PEM water electrolysis hydrogen production membrane electrode unit, preparation method and PEM water electrolysis hydrogen production tank

Abstract

The invention relates to the technical field of proton exchange membrane water electrolysis hydrogen production, in particular to a PEM water electrolysis hydrogen production membrane electrode unit and a preparation method thereof, and a PEM water electrolysis hydrogen production tank, which comprises a proton exchange membrane, a cathode catalyst layer and an anode catalyst layer, the cathode porous transmission layer is arranged on one side, on which the cathode catalyst layer is transferred, of the proton exchange membrane; the anode porous transmission layer is arranged on the other side of the proton exchange membrane; the cathode catalyst layer and the anode catalyst layer comprise a hydrocarbon ionic polymer and / or a perfluorosulfonic acid ionic polymer. According to the invention, the hydrocarbon ionic polymer is added into the cathode catalyst layer and the anode catalyst layer or the hydrocarbon ionic polymer and the perfluorosulfonic acid ionic polymer are added at the same time, so that the affinity among the cathode catalyst layer, the anode catalyst layer and the proton exchange membrane is improved, the air permeability of the cathode catalyst layer and the anode catalyst layer is improved, and the proton transmission rate is effectively improved; the performance of the membrane electrode unit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of proton exchange membrane water electrolysis hydrogen production, and in particular to a membrane electrode unit for PEM water electrolysis hydrogen production and a preparation method thereof, and a PEM water electrolysis hydrogen production tank. Background Art

[0002] Hydrogen energy is the chemical energy released by the chemical reaction of hydrogen and oxygen. It is a secondary clean energy and a clean energy that is being developed and utilized at an accelerated pace. Among them, proton exchange membrane (PEM) water electrolysis is an important aspect of the development of hydrogen energy technology. PEM water electrolysis has attracted more and more attention in recent years due to its high current density, fast response speed, high purity of hydrogen production, and small size. In addition, the good combination of PEM water electrolysis technology and the volatility of renewable energy is also the main driving force for its rapid development.

[0003] PEM water electrolysis cells are usually composed of a stack of membrane electrode units (MEA) and bipolar plates (BPPs); wherein the membrane electrode unit is usually composed of a proton exchange membrane (PEM), a catalyst layer (CLs) and a porous transport layer (PTL); and, according to the working principle of PEM water electrolysis cells, the catalyst layer (CLs) usually needs to be added with an ionic polymer as a binder. Ionic polymers are usually composed of ionized and electrically neutral units connected to the main chain by covalent bonds, and are used to mechanically bond the catalyst layer together and fix it on the underlying substrate, thereby improving the mechanical stability of the catalyst layer and extending the service life of the membrane electrode; at the same time, the ionic polymer also needs to be able to transfer the protons generated by electrolysis from the active sites of the anode catalyst layer through the proton exchange membrane to the active sites of the cathode catalyst layer, and needs to discharge the gas generated at the active sites in a timely manner; however, the commonly used ionomers are all fluorine-based polymers, which cannot meet the high permeability requirements of the catalyst layer; for example, the patent publication number is: CN116411 299A, discloses a PEM water electrolysis hydrogen production membrane electrode and its preparation method, wherein the cathode catalyst layer and the anode catalyst layer both include a catalyst, a perfluorosulfonic acid ionomer, a solvent and a perfluorosulfonic acid ionomer dispersion promoter; the perfluorosulfonic acid ionomer cannot make the catalyst layer have the characteristics of high permeability; the patent publication number is: CN119050394A, discloses a composite proton exchange membrane, a preparation method, a membrane electrode, and a fuel cell. Although the specification records that the ionomer can also be a non-fluorine polymer such as sulfonated polyetheretherketone, sulfonated polyarylethersulfone, sulfonated polyimide or sulfonated polybenzimidazole; but it still does not solve the problem of high permeability requirements for the catalyst layer. Therefore, it is necessary to develop a membrane electrode unit that can improve the compatibility of the proton exchange membrane and the catalyst layer, and at the same time make the catalyst layer have a higher permeability.

