Membrane electrode, preparation method thereof and electrolytic tank for proton exchange membrane electrolyzed water

Abstract

The invention discloses a membrane electrode and a preparation method thereof, and belongs to the technical field of membrane electrodes. The membrane electrode comprises a first bonding layer, a second bonding layer, a proton exchange membrane and a third bonding layer which are connected in sequence; wherein the first bonding layer comprises styrene butadiene rubber and an anode catalyst; the second bonding layer comprises perfluorinated sulfonic acid resin and an anode catalyst; and the third bonding layer comprises perfluorosulfonic acid resin and a cathode catalyst. The membrane electrode has relatively high catalytic activity and good stability. The preparation method of the membrane electrode is simple and suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of membrane electrodes, and in particular to a membrane electrode and a preparation method thereof, and an electrolytic cell for proton exchange membrane water electrolysis. Background Art

[0002] Among many renewable energy sources, hydrogen energy has attracted much attention due to its green, environmentally friendly and high efficiency. As a key technology for producing hydrogen energy, proton exchange membrane water electrolysis (PEMWE) technology has gradually become the focus of attention.

[0003] Binders are often used in proton exchange membrane water electrolysis technology. Using them to bond electrodes can maintain the structural integrity of the electrode active material. At present, the mainstream binder used in proton exchange membrane water electrolysis technology is perfluorosulfonic acid resin (Nafion). On the basis of bonding electrode components, it can also enhance the proton conductivity of the membrane electrode and reduce the internal resistance of the membrane electrode. However, the sulfonate contained in Nafion will react with the Ir-based material at the membrane electrode working point, resulting in poisoning of the electrode material, reducing the active sites, and thus seriously affecting the performance and stability of the material. Therefore, how to reduce the poisoning of Nafion to electrode materials has become a challenging topic.

[0004] On the other hand, compared with Nafion, other binders have significantly worse internal resistance performance. When using binders such as styrene-butadiene rubber, the high-frequency impedance of the battery is about 25% higher than that of batteries made of pure Nafion. This is because polymers such as styrene-butadiene rubber form an ionomer membrane on the surface of the proton exchange membrane, which hinders the proton exchange process, thereby affecting the internal resistance of the battery and reducing the performance of the battery.

[0005] In summary, it is of great significance to study and develop a membrane electrode with a structure of multiple binders to overcome the above-mentioned problems such as poisoning and performance degradation. Summary of the invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a membrane electrode and a preparation method thereof, and an electrolytic cell for proton exchange membrane water electrolysis. The membrane electrode has high catalytic activity and excellent stability.

[0007] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a membrane electrode, comprising a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer connected in sequence;

[0009] Wherein, the first bonding layer includes styrene-butadiene rubber (SBR) and an anode catalyst;

[0010] The second bonding layer includes a perfluorosulfonic acid resin (Nafion) and an anode catalyst;

[0011] The third bonding layer includes perfluorosulfonic acid resin and a cathode catalyst.

[0012] The membrane electrode of the present invention reduces the poisoning of the anode catalyst by the perfluorosulfonic acid resin and also avoids the blockage of the proton transmission channel between the proton exchange membrane and the above-mentioned bonding layer.

[0013] Preferably, the anode catalyst is selected from an iridium-based catalyst, an iridium-based supported catalyst or a ruthenium-based catalyst;

[0014] The iridium-based catalyst includes but is not limited to iridium oxide and the like.

[0015] The iridium-based supported catalyst includes, but is not limited to, niobium oxide-supported iridium or titanium oxide-supported iridium.

[0016] The ruthenium-based catalyst includes but is not limited to ruthenium oxide or iridium-ruthenium alloy.

[0017] In some specific embodiments of the present invention, iridium oxide is preferred.

[0018] Preferably, the cathode catalyst is selected from 20% Pt / C, 40% Pt / C or 60% Pt / C; more preferably, 60% Pt / C.

[0019] The 60% Pt / C means that the Pt / C catalyst contains 60% Pt.

[0020] Preferably, the total loading amount of the anode catalyst in the first adhesive layer and the second adhesive layer in the membrane electrode is 0.5-2 mg / cm 2 In some specific embodiments of the present invention, 1 mg / cm 2 .

