CN110875480A - Platinum carbon nanofiber electrode and preparation method thereof - Google Patents

Abstract

The invention relates to a platinum carbon nanofiber electrode and a preparation method thereof, wherein the preparation method comprises the following steps: mixing a carbon carrier, a Nafion solution and a binder to prepare spinning slurry; spinning the spinning slurry to obtain a nanofiber catalyst layer; transferring the nanofiber catalyst layer to the surface of a gas diffusion layer coated with carbon powder and polytetrafluoroethylene to obtain a gas diffusion electrode; and depositing platinum nano particles on the gas diffusion electrode in a three-electrode system by using the gas diffusion electrode as a working electrode and a solution containing chloroplatinic acid and sulfuric acid as an electrolyte by adopting a pulse electrodeposition technology to prepare the platinum-carbon nanofiber electrode. The platinum carbon nanofiber electrode and the preparation method thereof can improve the utilization rate of the catalyst Pt and the performance stability of the battery.

Description

Platinum carbon nanofiber electrode and preparation method thereof

technical field

The invention relates to the technical field of fuel cells, in particular to a platinum carbon nanofiber electrode and a preparation method thereof.

Background technique

Proton exchange membrane fuel cell (PEMFC) has the advantages of high power density, high energy conversion efficiency, low temperature startup, and environmental friendliness, and is regarded as an ideal power source for stationary power stations, electric vehicles, and portable power sources. . However, if it is to be successfully commercialized, it mainly faces two problems of cost and life. In fuel cell components, the cost of catalyst accounts for nearly half of the cost. Reducing the catalyst loading is the most direct way to reduce the cost of fuel cells. At the same time, the stability of catalysts also has an extremely important impact on fuel cells. Therefore, optimizing the electrode preparation process to improve the utilization and stability of the catalyst in the electrode, so that the fuel cell still has high activity and long life when the Pt (platinum) loading is low, which is the current research on low temperature fuel cells. The top priority is of great practical significance for reducing the cost of PEMFC and accelerating its commercialization process. The traditional electrode preparation method is mainly to spray or coat the catalyst slurry on the proton exchange membrane or gas diffusion layer, and its main shortcomings are the low utilization rate of Pt and the unstable battery performance. Some researchers use electrospinning technology to prepare Pd/C nanofiber layer and then deposit Pt to prepare electrodes. Although it improves the utilization rate of Pt, there is a situation in which noble metal Pd particles are coated with polymers and cannot deposit Pt, which reduces the The utilization rate of Pd; at the same time, it is difficult for the electrodeposited Pt to completely coat the Pd nanoparticles, and the exposed Pd nanoparticles are prone to dissolve in the operating environment of the fuel cell. The dissolved Pd has a toxic effect on the proton exchange membrane, which is not conducive to fuel. Further improvements in battery life.

SUMMARY OF THE INVENTION

Based on this, it is necessary to provide a platinum carbon nanofiber electrode and a preparation method thereof that can improve the utilization rate of precious metals and battery stability.

A preparation method of platinum carbon nanofiber electrode, comprising the following steps:

Mixing carbon carrier, Nafion solution and binder to prepare spinning slurry;

spinning the spinning slurry to obtain a nanofiber catalytic layer;

transferring the nanofiber catalytic layer to the surface coated with carbon powder and polytetrafluoroethylene on the gas diffusion layer to obtain a gas diffusion electrode;

Using the gas diffusion electrode as a working electrode, a solution containing chloroplatinic acid and sulfuric acid as an electrolyte, and using pulse electrodeposition technology, platinum nanoparticles are deposited on the gas diffusion electrode in a three-electrode system to prepare platinum carbon nanofibers electrode (denoted as Pt@C nanofiber electrode).

In one embodiment, the current of the pulse electrodeposition is (25～300) mA·cm ⁻² , the current supply time is 0.1ms～2ms, the current off time is 1.5ms～16ms, and the pulse electrodeposition time is 200s ~3600s.

In one embodiment, the current of the pulse electrodeposition is (115-235) mA·cm ^-2 , the current supply time is 0.8ms to 1.2ms, the current off time is 1.8ms to 4ms, and the pulse electrodeposition time is 400s～1200s.

In one embodiment, the mass ratio of the carbon support, the solid content in the Nafion solution and the binder is 20:(6-20):(5-10).

