CN113636556B - Ultra-small molybdenum carbide @ carbon composite material and preparation method and application thereof - Google Patents

Ultra-small molybdenum carbide @ carbon composite material and preparation method and application thereof Download PDF

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CN113636556B
CN113636556B CN202110830879.2A CN202110830879A CN113636556B CN 113636556 B CN113636556 B CN 113636556B CN 202110830879 A CN202110830879 A CN 202110830879A CN 113636556 B CN113636556 B CN 113636556B
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顾栋
张星
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Wuhan University WHU
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Abstract

The invention discloses an ultra-small molybdenum carbide @ carbon composite material and a preparation method and application thereof. The composite material prepared by the method is made of ultra-small molybdenum carbide (Mo) 2 C) Nanoparticles and mesoporous carbon, with ultra-small Mo 2 The C nanoparticles are uniformly distributed in the ordered mesoporous carbon. The invention aims to solve the problems of harsh preparation conditions, easy agglomeration and small specific surface area of the existing molybdenum carbide. The ultra-small molybdenum carbide @ carbon composite material prepared by the method has the advantages of a multi-stage structure, and the specific surface area and the pore volume are effectively increased; the conductive material has good conductivity, has good chemical adsorption capacity on LiPSs, can provide a binding site for reaction, and simultaneously has good electron transfer, so that the conversion of the conductive material to a discharge terminal product can be effectively catalyzed, and the shuttle effect is slowed down. Based on the synergistic effect, the method has important significance for improving the electrochemical performance of the lithium-sulfur battery.

Description

Ultra-small molybdenum carbide @ carbon composite material and preparation method and application thereof
Technical Field
The invention belongs to the technical field of nano composite materials, and particularly relates to an ultra-small molybdenum carbide @ carbon composite material as well as a preparation method and application thereof.
Background
When the elemental sulfur is used as the anode material of the lithium-sulfur battery, the elemental sulfur has very high theoretical specific capacity (1675 mAh g) -1 ) And theoretical specific energy (2600 Wh kg) -1 ) It is considered to be one of the best choices for the next-generation high energy density secondary battery. However, the lithium-sulfur battery cathode material still faces many challenges on the way to commercialization, for example: 1) S 8 And Li 2 S has low conductivity. S 8 And its discharge product Li 2 S is to electricitySeed and Li + Are all insulating, which limits the redox kinetics on the positive side. This results in low sulfur utilization and ultimately low specific capacity. 2) Dissolution and shuttling effects of intermediate polysulfides (LiPSs). The intermediate LiPSs produced during cycling readily dissolved into the electrolyte and then shuttled from the positive to the negative side. This results in low coulombic efficiency and severe capacity fade. 3) From S 8 To Li 2 Volume expansion during lithiation of S. In view of S 8 (2.07g cm -3 ) And Li 2 S(1.66g cm -3 ) Of different density, S 8 A large volume expansion of about 80% is experienced upon full lithiation. This may cause pulverization of the electrode after repeated volume changes of the positive electrode during cycling, resulting in poor cycle performance. In order to solve the above problems, it is imperative to improve the conductivity of elemental sulfur and suppress the shuttle effect in the electrode reaction. The ideal sulfur positive electrode matrix should satisfy the following preconditions: 1) High electronic and ionic conductivity; 2) High specific surface area and large pore volume to accommodate sulfur and LiPS; 3) Optimal affinity for LiPS, since too weak anchoring leads to severe shuttling effects, while too strong binding leads to slow diffusion processes of LiPSs; 4) Abundant catalytic active centers to accelerate redox kinetics.
