals, and wherein the embodiments described below with reference to the drawings are illustrative only, and are not understood as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and scope of the appended claims.

[0049] Reference Figure 1 As shown in the drawings, according to a first aspect of the present application, a method for structure-oriented regulation of coal-based activated coke is proposed, comprising the steps of:

[0050] S1: crushing, grinding and sieving the shaped coal-based activated coke to obtain activated coke powder with a particle size of hundreds of nanometers;

[0051] S2: placing the activated coke powder in a reducing atmosphere formed by mixing hydrogen and argon, and reducing at 800-1200°C for 0.5-5h, and then reducing to room temperature to obtain reduced activated coke powder;

[0052] S3: placing the reduced activated coke powder in an air atmosphere, an argon atmosphere or a carbon dioxide atmosphere, and ball milling to obtain a ball milling product; wherein the rotation speed during ball milling is 300r / min-1000r / min, and the time is 12-24h.

[0053] S4: The carbon-based electrocatalyst can be obtained by sequentially acid washing and water washing of the ball-milled product and then drying it.

[0054] Specifically, in S1, the shaped coal-based activated coke is refined by crushing, grinding, and sieving the shaped coal-based activated coke using a traditional Chinese medicine crusher to obtain activated coke powder with a particle size of hundreds of nanometers. The shaped coal-based activated coke is a commercially available coal-based activated coke that has already been formed. It can be coal-derived shaped activated coke, and activated coke developed from different types of coal can be used as raw materials. Therefore, the material sources are relatively wide and the cost is extremely low. In this embodiment, the shaped coal-based activated coke is crushed, ground, and sieved into activated coke powder with a particle size of hundreds of nanometers.

[0055] Specifically, S2 is the reduction process, in which the activated coke powder obtained in S1 is placed in an atmosphere furnace and heated at 0.1-10℃ / min in a reducing atmosphere formed by a mixture of hydrogen and argon. -1 The temperature is increased to 800-1200℃ and held for 0.5-5 hours for reduction treatment, then allowed to cool naturally to room temperature to obtain the reduced active coke powder. In this application, the reducing atmosphere formed by mixing hydrogen and argon contains different concentrations of hydrogen and argon in varying ratios; for example, based on the reducing atmosphere, the volume percentage of hydrogen is 5% and the volume percentage of argon is 95%. The heating rate during this process can be exemplified as 0.1℃ / min. -1 1℃min -1 3℃min -1 5℃min -1 7℃min -1 10℃min -1 For example, the heating temperature can be 800℃ / min. -1 900℃min -1 1000℃min -1 1100℃min -1 1200℃min -1 The heat preservation time can be 0.5h, 1h, 2h, 3h, 4h, or 5h. Higher temperatures and longer heat preservation times can easily lead to the graphitization of carbon structures.

[0056] Specifically, the mechanical-chemical treatment process in S3 is to place the reduced active coke powder obtained in S2 into a ball milling tank of a planetary ball mill, and ball milling is performed in an air atmosphere, an argon atmosphere or a carbon dioxide atmosphere. The argon atmosphere is directly introducing argon into the ball milling tank. The carbon dioxide atmosphere is directly introducing dry ice into the ball milling tank, wherein the mass ratio of the dry ice to the reduced active coke powder is 1:0.1-10. Exemplary mass ratios of the dry ice to the reduced active coke powder are 1:0.1, 1:1, 1:3, 1:5, 1:8 and 1:10. In this process, the ball milling tank of the planetary ball mill is made of stainless steel, agate or corundum, the rotation speed of the ball mill is 300-1000 r / min, and the ball milling time is 12-24 h. In this process, the rotation speed of the ball mill can be exemplarily 300 r / min, 400 r / min, 500 r / min, 600 r / min, 800 r / min or 1000 r / min, and the ball milling time can be exemplarily 12 h, 14 h, 15 h, 17 h, 20 h or 24 h.

[0057] In this process, the mechanical-chemical effect induced by the ball milling process can tailor the microcrystalline structure of the reduced active coke powder. For example, the amorphous carbon lattice size and the pore arrangement of the active coke can be controlled by adjusting the ball milling time and the rotation speed, and the types and contents of oxygen-containing functional groups on the carbon basal plane can be controlled by adjusting the ball milling atmosphere and concentration. Therefore, by reasonably adjusting the ball milling process parameters, the multi-scale structure such as the microcrystalline, the pore and the functional group of the ball milling product can be deeply controlled, and a low-cost and high-performance carbon-based catalyst for electrocatalytic synthesis of H2O2 can be developed.

