CN115924911A - Preparation method of porous carbon material - Google Patents

Preparation method of porous carbon material Download PDF

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CN115924911A
CN115924911A CN202211598411.6A CN202211598411A CN115924911A CN 115924911 A CN115924911 A CN 115924911A CN 202211598411 A CN202211598411 A CN 202211598411A CN 115924911 A CN115924911 A CN 115924911A
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porous carbon
drying
activating agent
solution
deionized water
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林立
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Abstract

A preparation method of a porous carbon material belongs to the fields of chemical industry and energy. The method comprises the following steps: drying and crushing the carbon source material, wherein the granularity is subject to passing through a 50-mesh sieve to obtain a porous carbon precursor; weighing an activating agent, dissolving activating agent powder in deionized water, and adding a passivating agent to prepare a suspension solution; soaking the porous carbon precursor in the solution, uniformly stirring, then evaporating deionized water to dryness to obtain a mixture, transferring the mixture into a sealed electric furnace with inert atmosphere protection, heating the electric furnace to 650-950 ℃ at the speed of 5-20 ℃/min to activate for 0.5-2h, and naturally cooling to room temperature to obtain an activated material; sequentially adopting acid solution and deionized water until the pH value is 7-7.5, and drying. According to the invention, the concentration of the activating agent contacted with the surface of the porous carbon precursor particle is properly reduced by properly passivating the activating agent, the average number of pores grown by a single carbon particle in the activating process is effectively controlled, and the preparation of the porous carbon with medium-low specific surface and uniformly distributed pores is realized.

Description

Preparation method of porous carbon material
Technical Field
The invention belongs to the field of chemical industry and energy, and particularly relates to a preparation method of a porous carbon material.
Background
Porous carbon, also called activated carbon, is a class of functional carbon materials and is widely used in the fields of sewage treatment, environmental protection, catalytic chemical industry, energy and the like. Generally, porous carbon materials are generally desired to have the following characteristics: uniform pore size distribution, developed pore structure, large pore volume and large specific surface area. The pore size distribution of the porous carbon material commercially used in each field is different according to the application field, and generally, the specific surface area is 1000m on the basis of uniform pore size distribution 2 More than g. In general, when porous carbon is applied to a capacitor, the larger the specific surface area is, the better the performance in each aspect is. In addition, in the traditional method for preparing the porous carbon material, in order to obtain a larger specific surface area, the carbonization temperature is not high and is generally not more than 1000 ℃, the graphitization degree is low, a carbon six-ring structure which is relatively orderly normalized cannot be obtained, the large pi bond is weaker, and the electronic conductivity is poor. In the fabrication of energy storage devices, it is often necessary to add large amounts of conductive agents to improve electron conductivity. The added conductive agent is in physical contact with the porous carbon particles, agglomeration and other non-uniform conditions are easy to occur in the mixing process, and the improvement of the electronic conductivity is limited.
In addition, the larger the specific surface area, the smaller the average cell wall thickness of the supporting cell structure. For the following application scenarios: the porous carbon material is used as a carrier of an energy storage material and compounded with the energy storage material to prepare the carbon composite material, and at the moment, if the specific surface of the porous carbon is too large, the average pore wall thickness is relatively thin, so that the possibility of collapse and fracture of a pore structure caused by too large volume expansion in energy storage application is caused, and the performance is deteriorated in the using process. [ Activated-phosphor as new electrode material for Li-ion batteries. C. Marino, A. Debenedetti, B. Fraisse, F. Viewer, L. Monconduit. Electrochemistry Communications 13 (2011) 346-349; rational Assembly of Hollow Microporous Carbons Spheres as P Hosts for Long-Life Sodium-Ion batteries.S.Yao, J.Cui, J.Huang, J.Huang, W.G.Chong, L.Qin, Y-W.Mai, J-K.Kim, adv.energy matrix.2018, 8,1702267.]. In this case, the larger the specific surface, the thinner the average pore wall thickness, and the possibility of the pore structure of the adsorbed substance being broken during expansion is present. While the simple use of increasing the carbonization temperature, for example, the carbonization temperature is above 1200 [ [ Buiel E R, george A E, dahn J R.model of microporous closure in hard carbon pre-separated from cross [ J ]].Carbon，1999，37(9)：1399-1407.]The carbon atom structure order degree can be improved, the electronic conductivity is improved, the large-area structure collapse of the pore structure can be caused, the proportion of the medium and large pores is increased, and at the moment, although the specific surface can also be reduced, the pore wall thickness is difficult to guarantee, and the requirements can not be met. In view of the above, in such special fields, it is necessary toPorous carbon material with uniform pore structure distribution and pore diameter distribution, 1-10nm of pore diameter, moderate specific surface area and thicker pore wall thickness (the specific surface area is 200-800 m) 2 /g) while the porous carbon material is required to have as high intrinsic electron conductivity as possible, increasing the electron conductivity of the material after compounding from the atomic scale. The porous carbon material meeting the requirements has relatively larger average pore wall thickness and higher pore wall supporting strength due to small pore volume, and can meet the special application requirements.