The porous carbon material with a specific topological structure is constructed, so that the porous carbon material with a specific topological structure is a common method for improving poor conductivity and relieving volume effect by utilizing good conductivity, large specific surface area and adjustable porous structure, such as one-dimensional Carbon Nanotubes (CNTs) or Carbon Nanowires (CNFs), two-dimensional graphene or carbon nanosheets, three-dimensional porous carbon materials and the like. However, the nonpolar surface of such materials interacts weakly with polar polysulfides and will face problems of loss of LiPSs dissolution and rapid capacity fade when sulfur loading is increased. To suppress the problems of low sulfur utilization and capacity fade caused by the "shuttling effect", the introduction of active substances with adsorption or catalytic capabilities is an effective strategy. Metal carbides such as Mo, as compared to weakly adsorbing non-polar carbon materials and poorly conducting polar active substances 2 C has better conductivity and better chemical adsorption capacity to LiPSs, can provide a binding site for reaction and has good electronsThe transfer can effectively catalyze the conversion of the discharge end product and slow down the shuttle effect. By constructing the molybdenum carbide @ carbon composite integrated electrode with an optimized structure, the synergistic promotion effect of all materials can be comprehensively exerted, the electrochemical performance and the cycling stability are effectively improved, and the service life of the battery is prolonged. Currently, the preparation methods of molybdenum carbide generally comprise the following steps: 1. temperature programmed reaction method, namely, molybdenum oxide precursor is added into light hydrocarbon or light hydrocarbon/H 2 The mixed gas is heated and carbonized. The method is simple and easy to regulate, and the product is purer, but the method is easy to cause the surface area of the catalyst to be carbonized, and the specific surface area of the obtained molybdenum carbide is smaller; 2. the carbothermic reduction method is characterized in that molybdenum oxide and a proper amount of carbon carrier react in a protective atmosphere or a reducing atmosphere, and the obtained product has a large specific surface area, but the reaction temperature is usually high; 3. a solvent thermal reduction method, which adopts a substance (KBH) with strong reducing power 4 ) The method is simple and easy to control, the temperature is low, but the product is impure; 4. the metal precursor cracking method is prepared by using a metal organic compound and a mixture of ammonium molybdate and hexamethylenetetramine for high-temperature cracking, but the precursor is complex to prepare, and the prepared particles are large. In addition, there are reports of CVD, hydrothermal method, ultrasonic method, microwave method, etc., but these methods also have problems of small yield, insufficient reaction, large product particles, and impure product. The above methods have limitations and inherent characteristics and have great disadvantages in practical applications, particularly in mass production of catalysts.
Disclosure of Invention
In order to solve the technical problems, the invention provides an ultra-small molybdenum carbide @ carbon composite material and a preparation method and application thereof.
The invention provides an effective, controllable, low-cost and environment-friendly modification method, which can overcome the defects in the prior art. The ultra-small molybdenum carbide @ carbon composite material prepared by the invention has the characteristics of high purity, small particles and regular and uniform appearance, and shows excellent electrochemical performance when assembled into a lithium-sulfur battery. The invention prepares the nano composite material with the characteristics of carbon composition, high specific surface area, large pore volume, ultra-small particles, uniform distribution and the like by a hard template method. The existence of the carbon skeleton can prevent the molybdenum carbide from being enlarged in particles in the preparation process and increase catalytic active sites; the conductivity of the electrode material can also be enhanced, thereby improving the electrochemical performance of the lithium sulfur battery. The ultra-small molybdenum carbide @ carbon composite material prepared by the method has the advantages of a multi-stage structure, and the specific surface area and the pore volume are effectively increased; the conductive material has good conductivity, has good chemical adsorption capacity on LiPSs, can provide a binding site for reaction, and simultaneously has good electron transfer, so that the conversion of the conductive material to a discharge terminal product can be effectively catalyzed, and the shuttle effect is slowed down. Based on the synergistic effect, the method has important significance for improving the electrochemical performance of the lithium-sulfur battery.
The technical scheme provided by the invention is as follows:
in a first aspect, the invention provides a preparation method of an ultra-small molybdenum carbide @ carbon composite material, which comprises the following steps:
(1) Adding tetraethyl orthosilicate (TEOS) into an acidic solution containing the amphiphilic block copolymer, stirring in a water bath, reacting, and filtering;
(2) Filtering the filtrate obtained in the step (1) and reserving part of mother liquor for hydrothermal aging, and then filtering and drying;
(3) Adding concentrated nitric acid and hydrogen peroxide into the product obtained in the step (2), stirring in a water bath to react completely, adding distilled water to dilute the mixed solution, performing suction filtration, and performing water washing, suction filtration and drying to obtain a silicon dioxide template;
(4) Adding a carbon source into a silicon dioxide template, fully mixing, and carrying out heat preservation to ensure that the carbon source is fully polymerized to obtain a polymer @ silicon dioxide template;
(5) Dissolving a molybdenum source in water, adding a polymer @ silicon dioxide template, continuing stirring at room temperature, and evaporating the solvent until the solvent is completely dried to obtain a precursor;
(6) Transferring the precursor to calcine in hydrogen atmosphere; after calcining, cooling to room temperature, and taking out a product;
(7) Removing the silicon dioxide template in the product obtained in the step (6), and freeze-drying to obtain the final ultra-small molybdenum carbide @ carbon composite materialNamed Mo 2 C@C。
Further, the amphiphilic block copolymer contained in the step (1) comprises P123, F127 and F108.