[0058] Specifically, the washing and drying process in S4 is to wash the ball milling product with dilute hydrochloric acid or nitric acid with a concentration of 0.1-2 mol / L for 2-3 times and with water for 2-5 times, and then dry treatment at 60-100°C for 12-24 h to obtain a carbon-based electrocatalyst with reduced amorphous carbon lattice size, rich edge defects, different oxygen doping concentrations and developed mesoporous structure.

[0059] The structural directional control method of the coal-based active coke provided in this embodiment is suitable for the coordinated control of the multi-scale structure of amorphous carbon. The multi-scale structure of the active coke is controlled through the ball milling process assisted by different reaction atmospheres. The overall process flow is simple to operate, no waste gas or waste liquid is generated, and it has the potential for large-scale production. The commercialization prospect is broad. The electrocatalytic performance of the low-cost and high-performance amorphous carbon-based catalyst developed by this method has reached the highest level in the current research. In the alkaline system, the catalyst exhibits high activity (the initial potential is 0.83 V), high selectivity (more than 90%) and stability.

[0060] Example 1

[0061] The shaped coal-based activated coke is crushed, ground and sieved using a traditional Chinese medicine crusher to obtain activated coke powder, and 2.5 g of the activated coke powder is placed in an atmosphere furnace; a reducing atmosphere composed of hydrogen and argon is introduced into the atmosphere furnace, wherein the hydrogen concentration in the reducing atmosphere accounts for 5%, and the gas flow is 150 ml / min; then the temperature is raised to 900°C at a rate of 10°C / min, and the temperature is kept for 2 h to obtain reduced activated coke powder; 0.8 g of the reduced activated coke powder is placed in a ball mill jar made of agate, and 1.3 g of dry ice is directly added into the ball mill jar to form a carbon dioxide atmosphere, and the rotation speed of the ball mill is set to 500 r / min to obtain a ball milling product; the ball milling product is washed with 1 mol / L dilute hydrochloric acid for 3 times and water for 5 times to obtain a cleaned product, which is kept at 80°C for 12 h to obtain a final product, which is marked as AC-CO2B. AC-CO2B is an amorphous carbon lattice size-reduced, edge-defect-rich, different oxygen-doped concentration and mesoporous structure-developed carbon-based electrocatalyst.

[0062] Comparative Example 1

[0063] The shaped Xinhua activated coke is crushed, ground and sieved using a traditional Chinese medicine crusher to obtain activated coke powder; the activated coke powder is washed with 1 mol / L dilute hydrochloric acid for 3 times and water for 5 times to obtain a cleaned product, which is kept at 80°C for 12 h to obtain a final product, which is marked as AC. 5 mg of AC catalyst powder is dispersed in a mixture of Nafion (30 μL) and ethanol (1 mL), and then ultrasonic treatment is performed for 30 min. The prepared catalyst ink is drop-casted on a glass carbon disc (area: 0.246 cm-2), and after drying at room temperature, H2O2 synthesis experiment is carried out

[0064] Comparative Example 2

[0065] The shaped Xinhua activated coke is crushed, ground and sieved using a traditional Chinese medicine crusher to obtain activated coke powder; the activated coke powder is placed in an atmosphere furnace, and the temperature is raised to 900°C at a rate of 10°C / min and kept for 2 h, and then naturally reduced to room temperature to obtain reduced activated coke powder; the reduced activated coke powder is washed with 1 mol / L dilute hydrochloric acid for 3 times and water for 5 times to obtain a cleaned product, which is kept at 80°C for 12 h to obtain a final product, which is marked as AC-H2. 5 mg of AC-H2 catalyst powder is dispersed in a mixture of Nafion (30 μL) and ethanol (1 mL), and then ultrasonic treatment is performed for 30 min. The prepared catalyst ink is drop-casted on a glass carbon disc (area: 0.246 cm-2), and after drying at room temperature, H2O2 synthesis experiment is carried out.