[0004] The present invention provides a membrane electrode unit for PEM water electrolysis hydrogen production and a preparation method, and a PEM water electrolysis hydrogen production cell, so as to solve the problems existing in the prior art of the existing membrane electrode unit, such as poor compatibility between the proton exchange membrane and the cathode and anode catalyst layers, and low air permeability of the cathode and anode catalyst layers. Summary of the invention

[0005] The purpose of the present invention is to provide a membrane electrode unit for PEM water electrolysis hydrogen production and a preparation method, and a PEM water electrolysis hydrogen production cell, so as to solve the problems existing in the prior art of the existing membrane electrode unit, such as poor compatibility between the proton exchange membrane and the cathode and anode catalyst layers, and low air permeability of the cathode and anode catalyst layers.

[0006] The technical solution of the present invention is: a membrane electrode unit for PEM water electrolysis hydrogen production, comprising a proton exchange membrane, a cathode catalyst layer and an anode catalyst layer symmetrically transferred on both sides of the proton exchange membrane, a cathode porous transport layer arranged on one side of the proton exchange membrane with the cathode catalyst layer transferred, and an anode porous transport layer arranged on the other side of the proton exchange membrane; wherein the cathode catalyst layer and the anode catalyst layer include hydrocarbon ion polymers and / or perfluorosulfonic acid ion polymers.

[0007] Preferably, the hydrocarbon ionomer is a sulfonated polyetheretherketone ionomer or a sulfonated polyetherethersulfone ionomer;

[0008] The main chain of the hydrocarbon ion polymer includes Structure; wherein R1 is a keto group or a sulfone group, R2 and R3 are selected from any one of hydrogen, a carbonyl group, an alkane segment having no more than 7 carbon atoms, and a siloxane segment having no more than 7 carbon atoms, and * is the site where the repeating unit is connected to other units.

[0009] Preferably, calculated by mass percentage, the amount of the hydrocarbon ion polymer added to the cathode catalyst layer and the anode catalyst layer is 2-10% of the amount of the catalytically active substance added to the cathode catalyst layer and the anode catalyst layer, respectively;

[0010] The amount of the perfluorosulfonic acid-based ion polymer added is 15% or less of the amount of the catalytically active substance added in the cathode catalyst layer and the amount of the catalytically active substance added in the anode catalyst layer.

[0011] Preferably, the ion exchange capacity of the hydrocarbon ion polymer is 1.4-2.5 mmol / g.

[0012] Preferably, the catalytically active component in the cathode catalyst layer is a platinum-based catalyst; the catalytically active component in the anode catalyst layer is an iridium-based catalyst; and the thickness of the cathode catalyst layer and the anode catalyst layer are both 1-30 μm.

[0013] Preferably, the cathode porous transport layer is prepared by using carbon paper as a substrate; the anode porous transport layer is prepared by using any one or more of titanium mesh, titanium felt, and titanium plate as a substrate;

[0014] The thickness of the cathode porous transport layer and the anode porous transport layer are both 200 μm-2000 μm;

[0015] The proton exchange membrane is a hydrocarbon non-fluorinated polymer proton exchange membrane.

[0016] The present application also provides a method for preparing the above-mentioned membrane electrode unit for PEM water electrolysis hydrogen production, which comprises the following steps: S1, weighing 60% of Pt / C nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in proportion, and dispersing the weighed 60% of Pt / C nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in water, isopropanol and glycerol in turn, mixing them evenly, and preparing a cathode catalyst ink with a solid content of 1.0wt%;

[0017] S2. Weigh IrO2 / TiO2 nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in proportion, and disperse the weighed IrO2 / TiO2 nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in isopropanol and glycerol in sequence, mix well, and prepare an anode catalyst ink with a solid content of 1.0 wt%;

[0018] S3, spraying the prepared cathode catalyst ink and anode catalyst ink on different transfer base films respectively, and then drying the transfer base films sprayed with the cathode catalyst ink or anode catalyst ink at 60-100° C. for 15-45 min, respectively, to prepare a cathode catalyst layer and an anode catalyst layer;

[0019] S4, cutting the prepared cathode catalyst layer and anode catalyst layer into a certain size, placing a proton exchange membrane between the cathode catalyst layer and the anode catalyst layer, and then hot pressing for 3 minutes at 110-130° C. and 7-9 MPa to transfer the cathode catalyst layer and the anode catalyst layer onto the proton exchange membrane, thereby obtaining a proton exchange membrane with the cathode catalyst layer and the anode catalyst layer transferred thereto;

[0020] S5. Sequentially press the cathode porous transport layer, the proton exchange membrane having the cathode catalyst layer and the anode catalyst layer, and the anode porous transport layer into one piece to prepare a membrane electrode unit.