Further, the water bath temperature in the step (1) is 35-38 ℃, and the stirring reaction time is 2-4 h.
Further, the silica template in the step (3) comprises SBA-15-OH, KIT-6-OH, MCF-OH, FDU-12-OH, SBA-16-OH and P-SBA-15-OH.
Further, in the step (3), the concentration of hydrogen peroxide is 40wt%, the water bath reaction temperature is 80 ℃, and the reaction time is 3 hours.
Further, in the step (3), the usage ratio of the product in the step (2), the concentrated nitric acid and the hydrogen peroxide is as follows: 1.0g; the water bath temperature is 80 ℃, and the reaction time is 3h.
Further, in the step (4), the carbon source is selected from furfuryl alcohol, phenolic resin, 2-thiophenemethanol, tryptophan, cysteine, tyrosine and dopamine.
Further, when the carbon source is used in the step (4), different solvents should be selected according to different properties. Preferably, when furfuryl alcohol is used as a carbon source, trimethylbenzene (TMB) is selected as a solvent and oxalic acid is selected as a catalyst for promoting polymerization; selecting ethanol as a solvent when phenolic resin and 2-thiophene methanol are used as carbon sources; when tryptophan, cysteine, tyrosine and dopamine are used as carbon sources, distilled water is selected as a solvent.
Further, the polymerization temperature of the polymer @ silica template in said step (4) is from room temperature to 130 ℃.
Further, in the step (5), the molybdenum source is phosphomolybdic acid, molybdenum acetylacetonate, ammonium molybdate or sodium molybdate.
Further, in the step (6), when calcining is carried out in a hydrogen atmosphere, the temperature is raised from room temperature to 700-900 ℃ at the temperature raising speed of 1-10 ℃/min, and the temperature is kept for 2-7 h.
Further, in the step (6), when the reduction is performed in a hydrogen atmosphere, the hydrogen content is 10 to 100% (v/v).
Further, in the step (7), 5 to 20wt% of HF or 0.2 to 2.0mol/L of NaOH solution is used to remove the silica template.
Further, in the step (7), the final product is obtained after freeze drying for 12 to 48 hours at the temperature of between 45 ℃ below zero and 85 ℃ below zero.
In a second aspect, the present invention provides an ultra-small molybdenum carbide @ carbon composite prepared by the method of the first aspect.
In a third aspect, the present invention provides the use of the ultra-small molybdenum carbide @ carbon composite of the second aspect as a catalyst and support in alkali metal ion batteries and lithium sulfur batteries.
The invention has the beneficial effects that:
1) The present invention mainly utilizes silica (e.g.: the pore channel in the template of SBA-15) is a micro-reactor, a certain amount of carbon source is filled into the pore channel in advance and polymerized, and then the molybdenum source is filled into the pore channel. During the temperature programming, the polymer gradually carbonizes and ultra-small molybdenum carbide nanoparticles are generated in situ due to the reduction of hydrogen.
2) According to the invention, the electronic structure of the molybdenum carbide @ carbon composite material can be regulated and controlled by using carbon sources with different heteroatoms, so that the adsorption and catalysis effects of molybdenum carbide on polysulfide are improved.
3) The method can prepare the molybdenum carbide in the hydrogen atmosphere, so that the preparation process is simpler, safer and more environment-friendly.
4) The invention is also applicable to different types of mesoporous silica templates, such as SBA-15-OH, KIT-6-OH, MCF-OH, FDU-12-OH, SBA-16-OH and P-SBA-15-OH.
5) The material prepared by the invention shows excellent cycling stability and higher specific capacity in the aspect of electrochemical performance.
6) The material prepared by the invention has a high specific surface, large pore volume and uniform pore channel structure, wherein the size of the generated molybdenum carbide nano particles is uniform and the distribution is uniform due to the limitation of the pore channels.
