A doped porous carbon and a preparation method and application thereof

Abstract

The application discloses doped porous carbon and a preparation method and application thereof. The doped porous carbon has a black powder-like morphology, a layered structure with a majority of micropores and mesopores, and a structure feature of dispersed heteroatoms on a material surface; a specific surface area is 50-1500 m 2 / g; doped with single-atom dispersed boron atoms and single-atom dispersed nitrogen atoms, a doping amount of the boron atoms is 0.01-10 wt% of a unit sample mass, and a doping amount of the nitrogen atoms is 0.01-10 wt% of the unit sample mass. The preparation method has simple process, mild conditions, low energy consumption, short cycle, good mixing dispersity, high performance, simultaneously introduces a carbon source, a nitrogen source and a boron source, and completes boron doping, boron and nitrogen co-doping and synthesis of a product in one step. By changing the dosages of the nitrogen source and the boron source, the doping amount, the internal pore structure and the specific surface area of the carbon material can be adjusted, and the carbon material exhibits good performance in a thermal catalytic reaction represented by EDC cracking.

Description

Technical Field

[0001] This application relates to a doped porous carbon, its preparation method and application, belonging to the field of porous carbon material preparation technology. Background Technology

[0002] Carbon materials possess abundant pore structures, large specific surface areas, strong adsorption, and high adsorption capacity. Currently, with the rapid development of my country's chemical industry, carbon materials, due to these characteristics, low cost, and environmental friendliness, are widely used in various fields such as adsorption, separation, and catalysis. Porous carbon materials have advantages such as smooth surfaces, controllable pore structures, adjustable pore sizes, and low fluid resistance. Classified by raw materials, they are mainly divided into: wood-based activated carbon, coal-based activated carbon, fruit shell activated carbon, and coconut shell activated carbon. Among them, porous carbon prepared using carbon black as the carbon source aligns with the direction of low-carbon and environmentally friendly development and has broad prospects. Based on this, non-metallic heteroatom doping has been applied to the catalytic cracking of EDC to produce vinyl chloride (VCM), showing excellent results. Among existing catalysts for this type of reaction, boron-doped and boron-nitrogen co-doped catalysts are relatively rare, and there is no research on one-step doping via ball milling. Summary of the Invention

[0003] The purpose of this invention is to propose a porous carbon catalyst applicable to EDC catalytic cracking, and its preparation method. This method is simple, operates under mild conditions, has low energy consumption, a short cycle time, and exhibits good mixing and dispersion. Simultaneously, carbon, nitrogen, and boron sources are introduced, and boron doping is completed in a one-step process. Boron and nitrogen co-doping can improve the active surface and suppress side reactions, thereby increasing the reaction activity. By changing the amounts of nitrogen and boron sources, the internal pore structure and specific surface area of ​​the carbon material can be adjusted, resulting in excellent performance in EDC catalytic cracking reactions and broad application prospects in the field of thermocatalysis.

[0004] According to one aspect of this application, a doped porous carbon is provided, the doped porous carbon having a black powdery morphology, a layered structure with micropores and mesopores predominating, and a structural feature of heteroatoms dispersed on the material surface;

[0005] The specific surface area of ​​the doped porous carbon is 50–1500 m². 2 / g;

[0006] Optionally, the specific surface area of ​​the doped porous carbon is 50 m². 2 / g, 100m 2 / g、200m 2 / g、300m 2 / g、400m 2 / g、500m 2 / g、600m 2 / g、700m 2 / g、800m2 / g、900m 2 / g, 1000m 2 / g、1100m 2 / g、1200m 2 / g、1300m 2 / g, 1400m 2 / g, 1500m 2 Any value in / g or any value between any two of the above points.

[0007] The doped porous carbon is doped with single-atom dispersed boron atoms;

[0008] The amount of boron atoms doped is 0.01 to 10 wt% of the doped porous carbon.

[0009] The doped porous carbon is doped with single-atom dispersed boron atoms and single-atom dispersed nitrogen atoms.

[0010] The amount of nitrogen atoms doped is 0.01 to 10 wt% of the doped porous carbon.