[0021] The present application also provides a PEM water electrolysis hydrogen production tank, which includes the above-mentioned PEM water electrolysis hydrogen production membrane electrode unit, an end plate, two insulating plates and two collecting plates; the end plate includes an upper end plate and a lower end plate; the upper end plate, one of the insulating plates and one of the collecting plates are sequentially pasted on the upper end of the membrane electrode unit from top to bottom, and the lower end plate, another insulating plate and another collecting plate are sequentially pasted on the lower end of the membrane electrode unit from bottom to top.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] (1) The present invention provides a membrane electrode unit for PEM water electrolysis hydrogen production and a preparation method, as well as a PEM water electrolysis hydrogen production cell. By adding hydrocarbon ion polymers or adding hydrocarbon ion polymers and perfluorosulfonic acid ion polymers to the cathode and anode catalyst layers, the compatibility between the cathode catalyst layer, the anode catalyst layer and the proton exchange membrane is improved, and the air permeability of the cathode and anode catalyst layers is improved, thereby effectively improving the proton transmission rate in the membrane electrode unit and improving the performance of the membrane electrode unit, so that the membrane electrode unit can be used in proton exchange membrane batteries that produce hydrogen at higher currents, thereby reducing the cost of hydrogen production. The problems existing in the prior art, such as poor compatibility between the proton exchange membrane and the cathode and anode catalyst layers, and low air permeability of the cathode and anode catalyst layers, are solved. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with specific embodiments:

[0025] A membrane electrode unit for hydrogen production by PEM water electrolysis includes a proton exchange membrane, a cathode catalyst layer, an anode catalyst layer, a cathode porous transport layer and an anode porous transport layer; wherein the cathode catalyst layer and the anode catalyst layer are symmetrically transferred on both sides of the proton exchange membrane, the cathode porous transport layer is arranged on the side of the proton exchange membrane on which the cathode catalyst layer is transferred, and the anode porous transport layer is arranged on the other side of the proton exchange membrane; and the cathode porous transport layer and the anode porous transport layer are parallel to the proton exchange membrane. In order to increase the affinity between the cathode and anode catalyst layers and the proton exchange membrane, and at the same time improve the air permeability of the cathode and anode catalyst layers, so as to achieve the purpose of improving the performance of the membrane electrode unit, a perfluorosulfonic acid ion polymer or a hydrocarbon ion polymer can be added to the cathode catalyst layer and / or the anode catalyst layer, or a perfluorosulfonic acid ion polymer and a hydrocarbon ion polymer can be added at the same time.

[0026] In the present application, the hydrocarbon ionomer can be selected from one or more of sulfonated polyaryletherketone, sulfonated polyarylethersulfone, sulfonated polyimide, and sulfonated polybenzimidazole; and, through a large number of experimental studies, it is found that when the hydrocarbon ionomer is selected as a sulfonated polyetheretherketone ionomer or a sulfonated polyetherethersulfone ionomer, that is, the main chain of the hydrocarbon ionomer includes When the structure is Formula I, the air permeability of the catalyst layer can be greatly improved, which is helpful to improve the performance of the membrane electrode unit; wherein, R1 is a ketone group or a sulfone group, R2 and R3 are selected from any one of hydrogen, carbonyl, an alkane segment with a carbon number not greater than 7, and a siloxane segment with a carbon number not greater than 7, * is the site where the repeating unit is connected to other units; and, from the perspective of cost and higher air permeability, the siloxane segment can be selected from one of a trimethylsiloxane segment, a triethylsiloxane segment, and a tripropylsiloxane segment. The main chain includes a sulfonated polyetheretherketone ionomer and a sulfonated polyetherethersulfone ionomer of Formula I structure, which is obtained by polycondensation of disulfonated difluorobenzophenone or disulfonated difluorodiphenyl sulfone with a dihydroxy aromatic compound containing R2 and R3 segments. During polymerization, N-methylpyrrolidone can be used as a solvent, potassium carbonate or sodium carbonate as a catalyst, and toluene as a water-carrying agent, and a condensation polymerization reaction is carried out at 100-180°C, and the reaction time is controlled within the range of 1-10 hours; after the reaction is completed, the product needs to be precipitated through methanol, and the precipitated product is dried; thereafter, N-methylpyrrolidone is used as a solvent to dissolve the product to form a hydrocarbon ion polymer compound liquid, which is used as a binder solution for standby use.