7) The invention has the advantages of environmental protection, low cost, high safety, large yield and the like in the preparation process.
Drawings
FIG. 1 is a TEM, HRTEM, and particle size distribution plot of ultra-small molybdenum carbide @ carbon composite.
Fig. 2 is an XRD pattern of ultra-small molybdenum carbide @ carbon composite.
FIG. 3 shows that when the ultra-small molybdenum carbide @ carbon composite material is applied to a lithium-sulfur battery, the composite material is 1.0Ag -1 Current density of (a).
Detailed Description
The following description will further describe the specific implementation steps of the present invention with reference to the drawings, but the present invention is not limited thereto at all.
Taking an SBA-15 template as an example, the main steps are as follows:
1. preparation of Polymer @ SBA-15 template:
1) 20.0g of the block copolymer P123 was added to a mixed solution containing 650mL of distilled water and 100mL of 37wt% hydrochloric acid, and stirred in a water bath at 35-38 ℃ for 2 hours. After P123 had dissolved sufficiently, 41.6g of tetraethyl orthosilicate (TEOS) were added to the solution and stirring was continued for 24h, with a speed of 500 rpm. After stirring, the solution is filtered and transferred to a 500mL polytetrafluoroethylene hydrothermal kettle and is hydrothermally processed for 24-48 h at 90-130 ℃ in an air-blast drying oven. And (3) cooling the hydrothermal kettle to room temperature, carrying out suction filtration on the aged SBA-15 template by using a Buchner funnel, drying in a forced air drying oven at the temperature of 50-80 ℃, and then keeping for later use.
2) And (3) taking 8.0g of the dried product obtained in the step 2), putting the product into a 1L round-bottom flask, adding 120mL of concentrated nitric acid and 40mL of 40wt% hydrogen peroxide, stirring in a water bath at 80 ℃ for 3 hours, adding distilled water, diluting, performing suction filtration, continuously washing with water, performing suction filtration, and drying at 50-80 ℃ to obtain an SBA-15 template (named as SBA-15-OH) with a surface rich in-OH for later use.
3) Using a pipette, 5.0mL of Trimethylbenzene (TMB) and 5.0mL of Furfuryl Alcohol (FA) were pipetted and 25.0mg of oxalic acid was added to make a 50% (v/v) furfuryl alcohol solution.
4) Putting 0.5g of SBA-15-OH dried in the step 3) into a 20mL glass bottle by using an electronic balance scale, then adding 0.337-2.211 mL of 50% (v/v) furfuryl alcohol solution into the bottle, manually stirring for 10-20 min until the solution and the SBA-15-OH template are fully mixed, sealing the glass bottle, putting the glass bottle into a forced air drying oven, preserving the temperature for 1 day at 50 ℃, and then regulating the temperature to 90 ℃ and preserving the temperature for 2 days to obtain the polymer @ SBA-15 template.
2. Preparing an ultra-small molybdenum carbide @ carbon composite material: and filling a molybdenum source into the polymer @ SBA-15 template, and filling a precursor into a template pore channel through a solvent volatilization process. And then reducing the mixture by high-temperature hydrogen to obtain the ultra-small molybdenum carbide @ carbon composite material.
3. Removing the silicon dioxide template by taking a certain amount of 5-20 wt% of HF or 0.2-2.0 mol/L NaOH solution, and then putting the silicon dioxide template into a freeze dryer for freeze drying to obtain the final ultra-small molybdenum carbide @ carbon composite material.
Example 1
1) Preparation of Polymer @ SBA-15 template: and (2) putting 0.5g of the dried SBA-15-OH template into a 20mL glass bottle by using an electronic balance scale, then adding 0.337mL of 50% (v/v) furfuryl alcohol solution into the bottle, manually stirring for 10min until the solution and the SBA-15-OH template are fully mixed, sealing the glass bottle, putting the glass bottle into a forced air drying oven, preserving the temperature for 1 day at 50 ℃, and then adjusting the temperature to 90 ℃ and preserving the temperature for 2 days to obtain the polymer @ SBA-15 template.