In the traditional method for preparing the porous carbon material, naOH or KOH or high-temperature steam is mostly adopted as an active agent, and the active agent is fully mixed and contacted with a porous carbon precursor, and reacts at a high temperature to carry out an activation pore-forming reaction. In order to obtain the largest specific surface area, the traditional porous carbon activation process generally has large concentration and using amount of the activating agent, and the mass ratio of the activating agent to the porous carbon raw material is often larger>1, the reaction in the pore-forming process is very violent, the activation reaction strength is not easy to control, and the obtained porous carbon material is generally 1000m 2 Above/g, a porous carbon material having a medium-low specific surface and a uniform pore distribution cannot be produced.
Disclosure of Invention
The first purpose of the invention is to solve the problem that the traditional preparation process of the porous carbon material can not prepare the porous carbon material with the aperture of 1-10nm, uniform aperture distribution and specific surface area of 200-800m 2 The problem of/g is to provide a preparation method of a porous carbon material, which adopts an activating agent passivation technology to realize the preparation of the porous carbon with medium and low specific surface area, the pore size distribution is uniform, the pore size distribution is mainly between 1 and 10nm, and the specific surface area is 300 to 1000m 2 Per g, the pore volume accounts for more than 40 percent of the total pore volume, and the total pore volume is 0.2 to 0.5cm 3 Per g, micropore volume of 0.1-0.3 cm 3 The porous structure is uniformly distributed, has larger wall thickness, and can be used for preparing various porous composite materials.
In order to achieve the purpose, the first technical scheme adopted by the invention is as follows:
a preparation method of a porous carbon material adopts a modified alkali activation method, and the method specifically comprises the following steps:
the method comprises the following steps: drying and crushing the carbon source material, wherein the granularity is subject to passing through a 50-mesh sieve to obtain a porous carbon precursor;
step two: weighing an activating agent, wherein the mass ratio of the activating agent to the porous carbon precursor is 1:1 to 100; after weighing, dissolving activator powder in deionized water, and adding a passivator to prepare a suspension solution; soaking the porous carbon precursor in the solution, uniformly stirring, heating and cooking until deionized water is evaporated to dryness to obtain a uniformly mixed mixture of an activating agent, a passivating agent and the porous carbon precursor, transferring the uniformly mixed mixture into a sealed electric furnace with inert atmosphere protection, heating the electric furnace to 650-950 ℃ at the speed of 5-20 ℃/min for activation for 0.5-2h, and naturally cooling to room temperature after activation to obtain an activated material;
step three: and washing the activated material by using an acid solution until the pH value of a water washing solution is between 8 and 9, finally washing the activated material by using deionized water until the pH value of the water washing solution is between 7 and 7.5, and drying to obtain the porous carbon material.
In the preparation method of the porous carbon, the passivating agent and the activating agent passivation technology combined with the preparation of the dilute solution are adopted, so that the concentration of the activating agent contacted with the surfaces of the porous carbon precursor particles is properly reduced, the average number of pores grown by a single carbon particle in the activation process is effectively controlled, and the preparation of the porous carbon with medium-low specific surface and uniformly distributed pores is realized. The carbon wall thickness is greater from cell to cell due to the reduction in the average number of cells possessed by a single carbon particle.
Further, in the first step, the carbon source is one or more of anthracite, petroleum coke and biomass, and the biomass is one or more of coconut shell carbonized material, shell carbonized material and rice hull carbonized material; the biomass is subjected to pre-carbonization treatment, the pre-carbonization treatment is a method known in the field, and the biomass is preferably a coconut shell carbonized material; the drying is evaporating, drying or sun drying, if the evaporating method is adopted, the temperature is 50-160 ℃, preferably the drying temperature is 70-130 ℃, and the drying degree is based on that the water content is less than 15 wt.%; the drying is further preferably carried out under vacuum conditions, the vacuum being less than 10Pa.