[0027] In this application, the cathode porous transport layer and the anode porous transport layer can be prepared by using one or more materials of titanium mesh, titanium felt, carbon paper, and titanium plate as the substrate; and the thickness of the cathode porous transport layer and the anode porous transport layer should be controlled within the range of 200-2000 μm. At the same time, according to the working principle of proton exchange membrane water electrolysis for hydrogen production, in order to further improve the performance of the membrane electrode unit, the cathode porous transport layer is preferably prepared by using carbon paper as the substrate. The proton exchange membrane can choose to use a perfluorosulfonic acid membrane or a hydrocarbon non-fluoropolymer proton exchange membrane. When a perfluorosulfonic acid membrane is selected, a proton exchange membrane with the trade name of Nafon or Aquvion can be selected; however, although the perfluorosulfonic acid membrane has high proton conductivity and chemical stability, its mechanical durability is poor, the hydrogen barrier is low, and the production cost is high, which will limit the commercialization of the proton exchange membrane water electrolyzer to a certain extent; therefore, the present application preferably uses a hydrocarbon non-fluoropolymer proton exchange membrane. When a hydrocarbon non-fluorine polymer proton exchange membrane is selected, a specific film made of sulfonated polysulfone, polyethersulfone, polyphenylene ether, polyarylene ether polymer, polyphenylene sulfide, polyphenylene sulfide sulfone, polyparaphenylene, polyarylene polymer, polyarylene ketone, polyetherketone, polyarylene phosphine oxide, polyether phosphine oxide, polybenzoxazole, polybenzothiazole, polybenzimidazole, polyamide, polyimide, polyetherimide, polyimide sulfone and the like polymer as a substrate can be selected; and, based on the considerations of oxidation stability and availability of raw materials, and in order to further improve the compatibility between the cathode and anode catalyst layers and the proton exchange membrane, a hydrocarbon non-fluorine polymer proton exchange membrane prepared with sulfonated polyetheretherketone or sulfonated polyarylene sulfone as a substrate is preferably selected.

[0028] The present application also provides a method for preparing the membrane electrode unit, which specifically comprises the following steps:

[0029] S1. Weigh 60% of Pt / C nanoparticles and disperse the weighed 60% of Pt / C nanoparticles in water, isopropanol, and glycerol to form a mixed solution. Then, weigh a hydrocarbon ion polymer compound liquid and / or a perfluorosulfonic acid ion polymer in a certain proportion as a binder, add them to the mixed solution, mix evenly, and prepare a cathode catalyst ink with a solid content of 1.0wt%.

[0030] S2. Weigh IrO2 / TiO2 nanoparticles and disperse them in isopropanol and glycerol. Then, weigh a hydrocarbon ion polymer compound liquid and / or a perfluorosulfonic acid ion polymer in a certain proportion as a binder, add them to the above-mentioned isopropanol and glycerol, mix well, and prepare an anode catalyst ink with a solid content of 1.0wt%.

[0031] S3, spray the prepared cathode catalyst ink and anode catalyst ink on different transfer base films respectively, then dry the transfer base films sprayed with cathode catalyst ink or anode catalyst ink at 60-100°C for 15-45 minutes to prepare cathode catalyst layer and anode catalyst layer respectively; after drying, calculate the catalyst density per unit area, if it is insufficient, repeat S3 until the loading amount of the catalyst active component reaches 0.4 mg / cm 2 . Among them, in the cathode catalyst layer, the amount of hydrocarbon ion polymer added is 2-10% of the total amount of catalytically active substances added in the cathode catalyst layer; similarly, in the anode catalyst layer, the amount of hydrocarbon ion polymer added is 2-10% of the total amount of catalytically active substances added; and the ion exchange capacity of the hydrocarbon ion polymer is in the range of 1.4-2.5mmol / g. When the ion exchange capacity is lower than 1.4, the ability to transfer protons from the proton exchange membrane to the catalyst active site may be insufficient, resulting in a decrease in the performance of the membrane electrode unit; and when the ion exchange capacity is higher than 2.5, it may cause the mechanical properties of the ionomer to deteriorate. After the membrane electrode unit is used for a long time, the cathode and anode catalyst layers are easily peeled off from the proton exchange membrane, which will affect its durability and shorten the service life of the membrane electrode unit. In the cathode catalyst layer and the anode catalyst layer, the amount of perfluorosulfonic acid ion polymer added is 15% or less of the total amount of catalytically active substances in the cathode catalyst layer and the anode catalyst layer, respectively.

