Metal carbon-based catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of batteries, in particular to a metal carbon-based catalyst and a preparation method and application thereof. The metal carbon-based catalyst disclosed by the invention is prepared from the following raw materials in parts by weight: 0.1 to 0.4 part of salt, 0.05 to 0.09 part of complexing agent and 1.0 to 1.4 parts of polyacrylonitrile, the salts comprise ferric acetate and cerium acetate. According to the metal carbon-based catalyst, the specific metal salt is adopted, and the use amount of the salt, the complexing agent and polyacrylonitrile is limited in a reasonable range value, so that the raw materials play a better synergistic effect, and the obtained metal carbon-based catalyst has good stability, has excellent catalytic activity under high current density, and is suitable for industrial production. And the catalyst performance requirements of current fuel cells or metal-air cells can be met.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a metal carbon-based catalyst and a preparation method and application thereof. Background Art

[0002] In the field of battery technology, with the development of science and technology, the demand for high-performance battery materials has become more urgent. Traditional batteries have limitations in energy density and charge and discharge performance, and it is difficult to meet the needs of industries such as modern electronic devices and electric vehicles.

[0003] Electrode catalysts play a vital role in the field of metal-air batteries and fuel cells. At present, electrode catalysts mainly include precious metal catalysts, non-metallic catalysts and metal-carbon-based catalysts. Precious metal catalysts include platinum and its alloys, iridium and ruthenium oxides, etc. These catalysts have high catalytic activity, but are expensive. Non-metallic catalysts include carbon nanotubes, carbon fibers and graphene, etc. These catalysts have limited specific capacity and low ion diffusion rate at high rate charge and discharge, which affects the improvement of battery performance. Metal-carbon-based catalysts are a combination of metal and carbon-based materials. The material cost is low, and the catalytic activity can be significantly improved through the synergistic effect between metal and carbon. However, compared with metal catalysts, metal-carbon-based catalysts have poor conductivity, which may limit their catalytic activity in high current density reactions. In addition, problems such as decarbonization or structural changes may occur during long-term use, thereby affecting their long-term stability. In addition, although the introduction of metals can increase active sites, the distribution, number and properties of active sites are difficult to accurately control, and active sites may aggregate or migrate, affecting the performance of the catalyst. Summary of the invention

[0004] The present invention provides a metal carbon-based catalyst and a preparation method and application thereof, so as to solve the above-mentioned problems existing in the existing metal carbon-based catalyst.

[0005] According to the first aspect of the present invention, the present invention provides a metal carbon-based catalyst prepared from raw materials including the following components: 0.1 to 0.4 parts by weight of salts, 0.05 to 0.09 parts by weight of complexing agents and 1.0 to 1.4 parts of polyacrylonitrile; the salts include ferric acetate and cerium acetate.

[0006] The metal-carbon-based catalyst of the present invention comprises salts, complexing agents and polyacrylonitrile. The function of the metal salts is to provide metal active components, reduce metal ions to metal nanoparticles or single atoms dispersed in carbon-based materials, and form metal-carbon composite structures. Appropriate selection and dosage of metal salts can promote uniform dispersion of metals, form smaller metal nanoparticles, thereby increasing the number of active sites and improving the activity of the catalyst. The complexing agent can form a stable complex with metal ions to prevent metal ions from precipitating or aggregating in the solution, thereby facilitating uniform distribution of metal ions on the carbon-based materials. Through coordination with metal ions, the complexing agent can change the coordination environment of the metal, affect the electronic structure and chemical properties of the metal, and then regulate the activity and selectivity of the catalyst. The high molecular polymer, as a carbon source and structural template, can be converted into a carbon material during pyrolysis to provide the main structure of the carbon-based catalyst. At the same time, its molecular structure and pore characteristics can be used as a template to regulate the pore structure and morphology of the carbon-based material. During the heat treatment process of polyacrylonitrile, the nitrogen element generated by the decomposition of polyacrylonitrile combines with the iron element to form an active Fe-N 4 Sites, these sites play a key catalytic role in the oxygen reduction reaction and can optimize the performance of the catalyst. The metal-carbon-based catalyst of the present invention uses specific metal salts, and limits the amount of salts, complexing agents and polyacrylonitrile to a reasonable range of values, so that the raw materials can play a better synergistic role, so that the obtained metal-carbon-based catalyst has good stability and excellent catalytic activity at high current density, which can meet the catalyst performance requirements of current fuel cells or metal-air batteries. The metal-carbon-based catalyst of the present invention is environmentally friendly and low in cost. It can meet the requirements of sustainable development while ensuring economic benefits, and provides a new idea for the research and development of alternatives to the currently expensive commercial platinum carbon.