Further, in the second step, the activating agent is one or more of potassium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide and zinc chloride, and preferably potassium hydroxide; the mixing mode is a mechanical mixing or dipping method, and mechanical mixing is preferred; in the suspension solution, the total mass concentration of the active agent and the passivating agent in the solution is 5-15%; the mass ratio of the activating agent to the porous carbon precursor is 1:2-50, preferably 1:2-10.
Further, in the second step, the passivating agent is SiC or SiO 2 One or more of; the median diameter D50 of the particle size of the passivator is 0.05-5 mu m, preferably 0.3-2 mu m; the mass ratio of the passivator to the activator is 1:1-10, preferably 1:1-4; the inert atmosphere is one or more of nitrogen, helium or argon; the activation temperature is 750-870 ℃, and the activation time is 0.5-1 h.
Further, in the third step, the acid solution is one or more of dilute hydrochloric acid, dilute sulfuric acid, dilute hydrofluoric acid or dilute nitric acid, and the concentration is preferably 0.1-0.5 mol/L.
The second purpose of the invention is to solve the problem that the traditional preparation process of the porous carbon material can not prepare the porous carbon material with high electronic conductance, uniform pore size distribution and specific surface area of 200-800m 2 The method adopts a potassium-based compound as an activating agent, combines a high-temperature activation process, realizes the preparation of the porous carbon with high electronic conductivity and medium-low specific surface area, has concentrated and uniform pore size distribution and larger wall thickness of a pore structure, and realizes the synergistic effect of a moderate pore structure and a graphitized structure. The specific surface area of the material is 200-800m 2 (g) the powder electronic resistivity is 0.3-0.02 ohm.m 2 Per meter, the pore volume of the pore size distribution in the range of 1-10nm accounts for more than 40 percent of the total pore volume, and the total pore volume is 0.2-0.5 cm 3 Per g, micropore volume of 0.1-0.3 cm 3 And the pore structure is uniformly distributed. The invention can be used as a carrier of an energy storage device and used for preparing various porous composite materials.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a porous carbon material comprises the following steps:
the method comprises the following steps: drying and crushing the carbon source material, wherein the granularity is subject to passing through a 50-mesh sieve to obtain a porous carbon precursor;
step two: weighing a potassium-based compound activator, wherein the mass ratio of the activator to the porous carbon precursor is 1:1 to 100; after weighing, dissolving activator powder in deionized water to prepare a solution with the concentration of 5-30%; soaking the porous carbon precursor in the solution, uniformly stirring, heating and cooking until deionized water is evaporated to dryness to obtain a uniformly mixed mixture of an activating agent and the porous carbon precursor, transferring the uniformly mixed mixture into a sealed electric furnace with inert atmosphere protection, heating the electric furnace to 1200-1800 ℃ at the speed of 5-20 ℃/min for activation for 0.2-2h, and naturally cooling to room temperature after activation to obtain an activated material;
step three: and washing the activated material by using an acid solution until the pH value of a water washing solution is between 8 and 9, finally washing the activated material by using deionized water until the pH value of the water washing solution is between 7 and 7.5, and drying to obtain the porous carbon material.
In the preparation method of the porous carbon, a potassium-based compound is used as an activating agent, and the catalytic graphitization of potassium simple substance generated by the potassium-based activating agent at high temperature of more than 900 [ Zhang J, zhang C, zhao Y, et al, three dimensional factory-layer porous carbon reagents reduction [ J ]. Applied Catalysis B: environmental,2017, 211:148-156 ], so that the carbon atom order degree is improved, the formation of a graphite sheet structure is facilitated, the conversion is carried out on the graphite sheet structure to a porous graphene material, and the electronic conductivity of the porous carbon material is improved; in addition, the concentration of the activating agent contacted with the surfaces of the porous carbon precursor particles is properly reduced, the average number of pores grown by a single carbon particle in the activation process is effectively controlled, the activation pore-forming strength is reduced, the situation that the pore structure of the produced pores collapses at high temperature is avoided, and the preparation of the porous carbon material with low resistivity, moderate specific surface and uniformly distributed pores is realized. Due to the reduction of the average number of pores possessed by a single carbon particle, the carbon wall thickness between pores is larger, and the carbon wall can bear larger volume expansion when being used as an energy storage device carrier.