[0032] S4. Cut the prepared cathode catalyst layer and anode catalyst layer into certain sizes, and then place the proton exchange membrane between the cathode catalyst layer and the anode catalyst layer. After that, hot press for 3 minutes at 110-130°C and 7-9MPa to transfer the cathode catalyst layer and the anode catalyst layer onto the proton exchange membrane, so as to obtain a proton exchange membrane with the cathode catalyst layer and the anode catalyst layer transferred thereto.

[0033] S5. Sequentially press the cathode porous transport layer, the proton exchange membrane having the cathode catalyst layer and the anode catalyst layer, and the anode porous transport layer into one piece to prepare a membrane electrode unit.

[0034] The present application also provides a PEM water electrolysis hydrogen production tank, which includes the above-mentioned membrane electrode unit, and also includes an upper end plate, a lower end plate, two insulating plates and two collecting plates; wherein the upper end plate, one of the insulating plates and one of the collecting plates are sequentially pasted on the upper end of the membrane electrode unit from top to bottom, and the lower end plate, another insulating plate and another collecting plate are sequentially pasted on the lower end of the membrane electrode unit from bottom to top.

[0035] In the following specific implementation methods, the hydrocarbon non-fluorine proton exchange membrane developed by our company is selected, such as the ALV01 proton exchange membrane, and the perfluorosulfonic acid membrane developed by Chemours, such as the Nafion115 and Nafion212 proton exchange membranes, can also be selected; and the performance comparison results between the ALV01 proton exchange membrane and the Nafion115 and Nafion212 proton exchange membranes are shown in Table 1.

[0036] Table 1. Performance comparison results between different types of proton exchange membranes

[0037] Proton Exchange Membrane Ion exchange capacity thickness ALV01 2.01meq / g 50μm Nafion115 0.89meq / g 128μm Nafion212 0.96meq / g 51μm

[0038] In the following specific implementations, the hydrocarbon ion polymers and perfluorosulfonic acid ionomers added to the cathode catalyst layer and the performance catalyst layer are selected from one or more of hydrocarbon 1-5 and Nafion respectively; the structures of the hydrocarbon ion polymers and perfluorosulfonic acid ionomers are shown in Table 2.

[0039] Table 2. Ionic polymers used in Examples and Comparative Examples

[0040]

[0041] In the following specific embodiments, the cathode porous transport layer is selected to be carbon paper with a thickness of 210 μm; the anode porous transport layer is selected to be platinum-coated titanium fiber felt with a thickness of 250 μm and a porosity of 60-70%; and the effective area of ​​the membrane electrode unit is 2 cm×2 cm.

[0042] Example 1

[0043] S1. Weigh 60% of Pt / C nanoparticles in a certain proportion, and disperse the weighed 60% of Pt / C nanoparticles in water, isopropanol, and glycerol to form a mixed solution. Then, weigh the hydrocarbon system 1 ionomer compound liquid in a certain proportion so that the addition amount of hydrocarbon system 1 is 2% of the addition amount of Pt / C nanoparticles, add it to the mixed solution, mix well, and prepare a cathode catalyst ink with a solid content of 1.0wt%.

[0044] S2. Weigh IrO2 / TiO2 nanoparticles in a certain proportion, and disperse the weighed IrO2 / TiO2 nanoparticles in isopropanol and glycerol. Then, weigh hydrocarbon 1 ionomer compound liquid in a certain proportion so that the addition amount of hydrocarbon 1 is 2% of the addition amount of IrO2 / TiO2 nanoparticles, and add it to the above-mentioned isopropanol and glycerol, mix evenly, and prepare an anode catalyst ink with a solid content of 1.0wt%.

