阅读说明：本技术 一种复合质子交换膜及其制备方法 (Composite proton exchange membrane and preparation method thereof ) 是由 杨大伟 曹朋飞 李冬海 成之阳 于 2021-06-23 设计创作，主要内容包括：公开了一种复合质子交换膜及其制备方法。该复合质子交换膜包括全氟磺酸树脂和非全氟磺酸树脂；其中,全氟磺酸树脂具有全氟主链结构；非全氟磺酸树脂具有部分氟化或者非氟化主链结构；全氟磺酸树脂和非全氟磺酸树脂均具有质子交换功能；该复合质子交换膜掺杂有金属氧化物或金属纳米粒子；非全氟磺酸树脂相对于复合质子交换膜总质量的质量百分比为1-30％。该复合质子交换膜具有延长的使用寿命、降低的氢气交叉渗透及更低的成本。(A composite proton exchange membrane and its preparing process are disclosed. The composite proton exchange membrane comprises perfluorinated sulfonic acid resin and non-perfluorinated sulfonic acid resin; wherein the perfluorinated sulfonic acid resin has a perfluorinated main chain structure; the non-perfluorinated sulfonic acid resin has a partially fluorinated or non-fluorinated backbone structure; the perfluorinated sulfonic acid resin and the non-perfluorinated sulfonic acid resin both have a proton exchange function; the composite proton exchange membrane is doped with metal oxide or metal nano particles; the mass percentage of the non-perfluorinated sulfonic acid resin relative to the total mass of the composite proton exchange membrane is 1-30%. The composite proton exchange membrane has the advantages of prolonged service life, reduced hydrogen cross permeation and lower cost.)

1. A composite proton exchange membrane is characterized in that the composite proton exchange membrane comprises perfluorinated sulfonic acid resin and non-perfluorinated sulfonic acid resin;

wherein the perfluorosulfonic acid resin has a perfluorinated backbone structure;

the non-perfluorinated sulfonic acid resin has a partially fluorinated or non-fluorinated backbone structure;

the perfluorinated sulfonic acid resin and the non-perfluorinated sulfonic acid resin both have a proton exchange function;

the composite proton exchange membrane is doped with metal oxide or metal nano particles;

the mass percentage of the non-perfluorinated sulfonic acid resin relative to the total mass of the composite proton exchange membrane is 1-30%;

the main chain of the non-perfluorinated sulfonic acid resin with the partially fluorinated main chain structure comprises one or more of polyvinyl fluoride, polyvinylidene fluoride or ethylene-tetrafluoroethylene copolymer, and the molecular side chain of the non-perfluorinated sulfonic acid resin with the partially fluorinated main chain contains sulfonic acid functional groups;

the non-perfluorinated sulfonic acid resin with a non-fluorinated backbone structure comprises one or more of sulfonated polyether ether ketone, sulfonated polyether sulfone, sulfonated polyaryl ether sulfone, or polybenzimidazole.

2. The composite proton exchange membrane according to claim 1, wherein the metal oxide is 0.1-2% by mass relative to the total mass of the composite proton exchange membrane.

3. The composite proton exchange membrane according to claim 1, wherein the mass percentage of the metal nanoparticles to the total mass of the composite proton exchange membrane is 0.01-1%.

4. The composite proton exchange membrane according to claim 1, wherein the metal oxide comprises one or more of an oxide of Ce, an oxide of Mn.

5. The composite proton exchange membrane according to claim 1, wherein the metal nanoparticles comprise one or more of Au nanoparticles, Pt nanoparticles, Ru nanoparticles.

6. A method of making a composite proton exchange membrane according to claims 1 to 5 comprising:

(1) dissolving perfluorosulfonic acid resin in a mixed solvent to form a solution A;

(2) adding metal oxide or metal nano particles into the solution A to form a solution B;

(3) adding non-perfluorinated sulfonic acid resin into the solution B to form a solution C;

(4) and coating the solution C on a base material, and drying to obtain the composite proton exchange membrane.

7. A method of making a composite proton exchange membrane according to claims 1 to 5 comprising:

(i) dissolving perfluorinated sulfonic acid resin and non-perfluorinated sulfonic acid resin in a mixed solvent to form a solution D;

(ii) adding metal oxide or metal nano particles into the solution D to form a solution E;

(iii) and coating the solution E on a base material, and drying to obtain the composite proton exchange membrane.

