Silica-carbon tube membrane electrode, its construction method and application

Abstract

The application discloses a kind of silicon dioxide carbon tube membrane electrode and its construction method and application.The construction process of the membrane electrode is as follows: carbon-based metal catalyst or the mixture of carbon-based metal catalyst and silicon dioxide carbon tube is dispersed in water, then organic solvent and binder solution are added in turn, to obtain catalyst ink;The catalyst ink is sprayed on carbon paper, and heat treatment is carried out in a protective atmosphere to obtain a gas diffusion electrode.If the aforementioned does not add silicon dioxide carbon tube, silicon dioxide carbon tube-organic solvent solution needs to be sprayed on the surface of the catalyst layer.The electrode is modified by silicon dioxide carbon tube, which on the one hand constructs a long-range ordered proton transport channel of membrane-catalyst-silicon dioxide carbon tube, and on the other hand adjusts the PA distribution in the membrane electrode assembly, suppresses PA loss, and improves the overall performance of the electrode.When applied to proton exchange membrane fuel cells, it can effectively solve the problems of poor stability, low activity and catalyst deactivation under high temperature conditions.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a membrane electrode, in particular to a silicon dioxide carbon tube membrane electrode and a construction method and application thereof, and belongs to the technical field of fuel cells. BACKGROUND

[0002] With the increasingly serious global warming problem and the continuous depletion of fossil fuels, it is urgent to develop clean and renewable energy. Therefore, in recent years, pollution-free electrochemical energy conversion technologies, such as lithium ion batteries and hydrogen fuel cells, have developed rapidly. Relatively speaking, hydrogen fuel cells are generally considered to be more suitable for heavy and high-power applications, while lithium ion batteries are more suitable for light and low-power applications. According to the properties of the electrolyte, fuel cells can be divided into alkaline polymer electrolyte fuel cells (APEFCs), proton exchange membrane fuel cells (PEMFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs) and solid oxide fuel cells (SOFCs). At present, proton exchange membrane fuel cells (PEMFCs) are gradually becoming an important part of new energy. However, the cost of high-purity hydrogen and noble metal catalysts, as well as the complexity of the PEMFC system, seriously hinders its commercialization process. Operating proton exchange membrane fuel cells (HT-PEMFCs) at high temperatures (above 160℃) has many advantages, such as higher tolerance to pollutants, lower catalyst cost and no need to use liquid water, thereby greatly simplifying the system. Although recent progress in HT-PEMFC proton exchange membrane technology has made this technology more feasible, however, during the operation of HT-PEMFCs, phosphoric acid not only diffuses unevenly into the catalyst layer, causing proton transport to be blocked. In addition, phosphoric acid adheres to the surface of the catalyst layer, reducing the utilization rate of Pt active sites, and seriously poisoning the catalytic sites, thereby causing the battery to fail. SUMMARY

[0003] In view of the problems existing in the prior art, a first object of the present application is to provide a silicon dioxide carbon tube membrane electrode. The membrane electrode uses silicon dioxide carbon tubes to construct a long-range ordered proton transport channel of membrane-catalyst-silicon dioxide carbon tube, solving the problem of blocked proton transport in high-temperature fuel cells. In addition, the membrane electrode uses silicon dioxide carbon tubes to construct a layer of silicon dioxide carbon tube interface phosphoric acid slow-release layer between the catalyst and the proton exchange membrane, which not only can adjust the PA distribution in the membrane electrode assembly and inhibit PA loss, but also can improve the overall performance of the electrode.

[0004] The second object of the present application is to provide a construction method of a silicon dioxide carbon tube membrane electrode.

[0005] The third object of the present application is to provide an application of the silicon dioxide carbon tube membrane electrode, which is used for preparing an electrode of a proton exchange membrane fuel cell. -2 -2 The third object of the present application is to provide an application of the silicon dioxide carbon tube membrane electrode, which is used for preparing an electrode of a proton exchange membrane fuel cell.