[0045] S3, spray the prepared cathode catalyst ink and anode catalyst ink on different transfer base films respectively, and then dry the transfer base films sprayed with cathode catalyst ink or anode catalyst ink at 80°C for 30 minutes to prepare cathode catalyst layer and anode catalyst layer respectively; after drying, calculate the catalyst density per unit area, if it is insufficient, repeat step S3 until the loading amount of the catalyst active component reaches 0.4 mg / cm 2 .

[0046] S4, cutting the prepared cathode catalyst transfer layer and anode catalyst transfer layer into a certain size, placing the ALV01 proton exchange membrane between the cathode and anode catalyst transfer layers, and then hot pressing for 3 minutes at 120° C. and 8 MPa to transfer the cathode and anode catalyst layers to the proton exchange membrane;

[0047] S5. Sequentially press the cathode porous transport layer, the proton exchange membrane having the cathode catalyst layer and the anode catalyst layer, and the anode porous transport layer into one piece to prepare a membrane electrode unit.

[0048] Example 2

[0049] The difference between this embodiment and embodiment 1 is that in step S1, the amount of hydrocarbon 1 ionomer added is 5% of the amount of Pt / C nanoparticles added; in step S2, the amount of hydrocarbon 1 ionomer added is 5% of the amount of IrO2 / TiO2 nanoparticles added.

[0050] Example 3

[0051] The difference between this embodiment and embodiment 1 is that in step S1, the amount of hydrocarbon 1 ionomer added is 10% of the amount of Pt / C nanoparticles added; in step S2, the amount of hydrocarbon 1 ionomer added is 10% of the amount of IrO2 / TiO2 nanoparticles added.

[0052] Example 4

[0053] The difference between this embodiment and embodiment 2 is that in step S4, the proton exchange membrane selected is Nafion 115 type.

[0054] Example 5

[0055] The difference between this embodiment and embodiment 2 is that in step S4, the proton exchange membrane selected is Nafion212 type.

[0056] Example 6

[0057] The difference between this embodiment and embodiment 3 is that in step S1, hydrocarbon 2 ionomer is selected, and in step S2, hydrocarbon 2 ionomer is selected.

[0058] Example 7

[0059] The difference between this embodiment and embodiment 3 is that in step S1, hydrocarbon 3 ionomer is selected, and in step S2, hydrocarbon 3 ionomer is selected.

[0060] Example 8

[0061] The difference between this embodiment and embodiment 3 is that in step S1, hydrocarbon 4 ionomer is selected, and in step S2, hydrocarbon 4 ionomer is selected.

[0062] Example 9

[0063] The difference between this embodiment and embodiment 3 is that in step S1, a hydrocarbon 5 ionomer is selected, and in step S2, a hydrocarbon 5 ionomer is selected.

[0064] Example 10

[0065] The difference between this embodiment and embodiment 2 is that: in step S1, Nafion D520 perfluorosulfonic acid resin is also added when preparing the cathode catalyst ink, and the amount of Nafion D520 perfluorosulfonic acid resin added is 5% of the amount of Pt / C nanoparticles added; in step S2, Nafion D520 perfluorosulfonic acid resin is also added when preparing the anode catalyst ink, and the amount of Nafion D520 perfluorosulfonic acid resin added is 5% of the amount of IrO2 / TiO2 nanoparticles added.

[0066] Embodiment 11

[0067] The difference between this embodiment and embodiment 10 is that in step S4, the proton exchange membrane selected is Nafion 115 type.

[0068] Example 12

[0069] The difference between this embodiment and embodiment 3 is that: in step S1, Nafion D520 perfluorosulfonic acid resin is selected as the binder; in step S2, Nafion D520 perfluorosulfonic acid resin is also selected as the binder.

[0070] Example 13

[0071] The difference between this embodiment and embodiment 1 is that in step S4, the proton exchange membrane selected is Nafion 115 type.

[0072] The membrane electrode units prepared in the above examples 1-13 were applied to the proton exchange membrane single cell for testing; the test results are shown in Table 3. Among them, the bipolar plates are all parallel channel titanium flow fields, and the bolts are tightened with a torque wrench with a torque of 2Nm. A silicone gasket is placed between the bipolar plate and the membrane electrode unit to seal it, so that the membrane electrode unit and the single cell are tightly combined. Before data collection, it is necessary to operate at normal pressure, a flow rate of 50mL / min, an operating temperature of 60℃, and a current density of 10mA / cm 2 The battery was operated for 60 minutes under the conditions of , and then a polarization curve (IV) test was performed in the scanning voltage range of 1.4 to 2.0 V.