[0011] According to another aspect of this application, a method for preparing the above-mentioned doped porous carbon is provided, comprising the following steps:

[0012] 1) Ball mill and mix the raw materials containing carbon precursor and heteroatom precursor to obtain a mixture;

[0013] 2) The mixture obtained in 1) is mixed with a solvent and hydrochloric acid solution, ball-milled and calcined to obtain the doped porous carbon.

[0014] 1) In,

[0015] The carbon precursor is selected from at least one of carbon black, activated carbon, graphite, and Ketjen black;

[0016] The heteroatom precursor includes a boron precursor;

[0017] The boron precursor is selected from at least one of boric acid, borate, phenylboronic acid and its derivatives, and boron halide;

[0018] Optionally, the heteroatom precursor may further include a nitrogen precursor;

[0019] The nitrogen precursor is selected from at least one of aziridine compounds, amine compounds, nitrogen-boron compounds, and ammonium salts;

[0020] Optionally, the nitrogen precursor is selected from at least one of melamine, dicyandiamide, cyanamide, cyanuric acid diamide, pyridine nitrogen, and boron nitride;

[0021] Optionally, the mass ratio of the carbon precursor to the heteroatom precursor is (0.05-1):1;

[0022] Optionally, the mass ratio of the carbon precursor to the heteroatom precursor is (0.05 to 0.5):1.

[0023] The ball milling speed is 100-500 rpm;

[0024] Optionally, the ball milling speed is 200-400 rpm;

[0025] Optionally, the ball mill speed is selected from any value among 200rpm, 250rpm, 300rpm, 350rpm, and 400rpm, or any value between any two of the above.

[0026] The ball milling mixing time is 1–8 hours;

[0027] Optionally, the ball milling mixing time is 2 to 4 hours.

[0028] Optionally, the ball milling mixing time is selected from any value among 2h, 2.5h, 3h, and 4h, or any value between any two of the above.

[0029] The ball milling mixture also includes the following parameters:

[0030] 10-25 φ1mm ceramic balls; 5-20 φ3mm ceramic balls; 1-15 φ5mm ceramic balls; 1-10 φ8mm ceramic balls; 1-5 φ10mm ceramic balls; The ceramic ball parameters can be selected by mixing any two or more of these sizes.

[0031] Forward and reverse rotation time: any value from 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 60 min, or any range between two of these.

[0032] Intermediate pause time: any value from 1 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, or any range between two of these.

[0033] 2) In,

[0034] The solvent is selected from at least one of water, ethanol, methanol, and propanol;

[0035] The concentration of the hydrochloric acid solution is 1–12 mol / L;

[0036] Optionally, the concentration of the hydrochloric acid solution is any value among 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, 10 mol / L, 11 mol / L, and 12 mol / L, or any value between any two of the above.

[0037] The volume ratio of the solvent to the hydrochloric acid solution is (1-10):1;

[0038] Optionally, the volume ratio of the solvent to the hydrochloric acid solution is (3-8):1;

[0039] The total mass ratio of the solvent and the hydrochloric acid solution to the mass ratio of the mixture obtained in step 1) is (1-10):1;

[0040] Optionally, the total mass ratio of the solvent and the hydrochloric acid solution to the mass ratio of the mixture obtained in step 1) is (1-5):1.

[0041] The mixing is achieved by adding the solvent and the hydrochloric acid solution dropwise to the mixture obtained in step 1);

[0042] Alternatively, the material can be ground and dried simultaneously with the dropwise addition;

[0043] The grinding time is 0.25 to 5 hours;

[0044] Optionally, the grinding time is 0.5 to 1 hour.

[0045] Optionally, the grinding time is selected from any value of 0.5 hours, 1 hour, or any value between any two of the above.

[0046] The drying temperature is 30–150°C;

[0047] Optionally, the drying temperature is 60–100°C.

[0048] Optionally, the drying temperature is selected from any value among 60℃, 70℃, 80℃, 90℃, and 100℃, or any value between any two of the above.