Further, in the first step, the carbon source is one or more of anthracite, petroleum coke and biomass, and the biomass is one or more of coconut shell carbonized material, shell carbonized material and rice hull carbonized material; the biomass is subjected to pre-carbonization treatment, the pre-carbonization treatment is a method known in the field, and the biomass is preferably a coconut shell carbonized material; the drying is evaporating, drying or sun drying, if the evaporating method is adopted, the temperature is 50-160 ℃, preferably the drying temperature is 70-130 ℃, and the drying degree is based on that the water content is less than 15 wt.%. The drying is further preferably carried out under vacuum conditions, the vacuum being less than 10Pa.
Further, in the second step, the potassium-based compound activator is K 2 CO 3 KOH and KHCO 3 One or a mixture of several of them; the mass ratio of the activating agent to the porous carbon precursor is 1:2 to 50, preferably 1:1 to 10; the inert atmosphere is one or more of nitrogen, helium or argon.
Further, in the second step, the activation temperature is 1300-1700 ℃, and the activation time is 0.3-1 h.
Further, in the third step, the acid solution is one or a mixture of more of dilute hydrochloric acid, dilute sulfuric acid or dilute nitric acid, and the concentration is preferably 0.1-0.5 mol/L.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
(1) When the added passivating agent is SiC, because the SiC material is a chemical inert substance, even if hydrofluoric acid is used for pickling, the SiC particles with nanometer to submicron order can not be effectively removed, and finally, the SiC particles with nanometer to submicron order are remained among the porous carbon materials. Because the size of the selected SiC particles is far larger than the pores of the porous carbon, the SiC particles can not block the pore structure of the porous carbon. Because SiC is a substance with very stable physical and chemical properties, the subsequent application of the porous carbon cannot be influenced; and because the SiC particles are in a nanometer-submicron grade, when the SiC particles are used in an electrode material, the SiC particles can also serve as a buffer pool for adsorbing electrolyte, so that the liquid retention capacity of the electrode electrolyte is improved.
(2) The porous carbon material prepared by the invention has the advantages that the pore size distribution is between 1 and 10nm, the pore size distribution range is narrow, the pore size distribution and the specific surface area are controllable and adjustable in a certain range, and the preparation method is obviously superior to the traditional preparation method of the porous carbon material. In addition, the method has the advantages of low cost of required raw materials, simple process flow, no need of great modification on the existing mature porous carbon material production line equipment, and suitability for industrial production.
(3) In the preparation method, the concentration of the activating agent contacted with the surfaces of the porous carbon precursor particles is properly reduced by properly passivating the activating agent, the average number of pores grown by a single carbon particle in the activating process is effectively controlled, and the preparation of the porous carbon with medium-low specific surface and uniformly distributed pores is realized. A greater thickness of the hole wall is obtained due to the reduction in the average number of holes occupied per unit area.
(4) In the preparation method, the total amount proportion of the required alkali active agent is reduced compared with the traditional process, and the acid demand in the subsequent acid washing process is correspondingly reduced, so that the corrosion of a reactor is reduced, the environmental-friendly treatment pressure of the later stage is reduced, and the production cost is reduced.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
(1) The porous carbon material prepared according to the invention has the specific surface area of 200-800m 2 Per gram, total pore volume of 0.2-0.5 cm 3 Per g, micropore volume of 0.1-0.3 cm 3 (iv) g, an average pore diameter of about 1 to 10nm, and a powder resistivity of about 0.3 to 0.02 ohm-m 2/m. When the porous carbon material is used as a carrier of an energy storage device, the porous carbon material has a moderate specific surface area and a thicker pore wall, can bear larger volume expansion, and has lower intrinsic resistivity. In addition, the method has the advantages of low cost of required raw materials, simple process flow, no need of great modification on the existing mature porous carbon material production line equipment, and suitability for industrial production.
(2) In the preparation method, a potassium-based compound is selected as an active agent, the catalytic graphitization effect of a potassium simple substance generated by the potassium-based compound at high temperature is utilized, and the application of a high-temperature carbonization process is combined, so that the carbon microcrystal evolves from an amorphous structure to a graphitized structure, the order degree of carbon atoms in the porous carbon is greatly improved, and the intrinsic resistivity of the material is reduced; when the carbon composite material is used as an energy storage device carrier, the intrinsic conductivity of the carbon composite material can be improved, and the electrochemical performance is improved.
(3) In the preparation method, the average number of pores grown by a single carbon particle in the activation process is effectively controlled by properly reducing the concentration of the activating agent contacted with the surface of the precursor particle, and the preparation of the porous carbon material with medium-low specific surface and uniformly distributed pores is realized by combining a high-temperature carbonization process. A greater thickness of the hole wall is obtained due to the reduction in the average number of holes occupied per unit area.