[0006] In order to achieve the above technical objects, the present application provides a construction method of a silicon dioxide carbon tube membrane electrode, comprising:

[0007] In step S1, carbon-based metal catalyst is uniformly dispersed in water, and then isopropanol is added and stirred to obtain a slurry, or carbon-based metal catalyst and silicon dioxide carbon tube are uniformly dispersed in water, and then an organic solvent is added and stirred to obtain a slurry;

[0008] In step S2, a binder solution is added to the slurry, and then is fully stirred and ultrasonically dispersed to obtain a catalyst ink with a solid content of 0.20-0.25%;

[0009] In step S3, the catalyst ink is ultrasonically sprayed or coated on carbon paper, and then is heat-treated in a protective atmosphere to obtain a gas diffusion electrode.

[0010] The carbon-based metal catalyst contains noble metal, and the mass fraction of the noble metal is 20-60 wt%;

[0011] The mass density of the carbon-based metal catalyst on the surface of the gas diffusion electrode is 0.1-1.2 mg / cm 2 ;

[0012] In the gas diffusion electrode, the mass ratio of the carbon-based metal catalyst to the silicon dioxide carbon tube is 20-50:1.

[0013] ​As a preferred scheme, if the silicon dioxide carbon tube is added in step S1, the silicon dioxide carbon tube is sprayed or not sprayed on the surface of the catalyst layer of the gas diffusion electrode.

[0014] The membrane electrode provided by the application is a long-range ordered membrane electrode from the aspects of high-temperature proton exchange membrane, interface and catalyst layer, wherein the silicon dioxide carbon tube can react with phosphoric acid to generate a new pyrophosphoric acid silicon proton conductor at high temperature, the proton conduction of the HT-PEMFCs is improved, and the performance of the membrane electrode is further improved.

[0015] As a preferred scheme, the carbon-based metal catalyst comprises a platinum catalyst and / or a palladium catalyst.

[0016] As a preferred scheme, in the slurry, the mass-volume ratio of the carbon-based metal catalyst, water and the organic solvent is 8-12 mg:1 ml:3-5 ml.

[0017] As a preferred scheme, the organic solvent is isopropyl alcohol and / or ethanol.

[0018] As a preferred scheme, the mass fraction of the solute of the binder solution is 4-6 wt%.

[0019] As a preferred scheme, the mass ratio of the added amount of the binder solution to the carbon-based metal catalyst in the slurry is 2-10:1.

[0020] As a preferred scheme, the binder is at least one of polytetrafluoroethylene, polybenzimidazole and polybenzimidazole derivatives.

[0021] As a preferred scheme, the protective atmosphere is nitrogen and / or argon.

[0022] As a preferred scheme, the heat treatment is performed at a temperature increasing rate of 1-5 ℃ / min from room temperature to 40-200 ℃, and then the temperature is kept for 10-50 min, and then the furnace is cooled to room temperature.

[0023] As a preferred scheme, the mass fraction of the silicon dioxide carbon tube in the organic solvent solution of the silicon dioxide carbon tube is 0.5-10 wt%.

[0024] As a preferred scheme, the mass fraction of the noble metal in the carbon-based metal catalyst is 30-50 wt%.

[0025] As a preferred scheme, the mass density of the carbon-based metal catalyst on the surface of the gas diffusion electrode is 0.1-1.0 mg / cm 2 .

[0026] As a preferred scheme, in the gas diffusion electrode, the mass ratio of the carbon-based metal catalyst to the silicon dioxide carbon tube is 35-50:1.

[0027] The application further provides a silicon dioxide carbon tube membrane electrode prepared by the construction method.

[0028] The application further provides an application of the silicon dioxide carbon tube membrane electrode, which is used for preparing an electrode of a proton exchange membrane fuel cell.

[0029] As a preferred scheme, the electrode of the proton exchange membrane fuel cell is prepared by assembling the silicon dioxide carbon tube membrane electrode and a phosphoric acid modified organic composite membrane.