8. The method for preparing a composite proton exchange membrane according to claim 6 or 7, wherein in the step (1) or (i), the mixed solvent comprises a lipophilic solvent and a hydrophilic solvent.

9. Use of a composite proton exchange membrane according to any one of claims 1 to 5 for the electrolysis of polymer electrolyte membrane water.

10. A polymer electrolyte membrane water electrolyzer comprising a composite proton exchange membrane according to any of claims 1 to 5.

Technical Field

The invention belongs to the technical field of hydrogen energy, and particularly relates to a novel composite proton exchange membrane for polymer electrolyte membrane water electrolysis and a preparation method thereof.

Background

Polymer Electrolyte Membrane Water Electrolysis (PEMWE) is an important technology for converting electrical energy into chemical energy, in the context of climate change and the related requirements for energy conversion.

However, the PEMWE technology is currently limited by the following problems that cannot be popularized and used in a large scale:

(1) because of using noble metal catalyst and proton exchange membrane, the disposable input cost is too high;

(2) proton exchange membranes have a limited long-term service life;

(3) since a thin Polymer Electrolyte Membrane (PEM) is used in a PEMWE cell, it tends to produce gas crossover phenomena, particularly crossover of hydrogen in the anode compartment, when it is used. Since the lower explosive limit for hydrogen in oxygen is about 4 vol%, a 2 vol% safety margin value cannot be achieved without a reasonable mitigation gas crossover strategy.

Therefore, a new composite proton exchange membrane for water electrolysis of polymer electrolyte membrane and a preparation method thereof are needed to solve the above technical problems.

Disclosure of Invention

In order to solve the technical problems, the invention provides a novel composite proton exchange membrane for polymer electrolyte membrane water electrolysis.

The composite proton exchange membrane comprises perfluorinated sulfonic acid resin and non-perfluorinated sulfonic acid resin,

the perfluorinated sulfonic acid resin has a perfluorinated main chain structure;

the non-perfluorinated sulfonic acid resin has a partially fluorinated or non-fluorinated backbone structure;

the perfluorinated sulfonic acid resin and the non-perfluorinated sulfonic acid resin both have a proton exchange function;

the composite proton exchange membrane is doped with metal oxide or metal nano particles;

wherein the mass percentage of the metal oxide relative to the total mass of the composite proton exchange membrane is 0.1-2%;

wherein the mass percentage of the metal nano particles relative to the total mass of the composite proton exchange membrane is 0.01-1%.

Wherein the mass percentage of the non-perfluorinated sulfonic acid resin relative to the total mass of the composite proton exchange membrane is 1-30%.

Wherein the metal oxide comprises one or more of Ce oxide and Mn oxide.

The metal nanoparticles comprise one or more of Au nanoparticles, Pt nanoparticles and Ru nanoparticles.

Wherein the main chain of the non-perfluorinated sulfonic acid resin with the partially fluorinated main chain structure comprises one or more of polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF) or ethylene-tetrafluoroethylene copolymer (ETFE), and the molecular side chain of the non-perfluorinated sulfonic acid resin with the partially fluorinated main chain contains sulfonic acid (-SO)₃H) A functional group.

Wherein the main chain of the non-perfluorinated sulfonic acid resin with the non-fluorinated main chain structure comprises one or more of sulfonated polyether ether ketone (sPEEK), sulfonated polyether sulfone (sPES) and sulfonated polyaryl ether sulfone (sAES).

The invention also provides a preparation method of the composite proton exchange membrane, which comprises the following steps:

(1) dissolving perfluorosulfonic acid resin (PFSA) in a mixed solvent to form a solution A;

(2) adding metal oxide or metal nano particles into the solution A to form a solution B;

(3) adding non-perfluorinated sulfonic acid resin into the solution B to form a solution C;

(4) and coating the solution C on a base material, and drying to obtain the composite proton exchange membrane.

The invention also provides another preparation method of the composite proton exchange membrane, which comprises the following steps:

(i) dissolving perfluorosulfonic acid resin (PFSA) and non-perfluorosulfonic acid resin in a mixed solvent to form a solution D;

(ii) adding metal oxide or metal nano particles into the solution D to form a solution E;

(iii) and coating the solution E on a base material, and drying to obtain the composite proton exchange membrane.