(4) In the preparation method, the total amount proportion of the required alkali active agent is reduced compared with the traditional process, and the acid demand in the subsequent acid washing process is correspondingly reduced, so that the corrosion of a reactor is reduced, the environmental-friendly treatment pressure of the later stage is reduced, and the production cost is reduced.
Drawings
FIG. 1 is a TEM transmission electron micrograph of porous carbon prepared in example 1 of the present invention;
FIG. 2 is a pore size distribution diagram of porous carbon prepared in example 1 of the present invention;
FIG. 3 is a TEM transmission electron micrograph of porous carbon prepared in example 2 of the present invention;
FIG. 4 is a pore size distribution diagram of porous carbon prepared in example 2 of the present invention;
FIG. 5 is a TEM transmission electron micrograph of a porous carbon prepared in example 3 of the present invention;
FIG. 6 is a pore size distribution diagram of porous carbon prepared in example 3 of the present invention;
FIG. 7 is a TEM transmission electron micrograph of a porous carbon prepared in example 4 of the present invention;
FIG. 8 is a pore size distribution diagram of porous carbon prepared in example 4 of the present invention;
FIG. 9 is a TEM transmission electron micrograph of a porous carbon prepared in example 5 of the present invention;
FIG. 10 is a pore size distribution diagram of porous carbon prepared in example 5 of the present invention;
FIG. 11 is a TEM transmission electron micrograph of a porous carbon prepared in example 6 of the present invention;
FIG. 12 is a pore size distribution diagram of porous carbon prepared in example 6 of the present invention.
Detailed Description
The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples, but not limited thereto, and it is intended to cover modifications and equivalents of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention.
Example 1:
20g of potassium hydroxide powder and 5g of SiC powder with a median diameter of 2 μm are weighed, placed in 200g of deionized water, and stirred uniformly. And then 60g of petroleum coke powder which is sieved by a 50-mesh sieve is weighed and added into the petroleum coke powder, the mixture is uniformly mixed and stirred, and the mixture is evaporated to dryness at the temperature of 100 ℃ to obtain a mixture. The mixture is placed in a high-temperature furnace protected by nitrogen atmosphere, preactivated for 4 hours at a lower temperature of 400 ℃, and then activated for 1 hour by heating to 850 ℃. And adding the activated sample into a nitric acid solution with the concentration of 0.5mol/L according to the mass ratio of 1. And drying the finally obtained porous carbon powder for 8 hours at 120 ℃ under a vacuum condition to obtain a porous carbon finished product, and recording as a sample TP-1.
The porous carbon prepared in example 1 of the present invention was characterized. FIG. 1 is a TEM image of the porous carbon prepared in example 1 of the present invention, and FIG. 2 is a distribution diagram of pore diameters of the porous carbon prepared in example 1 of the present invention, and specific surface areas and pore volume data are shown in Table 1.
Example 2:
30g of potassium carbonate powder and 10g of SiO having a median diameter of 1 μm were weighed 2 The powder was placed in 180g of deionized water and stirred well. And then 70g of petroleum coke powder which is sieved by a 50-mesh sieve is weighed and added into the petroleum coke powder, the mixture is uniformly mixed and stirred, and the mixture is evaporated to dryness at the temperature of 100 ℃ to obtain a mixture. The mixture is placed in a high-temperature furnace protected by nitrogen atmosphere, preactivation is carried out for 4 hours at the lower temperature of 450 ℃, and then the temperature is raised to 870 ℃ for activation for 0.8 hour. Adding the activated sample into 1:8 by mass ratioFully and uniformly stirring in hydrofluoric acid solution with the concentration of 0.5mol/L, then carrying out solid-liquid separation, and washing the obtained porous carbon powder with deionized water until the pH value of the filtrate is between 6.5 and 7.5. And drying the finally obtained porous carbon powder for 8 hours at 120 ℃ under a vacuum condition to obtain a porous carbon finished product, and recording as a sample TP-2.
The porous carbon prepared in example 2 of the present invention was characterized. FIG. 3 is a TEM image of the porous carbon prepared in example 2 of the present invention, and FIG. 4 is a distribution diagram of pore diameters of the porous carbon prepared in example 2 of the present invention, and specific surface areas and pore volume data are shown in Table 1.