[0021] More preferably, the loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.3-0.7 mg / cm 2 ; More preferably 0.3 mg / cm 2 , 0.5 mg / cm 2 or 0.7 mg / cm 2 .

[0022] More preferably, the loading amount of the anode catalyst in the second adhesive layer in the styrene-butadiene rubber is 0.3-0.7 mg / cm 2 ; More preferably 0.3 mg / cm 2 , 0.5 mg / cm 2 or 0.7 mg / cm 2 .

[0023] In some specific embodiments of the present invention, preferably, the loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.3 mg / cm 2 , and the loading amount of the anode catalyst in the second bonding layer in the styrene-butadiene rubber is 0.7 mg / cm 2 ; The membrane electrode is represented by 0.3Nafion+0.7SBR membrane electrode;

[0024] Alternatively, the loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.5 mg / cm 2 , and the loading amount of the anode catalyst in the second bonding layer in the styrene-butadiene rubber is 0.5 mg / cm 2 ; The membrane electrode is represented by 0.5Nafion+0.5SBR membrane electrode;

[0025] Or the loading amount of the anode catalyst in the first bonding layer in the perfluorosulfonic acid resin is 0.7 mg / cm 2 , and the loading amount of the anode catalyst in the second bonding layer in the styrene-butadiene rubber is 0.3 mg / cm 2 ; The membrane electrode is represented by 0.7Nafion+0.3SBR membrane electrode;

[0026] In the above-mentioned membrane electrode representation, the coefficients before Nafion and SBR both represent the loading amounts of the anode catalysts respectively loaded thereon.

[0027] Preferably, the Pt loading in the cathode catalyst is 0.2-0.6 mg / cm 2 ; More preferably 0.3 to 0.5 mg / cm 2 In some specific embodiments of the present invention, preferably 0.4 mg / cm 2 .

[0028] On the one hand, the membrane electrode can reduce the content of Nafion on the surface of the membrane electrode, effectively inhibit its poisoning effect on the membrane electrode, thereby increasing the electrochemical active area of ​​the membrane electrode, and improving the catalytic activity and stability of the membrane electrode; on the other hand, it ensures that the proton transmission channel is not blocked, improves the proton conduction capacity of the membrane electrode, thereby reducing the impedance of the membrane electrode and improving the catalytic activity of the membrane electrode.

[0029] Preferably, in the present invention, the mass ratio of the perfluorosulfonic acid resin to the anode catalyst in the second adhesive layer is 1:(5-20); in some specific embodiments of the present invention, it is preferably 1:7.5.

[0030] Preferably, the mass ratio of styrene-butadiene rubber to anode catalyst in the first bonding layer is 1:(5-20); in some specific embodiments of the present invention, it is preferably 1:19.

[0031] Preferably, the mass ratio of the perfluorosulfonic acid resin to the cathode catalyst in the third adhesive layer is 1:(3-15). In some specific embodiments of the present invention, it is preferably 1:4.

[0032] The present invention also provides a method for preparing the above-mentioned membrane electrode, comprising the following steps:

[0033] The first slurry and the second slurry are sequentially coated on the surface of the proton exchange membrane, the third slurry is coated on the other side surface of the proton exchange membrane, and dried to obtain the membrane electrode;

[0034] Wherein, the first slurry is obtained by mixing an anode catalyst, a solvent, and a perfluorosulfonic acid resin;

[0035] The second slurry is obtained by mixing an anode catalyst, a solvent, and styrene-butadiene rubber;

[0036] The third slurry is obtained by mixing a cathode catalyst, a solvent and a perfluorosulfonic acid resin.

[0037] Preferably, the solvent is selected from one or more of water, isopropanol, ethanol and butanol; more preferably, it is a mixed solvent of water and isopropanol, or a mixed solvent of water, isopropanol and ethanol.

[0038] Preferably, in the present invention, the mass ratio of the first slurry to the second slurry is (3-7):(3-7); more preferably 1:1.

[0039] The present invention has no particular limitation on the mixing method for obtaining the first slurry, the second slurry, and the third slurry, and any method well known to those skilled in the art may be used.