In one embodiment, the raw material of the spinning slurry further comprises polytetrafluoroethylene, and when preparing the spinning slurry, the polytetrafluoroethylene, the carbon carrier, the Nafion solution and the The binders are mixed.

In one embodiment, the mass ratio of the polytetrafluoroethylene in the spinning slurry to the carbon carrier is (1-5):20.

In one embodiment, the loading amount of the carbon support is (0.2˜2.0) mg·cm ⁻² .

In one of the embodiments, the preparation step of the gas diffusion layer coated with carbon powder and polytetrafluoroethylene on the surface is also included: the carbon powder and 4wt%-22wt% polytetrafluoroethylene slurry are mixed according to 10:(0.1 ～5) in mass ratio to obtain a coating slurry, and the coating slurry is blade-coated on the surface of the carbon paper, and the thickness of the blade coating is controlled to be 35 μm to 250 μm.

In one embodiment, the spinning step adopts electrospinning, the liquid flow rate of the electrospinning is (0.4-1.2) mL·h ^-1 , and the distance between the needle tip and the receiving plate is (5-25) cm , the voltage is (8 ~ 22) KV, and the receiving time is (1.5 ~ 6.5) h.

The platinum carbon nanofiber electrode prepared by the above preparation method.

In the above platinum carbon nanofiber electrode and its preparation method, the nanofiber catalytic layer is formed by spinning technology, and the network of the nanofiber structure is beneficial to improve the H proton conductivity. C and Nafion are uniformly dispersed on the surface of the nanofibers of the binder, which is conducive to the deposition of Pt at the interface between the carbon support and the proton conductor Nafion, which avoids the situation that the catalyst Pt is not in contact with Nafion or is completely covered by Nafion, and optimizes the proton , the three-phase reaction interface of electrons and gas improves the utilization rate of catalyst Pt. In addition, for the gas diffusion electrode formed by transfer printing, the Pt nanoparticles deposited by pulse deposition technology are irregular spherical, with an average diameter of about 15 nm, which improves the activity of Pt catalyst; at the same time, the deposited Pt has a larger particle size, which is conducive to mass transfer, and then It can improve the stability of Pt catalyst and battery performance.

Description of drawings

Fig. 1 is the scanning electron microscope image of the nanofiber catalytic layer prepared in Example 1 of the present invention;

2 is a transmission electron microscope image of the Pt@C nanofiber electrode prepared in Example 1 of the present invention;

3 is the discharge performance curve of the Pt@C nanofiber electrode prepared in Example 1 of the present invention and the traditional electrode prepared in Comparative Example 1;

4 is the stability test curve of the Pt@C nanofiber electrode prepared in Example 1 of the present invention and the traditional electrode prepared in Comparative Example 1.

Detailed ways

In order to facilitate understanding of the present invention, the present invention will be described more fully below, and preferred embodiments of the present invention will be given. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that a thorough and complete understanding of the present disclosure is provided.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The inventors have found that the traditional method for preparing electrodes is mainly to spray or coat the catalyst slurry on the proton exchange membrane or gas diffusion layer. Due to the poor uniformity of the carbon-supported Pt catalyst and electrolyte components in the catalyst slurry, the There is a problem that part of the carbon-supported Pt catalyst is not in contact with the Nafion membrane or part of the carbon-supported Pt catalyst is completely covered by Nafion, so the three-phase reaction interface of protons, electrons and gas cannot be effectively constructed, which is not conducive to the improvement of Pt utilization; and The electrode formed by coating is relatively dense, which is not conducive to mass transfer, resulting in low battery performance when the Pt load is low. Some researchers have prepared Pt@Pd/C nanofiber electrodes by depositing Pt after Pd/C nanofibers. Although it improves the utilization rate of Pt, the cost of Pd is also high, and the utilization rate of Pd needs to be improved. There is also the risk of Pd poisoning the proton exchange membrane.

Based on this, the present invention provides a platinum carbon nanofiber electrode and a preparation method thereof in one embodiment. The preparation method includes the following steps S1 to S4.

Step S1: mixing the carbon carrier, the Nafion solution and the binder to prepare a spinning slurry.