[0049] The ball mill rotates at a speed of 100–500 rpm;

[0050] Optionally, the rotational speed of the ball mill is 200–400 rpm;

[0051] Optionally, the ball mill speed is selected from any value among 200rpm, 250rpm, 300rpm, 350rpm, and 400rpm, or any value between any two of the above.

[0052] The ball milling time is 0.5 to 8 hours;

[0053] Optionally, the ball milling time is 1 to 4 hours;

[0054] Optionally, the ball milling time is selected from any value of 1h, 1.5h, 2h, 2.5h, 3h, 4h or any value between any two of the above points.

[0055] The ball milling mixture also includes the following parameters:

[0056] 10-25 φ1mm ceramic balls; 5-20 φ3mm ceramic balls; 1-15 φ5mm ceramic balls; 1-10 φ8mm ceramic balls; 1-5 φ10mm ceramic balls; The ceramic ball parameters can be selected by mixing any two or more of these sizes.

[0057] Forward and reverse rotation time: any value from 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 60 min, or any range between two of these.

[0058] Intermediate pause time: any value from 1 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, or any range between two of these.

[0059] The calcination temperature is 400–1000℃;

[0060] Optionally, the calcination temperature is 600–1000°C;

[0061] Optionally, the calcination temperature is any value among 600℃, 700℃, 800℃, 900℃, and 1000℃, or any value between any two of the above.

[0062] The calcination time is 1 to 12 hours;

[0063] Optionally, the calcination time is 2 to 4 hours;

[0064] Optionally, the calcination time is any value among 2h, 3h, and 4h, or any value between any two of the above.

[0065] The calcination atmosphere is a non-reactive gas atmosphere;

[0066] The inactive gas is selected from at least one of nitrogen, argon, and helium.

[0067] The ball milling mixing and ball milling parameters mentioned above will affect whether the material adheres to the wall.

[0068] According to another aspect of this application, a dichloroethane cracking catalyst is provided, wherein the dichloroethane cracking catalyst is selected from the doped porous carbon described above or the doped porous carbon prepared by the preparation method described above.

[0069] According to another aspect of this application, a method for producing vinyl chloride by cracking dichloroethane is provided, using the above-mentioned dichloroethane cracking catalyst.

[0070] The beneficial effects that this application can produce include:

[0071] This application uses a compound containing N, B, and C elements as a precursor, and introduces nitrogen, boron, and carbon sources to complete doping in a one-step process. The uniformly dispersed mixture is then calcined to obtain boron-doped porous carbon or boron-nitrogen co-doped porous carbon. This preparation method is simple, energy-efficient, and has a short cycle time, achieving boron doping and boron-nitrogen co-doping in a single step. In EDC pyrolysis reactions, it can increase active sites and suppress side reactions, thereby increasing reactivity. It also significantly reduces the cumbersome steps in traditional catalyst preparation processes, offering significant economic and environmental benefits and showing broad application prospects in the field of thermocatalysis. Attached Figure Description

[0072] Figure 1 This is the BET diagram of porous carbon obtained in Example 1 of the present invention.

[0073] Figure 2 This is the BET diagram of porous carbon obtained in Example 3 of the present invention.

[0074] Figure 3 This is the BET diagram of porous carbon obtained in Example 6 of the present invention.

[0075] Figure 4 This is the BET diagram of porous carbon obtained in Example 8 of the present invention.

[0076] Figure 5 The images shown are SEM images of porous carbon spheres obtained in Examples 1, 5, 6, and 10 of this invention ((a) SEM image of Example 1, (b) SEM image of Example 5, (c) SEM image of Example 6, and (d) SEM image of Example 10).

[0077] Figure 6 The images are AC-TEM images of porous carbon spheres obtained in Examples 3 and 8 of the present invention ((a) AC-TEM image of Example 3, (b) AC-TEM image of Example 8). Detailed Implementation

[0078] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0079] Unless otherwise specified, the raw materials and reagents used in the embodiments of this application were purchased commercially and used directly without processing.