[0040] In some specific embodiments of the present invention, ball milling mixing and ultrasonic dispersion are used.

[0041] The rotation speed of the ball milling mixing is 200-400 rpm; more preferably 300 rpm.

[0042] The ball milling mixing time is 12 to 24 hours, and more preferably 18 hours.

[0043] The ultrasonic dispersion time is 0.5 to 1.5 h, more preferably 1 h.

[0044] In the present invention, the drying temperature is preferably 60°C to 100°C, more preferably 70°C to 90°C, and in some specific embodiments of the present invention, preferably 80°C.

[0045] Preferably, the drying adsorption pressure is 0.2-0.4 MPa; more preferably 0.25-0.35 MPa; further preferably 0.3 MPa.

[0046] Preferably, the method for preparing the membrane electrode of the present invention comprises the following steps:

[0047] S1, mixing the electrolytic water anode catalyst and a mixed solvent of water and isopropanol to obtain a first suspension;

[0048] S2, mixing the water electrolysis cathode catalyst and a mixed solvent of water and isopropanol to obtain a second suspension;

[0049] S3, dividing the first suspension into two parts, adding Nafion dispersion and styrene-butadiene rubber dispersion respectively thereto, and performing ball milling and ultrasonic dispersion to obtain a first slurry and a second slurry respectively;

[0050] S4, mixing the second suspension and the Nafion dispersion, ball milling, and ultrasonic dispersion to obtain a third slurry;

[0051] S5, coating the first slurry and the second slurry on a proton exchange membrane in sequence, and drying to obtain an anode membrane electrode having a structure of multiple binders;

[0052] S6. Apply the third slurry on the other side of the proton exchange membrane and dry it to obtain a membrane electrode structured with multiple binders.

[0053] There is no order between the above steps S1 and S2, there is no order between S3 and S4, and there is no order between S5 and S6.

[0054] The mass ratio of the anode catalyst to water and isopropanol in the first suspension is (1-16): (250-1000): (250-1000).

[0055] Preferably, the mass ratio of the anode catalyst to water and isopropanol in the second suspension is (1-16): (250-1000): (250-1000).

[0056] The preparation method of the present invention disperses the anode catalyst and the cathode catalyst respectively by a mixed solvent of water and isopropanol, and then mixes the adhesive Nafion and styrene-butadiene rubber with the dispersed anode catalyst respectively to obtain a first slurry and a second slurry, and mixes the adhesive Nafion with the dispersed cathode catalyst to obtain a third slurry.

[0057] Then, the first slurry and the second slurry are sequentially layered and coated on the anode side of the membrane electrode, and the third slurry is coated on the cathode side of the membrane electrode, and finally a membrane electrode with multiple binders structure is obtained.

[0058] The preparation method is simple to operate, has little environmental pollution, and is suitable for large-scale industrial production.

[0059] The present invention also provides an electrolytic cell for proton exchange membrane water electrolysis, comprising the above-mentioned membrane electrode or the membrane electrode prepared by the above-mentioned preparation method.

[0060] The electrolytic cell has high catalytic activity and good stability when used for proton exchange membrane water electrolysis.

[0061] Compared with the prior art, the membrane electrode provided by the present invention comprises a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer connected in sequence; wherein the first adhesive layer comprises styrene-butadiene rubber and an anode catalyst; the second adhesive layer comprises a perfluorosulfonic acid resin and an anode catalyst; and the third adhesive layer comprises a perfluorosulfonic acid resin and a cathode catalyst. The membrane electrode has high catalytic activity and good stability. The preparation method of the membrane electrode is simple and suitable for large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 Flow chart of preparing structured membrane electrodes with various binders for Example 1;

[0063] Figure 2 It is a battery performance comparison diagram of the structured membrane electrode with various binders prepared in Example 1, the membrane electrode with conventional pure Nafion as a binder (Nafion electrode), and the membrane electrode with conventional pure SBR as a binder (SBR electrode);

[0064] Figure 3 This is a comparison diagram of the steady-state polarization curves of the structured membrane electrode with various binders prepared in Example 1 and the membrane electrode with conventional pure Nafion as a binder before and after a 100-hour accelerated aging experiment;

