CN104022301A - Macromolecular phytic acid supported metal organic framework composite membrane as well as preparation method and application thereof - Google Patents

Abstract

The invention discloses a macromolecule-loaded phytic acid metal organic frame material composite membrane, which uses the polymer loaded phytic acid metal organic frame material as the membrane material, and the macromolecule is perfluorosulfonic acid polyelectrolyte. The preparation method comprises: preparing the metal organic framework material, purifying the metal organic framework material, preparing the metal organic framework material loaded with phytic acid, and finally preparing a composite film. Among them, the preparation process of metal-organic framework materials is simple, the structure is controllable, the particle size is uniform, and it is cheap. Phytic acid is rich in phosphoric acid groups, which can promote better compatibility between proton exchange membrane materials and polymers under saturated humidity, and the dispersion in the membrane is relatively uniform. The membrane material prepared by the preparation method of the invention also has good proton conduction properties under low humidity, and can be used for hydrogen-oxygen fuel cells operated under low humidity and direct methanol fuel cells operated under saturated humidity.

Description

Polymer-loaded phytic acid metal-organic framework composite membrane and its preparation and application

technical field

The invention relates to a composite membrane, in particular to a polymer-loaded phytic acid metal organic framework material composite membrane and its preparation and application, belonging to the technical field of fuel cell proton exchange membranes. the

Background technique

Proton exchange membrane fuel cell is a representative of new energy. Proton exchange membrane is one of the core components of proton exchange membrane fuel cell. Enhancing the proton conductivity of the membrane is the key to improving the overall performance of the battery. Proton transfer is generally divided into two mechanisms: one is the transport mechanism, that is, protons diffuse through the form of hydrated protons, such as H ₃ O ⁺ , H ₅ O ₂ ⁺ and H ₉ O ₄ ⁺ ; the other is jumping The mechanism is that protons jump from one water molecule or functional group to the adjacent water molecule or functional group through the hydrogen bond network. Traditional sulfonic acid-based proton exchange membranes, such as DuPont's perfluorosulfonic acid series proton exchange membranes and sulfonated polyarylether ketones, etc., because their proton transfer channels will be closed under dehydration conditions, and sulfonic acid can It is difficult to dissociate under the condition of water loss, so the proton conductivity decreases exponentially under the condition of dehydration. At present, there are three main methods for improving the performance of proton exchange membranes under low humidity: 1. Introducing hydrophilic substances into the membrane to enhance the binding force to water and prevent water loss; 2. Using high boiling point proton carriers Instead of water, such as phosphoric acid, imidazole, etc.; 3. Develop new polymers suitable for low humidity. Among them, introducing phosphoric acid into the membrane combines the first two methods, and is considered to be a very effective way to improve the low-humidity performance of the proton exchange membrane. Phosphoric acid is highly hygroscopic, and even under anhydrous conditions, it can dissociate itself to form H ₂ PO ₄ ^- and H ₄ PO ₄ ⁺ ion pairs for the transfer of protons. In addition, its high density of hydroxyl groups is also conducive to the formation of efficient hydrogen bond network for proton conduction under low humidity. However, phosphoric acid has a high solubility in water. If it is directly added to the membrane, it will cause serious bleeding problems. As far as the current technology is concerned, the phosphorylation of organic matter is very difficult. These all limit the development of low humidity proton exchange membranes to a certain extent. Therefore, it is important to find a way to efficiently introduce phosphate groups into the membrane.

Contents of the invention

Phytic acid and metal-organic framework materials are a very suitable combination as the phosphate group provider and carrier, respectively. Phytic acid is cyclohexyl hexaphosphate, which is the compound containing the most phosphoric acid groups except phosphoric acid, and can chelate most metals with a valence of more than 2. Metal-organic frameworks (MOFs) are novel porous crystalline materials with highly ordered structures, and the size of their pores can be regulated by selecting ligands and metal ions. Phytic acid molecules of about 1.1nm can be locked by choosing an appropriate size. Metal-organic frameworks have many uncoordinated metal sites for chelation and anchoring of phytic acid. Phosphoric acid loss can be well prevented by size locking and chelation. In addition, the metal-organic framework material has a huge specific surface area and a highly ordered three-dimensional continuous pore structure, which provides a guarantee for increasing the loading capacity of phytic acid. the