[0080] The measuring instruments used in the embodiments of this application are as follows: the specific surface area of ​​the porous carbon spheres was tested using a QuantaChrome quadruple-station physisorption spectrometer (Quadrasorb S); the boron doping amount of the porous carbon prepared in Examples 3, 4, 8, and 9 was characterized using a PerkinElmer CP-OES 7300DV type ICP-OES; the nitrogen doping amount of the porous carbon prepared in Examples 3 and 4 was characterized using a Lehman 3000 type EA; SEM testing was performed using a SU8220 instrument to characterize the porous carbon spheres prepared in Examples 1, 5, 6, and 10. The single-atom dispersion was characterized using a JEM-ARM200F AC-TEM manufactured by Nippon Electronics for Examples 3 and 8.

[0081] Comparative Example 1

[0082] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 1100℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0083] The specific surface area measured using nitrogen physical adsorption is 379 m². 2 / g. In the EDC pyrolysis reaction, the VCM yield is 2%.

[0084] Comparative Example 2

[0085] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 300℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0086] The specific surface area measured by nitrogen physical adsorption is 85 m². 2 / g. In the EDC pyrolysis reaction, the VCM yield was 0.6%.

[0087] Comparative Example 3

[0088] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 3 x 10mm ceramic balls; 12 x 1mm ceramic balls; forward and reverse rotation time: 30min, pause time: 5min). Place the mixture in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. After drying, take the sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place it in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0089] The specific surface area measured by nitrogen physical adsorption is 412 m². 2 / g. In the EDC pyrolysis reaction, the VCM yield was 17.2%.

[0090] Comparative Example 4

[0091] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 1.5ml hydrochloric acid solution (12mol / L) and 7.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0092] The specific surface area measured by nitrogen physical adsorption is 310 m². 2 / g. In the EDC pyrolysis reaction, the VCM yield was 12.0%.

[0093] Comparative Example 5

[0094] Mix 0.3g Ketjen black and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 1100℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0095] The specific surface area, measured by nitrogen physical adsorption, is 265 m². 2 / g. In the EDC pyrolysis reaction, the VCM yield was 1.2%.

[0096] Comparative Example 6

[0097] Mix 0.3g Ketjen black and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 300℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0098] The specific surface area measured by nitrogen physical adsorption is 52 m². 2 / g. In the EDC pyrolysis reaction, the VCM yield was 0.5%.

[0099] Example 1

[0100] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0101] The specific surface area measured using nitrogen physical adsorption is 982 m². 2 / g, see Figure 1 SEM can be used to observe surface morphology, see... Figure 5 (a) shows that in the EDC pyrolysis reaction, the VCM yield was 34%.

[0102] Example 2

[0103] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 700℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0104] The specific surface area, measured using nitrogen physical adsorption, is 543 m². 2 / g, see Figure 2 In the EDC pyrolysis reaction, the VCM yield was 15%.

[0105] Example 3

[0106] Mix 0.3g Ketjen black, 12g melamine, and 4g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0107] The specific surface area measured by nitrogen physical adsorption is 1104 m². 2 / g. ICP analysis revealed boron and nitrogen doping levels of 3.27 wt% and 5.01 wt%, respectively. The circled areas in the AC-TEM images show boron atom doping, indicating single-atom dispersion of boron on the carbon material surface. Figure 6 (a) shows that in the EDC pyrolysis reaction, the VCM yield was 61%.

[0108] Example 4

[0109] Mix 0.3g Ketjen black, 12g melamine, and 4g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 700℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0110] The specific surface area measured using nitrogen physical adsorption is 665 m². 2 / g. ICP analysis revealed boron and nitrogen doping levels of 4.68 wt% and 4.85 wt% respectively. Its VCM yield in the EDC pyrolysis reaction was 22%.

[0111] Example 5

[0112] Mix 0.3g Ketjen black, 12g melamine, and 2g boric acid, and ball mill at 400rpm for 4 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 2 hours (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron and nitrogen co-doped porous carbon.