[0073] Table 3. (IV) polarization curve test results of proton exchange membrane single cell

[0074]

[0075] It can be seen from Table 3 that by adding hydrocarbon ionomers to the cathode catalyst layer and the anode catalyst layer, a membrane electrode unit is prepared and applied to a proton exchange membrane single cell, and the hydrogen production voltage at the same current is significantly lower, which is more conducive to hydrogen production at a higher current, can effectively improve the hydrogen production efficiency and reduce the cost of hydrogen production; and this conclusion can be verified by comparing Examples 12-13 with Examples 1-11. By comparing the membrane electrode units prepared in Examples 1-3, it can be seen that when the addition amount of hydrocarbon ionomers in the cathode catalyst layer and the anode catalyst layer is increased from 3% to 10%, and the prepared membrane electrode element is applied to a proton exchange membrane single cell, the hydrogen production voltage under the same current is significantly reduced; however, by comparing Example 2 with Example 3, it can be seen that when the addition amount of hydrocarbon ionomers in the cathode catalyst layer and the anode catalyst layer is increased from 5% to 10%, and the prepared membrane electrode element is applied to a proton exchange membrane single cell, the hydrogen production voltage under the same current is only slightly reduced. Therefore, from the perspective of the performance of the membrane electrode unit and cost savings, the addition amount of hydrocarbon ionomers in the cathode catalyst layer and the anode catalyst layer should not exceed 10% of the addition amount of catalytically active substances in the cathode catalyst layer or the catalytically active substances in the anode catalyst layer. By comparing Examples 1-9 with each other and with Examples 12 and 13, it can be seen that when a hydrocarbon ion polymer such as a sulfonated polyetheretherketone ionomer and a sulfonated polyetherethersulfone ionomer having a main chain including a structure of Formula I is used as a binder to prepare a membrane electrode unit and applied to a proton exchange membrane single cell, the hydrogen production voltages under the same current are similar, but are significantly lower than when Nafion D520 perfluorosulfonic acid resin is used as a binder; furthermore, it is shown that the use of a hydrocarbon ion polymer having a main chain including a structure of Formula I as a binder can effectively improve the air permeability of the catalyst layer and help improve the performance of the membrane electrode unit; and by comparing Examples 6-8 with each other, it can be seen that when the hydrocarbon ion polymer contains an alkane segment or a siloxane segment having a carbon number not exceeding 7, the air permeability of the catalyst layer can be more effectively improved, thereby further reducing the hydrogen production voltage under the same current. Comparing Example 10 and Example 11 with Example 3 and Example 4, it can be seen that, when the total amount of ion polymer added remains unchanged, adding hydrocarbon ion polymer and perfluorosulfonic acid ion polymer simultaneously in the cathode catalyst layer and the anode catalyst layer can further reduce the hydrogen production voltage under the same current, which further indicates that the hydrocarbon ion polymer and the perfluorosulfonic acid ion polymer can play a synergistic role, thereby improving the performance of the membrane electrode unit. At the same time, according to the above Examples 1-13, in order to increase the affinity between the cathode and anode catalyst layers and the proton exchange membrane, and thus improve the performance of the membrane electrode unit, when a hydrocarbon ion polymer is selected as a binder, a hydrocarbon non-fluorinated polymer proton exchange membrane is preferably selected.

[0076] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. A membrane electrode unit for hydrogen production by PEM water electrolysis, comprising a proton exchange membrane, a cathode catalyst layer and an anode catalyst layer symmetrically transferred on both sides of the proton exchange membrane, a cathode porous transport layer arranged on one side of the proton exchange membrane with the cathode catalyst layer transferred, and an anode porous transport layer arranged on the other side of the proton exchange membrane; characterized in that: The cathode catalyst layer and the anode catalyst layer include hydrocarbon-based ion polymers and / or perfluorosulfonic acid-based ion polymers.