Wherein, in the step (1) or (i), the mixed solvent comprises a lipophilic solvent and a hydrophilic solvent; wherein the lipophilic solvent is selected from one or more of N, N-Dimethylformamide (DMF), N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) and dimethyl sulfoxide (DMSO); the hydrophilic solvent is selected from one or more of tert-butyl alcohol, n-propyl alcohol, isopropyl alcohol, ethanol and water.

Wherein, in the mixed solvent, the volume ratio of the lipophilic solvent to the hydrophilic solvent is 1-3:8, preferably 2: 8.

Wherein, in the step (1) or (i), the mass ratio of the perfluorinated sulfonic acid resin to the mixed solvent is 8-12:90, preferably 10: 90.

Wherein in the step (3) or (i), the mass ratio of the non-perfluorinated sulfonic acid resin to the perfluorinated sulfonic acid resin is 15-40: 100.

Wherein, in the step (1) or (i), the solution A or the solution D is formed by dissolving for 3 to 6 days under the condition of 45 to 55 ℃ (preferably 50 ℃).

Wherein in the step (2) or (ii), the mass ratio of the added metal oxide to the perfluorosulfonic acid resin is 0.3-0.8:100 (preferably 0.5: 100); the mass ratio of the added metal nanoparticles to the perfluorosulfonic acid resin is 0.5-1.5:2000 (preferably 1:2000)

Wherein, in the step (2) or (ii), the solution B or the solution E is formed by dissolving for 0.5 to 2 days (preferably 1 day) under the condition of 45 to 55 ℃ (preferably 50 ℃).

Wherein, in the step (3), the solution A or the solution D is formed by dissolving for 0.5 to 2 days (preferably 1 day) under the condition of 45 to 55 ℃ (preferably 50 ℃).

Wherein, in the step (4) or (iii), the coating mode is knife coating, dipping, spin coating, and the like.

Wherein, in the step (4) or (iii), the drying manner is drying for 2-4h (preferably 3h) at 95-115 ℃ (preferably 100 ℃) under normal pressure.

The invention also provides the application of the composite proton exchange membrane in the water electrolysis of the polymer electrolyte membrane.

The invention also provides a polymer electrolyte membrane water electrolyzer, which comprises the composite proton exchange membrane.

The beneficial technical effects of the invention are embodied in the following aspects:

(1) the metal oxide is added as a free radical quencher, so that the service life of the proton exchange membrane can be prolonged by 2-5 times;

(2) the noble metal nano particles are used as a gas composite catalyst, so that the problem of overhigh hydrogen content in the anode gas caused by gas cross permeation can be solved;

(3) the sulfonic acid membrane having a partially fluorinated backbone or a non-fluorinated backbone has a lower hydrogen cross-permeation rate than the sulfonic acid membrane having a perfluorinated backbone, and thus the addition of a sulfonic acid resin having a partially fluorinated backbone or a non-fluorinated backbone to the composite membrane can reduce the hydrogen cross-permeation.

The above effects (2) and (3) in combination can reduce the hydrogen content in the anode gas to below 0.1 vol.% at a rated power load of the polymer electrolyte membrane water electrolyzer of 20% to 100%.

(4) The cost of the sulfonic acid resin having a partially fluorinated backbone or a non-fluorinated backbone relative to the perfluorosulfonic acid resin is about 1/5 to 1/2 of the perfluorosulfonic acid resin, which helps to reduce the cost of the water electrolyzer.

Brief description of the drawings

FIG. 1 shows N-CeO in example 1₂Electrolytic polarization profiles of P30 membrane and Nafion 115 membrane of comparative example.

FIG. 2 shows N-CeO in example 1₂Graph of hydrogen concentration in oxygen at the time of electrolysis for P30 membrane and Nafion 115 membrane of comparative example.