The carbon carrier is used as the carrier of Pt, and the Nafion solution is a perfluorosulfonic acid type polymer solution for electrode support; Nafion is mixed with a binder to form a nanofiber structure through subsequent spinning, and the network of the nanofiber structure is beneficial to improve H Proton conductivity. Moreover, C and Nafion are uniformly dispersed on the nanofiber surface of the binder, which is beneficial to the subsequent deposition of Pt at the interface between the carbon support and the proton conductor Nafion, which avoids the situation that the catalyst Pt is not in contact with Nafion or is completely covered by Nafion. The three-phase reaction interface of proton, electron and gas is optimized, and the utilization rate of catalyst Pt is improved.

In one embodiment, the loading amount of the carbon support is (0.2˜2.0) mg·cm ⁻² .

Preferably, the binder is at least one of polyacrylic acid, polyacrylonitrile and polyvinylpyrrolidone. These binders can be dissolved in at least one of isopropanol and water, and the binder can be dissolved in at least one of isopropanol and water to form a solution, which is added to the spinning slurry in the form of a binder solution. Specifically, the mass content of the binder solution is 8% to 15%.

In one embodiment, the mass content of the Nafion solution is 3%-9%, and the mass ratio of the carbon support, the Nafion solution and the binder is 20:(6-20):(5-10). Preferably, the mass ratio of the carbon support, the Nafion solution and the binder is 20:(15-20):(5-10).

In one embodiment, the raw material of the spinning slurry further includes polytetrafluoroethylene, which is obtained by mixing polytetrafluoroethylene, carbon carrier, Nafion solution and binder when preparing the spinning slurry. The inventors of the present invention have found that adding polytetrafluoroethylene into the spinning slurry is beneficial to improve the hydrophobicity of the prepared nanofiber catalytic layer. Preferably, the mass ratio of the polytetrafluoroethylene to the carbon carrier in the spinning slurry is (1-5):20.

Preferably, in step S1, ultrasonic treatment is used for mixing for 2h-4h, and then stirring is performed for 18h-40h.

Step S2: spinning the spinning slurry to obtain a nanofiber catalytic layer.

The nanofiber catalytic layer obtained in step S2 has a nanofiber structure, and the average diameter of the fibers is 250 μm. C and Nafion were uniformly dispersed on the surface of the nanofibers of the binder, which improved the utilization rate of the catalyst Pt.

In one embodiment, electrospinning is used in the spinning step, the liquid flow rate of electrospinning is (0.4-1.2) mL·h ^-1 , the distance between the needle tip and the receiving plate is (5-25) cm, and the voltage is ( 8～22)KV, the receiving time is (1.5～6.5)h.

Step S3: Transfer the nanofiber catalytic layer to the surface of the gas diffusion layer (GDL) coated with carbon powder and PTFE to obtain a gas diffusion electrode.

The main function of the gas diffusion layer in the gas diffusion electrode is to allow the reaction gas to pass through smoothly, and to transport the gas required for the corresponding reaction to the reactive active layer. The nanofiber catalytic layer is the place where the oxygen reduction reaction occurs, and the gas transported from the gas diffusion layer forms an electrochemical reaction activation point together with the catalyst and the electrolyte, and then reduces the reaction gas.

In one of the embodiments, it also includes the preparation step of the gas diffusion layer coated with carbon powder and polytetrafluoroethylene on the surface: mixing carbon powder and 4wt%-22wt% polytetrafluoroethylene slurry according to 10:(0.1-5 ) in the mass ratio to obtain the coating slurry, and the coating slurry is blade-coated on the surface of the carbon paper, and the thickness of the blade coating is controlled to be 35 μm to 250 μm.

The transfer printing step can be transferred by a hot pressing method. The hot pressing pressure of the transfer printing is (0.25～1) MPa, the time is 1min～5min, and the hot pressing temperature is 135℃～142℃. Preferably, the hot pressing pressure of the transfer printing is (0.25-0.5) MPa, the time is 3 min-4 min, and the hot pressing temperature is 139°C-141°C.

Step S4 : using the gas diffusion electrode as the working electrode, the solution containing chloroplatinic acid and sulfuric acid as the electrolyte, and adopting the pulse electrodeposition technique, platinum nanoparticles are deposited on the gas diffusion electrode in a three-electrode system to prepare a platinum carbon nanofiber electrode .

Specifically, a saturated calomel electrode can be used as a reference electrode, a graphite electrode can be used as a counter electrode, and a solution of chloroplatinic acid and sulfuric acid can be used as an electrolyte.