Therefore, by loading phytic acid with a suitable metal-organic framework material, and introducing phosphate groups into the polymer membrane to increase the water-holding capacity of the proton exchange membrane, an efficient hydrogen bond network can be formed at low humidity, and the low-humidity protons can be increased. delivery sites, thereby enhancing the proton conductivity of the membrane at low humidity. the

The invention provides a preparation method and application of a polymer-loaded phytic acid metal organic framework material composite film. The proton exchange membrane prepared by this method still has high proton conductivity under low humidity. the

The polymer-loaded phytic acid metal organic framework material composite membrane of the present invention uses the polymer loaded phytic acid metal organic framework material as the membrane material; wherein, the polymer is a perfluorosulfonic acid polyelectrolyte. Its preparation method comprises the following steps:

1) Preparation of metal organic framework materials: using terephthalic acid, chromium nitrate nonahydrate, hydrofluoric acid and water as raw materials, and obtained after modification by trifluoromethanesulfonic anhydride and concentrated sulfuric acid, the specific steps are: benzene Diformic acid, chromium nitrate nonahydrate, hydrofluoric acid, and water are mixed in a molar ratio of 1:1:0.825:266, reacted at 220°C for 8 hours under the corresponding saturated vapor pressure, and cooled at a rate of 10-20°C/min until 40°C, centrifugal washing, and vacuum drying at 50-80°C for 24 hours to obtain a metal organic framework material numbered MIL101;

2) Purification of the metal-organic framework material: Weigh the metal-organic framework material and add it to a flask, and add 200 times the mass of nitrogen nitrogen-dimethylformamide, 1wt% ammonium fluoride aqueous solution, ethanol, and dichloromethane in the solvent Boil one by one at the boiling point for 11-13 hours, and centrifuge and dry to obtain the purified metal organic framework material;

3) Preparation of phytic acid-loaded metal-organic framework material: the purified metal-organic framework material obtained in step 2) is added to the reactor, heated and degassed under vacuum at 80-120°C for 11-13h; then, the system is cooled to 60-80°C , add a phytic acid solution with a mass fraction of 0-50wt% under vacuum, and the concentration of the purified metal-organic framework material in the phytic acid solution is 5g/100mL; then connect to the atmosphere, stir for 5.5h-6.5h, centrifuge, Wash until the pH of the supernatant liquid is neutral, and dry to obtain a metal organic framework material loaded with phytic acid. the

4) Preparation of casting solution: at room temperature, weigh a certain amount of metal-organic framework material loaded with phytic acid prepared in step 3) and ultrasonically disperse it into nitrogen-nitrogen-dimethylacetamide, and add high Molecules, stirred at room temperature for 10-24h to obtain casting solution. Wherein, in the above solution, the ratio of metal organic framework material, polymer and nitrogen nitrogen-dimethylacetamide is 0.04:1:6.5-0.16:1:6.5, and the units are mass:mass:volume. the

5) Preparation of composite membrane:

At room temperature, cast the casting solution prepared in step 4) on a glass plate, and place it in an oven to dry, then heat-treat at 110-120°C for 1-2 hours, then peel off the film and place it in 2M sulfuric acid Treat for 10-24 hours, then rinse with deionized water until the washing solution is neutral, and vacuum-dry at 50-60° C. to obtain a polymer-loaded phytic acid metal organic framework material. the

The characteristics of composite film of the present invention are as follows:

(1) The metal organic framework material used is the metal organic framework material numbered MIL101;

(2) The metal-organic framework material is injected with a large amount of phytic acid by vacuum;

(3) There is a strong chelating ability between phytic acid and metal organic framework materials, and the molecular diameter (about 1.1nm) of phytic acid is close to the pore diameter (1.2nm) of MIL101, so that phytic acid can be firmly loaded on metal frame organic materials;

(4) Phytic acid is rich in phosphoric acid groups, which can act as a proton acceptor and donor at the same time, and can form a hydrogen bond network in the channels of metal organic framework materials to promote proton transfer. The membrane material prepared by the preparation method of the present invention also has good proton conduction characteristics under low humidity, and can be used for hydrogen-oxygen fuel cells operated under low humidity and direct methanol fuel cells operated under saturated humidity. the

Compared with prior art, the beneficial effect of the present invention is:

(1) The preparation process of metal organic framework materials is simple, the structure is controllable, the particle size is uniform, and it is cheap. the