[0007] Preferably, the metal carbon-based catalyst is prepared from raw materials including the following components: 0.20-0.22 parts by weight of salt, 0.06-0.07 parts by weight of complexing agent and 1.1-1.2 parts of polyacrylonitrile.

[0008] Furthermore, in the salt, the molar ratio of ferric acetate to cerium acetate is (8.5-9.5): 1. Under this condition, the metal carbon-based catalyst has better stability and better catalytic activity at high current density.

[0009] Furthermore, the complexing agent includes citric acid. This type of complexing agent can form a better synergistic effect with the selected metal ions to form a more stable complex, more effectively prevent the metal ions from precipitating or aggregating in the solution, thereby being more conducive to the uniform distribution of metal ions on the carbon-based material and better regulating the activity and selectivity of the catalyst.

[0010] Furthermore, the raw material also includes a solvent, and the solvent is selected from N, N-dimethylformamide and / or ethylene glycol. In the preparation process of the metal carbon-based catalyst, the solvent not only provides the physical effects of dissolution and dispersion, but also has an important influence on the performance of the catalyst by affecting the reaction environment, product structure and morphology and other factors. By selecting the right type of solvent, it can play a better dissolution and dispersion role, and is conducive to the improvement of the catalytic performance of the catalyst.

[0011] Further, the solvent includes 8-10 parts by volume of N,N-dimethylformamide and 0.03-0.09 parts by weight of ethylene glycol; the parts by volume are measured in milliliters, and the corresponding parts by weight are measured in grams, or the parts by volume are measured in liters, and the corresponding parts by weight are measured in kilograms. By selecting a solvent of a suitable type and dosage ratio, it can play a better dissolving and dispersing role, and is conducive to improving the catalytic performance of the catalyst. Preferably, the solvent includes 8-9 parts by volume of N,N-dimethylformamide and 0.06-0.07 parts by weight of ethylene glycol.

[0012] Furthermore, the metal carbon-based catalyst is in a fibrous form, and the fiber is a micron-sized fiber.

[0013] According to a second aspect of the present invention, the present invention also provides a method for preparing the above-mentioned metal carbon-based catalyst, comprising the following steps: dissolving salts, complexing agents and polyacrylonitrile in a solvent to obtain an electrospinning precursor solution; The electrospinning precursor solution is taken for electrospinning; the product obtained by electrospinning is dried, and then placed in a muffle furnace for calcination at 200-300°C for 1-5 hours, and then placed in a tube furnace for calcination at 500-1000°C for 3-6 hours after cooling to room temperature, and finally cooled. It should be noted that room temperature generally refers to 20-30°C.

[0014] The preparation method of the metal carbon-based catalyst of the present invention adopts electrostatic spinning technology, which can accurately control the microstructure, and can obtain the catalyst microstructure with ideal fiber diameter, length and orientation by adjusting the parameters. At the same time, electrostatic spinning technology is also convenient for material compounding, and can fully mix the monometallic salt or bimetallic salt with the carbon source in the electrostatic spinning precursor solution, and realize the uniform distribution of the metal in the carbon-based material through subsequent treatment, so as to create conditions for the preparation of high-performance monometallic and bimetallic carbon-based catalysts. These materials have great application potential in various battery systems such as lithium ion batteries and sodium ion batteries.