Step S4 uses pulse electrodeposition technology to deposit Pt on the gas diffusion electrode, and Pt is deposited at the interface between the carbon support and the proton conductor Nafion, which avoids the situation that the catalyst Pt is not in contact with Nafion or is completely covered by Nafion, and optimizes the proton, The three-phase reaction interface of electrons and gas improves the utilization rate of catalyst Pt. In addition, the deposited Pt nanoparticles are irregular spherical with an average diameter of about 15 nm, which improves the activity of the Pt catalyst; at the same time, the deposited Pt has a larger particle size, which is conducive to mass transfer and improves the stability of the Pt catalyst.

In one embodiment, the current of the pulse electrodeposition is (25-300) mA·cm ^-2 , the current supply time is 0.1ms-2ms, the current disconnection time is 1.5ms-16ms, and the pulse electrodeposition time is 200s-3600s .

Preferably, the current of the pulse electrodeposition is (115-235) mA·cm ^-2 , the current supply time is 0.8ms-1.2ms, the current off time is 1.8ms-4ms, and the pulse electrodeposition time is 400s-1200s.

In the electrolyte, the concentration of chloroplatinic acid is (0.1-60) mmol/L, and the concentration of sulfuric acid is (0.1-2) mol/L.

For the platinum carbon nanofiber electrode and its preparation method, the nanofiber catalytic layer is formed by spinning technology, and the gas diffusion electrode is formed by transfer printing, and the catalyst Pt is deposited by the pulse deposition technology. This avoids the situation that the catalyst Pt is not in contact with Nafion or is completely covered by Nafion, optimizes the three-phase reaction interface of protons, electrons and gas, and improves the utilization rate of catalyst Pt; the deposited Pt nanoparticles are irregular spherical, average The diameter is about 15 nm, which improves the activity of the Pt catalyst; at the same time, the deposited Pt has a larger particle size, which is conducive to mass transfer, thereby improving the stability of the Pt catalyst and battery performance.

In addition, the use of a carbon support without a metal catalyst can further avoid the problem of low utilization rate caused by the catalyst being coated with Nafion in step S1, and the pulse deposition technique is used to deposit the catalyst Pt in step S4, avoiding the use of Pd catalyst on the Nafion film. The degradation leads to the instability problem of Nafion membrane, which improves the utilization of catalyst and the stability of battery performance.

The structure of the prepared platinum carbon nanofiber electrode is as follows: a nanofiber catalytic layer is formed on the gas diffusion layer coated with carbon powder and polytetrafluoroethylene on the surface, and the catalyst Pt is deposited on the nanofiber catalytic layer. Among them, the nanofiber catalytic layer has a nanofiber structure with an average fiber diameter of 250 μm. C and Nafion are uniformly dispersed on the nanofiber surface of the binder; Pt is deposited at the interface between the carbon support and the proton conductor Nafion, and the deposited Pt nanofibers The particles are irregular spherical with an average diameter of about 15 nm.

Further, the Pt loading of the prepared platinum carbon nanofiber electrode was (0.03-0.4) mg·cm ^-2 . Due to the large particle size of Pt, which is conducive to mass transfer, the battery performance is still relatively good when the Pt loading is low, which improves the stability of the Pt catalyst.

The following are specific examples.

Example 1

(1) Weigh 1 g of polyacrylic acid as a binder, dissolve it in a mixed solvent of 6 g of isopropanol and 1 g of water, and stir for 24 hours to prepare a binder solution of 12.5 wt %. Weigh 0.05g of Vulcan XC-72 carbon carrier, 0.75g of Nafion solution (5wt%) and 0.003g of PTFE powder and mix them uniformly, add 0.1g of binder solution after sonicating for 3h, and stir for 24h to prepare a spinning slurry. Among them, the loading amount of Vulcan XC-72 carbon carrier was 0.27 mg·cm ^-2 .

(2) The catalytic layer was then prepared by electrospinning technology, the aluminum foil was wrapped on the surface of the drum collector, and the ^nanofiber catalytic layer was obtained by electrospinning. The distance of the receiving plate is 12cm, the voltage is 10KV, and the receiving time is 1h, to obtain the nanofiber catalytic layer.