2) Preparing an ultra-small molybdenum carbide @ carbon composite material: 0.7556g of phosphomolybdic acid was added to a beaker containing 10mL of water (50 mL) and magnetically stirred at room temperature, after sufficient dissolution and dispersion, 1.0g of polymer @ SBA-15 template was added and stirred for 2h, and the mixture was transferred to an 80 ℃ forced air drying oven and stirred until all the water evaporated. The obtained powder precursor is transferred into a tube furnace and calcined for 2h at the temperature of 2 ℃/min under the atmosphere of 20 percent (v/v) hydrogen at the temperature of 700 ℃. And (3) taking 40mL of 5wt% HF to remove the silicon dioxide template, and then putting the template into a freeze dryer at-85 ℃ for freeze drying for 24 hours to obtain the final ultra-small molybdenum carbide @ carbon composite material. As shown in figures 1 and 2, the obtained ultra-small nickel phosphide nano-particles are uniformly distributed on a carbon skeleton, and the average particle size of the ultra-small nickel phosphide nano-particles is about 2.0nm.
Example 2
0.7556g of molybdenum acetylacetonate was added to a beaker (50 mL) containing 20mL of water and magnetically stirred at room temperature to dissolve and disperse the molybdenum acetylacetonate, and then 1.0g of the polymer @ SBA-15 template prepared in step (1) of example 1 was added and stirred for 2 hours, and the mixture was transferred to a forced air drying oven at 80 ℃ and stirred until all the water was evaporated. The obtained powder precursor is transferred into a constant-temperature tube furnace, and is calcined for 2h at the temperature of 800 ℃ and at the speed of 5 ℃/min under the atmosphere of 10% (v/v) hydrogen. 80mL of 0.5mol/L NaOH solution is taken to remove the silicon dioxide template, and then the silicon dioxide template is put into a freeze dryer at-85 ℃ for freeze drying for 24 hours, so that the final ultra-small molybdenum carbide @ carbon composite material is obtained.
Example 3
MCF-OH is used as a template to prepare the ultra-small molybdenum carbide @ carbon composite material.
1) Preparation of polymer @ MCF template: putting 0.5g of the dried MCF-OH template into a 20mL glass bottle by using an electronic balance, then adding 0.674mL of 50% (v/v) furfuryl alcohol solution into the bottle, manually stirring for 15min until the solution and the MCF-OH template are fully mixed, sealing the glass bottle, putting the glass bottle into a forced air drying oven, preserving the temperature at 50 ℃ for 1 day, and then regulating the temperature to 90 ℃ for 2 days to obtain the polymer @ MCF template.
2) Preparing an ultra-small molybdenum carbide @ carbon composite material: 0.7846g of phosphomolybdic acid was added to a beaker (50 mL) containing 10mL of water, magnetic stirring was carried out at room temperature, after sufficient dissolution and dispersion, 1.0g of polymer @ MCF template was added, stirring was carried out for 2h, and the mixture was transferred to an air-blown dry box at 80 ℃ and stirred until all the water was evaporated. And putting the obtained powder precursor into a constant-temperature tubular furnace, and calcining for 2h at the temperature of 700 ℃ and at the speed of 2 ℃/min under the atmosphere of 10% (v/v) hydrogen. And (3) taking 40mL of 5wt% HF to remove the silicon dioxide template, and then putting the template into a freeze dryer at-85 ℃ for freeze drying for 24 hours to obtain the final ultra-small molybdenum carbide @ carbon composite material.
Application example 1
The prepared ultra-small molybdenum carbide @ carbon composite material is used for preparing a CR2025 button type potassium ion battery, electrochemical performance tests are carried out, such as testing the cycle life, the coulombic efficiency, the alternating current impedance and the like of the battery under different current densities, and the reason for the excellent electrochemical performance is analyzed. The preparation method comprises the following steps:
1) Mixing a molybdenum carbide @ carbon composite material and sulfur powder in a mass fraction of 3:7 in a mass ratio. Then transferring the mixture into a constant-temperature tube furnace, keeping the temperature of 155 ℃ for 12 hours under the argon atmosphere, melting and pouring the single-substance sulfur into the molybdenum carbide @ carbon compositeIn the pore channel of the material, S @ Mo is obtained 2 C @ C composite.