[0015] Furthermore, the electrospinning comprises the following steps: (1) Prepare the electrospinning device: wipe the dust of the electrospinning machine with ethanol solution, wrap aluminum foil around the internal roller of the electrospinning machine, and stick it with transparent tape to ensure that the aluminum foil does not fall off; take 4 to 10 ml of the electrospinning precursor solution into the syringe barrel, and remove the bubbles in the syringe barrel; fix the syringe barrel on the propeller of the electrospinning machine; connect the needle of the syringe and the jet of the electrospinning machine with a hose; keep the spinneret of the electrospinning machine vertical and spaced apart from the roller, clamp the positive electrode of the high-voltage power supply on the spinneret, and connect the negative electrode to the receiving device; keep the needle of the syringe spaced apart from the receiving device, and close the electrospinning machine door; (2) Adjusting parameters: setting the speed of the motor of the receiving device to 400-600 rpm; setting the spinning rate to 8-10 μl per minute. After the electrospinning precursor solution is extruded, turning on the high-voltage power supply, adjusting the voltage to 17-18 kV, and performing the electrospinning operation for 2-10 h to obtain a fiber membrane sample.

[0016] By finely optimizing the electrospinning process, the diameter, length and other structural characteristics of the fiber can be better and more accurately controlled, thereby achieving fine regulation of the catalyst structure and improving the stability and catalytic performance of metal carbon-based catalysts.

[0017] According to the first aspect of the present invention, salts, complexing agents and polyacrylonitrile are dissolved in a solvent, and stirred for 12 to 24 hours at a stirring speed of 400 to 600 r / min to obtain an electrospinning precursor solution. By reasonably limiting the stirring speed and time, a uniform electrospinning precursor solution can be obtained, which is conducive to the realization of the electrospinning process of the subsequent electrospinning precursor solution, and a metal carbon-based catalyst with an ideal structure is obtained.

[0018] According to the third aspect of the present invention, the present invention also provides the use of the above-mentioned metal-carbon-based catalyst or the metal-carbon-based catalyst prepared by the above-mentioned preparation method in a fuel cell or a metal-air battery.

[0019] The metal-carbon-based catalyst of the present invention adopts specific metal salts, and limits the amount of salts, complexing agents and polyacrylonitrile to a reasonable range value, so that the raw materials can play a better synergistic role, so that the obtained metal-carbon-based catalyst has good stability and excellent catalytic activity at high current density, which can meet the catalyst performance requirements of current fuel cells or metal-air batteries. The metal-carbon-based catalyst of the present invention is environmentally friendly and low in cost. It can meet the requirements of sustainable development while ensuring economic benefits, and provides a new idea for the research and development of substitutes for the currently expensive commercial platinum carbon. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a linear voltammetric scan diagram of the metal carbon-based catalyst prepared in Example 1 and Comparative Examples 1 and 2 provided by the present invention.

[0022] Figure 2 It is a cyclic voltammetry curve diagram of the metal carbon-based catalyst prepared in Example 1 and Comparative Examples 1 and 2 provided by the present invention.

[0023] Figure 3 It is a scanning electron microscope image of the metal carbon-based catalyst of Example 1 provided by the present invention.

[0024] Figure 4 This is the XRD test diagram of the metal carbon-based catalyst of Example 1 provided by the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1 This embodiment provides a bimetallic carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.1746 g of ferric acetate, 0.0318 g of cerium acetate, 1.2 g of polyacrylonitrile, 0.0633 g of citric acid, and 0.0633 g of ethylene glycol in a 50 ml small beaker, measure 8 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved to obtain an electrospinning precursor solution.

[0027] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0028] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0029] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0030] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0031] The prepared metal carbon-based catalyst was subjected to linear voltammetric scanning test and cyclic voltammetric scanning test using a rotating disk electrode device. The catalytic activity of the catalyst was reflected by its half-wave potential and starting potential. The results are shown in Figure 1 and Figure 2 As shown, the half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example are 0.8515 V and 1.0199 V, respectively.

[0032] like Figure 3 As shown, the obtained metal carbon-based catalyst is in the form of micron-sized fibers. Figure 4 As shown, the peak at 25.1° of the obtained metal carbon-based catalyst may be the (002) plane of high-temperature carbonization, and the sharp peak at 44.7° may be the amorphous carbon in the catalyst.

[0033] Example 2 This embodiment provides a bimetallic carbon-based catalyst, which is different from Example 1 in that the molar ratio of ferric acetate to cerium acetate is 8.5:1. Its preparation method is the same as that of Example 1.