(2) Phytic acid is rich in phosphoric acid groups. Phosphoric acid has a strong ability to bind water and has a strong ability to form hydrogen bonds. It can form a continuous and orderly hydrogen bond network that can promote proton conduction, so it can promote saturation. Proton exchange membrane materials have good compatibility with polymers under humidity, and the dispersion in the membrane is relatively uniform. the

(3) The prepared composite membrane still has good proton conduction characteristics under low humidity, and can be used in low humidity hydrogen-oxygen fuel cells and direct methanol fuel cells under saturated humidity. the

Description of drawings

Fig. 1 is made in comparative example High magnification cross-sectional scanning electron microscope (FESEM) photo of 117 recast film;

Fig. 2 is made in embodiment 3 117-High-magnification cross-sectional scanning electron microscope (FESEM) photos of metal-organic framework material composite films;

Fig. 3 is made in embodiment 4 117- High magnification cross-sectional scanning electron microscope (FESEM) photograph of metal-organic framework material composite film.

Detailed ways

The invention discloses a macromolecule-loaded phytic acid metal organic framework material composite membrane, which uses the polymer loaded phytic acid metal organic framework material as the membrane material; wherein, the macromolecule is a perfluorosulfonic acid polyelectrolyte. Its preparation method comprises the following steps:

1) Preparation of metal organic framework materials: using terephthalic acid, chromium nitrate nonahydrate, hydrofluoric acid and water as raw materials, and obtained after modification by trifluoromethanesulfonic anhydride and concentrated sulfuric acid, the specific steps are: benzene Diformic acid, chromium nitrate nonahydrate, hydrofluoric acid, and water are mixed in a molar ratio of 1:1:0.825:266, reacted at 220°C for 8 hours under the corresponding saturated vapor pressure, and cooled at a rate of 10-20°C/min until 40°C, centrifugal washing, and vacuum drying at 50-80°C for 24 hours to obtain a metal organic framework material numbered MIL101;

2) Purification of the metal-organic framework material: Weigh the metal-organic framework material and add it to a flask, and add 200 times the mass of nitrogen nitrogen-dimethylformamide, 1wt% ammonium fluoride aqueous solution, ethanol, and dichloromethane in the solvent Boil one by one at the boiling point for 11-13 hours, and centrifuge and dry to obtain the purified metal organic framework material;

3) Preparation of phytic acid-loaded metal-organic framework material: the purified metal-organic framework material obtained in step 2) is added to the reactor, heated and degassed under vacuum at 80-120°C for 11-13h; then, the system is cooled to 60-80°C , add a phytic acid solution with a mass fraction of 0-50wt% under vacuum, and the concentration of the purified metal-organic framework material in the phytic acid solution is 5g/100mL; then connect to the atmosphere, stir for 5.5h-6.5h, centrifuge, Wash until the pH of the supernatant liquid is neutral, and dry to obtain a metal organic framework material loaded with phytic acid. the

4) Preparation of casting solution: at room temperature, weigh a certain amount of metal-organic framework material loaded with phytic acid prepared in step 3) and ultrasonically disperse it into nitrogen-nitrogen-dimethylacetamide, add high Molecules, stirred at room temperature for 10-24h to obtain casting solution. Wherein, in the above solution, the ratio of metal organic framework material, polymer and nitrogen nitrogen-dimethylacetamide is 0.04:1:6.5-0.16:1:6.5, and the units are mass:mass:volume. the

5) Preparation of composite membrane:

At room temperature, cast the casting solution prepared in step 4) on a glass plate, and place it in an oven to dry, then heat-treat at 110-120°C for 1-2 hours, then peel off the film and place it in 2M sulfuric acid Treat for 10-24 hours, then rinse with deionized water until the washing solution is neutral, and vacuum-dry at 50-60° C. to obtain a polymer-loaded phytic acid metal organic framework material. the

The details of the present invention are described below through the examples, and the examples are provided for the convenience of understanding, and are by no means limiting the present invention. the

Example 1:

1) Preparation of metal-organic framework materials: mix terephthalic acid, chromium nitrate nonahydrate, hydrofluoric acid, and water in a molar ratio of 1:1:0.825:266, and react at 220°C for 8 hours under the corresponding saturated vapor pressure, and then Cool down to 40°C at a rate of 15°C/min, centrifuge wash, and vacuum dry at 60°C for 24 hours to obtain a metal organic framework material numbered MIL101. the