(3) Mix carbon powder XC-72 and 5wt% polytetrafluoroethylene slurry (commercially available) to obtain a coating slurry, and scrape the coating slurry on one side of the carbon paper to prepare a gas diffusion layer. The thickness of the scraping coating is 50μm. The carbon paper was purchased from Japan Toray Company. Finally, the prepared nanofiber catalytic layer is transferred to the side of the gas diffusion layer coated with carbon powder and polytetrafluoroethylene by hot pressing to obtain a gas diffusion electrode.

(4) Using the gas diffusion electrode as the working electrode, the saturated calomel electrode as the reference electrode, the graphite electrode as the counter electrode, and the chloroplatinic acid and sulfuric acid solution as the electrolyte, the pulse electrodeposition technique was used to electrodeposit platinum in the three-electrode system, and the deposition The current was 125mA·cm ^-2 , the current supply time was 1.0ms, the current disconnection time was 4.0ms, and the pulse electrodeposition time was 750s, and the platinum carbon nanofiber electrode with a Pt load of 0.1mg·cm ^-2 was prepared (denoted as Pt@C nanofiber electrode).

Example 2

Basically the same as Example 1, the difference is: changing the pulse electrodeposition parameters in step (4) (the deposition current is 150mA cm ^-2 , the current supply time is 0.8ms, the current disconnection time is 3.8ms, and the pulse electrodeposition time is 200 ~500 s) to prepare Pt@C nanofiber electrodes with Pt loadings ranging from 0.03 to 0.05 mg·cm ^-2 .

Example 3

Basically the same as Example 1, the difference is: the thickness of the blade coating in the step (3) is 250 μm; the deposition current of the pulse electrodeposition in the step (4) is 300mA·cm ^-2 , the current supply time is 0.1ms, and the current is cut off. The on time was 16ms, and the pulse electrodeposition time was 3600s.

Example 4

It is basically the same as Example 1, except that: the nanofiber catalytic layer with the mass ratio of solid content to carbon support in Nafion solution is 0.5.

Example 5

Basically the same as Example 1, the difference is: the 5wt% Nafion solution in the spinning slurry is 1 g, the PTFE powder is 0.0125 g, and the mass of the binder solution is 0.2 g. The mass ratio of carbon support, solid content in Nafion solution, binder and PTFE powder is 20:20:10:5.

Example 6

It is basically the same as Example 1, except that no PTFE powder is added to the spinning slurry.

Comparative Example 1

Traditional electrode preparation method: A commercialized 40wt% Pt/C catalyst was sprayed onto the surface of the gas diffusion layer to prepare a single-sided gas diffusion electrode as the cathode.

The following are performance tests.

The nanofiber catalytic layer prepared in Example 1 was tested by scanning electron microscope, and the obtained scanning electron microscope image was shown in FIG. 1 . It can be seen from FIG. 1 that the nanofiber catalytic layer prepared by the electrospinning technology in Example 1 has a nanofiber structure, and the average diameter of the fibers is 250 μm.

The Pt@C nanofiber electrode prepared in Example 1 was tested by transmission electron microscope, and the obtained transmission electron microscope image was shown in FIG. 2 . It can be seen from Figure 2 that the Pt catalyst deposited on the nanofiber catalytic layer is irregular spherical with an average diameter of 15 nm.

The electrodes obtained in Example 1 and Comparative Example 1 were used as cathodes to make membrane electrodes for performance testing. The Pt loading of the Pt@C nanofiber electrode prepared in Example 1 was 0.1 mg·cm ^-2 ; the Pt loading of the conventional electrode prepared in Comparative Example 1 was 0.18 mg·cm ^-2 .

Specifically, the electrodes obtained in Example 1 and Comparative Example 1 were used as cathodes; a commercial 40wt% Pt/C catalyst was sprayed onto one side of the Nafion membrane by a traditional preparation method as an anode, and its Pt loading was 0.2 mg ·cm ^-2 ; finally, the prepared cathode and anode are hot-pressed to form a film electrode, and electrochemical performance evaluation, including discharge performance and battery stability test, is carried out on a single cell evaluation device.

3 is the discharge performance curve of the Pt@C nanofiber electrode prepared in Example 1 of the present invention and the traditional electrode prepared in Comparative Example 1. The battery operating conditions for the discharge performance test are: battery temperature: 65° C.; gas wettability: 80%; H ₂ flow rate: 100 mL·min ⁻¹ ; Air flow rate: 500 mL·min ⁻¹ .