[0034] The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example are 0.8319 V and 0.9978 V, respectively.

[0035] Example 3 This embodiment provides a bimetallic carbon-based catalyst, which is different from Example 1 in that the molar ratio of ferric acetate to cerium acetate is 9.5:1. Its preparation method is the same as that of Example 1.

[0036] The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example are 0.8648 V and 0.9899 V, respectively.

[0037] Example 4 This embodiment provides a bimetallic carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.1243 g of ferric acetate, 0.0239 g of cerium acetate, 1.0 g of polyacrylonitrile, 0.0567 g of citric acid, and 0.0359 g of ethylene glycol in a 50 ml small beaker, measure 10 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved, to obtain the electrospinning precursor solution.

[0038] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0039] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0040] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0041] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0042] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflected the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example were 0.8167 V and 0.9658 V, respectively.

[0043] Example 5 This embodiment provides a bimetallic carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.2369 g of ferric acetate, 0.0409 g of cerium acetate, 1.4 g of polyacrylonitrile, 0.0735 g of citric acid, and 0.0689 g of ethylene glycol in a 50 ml small beaker, measure 10 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved, to obtain an electrospinning precursor solution.

[0044] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0045] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0046] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0047] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0048] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflected the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example were 0.8431 V and 0.9856 V, respectively.

[0049] Example 6 This embodiment provides a bimetallic carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.2909 g of ferric acetate, 0.0559 g of cerium acetate, 1.2 g of polyacrylonitrile, 0.0834 g of citric acid, and 0.0867 g of ethylene glycol into a 50 ml small beaker, measure 10 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved, to obtain an electrospinning precursor solution.

[0050] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0051] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0052] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0053] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0054] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflected the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example were 0.8368 V and 0.9869 V, respectively.

[0055] Example 7 This embodiment provides a bimetallic carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.1965 g of ferric acetate, 0.0356 g of cerium acetate, 1.2 g of polyacrylonitrile, 0.0676 g of citric acid, and 0.0682 g of ethylene glycol in a 50 ml small beaker, measure 10 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic particle and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved to obtain an electrospinning precursor solution.

[0056] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0057] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0058] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0059] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0060] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflect the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this example were 0.8167 V and 0.9359 V, respectively.

[0061] Comparative Example 1 This comparative example provides a metal carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.1552 g of ferric acetate, 0.0318 g of cerium acetate, 1.2 g of polyacrylonitrile, 0.0633 g of citric acid, and 0.0633 g of ethylene glycol into a 50 ml small beaker, measure 8 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved, to obtain an electrospinning precursor solution.

[0062] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0063] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate. After the electrospinning precursor liquid is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 hours to obtain a fiber membrane sample.

[0064] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0065] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0066] The prepared metal carbon-based catalyst was subjected to linear voltammetric scanning test and cyclic voltammetric scanning test using a rotating disk electrode device. The catalytic activity of the catalyst was reflected by its half-wave potential and starting potential. The results are shown in Figure 1 and Figure 2 As shown, the half-wave potential and the starting potential of the metal carbon-based catalyst prepared in this comparative example are 0.6695V and 0.9252V, respectively.

[0067] Comparative Example 2 This comparative example provides a metal carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.1940 g of ferric acetate, 0.0318 g of cerium acetate, 1.2 g of polyacrylonitrile, 0.0633 g of citric acid, and 0.0633 g of ethylene glycol in a 50 ml small beaker, measure 8 ml of N,N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved, to obtain the electrospinning precursor solution.

[0068] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0069] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate. After the electrospinning precursor liquid is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 hours to obtain a fiber membrane sample.

[0070] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0071] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0072] The prepared metal carbon-based catalyst was subjected to linear voltammetric scanning test and cyclic voltammetric scanning test using a rotating disk electrode device. The catalytic activity of the catalyst was reflected by its half-wave potential and starting potential. The results are shown in Figure 1 and Figure 2 As shown, the half-wave potential and the starting potential of the metal carbon-based catalyst prepared in this comparative example are 0.6365V and 0.8992V, respectively.