Example 3:
25g of potassium hydroxide powder and 12g of SiC powder having a median diameter of 1 μm were weighed, placed in 213g of deionized water, and stirred uniformly. And then 111g of the coconut shell carbonized material which is sieved by a 50-mesh sieve is weighed and added into the mixture to be mixed and stirred evenly, and the mixture is obtained by evaporation at the temperature of 100 ℃. The mixture is placed in a high-temperature furnace protected by nitrogen atmosphere, preactivated for 4 hours at a lower temperature of 500 ℃, and then activated for 1 hour by heating to 850 ℃. And adding the activated sample into a nitric acid solution with the concentration of 0.5mol/L according to the mass ratio of 1. And drying the finally obtained porous carbon powder for 8 hours at 120 ℃ under a vacuum condition to obtain a porous carbon finished product, and recording the porous carbon finished product as a sample TP-3.
The porous carbon prepared in example 3 of the present invention was characterized. Fig. 5 is a TEM transmission electron micrograph of the porous carbon prepared in example 3 of the present invention, and fig. 6 is a pore size distribution diagram of the porous carbon prepared in example 3 of the present invention, and specific surface area and pore volume data are shown in table 1.
TABLE 1 data for porous carbon products
Sample name Specific surface area m 2 /g Total pore volume ml/g Micropore volume ml/g Average pore diameter/nm
TP-1 652 0.553 0.3318 2.68
TP-2 784 0.644 0.3664 2.47
TP-3 456 0.486 0.2816 2.39
Example 4:
50g of potassium carbonate powder is weighed, placed in 200g of deionized water and stirred uniformly. And then 50g of petroleum coke powder which is sieved by a 50-mesh sieve is weighed and added into the mixture to be mixed and stirred uniformly, and the mixture is evaporated to dryness at the temperature of 100 ℃ to obtain a mixture. The mixture is placed in a high-temperature furnace protected by nitrogen atmosphere, preactivated for 4 hours at a lower temperature of 400 ℃, and then activated for 1 hour by heating to 1550 ℃. And adding the activated sample into a nitric acid solution with the concentration of 0.5mol/L according to the mass ratio of 1. And drying the finally obtained porous carbon powder for 8 hours at 120 ℃ under a vacuum condition to obtain a porous carbon finished product, and recording as a sample CP-4.
The porous carbon prepared in example 4 of the present invention was characterized. FIG. 7 is a TEM image of the porous carbon prepared in example 4 of the present invention, and FIG. 8 is a distribution diagram of the pore diameter of the porous carbon prepared in example 4 of the present invention, and the specific surface area, pore volume and powder resistivity data are shown in Table 2.
Example 5:
80g of potassium carbonate powder is weighed, placed in 250g of deionized water and stirred uniformly. And then 80g of petroleum coke powder which is sieved by a 50-mesh sieve is weighed and added into the petroleum coke powder, the mixture is uniformly mixed and stirred, and the mixture is evaporated to dryness at the temperature of 100 ℃ to obtain a mixture. The mixture is placed in a high-temperature furnace protected by nitrogen atmosphere, preactivated for 4h at the lower temperature of 450 ℃, and then activated for 0.8h by heating to 1450 ℃. And adding the activated sample into a nitric acid solution with the concentration of 0.5mol/L according to the mass ratio of 1:8, fully and uniformly stirring, carrying out solid-liquid separation, and washing the obtained porous carbon powder by using deionized water until the pH value of the filtrate is between 6.5 and 7.5. And drying the finally obtained porous carbon powder for 8h at 120 ℃ under a vacuum condition to obtain a porous carbon finished product, and recording the porous carbon finished product as a sample CP-5.
The porous carbon prepared in inventive example 5 was characterized. FIG. 9 is a TEM image of the porous carbon prepared in example 5 of the present invention, and FIG. 10 is a distribution diagram of the pore diameter of the porous carbon prepared in example 5 of the present invention, and the specific surface area, pore volume and powder resistivity data are shown in Table 2.
Example 6:
150g of potassium hydroxide powder is weighed and placed in 350g of deionized water, and the mixture is stirred uniformly. And then 200g of the coconut shell carbonized material which is sieved by a 50-mesh sieve is weighed and added into the mixture to be mixed and stirred evenly, and the mixture is obtained by evaporation at the temperature of 100 ℃. The mixture is placed in a high-temperature furnace protected by nitrogen atmosphere, preactivation is carried out for 4 hours at the lower temperature of 500 ℃, and then the temperature is raised to 1650 ℃ for activation for 0.3 hour. And adding the activated sample into a nitric acid solution with the concentration of 0.5mol/L according to the mass ratio of 1. And drying the finally obtained porous carbon powder for 8 hours at 120 ℃ under a vacuum condition to obtain a porous carbon finished product, and recording the porous carbon finished product as a sample CP-6.