2) Uniformly mixing an active substance, acetylene black and 5% by mass of polytetrafluoroethylene aqueous dispersion emulsion together to obtain a mixture; dropwise adding N-methyl pyrrolidone into the mixture to obtain a mixture for coating;
the active substance in the step 2) is S @ Mo prepared in the step 1) 2 C @ C composite;
the mass fraction of active substances in the mixture in the step 2) is 70%, the mass fraction of acetylene black is 20%, and the mass fraction of polytetrafluoroethylene is 10%;
the mass ratio of the volume of the N-methylpyrrolidone to the active substance in the step 1) is (1-2 mL): (5-10 mg);
3) Uniformly coating the mixture for coating obtained in the step 2) on an aluminum foil with the diameter of 14mm, and then carrying out vacuum drying at the temperature of 60 ℃ for 12h to obtain a pole piece with the surface containing active substances; obtaining the mass of the active substance on the pole piece by using a difference method;
4) And transferring the pole piece with the surface containing the active substances into a vacuum glove box to complete the assembly of the button cell, wherein the PP diaphragm is a cell diaphragm, the lithium piece is a counter electrode, the pole piece with the surface containing the active substances is a working electrode, assembling the working electrode, the diaphragm, the counter electrode, a gasket and a cell shell into the CR2025 button cell in the glove box, sealing the button cell by using a sealing machine, and finally standing the prepared button cell at room temperature for 12h to activate the cell, thus completing the preparation of the CR2025 button cell.
FIG. 3 shows the lithium-sulfur battery prepared in application example 1 at 1.0A g -1 Long cycle life test plots at current density. As shown in FIG. 3, when the ultra-small molybdenum carbide @ carbon composite material is applied to a lithium-sulfur battery, the current density is 1.0A g -1 When the material is circulated for 100 circles, the reversible specific capacity is still maintained at 760mAh g -1 And the composite material shows high reversible specific capacity and excellent rate performance and cycling stability.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any modification, equivalent replacement, and improvement made by those skilled in the art within the technical scope of the present invention should be included in the scope of the present invention.

Claims (10)

1. A preparation method of an ultra-small molybdenum carbide @ carbon composite material is characterized by comprising the following steps:
(1) Adding tetraethyl orthosilicate into an acidic solution containing the amphiphilic block copolymer, stirring in a water bath, reacting, and then filtering;
(2) Carrying out hydrothermal aging on the filtrate obtained in the step (1), and then carrying out suction filtration and drying;
(3) Adding concentrated nitric acid and hydrogen peroxide into the product obtained in the step (2), stirring in a water bath to react completely, adding distilled water to dilute the mixed solution, performing suction filtration, and performing water washing, suction filtration and drying to obtain a silicon dioxide template;
(4) Adding a carbon source into the silica template, fully mixing, and preserving heat to fully polymerize the carbon source to obtain a polymer @ silica template;
(5) Dissolving a molybdenum source in water, adding a polymer @ silicon dioxide template, continuing stirring at room temperature, and evaporating the solvent until the solvent is completely dried to obtain a precursor;
(6) Transferring the precursor to calcine in hydrogen atmosphere; after calcination, cooling to room temperature, and taking out the product;
(7) And (4) removing the silicon dioxide template in the product obtained in the step (6), and freeze-drying to obtain the final ultra-small molybdenum carbide @ carbon composite material.
2. The method of claim 1, wherein: the amphiphilic block copolymer contained in the step (1) comprises one of P123, F127 and F108; the silicon dioxide template in the step (3) comprises one of SBA-15-OH, KIT-6-OH, MCF-OH, P-SBA-15-OH, FDU-12-OH and SBA-16-OH.
3. The method of claim 1, wherein: the concentration of the hydrogen peroxide in the step (3) is 40wt%, the water bath reaction temperature is 80 ℃, and the reaction time is 3 hours.
4. The method of claim 1, wherein: the carbon source used in the step (4) is one selected from furfuryl alcohol, phenolic resin, 2-thiophene methanol, tryptophan, cysteine, tyrosine and dopamine.
5. The method of claim 4, wherein: selecting different solvents for the carbon source in the step (4) according to properties;
wherein, when furfuryl alcohol is used as a carbon source, trimethylbenzene is selected as a solvent and oxalic acid is selected as a catalyst for promoting polymerization; selecting ethanol as a solvent when phenolic resin and 2-thiophene methanol are used as carbon sources; when tryptophan, cysteine, tyrosine and dopamine are selected as carbon sources, distilled water is selected as a solvent.