FIG. 3 shows N-CeO of example 1₂Stability of the P30 film on electrolysis.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

A preparation method of a composite proton exchange membrane comprises the following steps:

(1) dissolving a perfluorosulfonic acid resin (PFSA) in a mixed solvent of NMP and water (the volume ratio of the NMP to the water is 2:8), wherein the mass ratio of the PFSA to the mixed solvent is 10:90, and dissolving the mixed solution at 50 ℃ for 3 days to form a solution A;

(2) adding cerium oxide nanoparticles into the solution A, wherein the mass ratio of cerium oxide to PFSA is 0.2:100, and dissolving the mixed solution at 50 ℃ for 1 day to form a solution B;

(3) adding polyvinylidene fluoride-g-styrene sulfonic acid (PVDF-g-PSSA) into the solution B, wherein the mass ratio of PVDF-g-PSSA to PFSA is 30:100, and dissolving the mixed solution at 50 ℃ for 1 day to form a solution C;

(4) coating the solution C on a base material in a blade mode, and then drying the solution C for 3 hours at the temperature of 100 ℃ under normal pressure to obtain N-CeO₂-P30 composite proton exchange membrane.

Example 2

A preparation method of a composite proton exchange membrane comprises the following steps:

(1) dissolving a perfluorosulfonic acid resin (PFSA) in a mixed solvent of NMP and water (the volume ratio of the NMP to the water is 2:8), wherein the mass ratio of the PFSA to the mixed solvent is 10:90, and dissolving the mixed solution at 50 ℃ for 3 days to form a solution A;

(2) adding Pt nanoparticles into the solution A, wherein the mass ratio of Pt to PFSA is 1: 2000; dissolving the mixed solution at 50 ℃ for 1 day to form a solution B;

(3) adding polyvinylidene fluoride-g-styrene sulfonic acid (PVDF-g-PSSA) into the solution B, wherein the mass ratio of PVDF-g-PSSA to PFSA is 20:100, and dissolving the mixed solution at 50 ℃ for 1 day to form a solution C;

(4) coating the solution C on a substrate in a blade mode, and then drying the substrate for 3 hours at 100 ℃ under normal pressure to obtain an N-Pt-P20 composite film;

example 3

A preparation method of a composite proton exchange membrane comprises the following steps:

(1) dissolving a perfluorosulfonic acid resin (PFSA) and a polyvinylidene fluoride-g-styrene sulfonic acid (PVDF-g-PSSA) resin in a mixed solvent of NMP and water (the volume ratio of the NMP to the water is 2:8), wherein the mass ratio of the PFSA to the mixed solvent is 10:90, the mass ratio of the PVDF-g-PSSA to the PFSA is 30:100, and the mixed solution is dissolved at 50 ℃ for 5 days to form a solution D;

(2) adding cerium oxide nanoparticles into the solution D, wherein the mass ratio of cerium oxide to PFSA is 0.5:100, and dissolving the mixed solution at 50 ℃ for 1 day to form a solution E;

(3) solution E was knife coated onto a substrate and then dried under atmospheric pressureDrying for 3h at 100 ℃ to obtain N-CeO₂-P30 composite proton exchange membrane.

Performance testing

The membrane of example 1 was fabricated into a membrane electrode for PEM electrolysis of water. In addition, for comparison, experiments were simultaneously conducted using a Nafion 115 membrane manufactured by dupont as a comparative example. The loading capacity of the membrane electrode catalyst is respectively anode IrO₂2mg/cm²Cathode 70% Pt/C catalyst 1mg/cm²And the temperature of the electrolyzed pure water is 80 ℃, and a performance test, a hydrogen in oxygen test and a durability test are respectively carried out. The results are shown in FIGS. 1, 2 and 3, respectively.

As can be seen from FIG. 1, N-CeO of example 1₂When the-P30 film is used as a proton exchange membrane for electrolyzing water, the current density is 1.5A/cm²When is N-CeO₂The electrolytic voltages of the-P30 and Nafion 115 membranes were 1.76V and 1.74V, respectively, indicating that the two membranes perform equivalently.

As can be seen from FIG. 2, when the electrolytic current density is more than 0.5A/cm²When using the N-CeO of example 1₂The content of hydrogen in oxygen electrolyzed by the P30 membrane is lower than 0.1 vol.%, and is far lower than the lower explosion limit of hydrogen.

As can be seen from FIG. 3, when the N-CeO2-P30 membrane of example 1 was used as a proton exchange membrane for electrolyzed water, the electrolytic voltage did not increase after a long time of electrolysis of 700 hours, indicating that the membrane had good durability.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.