[0065] Figure 4 A comparison diagram of steady-state polarization curves of the membrane electrode with various binder structures prepared in Example 2 and the membrane electrode with conventional pure Nafion as a binder;

[0066] Figure 5 A comparison diagram of steady-state polarization curves of a membrane electrode structured with various binders prepared in Example 3 and a membrane electrode with conventional pure Nafion as a binder;

[0067] Figure 6 A comparison diagram of steady-state polarization curves of a membrane electrode structured with various binders prepared in Example 4 and a membrane electrode with conventional pure Nafion as a binder;

[0068] Figure 7 This is a comparison diagram of the steady-state polarization curves of the membrane electrode with various binder structures prepared in Example 5 and the membrane electrode with conventional pure Nafion as a binder. DETAILED DESCRIPTION

[0069] In order to further illustrate the present invention, the membrane electrode and its preparation method, and the electrolytic cell for proton exchange membrane water electrolysis provided by the present invention are described in detail below in conjunction with embodiments.

[0070] Example 1

[0071] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 30 mL of water and 30 mL of isopropanol to obtain a first suspension, and 160 mg of commercial 60% Pt / C was added to a mixed solution of 20 mL of water and 20 mL of isopropanol to obtain a second suspension;

[0072] Step S2: Take the first suspension prepared in step S1 and divide it into two parts, add 339 μL of 5% Nafion-ethanol dispersion (15.75 mg of Nafion) to the first part, add 632 μL of SBR (styrene-butadiene rubber) aqueous solution (10 mg / mL, 6.32 mg of SBR) to the second part, ball mill and ultrasonically disperse to obtain the first and second slurries respectively, take the second suspension prepared in step S1, add 826 μL of 5% Nafion-ethanol dispersion (38.4 mg of Nafion) thereto, ball mill and ultrasonically disperse to obtain the third slurry;

[0073] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and each is coated with 0.5 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying condition is 80°C and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with a structure of multiple binders is obtained, which is expressed as 0.5Nafion+0.5SBR membrane electrode.

[0074] The membrane electrode with various binder structures prepared in Example 1, the membrane electrode with conventional pure Nafion as a binder (i.e., Nafion electrode), and the membrane electrode with conventional pure SBR as a binder (i.e., SBR electrode) were assembled into water electrolysis cells, and the steady-state polarization curves of the electrodes were as follows: Figure 2 The results show that compared with the Nafion electrode and the SBR electrode, the 0.5Nafion+0.5SBR membrane electrode prepared in Example 1 has better activity at 3A / cm 2 At high current density, the performance is improved by 43 mV compared with Nafion electrode and 135 mV compared with SBR electrode.

[0075] Figure 3 The steady-state polarization curves of the membrane electrode with multiple binder structures (0.5Nafion+0.5SBR membrane electrode) in Example 1 of the present invention and the membrane electrode with conventional pure Nafion as a binder (Nafion electrode) before and after 100h accelerated aging experiment. The results show that after 100h accelerated aging experiment, the performance of the membrane electrode with conventional pure Nafion as a binder (Nafion electrode) decreased by 15mV, while the performance of the membrane electrode with multiple binder structures (0.5Nafion+0.5SBR membrane electrode) prepared in Example 1 decreased by 7mV, indicating that the membrane electrode with multiple binder structures prepared by the present invention has better stability.

[0076] Example 2

[0077] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 30 mL of water and 30 mL of isopropanol to obtain a first suspension, and 80 mg of commercial 60% Pt / C was added to a mixed solution of 10 mL of water and 10 mL of isopropanol to obtain a second suspension;

[0078] Step S2: The first suspension prepared in step S1 was divided into 18 mL and 42 mL, 203 μL of 5% Nafion-ethanol dispersion (9.45 mg of Nafion) was added to the first portion, and 884 μL of SBR aqueous solution (10 mg / mL, 8.84 mg of SBR) was added to the second portion, and the first and second slurries were obtained by ball milling and ultrasonic dispersion. The second suspension prepared in step S1 was taken, 413 μL of 5% Nafion-ethanol dispersion (19.2 mg Nafion) was added thereto, and the third slurry was obtained by ball milling and ultrasonic dispersion.