6. The method of claim 1, wherein: the polymerization temperature of the polymer @ silica template in said step (4) is from room temperature to 130 ℃.
7. The method of claim 1, wherein: in the step (5), the molybdenum source is phosphomolybdic acid, molybdenum acetylacetonate, ammonium molybdate or sodium molybdate.
8. The method of claim 1, wherein: the volume content of hydrogen in the hydrogen atmosphere in the step (6) is 10 to 100%.
9. The ultra-small molybdenum carbide @ carbon composite material is characterized in that: prepared by the process of any one of claims 1 to 8.
10. Use of the ultra-small molybdenum carbide @ carbon composite of claim 9 as a catalyst and support in lithium sulfur batteries.
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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101299397A (en) * 2008-03-21 2008-11-05 中国科学院上海硅酸盐研究所 Stephanoporate carbon electrode material and preparation method thereof
CN102049273A (en) * 2009-10-27 2011-05-11 中国科学院大连化学物理研究所 Mesoporous carbon-supported tungsten carbide catalyst and preparation and application thereof
CN103050702A (en) * 2011-10-17 2013-04-17 中国科学院大连化学物理研究所 Application of carbon material containing in-situ doped component with catalytic activity to lithium-air battery
CN103449403A (en) * 2013-08-26 2013-12-18 中国科学院上海硅酸盐研究所 Method for manufacturing nitrogen-doped multi-wall carbon nano tube
CN103896250A (en) * 2014-03-25 2014-07-02 华南理工大学 Method for preparing ordered mesoporous carbon material
CN107311176A (en) * 2017-08-07 2017-11-03 太原理工大学 A kind of preparation method of order mesoporous carbonization molybdenum
CN110759328A (en) * 2019-10-22 2020-02-07 济南大学 Preparation method of hollow carbon micro-flower-loaded superfine molybdenum carbide material and application of hollow carbon micro-flower-loaded superfine molybdenum carbide material in lithium-sulfur battery
CN110921669A (en) * 2019-12-10 2020-03-27 福州大学 Preparation and application of hollow tungsten carbide nano material
CN111244445A (en) * 2020-01-16 2020-06-05 中南大学 Lithium-sulfur battery composite positive electrode active material and preparation and application thereof

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101299397A (en) * 2008-03-21 2008-11-05 中国科学院上海硅酸盐研究所 Stephanoporate carbon electrode material and preparation method thereof
CN102049273A (en) * 2009-10-27 2011-05-11 中国科学院大连化学物理研究所 Mesoporous carbon-supported tungsten carbide catalyst and preparation and application thereof
CN103050702A (en) * 2011-10-17 2013-04-17 中国科学院大连化学物理研究所 Application of carbon material containing in-situ doped component with catalytic activity to lithium-air battery
CN103449403A (en) * 2013-08-26 2013-12-18 中国科学院上海硅酸盐研究所 Method for manufacturing nitrogen-doped multi-wall carbon nano tube
CN103896250A (en) * 2014-03-25 2014-07-02 华南理工大学 Method for preparing ordered mesoporous carbon material
CN107311176A (en) * 2017-08-07 2017-11-03 太原理工大学 A kind of preparation method of order mesoporous carbonization molybdenum
CN110759328A (en) * 2019-10-22 2020-02-07 济南大学 Preparation method of hollow carbon micro-flower-loaded superfine molybdenum carbide material and application of hollow carbon micro-flower-loaded superfine molybdenum carbide material in lithium-sulfur battery
CN110921669A (en) * 2019-12-10 2020-03-27 福州大学 Preparation and application of hollow tungsten carbide nano material
CN111244445A (en) * 2020-01-16 2020-06-05 中南大学 Lithium-sulfur battery composite positive electrode active material and preparation and application thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
Carbon-Supported Molybdenum Carbide Catalysts for the Conversion of Vegetable Oils;Junxing Han et al;《ChemSusChem》;20120228;第5卷(第4期);全文 *
多孔二氧化硅负载碳化钼催化合成低碳混合纯;邹隽等;《第十一届全国青年催化会议论文集》;20070801;全文 *
多孔碳材料的研究进展;王同洲等;《中国科学:化学》;20190301(第05期);全文 *

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