[0030] As a preferred scheme, the phosphoric acid modified organic composite membrane is at least one of a phosphoric acid modified n-PBI POSS composite membrane, a phosphoric acid modified polybenzimidazole composite membrane and a phosphoric acid modified polybenzimidazole derivative composite membrane.

[0031] As a preferred scheme, when the phosphoric acid modified organic composite membrane is the phosphoric acid modified n-PBI POSS composite membrane, the loading amount of n-PBI is 5-15%.

[0032] As a preferred scheme, the modification mode of the phosphoric acid modified organic composite membrane is dip modification, and the dip modification conditions are as follows: the mass concentration of phosphoric acid is 85 wt%, the temperature is 50-80 ℃, and the time is 36-60 h.

[0033] Compared with the prior art, the application has the beneficial technical effects that:

[0034] (1) The membrane electrode provided by the application utilizes the silicon dioxide carbon tube to construct a long-range ordered proton transmission channel of membrane-catalyst-silicon dioxide carbon tube, and solves the problem of blocked proton transmission in a high-temperature fuel cell. In addition, the membrane electrode utilizes the silicon dioxide carbon tube to construct a silicon dioxide carbon tube interface phosphoric acid slow-release layer between the catalyst and the proton exchange membrane, which can not only adjust the PA distribution in the membrane electrode assembly and inhibit the PA loss, but also improve the comprehensive performance of the electrode.

[0035] (2) The construction method provided by the application constructs a high-temperature-resistant, phosphorus-resistant and acid-resistant membrane electrode from the interface layer and the catalyst layer by using the silicon dioxide carbon tube. The addition of the silicon dioxide carbon tube can not only effectively adsorb phosphoric acid and greatly reduce the poisoning of the phosphoric acid to the active sites of the catalyst, but also effectively improve the combination stability of the interface and the catalyst layer, thereby greatly improving the stability of the electrode under high-temperature working conditions.

[0036] (3) The technical scheme provided by the application is applied to a proton exchange membrane fuel cell based on the excellent performance of the above-mentioned membrane electrode, which can effectively solve the problems of poor stability, low activity and easy deactivation of the catalyst of the battery under high temperature conditions in the prior art, and the peak power density of the proton exchange membrane fuel cell obtained by using the above-mentioned membrane electrode can reach 1.66 W cm -2 under a high temperature condition of 220 DEG C, the current density can reach 0.75 A cm -2 , and excellent high-temperature stability and catalytic activity are exhibited. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 The electron microscope analysis diagram of the silicon dioxide carbon tube used in the specific embodiment of the application;

[0038] Among them, Figure 1 (a)-(c) are STEM diagrams of the silicon dioxide carbon tube, Figure 1 (d) is a HAADF-STEM diagram of the silicon dioxide carbon tube, Figure 1 (e)-(h) are EDS analysis diagrams of the silicon dioxide carbon tube;

[0039] Figure 2 The polarization curve test performance diagram of the membrane electrode in Example 1 of the application;

[0040] Figure 3 The polarization curve test performance diagram of the membrane electrode in Example 2 of the application;

[0041] Figure 4 The polarization curve test performance diagram of the membrane electrode in Example 3 of the application;

[0042] Figure 5 The polarization curve test performance diagram of the membrane electrode in Example 4 of the application;

[0043] Figure 6 The polarization curve test performance diagram of the membrane electrode in Example 5 of the application;

[0044] Figure 7 The polarization curve test performance diagram of the membrane electrode in Example 6 of the application;

[0045] Figure 8 The polarization curve test performance diagram of the membrane electrode in Example 7 of the application;

[0046] Figure 9 The polarization curve test performance diagram of the membrane electrode in Example 8 of the application;

[0047] Figure 10 The polarization curve test performance diagram of the membrane electrode in Example 9 of the application;

[0048] Figure 11 Performance chart for polarization curve test of the membrane electrode in Inventive Example 1;

[0049] Figure 12 Performance chart for polarization curve test of the membrane electrode in Inventive Example 1;

[0050] Figure 13 Performance chart for polarization curve test of the membrane electrode in Inventive Example 1. DETAILED DESCRIPTION

[0051] The present application will be described in detail below with reference to the accompanying drawings and specific examples, which are used to explain the present application but not to limit the present application.