[0079] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1. 0.3 mg / cm 2 of catalyst (iridium oxide) and 0.7 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying condition is 80°C and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with a structure of multiple binders is obtained, which is expressed as 0.3Nafion+0.7SBR membrane electrode.

[0080] Different from Example 1, in Example 2, the iridium oxide loading in the Nafion layer is reduced, and the iridium oxide loading in the SBR layer is increased.

[0081] Example 3

[0082] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 30 mL of water and 30 mL of isopropanol to obtain a first suspension, and 80 mg of commercial 60% Pt / C was added to a mixed solution of 10 mL of water and 10 mL of isopropanol to obtain a second suspension;

[0083] Step S2: The first suspension prepared in step S1 was divided into 24 mL and 18 mL, 474 μL of 5% Nafion-ethanol dispersion (22.06 mg Nafion) was added to the first portion, and 379 μL of SBR aqueous solution (10 mg / mL, 3.79 mg SBR) was added to the second portion, and the first and second slurries were obtained by ball milling and ultrasonic dispersion. The second suspension prepared in step S1 was taken, 413 μL of 5% Nafion-ethanol dispersion (19.2 mg Nafion) was added thereto, and the third slurry was obtained by ball milling and ultrasonic dispersion.

[0084] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and 0.7 mg / cm 2 of catalyst (iridium oxide) and 0.3 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying condition is 80°C and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with a structure of multiple binders is obtained, which is expressed as 0.7Nafion+0.3SBR membrane electrode.

[0085] Different from Example 1, in Example 3, the iridium oxide loading amount of the Nafion layer is increased, and the iridium oxide loading amount of the SBR layer is reduced.

[0086] Example 4

[0087] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 15 mL of water and 45 mL of isopropanol to obtain a first suspension, and 160 mg of commercial 60% Pt / C was added to a mixed solution of 10 mL of water and 30 mL of isopropanol to obtain a second suspension;

[0088] Step S2: Take the first suspension prepared in step S1 and divide it into two parts, add 339 μL of 5% Nafion-ethanol dispersion (15.75 mg of Nafion) to the first part, add 632 μL of SBR aqueous solution (10 mg / mL, 6.32 mg of SBR) to the second part, ball mill and ultrasonically disperse to obtain the first and second slurries, take the second suspension prepared in step S1, add 826 μL of 5% Nafion-ethanol dispersion (38.4 mg of Nafion) to it, ball mill and ultrasonically disperse to obtain the third slurry;

[0089] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and each is coated with 0.5 mg / cm 2 The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying condition is 80°C and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with a structure of multiple binders is obtained, which is expressed as 0.5Nafion+0.5SBR membrane electrode.

[0090] Different from Example 1, in Example 4, the ratio of water to isopropanol in the slurry was changed.

[0091] Example 5

[0092] Step S1: At room temperature, 240 mg of iridium oxide was added to a mixed solution of 15 mL of water and 15 mL of isopropanol to obtain a first suspension, and 80 mg of commercial 60% Pt / C was added to a mixed solution of 5 mL of water and 5 mL of isopropanol to obtain a second suspension;

[0093] Step S2: Take the first suspension prepared in step S1 and divide it into two parts, add 339 μL of 5% Nafion-ethanol dispersion (15.75 mg of Nafion) to the first part, add 632 μL of SBR aqueous solution (10 mg / mL, 6.32 mg of SBR) to the second part, ball mill and ultrasonically disperse to obtain the first and second slurries, take the second suspension prepared in step S1, add 826 μL of 5% Nafion-ethanol dispersion (38.4 mg of Nafion) to it, ball mill and ultrasonically disperse to obtain the third slurry;

[0094] Step S3: Use an automatic coating machine to sequentially coat the first and second slurries on one side of the proton exchange membrane and dry them. The mass ratio of the first and second slurries is 1:1, and each is coated with 0.5 mg / cm 2The catalyst (iridium oxide) was coated and dried on the other side of the proton exchange membrane, with a coating of 0.67 mg / cm 2 The catalyst 60% Pt / C (containing 0.4 mg / cm 2 The drying condition is 80°C and the adsorption pressure is 0.3 MPa. Finally, a membrane electrode with a structure of multiple binders is obtained, which is expressed as 0.5Nafion+0.5SBR membrane electrode.