[0073] Comparative Example 3 This comparative example provides a single metal carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.2241 g of cobalt acetate, 0.0633 g of citric acid, 0.0633 g of ethylene glycol, 1.3 g of polyacrylonitrile, and 0.1 g of F-127 (full name: polypropylene glycol-polyethylene glycol-polypropylene glycol, PPG-PEG-PPG) in a 50 ml small beaker, measure 8 ml of N, N-dimethylformamide solution and pour it into the beaker, take a magnetic particle and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until it is completely dissolved to obtain an electrospinning precursor solution.

[0074] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0075] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate. After the electrospinning precursor liquid is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 hours to obtain a fiber membrane sample.

[0076] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0077] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0078] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflected the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this comparative example were 0.7185V and 0.9343V, respectively.

[0079] Comparative Example 4 This comparative example provides a bimetallic carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.0317 g cerium acetate, 0.2241 g cobalt acetate, 0.0633 g citric acid, 0.0633 g ethylene glycol, 1.3 g polyacrylonitrile, 0.1 g F-127, and 0.3 g urea into a 50 ml beaker, measure 8 ml N, N-dimethylformamide solution and pour it into the beaker, take a magnetic particle and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved to obtain an electrospinning precursor solution.

[0080] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0081] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0082] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0083] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0084] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflected the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this comparative example were 0.6934V and 0.9138V, respectively.

[0085] Comparative Example 5 This comparative example provides a single metal carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: Weigh 0.1746 g ferric acetate, 0.0633 g citric acid, 0.0633 g ethylene glycol, and 1.2 g polyacrylonitrile into a 50 ml small beaker, measure 8 ml N, N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved to obtain the electrospinning precursor solution.

[0086] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0087] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate to 9 μl / min. After the electrospinning precursor solution is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 h to obtain a fiber membrane sample.

[0088] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0089] (5) After the aluminum foil is removed and placed in a high-temperature drying oven for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and roasted at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst is obtained after the temperature is lowered to 950°C in a tube furnace. The prepared metal carbon-based catalyst is subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. The catalytic activity of the catalyst is reflected by its half-wave potential and starting potential. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this comparative example are 0.7539V and 0.9352V, respectively.

[0090] Comparative Example 6 This comparative example provides a single metal carbon-based catalyst, and the specific preparation method is as follows: (1) Preparation of electrospinning precursor solution: weigh 0.0318 g cerium acetate, 0.0633 g citric acid, 0.0633 g ethylene glycol, and 1.2 g polyacrylonitrile into a 50 ml small beaker, measure 8 ml N, N-dimethylformamide solution and pour it into the beaker, take a magnetic bar and put it into the beaker, place the beaker on a magnetic stirrer and stir at 500 rpm / min for 24 h until completely dissolved to obtain the electrospinning precursor solution.

[0091] (2) Prepare the electrospinning device: Dip an appropriate amount of ethanol solution with alcohol cotton to wipe off the dust on the electrospinning machine. Use transparent tape to tape aluminum foil around the roller inside the spinning machine to ensure that the aluminum foil does not fall off. Use a knife to cut a catheter of appropriate length. After completing the installation of the syringe, draw 6 ml of electrospinning precursor liquid into the syringe. Slowly push the syringe forward to remove the bubbles at the top; fix the syringe on the pusher; connect the needle and the injection point with a hose; the spinneret is perpendicular to the roller and separated by a finger distance. Clamp the positive electrode of the high-voltage power supply on the spinneret and connect the negative electrode to the receiving device; adjust the distance between the needle and the receiving device to about 11 to 12 cm, and close the electrospinning machine door.

[0092] (3) Adjustment parameters: Set the motor speed of the receiving device (drum) to 500 rpm; set the spinning rate. After the electrospinning precursor liquid is slowly extruded, turn on the high-voltage power supply and adjust the voltage to about 17-18 kV. Perform the electrospinning operation for 6 hours to obtain a fiber membrane sample.

[0093] (4) After spinning is completed, turn off the high-voltage power supply first, then turn off the electrospinning machine switch, take out the syringe, disassemble it and soak it in ethanol solution, put the beaker into an ultrasonic cleaner for 30 minutes to remove the spinning solution attached to the inner and outer surfaces of the needle, and soak the cleaned needle and other containers in DMF solution for the next use.