The porous carbon prepared in example 6 of the present invention was characterized. FIG. 11 is a TEM image of the porous carbon prepared in example 6 of the present invention, and FIG. 12 is a distribution diagram of pore size of the porous carbon prepared in example 6 of the present invention, and specific surface area, pore volume and powder resistivity data are shown in Table 2.
TABLE 2 data for porous carbon products
Sample name Specific surface area m 2 /g Total pore volume ml/g Micropore volume ml/g Average pore diameter/nm Resistivity of powder/omega.m 2 /m
CP-4 450 0.4633 0.278 2.48 0.0634
CP-5 553 0.4767 0.286 2.67 0.126
CP-6 257 0.4383 0.263 3.05 0.024

Claims (10)

1. A preparation method of a porous carbon material is characterized by comprising the following steps: the method specifically comprises the following steps:
the method comprises the following steps: drying and crushing the carbon source material, wherein the granularity is subject to passing through a 50-mesh sieve to obtain a porous carbon precursor;
step two: weighing an activating agent, wherein the mass ratio of the activating agent to the porous carbon precursor is 1:1 to 100; after weighing, dissolving activator powder in deionized water, and adding a passivator to prepare a suspension solution; soaking the porous carbon precursor in the solution, uniformly stirring, heating and cooking until deionized water is evaporated to dryness to obtain a uniformly mixed mixture of an activating agent, a passivating agent and the porous carbon precursor, transferring the uniformly mixed mixture into a sealed electric furnace with inert atmosphere protection, heating the electric furnace to 650-950 ℃ at the speed of 5-20 ℃/min for activation for 0.5-2h, and naturally cooling to room temperature after activation to obtain an activated material;
step three: and (3) washing the activated material by adopting an acid solution until the pH value of a water washing solution is between 8 and 9, finally washing by using deionized water until the pH value of the water washing solution is between 7 and 7.5, and drying to obtain the porous carbon material.
2. The method for preparing a porous carbon material according to claim 1, wherein: in the first step, the carbon source is one or more of anthracite, petroleum coke and biomass, and the biomass is one or more of a coconut shell carbonized material, a fruit shell carbonized material and a rice hull carbonized material; the biomass is subjected to pre-carbonization treatment; the drying is drying by distillation, oven drying or sun drying, and the drying degree is based on the water content of less than 15 wt.%.
3. The method for preparing a porous carbon material according to claim 1, wherein: in the second step, the activating agent is one or more of potassium carbonate, potassium hydroxide, sodium hydroxide, calcium hydroxide and zinc chloride, and the mixing mode is a mechanical mixing or dipping method; in the suspension solution, the active agent and the passivating agent account for 5-15% of the total mass concentration of the solution; the mass ratio of the activating agent to the porous carbon precursor is 1:2-50.
4. The method for preparing a porous carbon material according to claim 1, wherein: in the second step, the passivating agent is SiC or SiO 2 One or more of; the grain size median diameter D50 of the passivator is 0.05-5 mu m; the mass ratio of the passivating agent to the activating agent is 1:1-10; the inert atmosphere is one or more of nitrogen, helium or argon; the activation temperature is 750-870 ℃, and the activation time is 0.5-1 h.
5. The method for preparing a porous carbon material according to claim 1, wherein: in the third step, the acid solution is one or more of dilute hydrochloric acid, dilute sulfuric acid, dilute hydrofluoric acid or dilute nitric acid.
6. A preparation method of a porous carbon material is characterized by comprising the following steps: the method specifically comprises the following steps:
the method comprises the following steps: drying and crushing the carbon source material, wherein the granularity is subject to passing through a 50-mesh sieve to obtain a porous carbon precursor;
step two: weighing a potassium-based compound activating agent, wherein the mass ratio of the activating agent to the porous carbon precursor is 1:1 to 100; after weighing, dissolving activator powder in deionized water to prepare a solution with the concentration of 5-30%; soaking the porous carbon precursor in the solution, uniformly stirring, heating and cooking until deionized water is evaporated to dryness to obtain a uniformly mixed mixture of an activating agent and the porous carbon precursor, transferring the uniformly mixed mixture into a sealed electric furnace with inert atmosphere protection, heating the electric furnace to 1200-1800 ℃ at the speed of 5-20 ℃/min for activation for 0.2-2h, and naturally cooling to room temperature after activation to obtain an activated material;
step three: and washing the activated material by using an acid solution until the pH value of a water washing solution is between 8 and 9, finally washing the activated material by using deionized water until the pH value of the water washing solution is between 7 and 7.5, and drying to obtain the porous carbon material.