It can be seen from Figure 3 that compared with the electrode prepared by the traditional spray method in Comparative Example 1, the Pt@C nanofiber electrode prepared in Example 1 of the present invention has better initial activity. When the Pt loading of the Pt@C nanofiber electrode prepared in Example 1 of the present invention is 0.1 mg·cm ^-2 , the highest power density reaches 0.65 W·cm ^-2 , which is comparable to the Pt loading of 0.18 mg·cm ^-2 . The performance of conventional Pt/C electrodes (0.66W·cm ^-2 ) is comparable. That is to say, the embodiment of the present invention improves the utilization rate of Pt.

(a) and (b) in FIG. 4 are the stability test curves of the Pt@C nanofiber electrode prepared in Example 1 of the present invention and the traditional electrode prepared in Comparative Example 1, respectively. The accelerated decay test conditions of the stability test are: the voltage range is 0.6-1.2V; the scanning speed is 0.1V·s ^-1 . The battery operating conditions were: battery temperature: 65° C.; gas wettability: 100%; H ₂ flow rate: 100 mL·min ⁻¹ ; Air flow rate: 500 mL·min ⁻¹ .

It can be seen from FIG. 4 that, compared with the electrode prepared by the traditional spray method in Comparative Example 1, the Pt@C nanofiber electrode prepared in Example 1 of the present invention has better stability. After 3000 cycles of acceleration and decay, its highest power density only decays by 9.1%, while the highest power density of traditional Pt/C electrodes decays by 24.3%.

The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction between the combinations of these technical features, All should be regarded as the scope described in this specification.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (10)

1. A preparation method of a platinum carbon nanofiber electrode is characterized by comprising the following steps:

mixing a carbon carrier, a Nafion solution and a binder to prepare spinning slurry;

spinning the spinning slurry to obtain a nanofiber catalyst layer;

transferring the nanofiber catalyst layer to the surface of a gas diffusion layer coated with carbon powder and polytetrafluoroethylene to obtain a gas diffusion electrode;

and depositing platinum nano particles on the gas diffusion electrode in a three-electrode system by using the gas diffusion electrode as a working electrode and a solution containing chloroplatinic acid and sulfuric acid as an electrolyte by adopting a pulse electrodeposition technology to prepare the platinum-carbon nanofiber electrode.

2. The method according to claim 1, wherein the pulse electrodeposition current is (25 to 300) mA-cm^-2The current supply time is 0.1-2 ms, the current off time is 1.5-16 ms, and the pulse electrodeposition time is 200-3600 s.

3. The method according to claim 2, wherein the pulse electrodeposition current is (115 to 235) mA-cm^-2The current supply time is 0.8-1.2 ms, the current off time is 1.8-4 ms, and the pulse electrodeposition time is 400-1200 s.

4. The method according to claim 1, wherein the mass ratio of the carbon carrier to the solid content of the Nafion solution to the binder is 20 (6-20) to (5-10).

5. The method according to any one of claims 1 to 4, wherein the raw material of the spinning dope further comprises polytetrafluoroethylene, and the spinning dope is prepared by mixing the polytetrafluoroethylene, the carbon support, the Nafion solution, and the binder.

6. The preparation method according to claim 5, wherein the mass ratio of the polytetrafluoroethylene to the carbon carrier in the spinning slurry is (1-5): 20.

7. The method according to any one of claims 1 to 4, wherein the amount of the carbon carrier supported is (0.2 to 2.0) mg-cm^-2。

8. The method according to any one of claims 1 to 4, further comprising a step of preparing the gas diffusion layer coated with carbon powder and polytetrafluoroethylene on the surface: mixing carbon powder and 4-22 wt% of polytetrafluoroethylene slurry according to the mass ratio of 10 (0.1-5) to obtain coating slurry, blade-coating the coating slurry on the surface of carbon paper, and controlling the blade-coating thickness to be 35-250 microns to obtain the carbon paper.

9. The method according to any one of claims 1 to 4, wherein the spinning step is electrospinning at a liquid flow rate of (0.4 to 1.2) mL-h^-1The distance between the needle point and the receiving plate is (5-25) cm, the voltage is (8-22) KV, and the receiving time is (1.5-6.5) h.

10. The platinum-carbon nanofiber electrode prepared by the preparation method as set forth in any one of claims 1 to 9.

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