2. A membrane electrode unit for hydrogen production by PEM water electrolysis according to claim 1, characterized in that: The hydrocarbon ionomer is a sulfonated polyetheretherketone ionomer or a sulfonated polyetherethersulfone ionomer; The main chain of the hydrocarbon ion polymer includes Formula I structure; wherein R1 is a keto group or a sulfone group, R2 and R3 are selected from any one of hydrogen, a carbonyl group, an alkane segment with a carbon number not greater than 7, and a siloxane segment with a carbon number not greater than 7, and * is the site where the repeating unit is connected to other units.

3. A membrane electrode unit for hydrogen production by PEM water electrolysis according to claim 2, characterized in that: Calculated by mass percentage, the amount of the hydrocarbon ion polymer added to the cathode catalyst layer and the anode catalyst layer is 2-10% of the amount of the catalytically active substance added to the cathode catalyst layer and the anode catalyst layer, respectively; The amount of the perfluorosulfonic acid-based ion polymer added is 15% or less of the amount of the catalytically active substance added in the cathode catalyst layer and the amount of the catalytically active substance added in the anode catalyst layer.

4. A membrane electrode unit for hydrogen production by PEM water electrolysis according to claim 2, characterized in that: The ion exchange capacity of the hydrocarbon ion polymer is 1.4-2.5 mmol / g.

5. A membrane electrode unit for hydrogen production by PEM water electrolysis according to claim 2, characterized in that: The catalytically active component in the cathode catalyst layer is a platinum-based catalyst; the catalytically active component in the anode catalyst layer is an iridium-based catalyst; the thickness of the cathode catalyst layer and the anode catalyst layer are both 1-30 μm.

6. A membrane electrode unit for hydrogen production by PEM water electrolysis according to claim 2, characterized in that: The cathode porous transport layer is prepared by using carbon paper as a substrate; the anode porous transport layer is prepared by using any one or more of titanium mesh, titanium felt, and titanium plate as a substrate; The thickness of the cathode porous transport layer and the anode porous transport layer are both 200 μm-2000 μm; The proton exchange membrane is a hydrocarbon non-fluorinated polymer proton exchange membrane.

7. A method for preparing a membrane electrode unit for hydrogen production by PEM water electrolysis according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Weigh 60% of Pt / C nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in proportion, and disperse the weighed 60% of Pt / C nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in water, isopropanol and glycerol in sequence, mix them evenly, and prepare a cathode catalyst ink with a solid content of 1.0wt%; S2. Weigh IrO2 / TiO2 nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in proportion, and disperse the weighed IrO2 / TiO2 nanoparticles, hydrocarbon ion polymer compound liquid and / or perfluorosulfonic acid ion polymer in isopropanol and glycerol in sequence, mix well, and prepare an anode catalyst ink with a solid content of 1.0 wt%; S3, spraying the prepared cathode catalyst ink and anode catalyst ink on different transfer base films respectively, and then drying the transfer base films sprayed with the cathode catalyst ink or anode catalyst ink at 60-100° C. for 15-45 min, respectively, to prepare a cathode catalyst layer and an anode catalyst layer; S4, cutting the prepared cathode catalyst layer and anode catalyst layer into a certain size, placing a proton exchange membrane between the cathode catalyst layer and the anode catalyst layer, and then hot pressing for 3 minutes at 110-130° C. and 7-9 MPa to transfer the cathode catalyst layer and the anode catalyst layer onto the proton exchange membrane, thereby obtaining a proton exchange membrane with the cathode catalyst layer and the anode catalyst layer transferred thereto; S5. Sequentially press the cathode porous transport layer, the proton exchange membrane having the cathode catalyst layer and the anode catalyst layer, and the anode porous transport layer into one piece to prepare a membrane electrode unit.

8. A PEM water electrolysis hydrogen production cell, characterized in that: It comprises a membrane electrode unit for hydrogen production by water electrolysis of PEM as described in any one of claims 1 to 6, an end plate, two insulating plates and two collecting plates; the end plate comprises an upper end plate and a lower end plate; the upper end plate, one of the insulating plates and one of the collecting plates are sequentially pasted on the upper end of the membrane electrode unit from top to bottom, and the lower end plate, another of the insulating plates and another of the collecting plates are sequentially pasted on the lower end of the membrane electrode unit from bottom to top.

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