[0052] Example 1

[0053] The present embodiment provides a silicon dioxide carbon tube membrane electrode, and a construction method thereof is as follows:

[0054] 1) Take 0.015 g of silicon dioxide carbon tube and ultrasonically disperse it in 0.6 g of isopropyl alcohol (IPA);

[0055] 2) Add 40 mg of Pt / C catalyst (40 wt%) to 4 mL of deionized water and stir to make it wet; then add 16 mL of isopropyl alcohol to disperse it into a slurry, and then add 260 mg of PBI DMSO solution with a mass fraction of 5 wt% to the slurry; after stirring and mixing, a catalyst slurry is obtained, and the solid content of the catalyst slurry is 0.2~0.25; after 40 minutes of ultrasonic dispersion, the uniform catalyst ink is sprayed onto the carbon paper by ultrasonic spraying, and the loading of Pt is controlled at 0.9 mg cm -2 , and then heated to 80 ℃ in a tube furnace in a nitrogen atmosphere for 40 minutes; then, the silicon dioxide carbon tube / IPA solution is sprayed onto the surface of the previously prepared catalyst layer by a spray gun, and the loading of the silicon dioxide carbon tube on the surface of the membrane electrode is 0.030 mg cm -2 .

[0056] Example 2

[0057] The difference between the present embodiment and Example 1 is that the loading of the silicon dioxide carbon tube is 0.045 mg cm -2 .

[0058] Example 3

[0059] The difference between the present embodiment and Example 1 is that the loading of the silicon dioxide carbon tube is 0.060 mg cm -2 .

[0060] Example 4

[0061] The embodiment provides a silicon dioxide carbon tube membrane electrode, and a construction method thereof is as follows: 40 mg of Pt / C catalyst (40 wt%) and 0.8 mg of silicon dioxide carbon tube are added into 4 mL of deionized water for stirring, so as to be wetted; then 16 mL of isopropyl alcohol is added to disperse into a slurry, and then 260 mg of PBI DMSO solution with a mass fraction of 5 wt% is added into the slurry; after stirring and mixing, a catalyst slurry is obtained, and a solid content of the catalyst slurry is 0.2-0.25; after ultrasonic dispersion for 40 minutes, the uniform catalyst ink is sprayed onto carbon paper through ultrasonic spraying, and the loading amount of Pt is controlled to be 0.9 mg cm -2 , and then heated to 80 DEG C in a tube furnace in a nitrogen atmosphere for 40 minutes.

[0062] Embodiment 5

[0063] The embodiment is different from the embodiment 4 in that the added amount of the silicon dioxide carbon tube is 1.0 mg.

[0064] Embodiment 6

[0065] The embodiment is different from the embodiment 4 in that the added amount of the silicon dioxide carbon tube is 1.4 mg.

[0066] Embodiment 7

[0067] The embodiment provides a silicon dioxide carbon tube membrane electrode, and a construction method thereof is as follows:

[0068] 1) 0.015 g of silicon dioxide carbon tube is ultrasonically dispersed in 0.6 g of isopropyl alcohol (IPA);

[0069] 2) 40 mg of Pt / C catalyst (40 wt%) and 0.8 mg of silicon dioxide carbon tube are added into 4 mL of deionized water for stirring, so as to be wetted; then 16 mL of isopropyl alcohol is added to disperse into a slurry, and then 260 mg of PBI DMSO solution with a mass fraction of 5 wt% is added into the slurry; after stirring and mixing, a catalyst slurry is obtained, and a solid content of the catalyst slurry is 0.2-0.25; after ultrasonic dispersion for 40 minutes, the uniform catalyst ink is sprayed onto carbon paper through ultrasonic spraying, and the loading amount of Pt is controlled to be 0.9 mg cm -2 , and then heated to 80 DEG C in a tube furnace in a nitrogen atmosphere for 40 minutes; then, the silicon dioxide carbon tube / IPA solution is sprayed onto the surface of the prepared catalyst layer through a spray gun, and the loading amount of the silicon dioxide carbon tube sprayed on the surface of the membrane electrode is 0.015 mg cm -2 .