[0113] The specific surface area, measured using nitrogen physical adsorption, is 969 m². 2 / g. Surface morphology can be observed using SEM, see [link / g]. Figure 5 (b) shows that in the EDC pyrolysis reaction, the VCM yield was 31%.

[0114] Example 6

[0115] Mix 0.3g Ketjen black and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0116] The specific surface area measured using nitrogen physical adsorption is 949 m². 2 / g, see Figure 3 SEM can be used to observe surface morphology, see... Figure 5 (c) shows that in the EDC pyrolysis reaction, the VCM yield was 42%.

[0117] Example 7

[0118] Mix 0.3g Ketjen black and 2g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 700℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0119] The specific surface area measured by nitrogen physical adsorption is 502 m². 2 / g, see Figure 4 In the EDC pyrolysis reaction, the VCM yield was 11%.

[0120] Example 8

[0121] Mix 0.3g Ketjen black and 4g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0122] The specific surface area measured using nitrogen physical adsorption is 965 m². 2 / g. ICP analysis showed a boron doping concentration of 4.13 wt%. The circled areas in the AC-TEM images show boron atom doping, indicating single-atom dispersion of boron on the carbon material surface. Figure 6 (b) shows that in the EDC pyrolysis reaction, the VCM yield was 58%.

[0123] Example 9

[0124] Mix 0.3g Ketjen black and 4g boric acid, and ball mill at 400rpm for 2 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in a 60℃ oven. Take the dried sample and continue ball milling at 400rpm for 1 hour (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 700℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0125] The specific surface area measured using nitrogen physical adsorption is 379 m². 2 / g. ICP analysis showed a boron doping level of 5.08 wt%. Its VCM yield in the EDC pyrolysis reaction was 26%.

[0126] Example 10

[0127] Mix 0.3g Ketjen black and 2g boric acid, and ball mill at 400rpm for 4 hours (milling parameters: 6 φ5mm ceramic balls; 12 φ3mm ceramic balls; forward and reverse rotation time: 5min, intermediate pause time: 1min). Place in a mortar, add 2.5ml hydrochloric acid solution (12mol / L) and 12.5ml anhydrous ethanol, and grind to ensure sufficient contact between the powder and the mixed solution. Grind until the ethanol evaporates, and dry in an 80℃ oven. Take the dried sample and continue ball milling at 400rpm for 2 hours (milling parameters as above), then place in a tube furnace and calcine under a nitrogen atmosphere. The temperature is programmed to rise to 900℃ and calcine at a constant temperature for 2 hours to complete carbonization, obtaining boron-doped porous carbon.

[0128] The specific surface area, measured by nitrogen physical adsorption, is 932 m². 2 / g. Surface morphology can be observed using SEM, see [link / g]. Figure 5 (d) In the EDC pyrolysis reaction, the VCM yield was 38%.

[0129] Example 11 Morphology and structural characterization of porous carbon

[0130] Figures 1-4 BET characterization was performed on the porous carbon obtained in Examples 1, 2, 6, and 7, respectively, demonstrating that a porous structure with a large specific surface area was obtained after doping. The porous carbon spheres in Examples 1-10 were subjected to SEM and AC-TEM using scanning electron microscopy. Examples 1, 5, 6, and 10 are typical examples, yielding... Figure 5 The results shown reveal the boron and nitrogen doping and the porous structure. Examples 3 and 8 are typical examples, yielding the following results: Figure 6 The results shown demonstrate the single-atom dispersion of boron on the surface of the carbon material.

[0131] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A doped porous carbon, characterized in that, The doped porous carbon has micropores and mesopores; The specific surface area of ​​the doped porous carbon is 50~1500 m². 2 / g; The doped porous carbon is doped with single-atom dispersed boron atoms; The amount of boron atoms doped is 0.01~10 wt% of the doped porous carbon. The doped porous carbon is prepared by the following method: 1) Ball mill and mix the raw materials containing carbon precursors and heteroatom precursors to obtain a mixture; 2) The mixture obtained in 1) is mixed with a solvent and hydrochloric acid solution, ball-milled and calcined to obtain the doped porous carbon; The mixing process involves adding the solvent and the hydrochloric acid solution dropwise to the mixture obtained in step 1), while simultaneously grinding and drying the mixture. The calcination temperature is 600~1000℃.