7. The method for preparing a porous carbon material according to claim 6, wherein: in the first step, the carbon source is one or more of anthracite, petroleum coke and biomass, and the biomass is one or more of a coconut shell carbonized material, a shell carbonized material and a rice hull carbonized material; carrying out pre-carbonization treatment on the biomass; the drying is drying by distillation, oven drying or sun drying, and the drying degree is based on the water content of less than 15 wt.%.
8. The method for preparing a porous carbon material according to claim 6, wherein: in the second step, the potassium-based compound activator is K 2 CO 3 KOH and KHCO 3 One or a mixture of several of them; the mass ratio of the activating agent to the porous carbon precursor is 1:2 to 50 percent; the inert atmosphere is one or more of nitrogen, helium or argon.
9. The method for preparing a porous carbon material according to claim 6, wherein: in the second step, the activation temperature is 1300-1700 ℃, and the activation time is 0.3-1 h.
10. The method for preparing a porous carbon material according to claim 6, wherein: in the third step, the acid solution is one or a mixture of more of dilute hydrochloric acid, dilute sulfuric acid or dilute nitric acid.
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD268677A1 (en) * 1988-02-08 1989-06-07 Leuna Werke Veb PROCESS FOR PRODUCING MICROPOROESE ACTIVATED CARBON
CN102205961A (en) * 2011-03-10 2011-10-05 大连理工大学 Method for adjusting pore structure of activated carbon
CN102275915A (en) * 2011-05-30 2011-12-14 大连理工大学 Preparation method of high specific surface area scalar porous active carbon material
CN105921109A (en) * 2016-06-01 2016-09-07 湖南农业大学 Biological carbon prepared from tobacco stems as well as preparation method and application thereof
CN106147770A (en) * 2015-03-11 2016-11-23 周宝龙 One utilizes rice husk to prepare heavy metal deactivator and application process
CN106410155A (en) * 2016-10-28 2017-02-15 林天安 Preparing method of graphene silica carbon negative material
CN106672966A (en) * 2015-11-05 2017-05-17 长春工业大学 Preparation method of ethylene tar-based porous carbon with narrow aperture distribution
CN108314018A (en) * 2018-05-09 2018-07-24 曾功昶 A kind of eucalyptus Quito hole carbon graphite method
CN110723736A (en) * 2019-07-12 2020-01-24 超威电源有限公司 Biomass porous activated carbon material and preparation method and application thereof

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD268677A1 (en) * 1988-02-08 1989-06-07 Leuna Werke Veb PROCESS FOR PRODUCING MICROPOROESE ACTIVATED CARBON
CN102205961A (en) * 2011-03-10 2011-10-05 大连理工大学 Method for adjusting pore structure of activated carbon
CN102275915A (en) * 2011-05-30 2011-12-14 大连理工大学 Preparation method of high specific surface area scalar porous active carbon material
CN106147770A (en) * 2015-03-11 2016-11-23 周宝龙 One utilizes rice husk to prepare heavy metal deactivator and application process
CN106672966A (en) * 2015-11-05 2017-05-17 长春工业大学 Preparation method of ethylene tar-based porous carbon with narrow aperture distribution
CN105921109A (en) * 2016-06-01 2016-09-07 湖南农业大学 Biological carbon prepared from tobacco stems as well as preparation method and application thereof
CN106410155A (en) * 2016-10-28 2017-02-15 林天安 Preparing method of graphene silica carbon negative material
CN108314018A (en) * 2018-05-09 2018-07-24 曾功昶 A kind of eucalyptus Quito hole carbon graphite method
CN110723736A (en) * 2019-07-12 2020-01-24 超威电源有限公司 Biomass porous activated carbon material and preparation method and application thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
LIN, L ET AL: ""Surface Engineering of Copper Foils for Growing Centimeter-Sized Single-Crystalline Graphene"", 《ACS NANO》 *
吕文辉: ""硅碳复合材料的制备及其锂离子电池负极性能研究"", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 *

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