[0094] (5) After the removed aluminum foil is placed in a high-temperature drying oven and dried for 2 hours (to remove moisture from the fiber membrane), the fiber membrane on the surface of the aluminum foil is torn off and placed in a long crucible, which is then placed in a muffle furnace and baked at 270°C for 2 hours. After cooling to room temperature, the metal carbon-based catalyst can be obtained after cooling.

[0095] The prepared metal carbon-based catalyst was subjected to linear voltammetry scanning test and cyclic voltammetry scanning test using a rotating disk electrode device. Its half-wave potential and starting potential reflected the catalytic activity of the catalyst. The half-wave potential and starting potential of the metal carbon-based catalyst prepared in this comparative example were 0.6599V and 0.9245V, respectively.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A metal-carbon-based catalyst, characterized in that: The invention is prepared from raw materials including the following components: 0.1-0.4 weight parts of salts, 0.05-0.09 weight parts of complexing agents and 1.0-1.4 weight parts of polyacrylonitrile; the salts include ferric acetate and cerium acetate.

2. The metal-carbon-based catalyst according to claim 1, characterized in that In the salts, the molar ratio of ferric acetate to cerium acetate is (8.5-9.5):

1.

3. The metal-carbon-based catalyst according to claim 1 or 2, characterized in that: The complexing agent is citric acid.

4. The metal-carbon-based catalyst according to any one of claims 1 to 3, characterized in that The raw material also includes a solvent, and the solvent is selected from N,N-dimethylformamide and / or ethylene glycol.

5. The metal-carbon-based catalyst according to claim 4, characterized in that The solvent includes 8-10 parts by volume of N,N-dimethylformamide and 0.03-0.09 parts by weight of ethylene glycol; the parts by volume are measured in milliliters, and the corresponding parts by weight are measured in grams, or the parts by volume are measured in liters, and the corresponding parts by weight are measured in kilograms.

6. The method for preparing the metal-carbon-based catalyst according to any one of claims 1 to 5, characterized in that: The steps include: dissolving salts, complexing agents and polyacrylonitrile in a solvent to obtain an electrospinning precursor solution; The electrospinning precursor solution is taken for electrospinning; the product obtained by electrospinning is dried, and then placed in a muffle furnace for roasting at 200-300° C. for 1-5 hours, then cooled to room temperature, placed in a tubular furnace for roasting at 500-1000° C. for 3-6 hours, and finally cooled.

7. The preparation method according to claim 6, characterized in that: The electrospinning comprises the following steps: (1) Prepare the electrospinning device: wipe the dust of the electrospinning machine with ethanol solution, wrap aluminum foil around the internal roller of the electrospinning machine, and stick it with transparent tape to ensure that the aluminum foil does not fall off; take 4 to 10 ml of the electrospinning precursor solution into the syringe barrel, and remove the bubbles in the syringe barrel; fix the syringe barrel on the propeller of the electrospinning machine; connect the needle of the syringe and the jet of the electrospinning machine with a hose; keep the spinneret of the electrospinning machine vertical and spaced apart from the roller, clamp the positive electrode of the high-voltage power supply on the spinneret, and connect the negative electrode to the receiving device; keep the needle of the syringe spaced apart from the receiving device, and close the electrospinning machine door; (2) Adjusting parameters: setting the speed of the motor of the receiving device to 400-600 rpm; setting the spinning rate to 8-10 μl per minute. After the electrospinning precursor solution is extruded, turning on the high-voltage power supply, adjusting the voltage to 17-18 kV, and performing the electrospinning operation for 2-10 h to obtain a fiber membrane sample.

8. The preparation method according to claim 6, characterized in that: The salts, the complexing agent and the polyacrylonitrile are dissolved in a solvent, and stirred at a stirring speed of 400-600 r / min for 12-24 hours to obtain an electrospinning precursor solution.

9. Use of the metal-carbon-based catalyst described in any one of claims 1 to 5 or the metal-carbon-based catalyst prepared by the preparation method described in any one of claims 6 to 8 in a fuel cell or a metal-air battery.

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