[0070] Example 8

[0071] This embodiment is exactly the same as Embodiment 7, except that the loading of the silica carbon nanotubes sprayed on the surface of the membrane electrode is 0.030 mg cm⁻¹. -2 .

[0072] Example 9

[0073] This embodiment is exactly the same as Embodiment 7, except that the loading of the silica carbon nanotubes sprayed on the surface of the membrane electrode is 0.045 mg cm⁻¹. -2 .

[0074] Comparative Example 1

[0075] This comparative example is exactly the same as Example 1, except that the surface of the membrane electrode is not coated with carbon dioxide.

[0076] The present invention performed electron microscopy scanning on the carbon dioxide tubes used in the above embodiments, and the results are as follows: Figure 1 As shown, through Figure 1 It can be seen that the silica exhibits a long-range ordered porous structure along the entire length of the bottom single-walled carbon nanotubes. Furthermore, the present invention also tested the electrochemical performance of the membrane electrodes obtained in Examples 1-9 and Comparative Example 1 under high temperature conditions, the process of which is as follows:

[0077] 1) Cut the n-PBI-10% POSS membrane into 3cm×3cm pieces and immerse it in 85 wt% phosphoric acid at 60 ℃ for 48h to obtain the n-PBI-10% POSS / H3PO4 composite membrane.

[0078] 2) The membrane electrodes obtained in Examples 1-9 and Comparative Example 1 were assembled with an n-PBI-10% POSS / H3PO4 composite membrane to obtain the electrodes for the fuel cell. High-temperature proton exchange membrane fuel cell (HT-PEMFC) tests were conducted at 160-240°C. During the tests, the anode was fed with pure hydrogen gas at a flow rate of 400 sccm / min. -1 The cathode is fed with pure oxygen at a flow rate of 350 sccmmin. -1 .

[0079] Comparative Example 2

[0080] This comparative example uses the membrane electrode provided in Comparative Example 1. In the process of assembling the electrode of the fuel cell, the composite membrane is replaced by an n-PBI membrane with an n-PBI-10% POSS membrane.

[0081] Comparative Example 3

[0082] The comparative example uses the membrane electrode provided in Comparative Example 1, and in the process of assembling the fuel cell, the composite membrane is replaced by the n-PBI-10% POSS membrane.

[0083] The high-temperature proton exchange membrane fuel cell performance chart after testing of Examples 1-9 and Comparative Examples 1-3 can be seen in FIGS. 1-9, respectively. Figures 2-13 .

[0084] At 220°C, the peak power density of the membrane electrode corresponding to Examples 1-3 of the application was measured to be 1.53 W cm -2 , 1.66 W cm -2 , 1.39 W cm -2 , respectively; at a voltage of 0.65 V, the current density of the membrane electrode corresponding to Examples 1-3 of the application was measured to be 1.11 A cm -2 , 1.22 A cm -2 , 1.02 A cm -2 , respectively. However, at 220°C, the peak power density of the membrane electrode corresponding to Comparative Examples 1-3 of the application was 1.10 W cm -2 , 0.65 W cm -2 , 0.35 W cm -2 , respectively; at a voltage of 0.65 V, the current density of the membrane electrode corresponding to Examples 1-3 of the application was measured to be 0.75 A cm -2 , 0.52 A cm -2 , 0.23 A cm -2 . At 220°C, the loading of the silica carbon tube is 0.045 mg cm -2 of the interface slow-release layer corresponding to the membrane electrode with the optimal performance, the peak power density is 1.5 times that of the membrane electrode prepared by the commercial platinum carbon catalyst, and the current density at 0.65 V is 1.6 times. Compared with the membrane electrode prepared by the pure commercial platinum carbon catalyst, the application uses a silica carbon tube interface phosphoric acid slow-release layer between the catalyst and the proton exchange membrane, which can adjust the PA distribution in the membrane electrode assembly, inhibit the loss of PA, and improve the performance of the electrode.