[0066] Comparative Example 3

[0067] The briquetted coal-based activated coke is crushed, ground and sieved using a traditional Chinese medicine crusher to obtain activated coke powder, and 2.5 g of the activated coke powder is placed in an atmosphere furnace; a reducing atmosphere composed of hydrogen and argon is introduced into the atmosphere furnace, wherein the hydrogen concentration in the reducing atmosphere accounts for 5%, and the flow rate of the reducing atmosphere is 150 ml / min; then the temperature is raised to 900°C at a rate of 10°C / min, and the temperature is maintained for 2 h to obtain reduced activated coke powder; 0.8 g of the reduced activated coke powder is placed in a ball mill jar made of agate, and 1.3 g of dry ice is directly added to the ball mill jar to form a carbon dioxide atmosphere, and the rotation speed of the ball mill is set to 500 r / min to obtain a ball milling product; the ball milling product is washed with 1 mol / L hydrochloric acid for 3 times and water for 5 times to obtain a cleaned product, and the cleaned product is maintained at 80°C for 12 h to obtain a final product, which is marked as AC-CO2B; the AC-CO2B is subjected to annealing treatment in an atmosphere furnace, and the annealing treatment process is as follows: the temperature is raised to 800°C at a rate of 10°C / min, and the temperature is maintained for 2 h; the atmosphere in the atmosphere furnace is a mixed atmosphere of hydrogen and argon with a volume fraction of 5%; finally, an annealed product AC-CO2B-Ar is obtained. 5 mg of AC-CO2B and AC-CO2B-Ar catalyst powders are dispersed in a mixture of Nafion (30 μL) and ethanol (1 mL), and then ultrasonic treatment is performed for 30 min. The prepared catalyst ink is drop-casted on a glass carbon disc (area: 0.246 cm-2), and then dried at room temperature to carry out H2O2 synthesis experiments.

[0068] The products in Example 1 and Comparative Examples 1-3 are subjected to performance detection, wherein the AC-CO2B in Example 1, the AC in Comparative Example 1 and the AC-CO2B-Ar in Comparative Example 3 are observed by scanning electron microscopy, wherein Figure 2 The SEM image of the AC-CO2B prepared in Example 1 is shown in the figure, and it can be seen from the figure that the ball milling process can refine the particle size of the activated coke to the order of hundreds of nanometers; Figure 9 The SEM image of the AC prepared in Comparative Example 1 is shown in the figure, and it can be seen from the figure that the AC presents a blocky morphology rather than a granular morphology at the scale of hundreds of nanometers; Figure 17 The SEM image of the AC-CO2B-Ar prepared in Comparative Example 3 is shown in the figure, and it can be seen from the figure that the AC-CO2B-Ar still maintains a particle size of hundreds of nanometers.

[0069] The AC-CO2B in Example 1, the AC in Comparative Example 1 and the AC-CO2B-Ar in Comparative Example 3 are observed by transmission electron microscopy, and the following results are obtained Figure 3 The TEM image of the AC-CO2B prepared in Example 1 shows that the ball-milled activated coke presents an amorphous structure, and almost no graphite-like lattice fringes can be seen; Figure 10 The TEM image of the AC shows that the AC presents an amorphous carbon structure with long-range disorder and short-range order, and obvious graphite-like lattice fringes can be seen;Figure 18 For TEM image of AC-CO2B-Ar, it can be seen that the product still maintains the amorphous carbon structure similar to AC-CO2B.

[0070] And for X-ray photoelectron spectroscopy analysis of AC-CO2B in Example 1, AC in Comparative Example 1, AC-H2 in Comparative Example 2 and AC-CO2B-Ar in Comparative Example 3, wherein Figure 4 For X-ray photoelectron spectroscopy analysis (XPS) of AC-CO2B, it can be seen that the oxygen atom content is 6.82%; Figure 11 For XPS of AC, it can be seen that the oxygen atom content is 5.31%; Figure 14 For XPS of AC-H2 obtained in Comparative Example 2, it can be seen that the oxygen content of AC-H2 is reduced to 3.12%; Figure 19 For XPS of AC-CO2B-Ar, it can be seen that the oxygen atom content is reduced to 3.51%.

[0071] And for cyclic voltammetry test of the electrocatalyst of AC-CO2B in Example 1, AC in Comparative Example 1 and AC-H2 in Comparative Example 2, the results are Figure 5 For cyclic voltammetry test curve (CV) of AC-CO2B under saturated nitrogen and oxygen conditions, it can be seen from the figure that AC-CO2B exhibits oxygen reduction activity under saturated oxygen conditions; Figure 12 For CV curve of AC under saturated nitrogen and oxygen conditions, it can be seen from the figure that AC exhibits oxygen reduction activity under saturated oxygen conditions; Figure 15 For cyclic voltammetry test curve (CV) of AC-H2 under saturated nitrogen and oxygen conditions, it can be seen from the figure that AC-H2 still has electrocatalytic activity.