[0095] Different from Example 1, the concentration of the slurry was changed in Example 5.

[0096] The membrane electrodes with various binder structures prepared in Examples 2 to 5 were assembled into water electrolysis cells, and their steady-state polarization curves were as follows: Figures 4 to 7 shown.

[0097] Figures 4 to 7 The steady-state polarization curves of the membrane electrodes with various binder structures prepared in Examples 2 to 5 of the present invention and the conventional pure Nafion membrane electrode as the binder are compared. Figures 4 to 7 As shown in the figure, under the conditions of different anode catalyst loadings of Nafion layer and SBR layer and different water-to-alcohol ratios defined in the present invention, membrane electrodes with various binder structures having good catalytic activity and stability can be synthesized, which have a high catalytic activity at 3 A / cm 2 The potential required for aging is 30-50 mV lower than that of the conventional membrane electrode with pure Nafion as a binder, and the performance degradation after accelerated aging is 45% of that of the conventional membrane electrode with pure Nafion as a binder, that is, the membrane electrode described in the present invention has higher electrochemical activity and better stability.

[0098] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A membrane electrode, characterized in that: It includes a first adhesive layer, a second adhesive layer, a proton exchange membrane, and a third adhesive layer connected in sequence; Wherein, the first bonding layer comprises styrene-butadiene rubber and an anode catalyst; The second bonding layer includes perfluorosulfonic acid resin and an anode catalyst; The third bonding layer includes perfluorosulfonic acid resin and a cathode catalyst.

2. The membrane electrode according to claim 1, characterized in that: The anode catalyst is selected from an iridium oxide-based catalyst, an iridium-based supported catalyst or a ruthenium-based catalyst; The cathode catalyst is selected from 20% Pt / C, 40% Pt / C or 60% Pt / C.

3. The membrane electrode according to claim 1 or 2, characterized in that: The total loading amount of the anode catalyst in the first adhesive layer and the second adhesive layer in the membrane electrode is 0.5-2 mg / cm 2 .

4. The membrane electrode according to claim 1 or 2, characterized in that: The Pt loading in the cathode catalyst is 0.2-0.6 mg / cm 2 .

5. The membrane electrode according to claim 1 or 2, characterized in that: The mass ratio of the perfluorosulfonic acid resin to the anode catalyst in the second adhesive layer is 1:(5-20); The mass ratio of styrene-butadiene rubber to cathode catalyst in the first bonding layer is 1:(5-20); The mass ratio of the perfluorosulfonic acid resin to the cathode catalyst in the third bonding layer is 1:(3-15).

6. The method for preparing a membrane electrode according to any one of claims 1 to 5, characterized in that: The following steps are involved: The first slurry and the second slurry are sequentially coated on the surface of the proton exchange membrane, the third slurry is coated on the other side of the proton exchange membrane, and dried to obtain the membrane electrode; Wherein, the first slurry is obtained by mixing an anode catalyst, a solvent, and a perfluorosulfonic acid resin; The second slurry is obtained by mixing an anode catalyst, a solvent, and styrene-butadiene rubber; The third slurry is obtained by mixing a cathode catalyst, a solvent and a perfluorosulfonic acid resin.

7. The preparation method according to claim 6, characterized in that: The solvent is selected from one or more of water, isopropanol, ethanol and butanol.

8. The preparation method according to claim 6, characterized in that: The mass ratio of the first slurry to the second slurry is (3-7): (3-7).

9. The preparation method according to claim 6, characterized in that: The drying temperature is 60°C to 100°C; The drying adsorption pressure is 0.2-0.4 MPa.

10. An electrolytic cell for proton exchange membrane water electrolysis, characterized in that: It comprises the membrane electrode according to any one of claims 1 to 5 or the membrane electrode prepared by the preparation method according to any one of claims 6 to 9.

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