[0085] At 220°C, the peak power density of the membrane electrode corresponding to Examples 4-6 of the application was 1.45 W cm -2 , 1.48 W cm -2 , 1.40 W cm -2 , respectively; at a voltage of 0.65 V, the current density of the membrane electrode corresponding to Examples 4-6 of the application was measured to be 1.11 A cm -2 , 1.02 A cm -2 , 0.94 A cm-2 The silica carbon nanotube is added in the catalyst layer at 2.5 wt% at 220 DEG C, and the corresponding membrane electrode has the optimal performance, the peak power density is 1.3 times of that of the corresponding membrane electrode prepared by using the commercial platinum carbon catalyst, and the corresponding current density at 0.65 V is 1.5 times. The new membrane electrode constructed by adding the silica carbon nanotube in the catalyst layer in the application can adsorb phosphoric acid, reduce the poisoning of the phosphoric acid to the active sites of the catalyst, and effectively improve the performance of the HT-PEMFCs.

[0086] After the interface and the catalyst layer are combined and the test conditions are optimized, the peak power densities of the membrane electrodes corresponding to the examples 7-9 in the application are 1.67 W cm -2 , 1.56 W cm -2 , and 1.55 W cm -2 , respectively, at 220 DEG C, and the current densities of the membrane electrodes corresponding to the examples 7-9 in the application are 1.14 A cm -2 , 1.48 A cm -2 , and 1.12 A cm -2 , respectively, at 0.65 V. The performance of the HT-PEMFCs can be further improved by synergistically optimizing the interface and the addition amount of the silica carbon nanotube in the catalyst layer at 220 DEG C, and compared with the membrane electrode prepared by using the commercial platinum carbon catalyst, the peak power density of the new membrane electrode constructed by using the silica carbon nanotube in the application is improved by 1.5 times, and the corresponding current density at 0.65 V is improved by 2.0 times.

[0087] Compared with the comparative examples 2 and 3, the performance of the membrane electrode corresponding to the comparative example 1 is more excellent, because the siloxane cage in the n-PBI-10% POSS / H3PO4 composite membrane helps to adsorb a large amount of phosphoric acid, and effectively improves the phosphoric acid escape under the high-temperature working condition of the HT-PEMFCs. Moreover, the POSS can react with phosphonic acid to generate a new proton conductor at high temperature, and further improve the performance of the HT-PEMFCs.

[0088] The application constructs a silica carbon nanotube interface phosphoric acid slow-release layer between the catalyst and the proton exchange membrane by using the silica carbon nanotube, can adjust the PA distribution in the membrane electrode assembly, inhibit the PA loss, and improve the performance of the electrode. Moreover, the silica carbon nanotube is added in the catalyst layer to adsorb the phosphoric acid, reduce the poisoning of the phosphoric acid to the active sites of the catalyst under the high-temperature working condition, and improve the performance of the electrode. In addition, the new membrane electrode based on the silica carbon nanotube prepared in the application is helpful to form a new proton conductor under the high-temperature working condition, can further improve the working temperature of the high-temperature fuel cell, improve the catalyst utilization rate, and improve the performance and the service life of the cell.

[0089] The application constructs a long-range ordered new membrane electrode based on silica carbon nanotubes from three aspects of high temperature proton exchange membrane, interface and catalyst layer, and greatly improves the performance of HT-PEMFCs.