[0072] And for rotating ring disc test of the electrocatalyst of AC-CO2B in Example 1, AC in Comparative Example 1, AC-H2 in Comparative Example 2 and AC-CO2B-Ar in Comparative Example 3, the results are Figure 6 For rotating ring disc test curve (RRDE) of AC-CO2B, it can be seen from the figure that the ball milling product has high electrocatalytic activity, and the initial potential is 0.83V; Figure 13 For RRDE test curve of AC, the overpotential and selectivity calculated are both reduced compared with AC-CO2B; Figure 16 For rotating ring disc test curve (RRDE) of AC-H2, it presents the lowest oxygen reduction activity. Figure 20 For RRDE test curve of AC-CO2B-Ar, it can be calculated from the figure that AC-CO2B-Ar still has high oxygen reduction activity, but the 2-electron path selectivity is significantly reduced.

[0073] And the rotating disc test and stability test of the electrocatalyst of AC-CO2B in Example 1, Figure 7 The selectivity obtained for the RDE test curve of AC-CO2B reached more than 90%; Figure 8 The electrocatalytic stability test curve of AC-CO2B, AC-CO2B still maintained stability after 20h stability test at 0.5V (RHE).

[0074] And nitrogen adsorption test was carried out on AC-CO2B in Example 1, AC in Comparative Example 1, AC-H2 in Comparative Example 2 and AC-CO2B-Ar in Comparative Example 3, as shown in Figure 21 Figure 21 The nitrogen adsorption isotherm graph, compared with AC and AC-H2, it can be seen that AC-CO2B and AC-CO2B-Ar have similar and more developed pores.

[0075] It should be noted that in the description of the present application, the terms "first", "second" and the like are used only for the purpose of description and should not be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0076] Any process or method descriptions in flow charts or described elsewhere herein can be understood as representing code modules, segments, or portions of code that include one or more executable instructions for implementing specific logic functions (or steps) in the process, and the various embodiments of the application include additional implementations in which the functions are performed in a different order, or are performed substantially concurrently, or are performed in reverse order, or are performed in an alternative manner, as will be understood by those skilled in the art. The various embodiments of the application include additional implementations in which the functions are performed in a different order, or are performed substantially concurrently, or are performed in reverse order, or are performed in an alternative manner, as will be understood by those skilled in the art.

[0077] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any of the at least one embodiment or example.

[0078] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.​

Claims

1. A method for structural directional regulation of coal-based activated coke, characterized in that, The method comprises the steps of: crushing, grinding and screening the briquette to obtain a nano-sized active coke powder; The active coke powder is placed in a reducing atmosphere formed by mixing hydrogen and argon, heated at 800-1200℃ for 0.5-5h, and then cooled to room temperature to obtain reduced active coke powder; when the active coke powder is heated in the reducing atmosphere, the heating rate is 0.1-10℃ / min -1 ; based on the reducing atmosphere, the volume percentage of hydrogen is 5%, and the volume percentage of argon is 95%. ball-milling the reduced active coke powder in an air atmosphere, an argon atmosphere or a carbon dioxide atmosphere to obtain a ball-milled product; wherein the rotation speed is 300 r / min-1000 r / min and the time is 12-24 h; subjecting the ball-milled product to acid washing and water washing in sequence and then drying to obtain the carbon-based electrocatalyst.

2. The method of claim 1, wherein, The ball-milling tank is made of stainless steel, agate or corundum.

3. The control method according to claim 2, characterized in that, The argon atmosphere is obtained by directly introducing argon into the ball-milling tank.

4. The method of claim 2 or 3, wherein, The carbon dioxide atmosphere is obtained by directly introducing dry ice into the ball-milling tank, wherein the mass ratio of the dry ice to the reduced active coke powder is 1:0.1-10.

5. The method of claim 1, wherein the step of modulating comprises: The acid washing method is to clean the ball-milled product with dilute hydrochloric acid or nitric acid with a concentration of 0.1-2 mol / L for 2-3 times.

6. The method of claim 1 or 5, wherein, The ball-milled product is washed with water for 2-5 times and then dried at 60-100 ℃ for 12-24 h to obtain the carbon-based electrocatalyst.

7. A carbon-based electrocatalyst based on the directional regulation of a coal-based activated coke structure, characterized in that, The carbon-based electrocatalyst is prepared by the method of any one of claims 1-6, is amorphous carbon with a sub-nanometer lattice size, is rich in edge defects and different oxygen doping concentrations, and has a mesopore ratio of greater than 50%.

8. The carbon-based electrocatalyst of claim 7, wherein, The carbon-based electrocatalyst is an alkaline system catalyst with an initial potential of 0.83 V and a selectivity of greater than 90%.

9. Use of the carbon-based electrocatalyst according to claim 7 or 8 for catalysing the synthesis of H2O2, characterised in that, The carbon-based electrocatalyst electrocatalytically synthesizes H2O2.

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