2. The doped porous carbon according to claim 1, characterized in that, The doped porous carbon is doped with single-atom dispersed boron atoms and single-atom dispersed nitrogen atoms. The amount of nitrogen atoms doped is 0.01 to 10 wt% of the doped porous carbon.

3. A method for preparing doped porous carbon according to any one of claims 1 or 2, characterized in that, Includes the following steps: 1) Ball mill and mix the raw materials containing carbon precursors and heteroatom precursors to obtain a mixture; 2) The mixture obtained in 1) is mixed with a solvent and hydrochloric acid solution, ball-milled and calcined to obtain the doped porous carbon; The mixing process involves adding the solvent and the hydrochloric acid solution dropwise to the mixture obtained in step 1), while simultaneously grinding and drying the mixture. The calcination temperature is 600~1000℃.

4. The preparation method according to claim 3, characterized in that, 1) In, The carbon precursor is selected from at least one of carbon black, activated carbon, graphite, and Ketjen black. The heteroatom precursor includes a boron precursor; The boron precursor is selected from at least one of boric acid, borate, phenylboronic acid, and boron halide; The heteroatom precursor also includes a nitrogen precursor; The nitrogen precursor is selected from at least one of aziridine compounds, amine compounds, nitrogen-boron compounds, and ammonium salts; The mass ratio of the carbon precursor to the heteroatom precursor is (0.05~1):

1.

5. The preparation method according to claim 4, characterized in that, In 1), the nitrogen precursor is selected from at least one of melamine, dicyandiamide, cyanamide, cyanuric acid diamide, pyridine nitrogen, and boron nitride; The mass ratio of the carbon precursor to the heteroatom precursor is (0.05~0.5):

1.

6. The preparation method according to claim 3, characterized in that, 1) In, The ball milling speed is 100~500 rpm; The ball milling mixing time is 1 to 8 hours.

7. The preparation method according to claim 3, characterized in that, In step 1), the ball milling speed is 200~400 rpm; The ball milling mixing time is 2-4 hours.

8. The preparation method according to claim 3, characterized in that, 2) In, The solvent is selected from at least one of water, ethanol, methanol, and propanol; The concentration of the hydrochloric acid solution is 1~12 mol / L; The volume ratio of the solvent to the hydrochloric acid solution is (1~10):1; The total mass ratio of the solvent and the hydrochloric acid solution to the mass ratio of the mixture obtained in step 1) is (1~10):

1.

9. The preparation method according to claim 3, characterized in that, In step 2), the volume ratio of the solvent to the hydrochloric acid solution is (3~8):1; The total mass ratio of the solvent and the hydrochloric acid solution to the mass ratio of the mixture obtained in step 1) is (1~5):

1.

10. The preparation method according to claim 3, characterized in that, 2) In, The grinding time is 0.25~5 hours; The drying temperature is 30~150℃.

11. The preparation method according to claim 3, characterized in that, In step 2), the grinding time is 0.5~1h; The drying temperature is 60~100℃.

12. The preparation method according to claim 3, characterized in that, 2) In, The ball mill rotates at a speed of 100~500 rpm; The ball milling time is 0.5~8 hours; The calcination time is 1~12 hours; The calcination atmosphere is a non-reactive gas atmosphere; The inactive gas is selected from at least one of nitrogen, argon, and helium.

13. The preparation method according to claim 3, characterized in that, The ball mill rotates at a speed of 200-400 rpm; The ball milling time is 1-4 hours; The calcination time is 2-4 hours.

14. A dichloroethane cracking catalyst, characterized in that, The dichloroethane cracking catalyst is selected from the doped porous carbon according to any one of claims 1 or 2, or the doped porous carbon prepared by the preparation method according to any one of claims 3 to 13.

15. A method for producing vinyl chloride by cracking dichloroethane, characterized in that, The dichloroethane cracking catalyst described in claim 14 is used.

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