[0090] The above only describes the preferred embodiments of the present application, and it should be pointed out that the ordinary skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for constructing a silicon dioxide carbon nanotube film electrode, characterized in that: include, Step S1: Disperse the carbon-based metal catalyst evenly in water, then add an organic solvent and stir to obtain a slurry; or, disperse the carbon-based metal catalyst and carbon dioxide evenly in water, then add an organic solvent and stir to obtain a slurry. Step S2: Add binder solution to slurry, stir thoroughly, and then disperse by ultrasonication to obtain catalyst ink with a solid content of 0.20~0.25%; Step S3: Ultrasonically spray or coat the catalyst ink onto carbon paper, and then perform heat treatment under a protective atmosphere to obtain a gas diffusion electrode. If carbon dioxide tubes were not added in step S1, then an organic solvent solution of carbon dioxide tubes is further sprayed onto the catalyst layer surface of the gas diffusion electrode. The carbon-based metal catalyst contains a noble metal, wherein the noble metal has a mass fraction of 20-60 wt%. The carbon-based metal catalyst on the surface of the gas diffusion electrode has a mass density of 0.1~1.2 mg / cm³. 2 ; In the gas diffusion electrode, the mass ratio of carbon-based metal catalyst to carbon dioxide tube is 20~50:

1.

2. The method for constructing a silicon dioxide carbon nanotube film electrode according to claim 1, characterized in that: The carbon-based metal catalyst includes a platinum catalyst and / or a palladium catalyst; In the slurry, the mass-to-volume ratio of carbon-based metal catalyst to deionized water and organic solvent is 8-12 mg: 1 ml: 3-5 ml; the organic solvent is isopropanol and / or ethanol.

3. The method for constructing a silicon dioxide carbon nanotube film electrode according to claim 1, characterized in that: The solute mass fraction of the binder solution is 4~6wt%; the mass ratio of the binder solution added to the carbon-based metal catalyst in the slurry is 2~10:1; the binder is at least one of polytetrafluoroethylene, polybenzimidazole and polybenzimidazole derivatives.

4. The method for constructing a silicon dioxide carbon nanotube film electrode according to claim 1, characterized in that: The protective atmosphere is nitrogen and / or argon; the heat treatment conditions are: heating from room temperature to 40-200°C at a rate of 1-5°C / min, holding at that temperature for 10-50min, and then cooling to room temperature with the furnace.

5. The method for constructing a silicon dioxide carbon nanotube film electrode according to claim 1, characterized in that: The mass fraction of the silica carbon nanotubes in the organic solvent solution is 0.5~10wt%.

6. The method for constructing a silicon dioxide carbon nanotube film electrode according to claim 1, characterized in that: The carbon-based metal catalyst contains 30-50 wt% noble metal; the carbon-based metal catalyst on the gas diffusion electrode surface has a mass density of 0.1-1.0 mg / cm³. 2 In the gas diffusion electrode, the mass ratio of carbon-based metal catalyst to carbon dioxide tube is 35~50:

1.

7. A silicon dioxide carbon nanotube film electrode, characterized in that: It is prepared by the construction method described in any one of claims 1 to 6.

8. The application of the silicon dioxide carbon nanotube film electrode according to claim 7, characterized in that: Electrodes used in the fabrication of proton exchange membrane fuel cells.

9. The application of a silicon dioxide carbon nanotube film electrode according to claim 8, characterized in that: The electrode preparation process of the proton exchange membrane fuel cell is as follows: assembling a silica carbon nanotube membrane electrode with a phosphoric acid modified organic composite membrane; the phosphoric acid modified organic composite membrane is at least one of a phosphoric acid modified n-PBI POSS composite membrane, a phosphoric acid modified polybenzimidazole composite membrane, and a phosphoric acid modified polybenzimidazole derivative composite membrane; when the phosphoric acid modified organic composite membrane is a phosphoric acid modified n-PBI POSS composite membrane, its n-PBI loading is 5~15%.

10. The application of a silicon dioxide carbon nanotube film electrode according to claim 9, characterized in that: The modification method of the phosphoric acid modified organic composite film is impregnation modification, and the impregnation conditions are: phosphoric acid mass concentration of 85wt%, temperature of 50~80℃, and time of 36~60h.

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