2) Purification of metal-organic framework materials: Weigh 1.5g of metal-organic framework materials and add them to a flask, and add nitrogen nitrogen dimethylformamide, 1wt% ammonium fluoride aqueous solution, ethanol, and dichloromethane one by one at the boiling point of the solvent. Boiling for 12 hours in turn, and drying by centrifugation to obtain a purified metal organic framework material. the

3) Preparation of metal-organic framework material loaded with phytic acid: Weigh 1.5 g of the purified metal-organic framework material prepared in the above step 2) into a 100 mL Schrank tube, and heat and degas under vacuum at 120° C. for 12 hours. Subsequently, the temperature of the system was lowered to 80° C., and 30 mL of a phytic acid solution with a mass fraction of 25 wt % was added under vacuum. Then connect to the atmosphere, stir for 6 hours, centrifuge, wash until the pH of the supernatant liquid is neutral, and dry to obtain a metal organic framework material loaded with phytic acid. the

4) Preparation of casting solution: at room temperature, weigh 0.026 g of the metal-organic framework material loaded with phytic acid prepared in step 3) and ultrasonically disperse it into 6.5 mL of nitrogen-nitrogen dimethylacetamide, and add 0.65 g of 117 resin, stirred at room temperature for 24 hours to obtain a casting solution.

5) Preparation of composite film: at room temperature, cast the film casting liquid obtained in step 4) on a glass plate, and place it in an oven to dry, and then heat-treat at 120°C for 2 hours, then peel off the film and place it in Treat in 2M sulfuric acid for 24h, then rinse with deionized water until the washing solution is neutral, and dry the wet film under vacuum at 50°C to obtain 117 - Metal organic framework material composite membrane loaded with phytic acid (corresponding membrane 1 in Table 1), the methanol permeability and proton conductivity of the composite membrane are as membrane 1 shown in Table 1.

Example 2:

The preparation method is basically the same as that of Example 1, the only difference being that step 4) is: at room temperature, weigh 0.052 g of phytic acid metal-organic framework material and ultrasonically disperse it into 6.5 mL of nitrogen nitrogen dimethylacetamide, and after 9 hours of dispersion Add 0.65g of 117 resin, stirred at room temperature for 24 hours to obtain a casting solution. Embodiment 2 obtains 117-Phytate-loaded metal-organic framework composite membrane (corresponding to membrane 2 in Table 1), the methanol permeability and proton conductivity of the composite membrane are as membrane 2 shown in Table 1.

Example 3:

The preparation method is basically the same as that in Example 1, the only difference being: Step 4) is: at room temperature, weigh 0.078g of phytic acid metal-organic framework material and ultrasonically disperse it into 6.5mL of nitrogen nitrogen dimethylacetamide, and after 9 hours of dispersion Add 0.65g of 117 resin, stirred at room temperature for 24 hours to obtain a casting solution. Embodiment 3 obtains 117-loaded phytic acid metal organic framework material composite membrane (corresponding membrane 3 in Table 1), Fig. 2 is the FESEM photograph of the composite membrane of Example 3, its methanol permeability and proton conductivity are as shown in Table 1 membrane 3 .

Example 4:

The preparation method is basically the same as that of Example 1, the only difference being that step 4) is: at room temperature, weigh 0.104 g of phytic acid metal-organic framework material and ultrasonically disperse it into 6.5 mL of nitrogen-nitrogen dimethylacetamide, and after dispersing for 9 hours, Add 0.65g of 117 resin, stirred at room temperature for 24 hours to obtain a casting solution. Embodiment 4 obtains 117 - Severe coagulation occurred in the filling of the metal organic framework material composite membrane loaded with phytic acid (corresponding membrane 4 in Table 1). FIG. 3 shows the FESEM photo of the composite membrane of Example 4.

Embodiment 5:

1) Preparation of metal-organic framework materials: mix terephthalic acid, chromium nitrate nonahydrate, hydrofluoric acid, and water in a molar ratio of 1:1:0.825:266, and react at 220°C for 8 hours under the corresponding saturated vapor pressure, and then Cool down to 40°C at a rate of 15°C/min, centrifuge wash, and vacuum dry at 60°C for 24 hours to obtain a metal organic framework material numbered MIL101. the

2) Purification of metal-organic framework materials: Weigh 1.5 g of the metal-organic framework materials prepared in the above step 1) into a flask, and add nitrogen-nitrogen dimethylformamide, 1 wt % ammonium fluoride aqueous solution, ethanol, di Methyl chloride was boiled one by one at the boiling point of the solvent for 12 hours, and dried by centrifugation to obtain a purified metal-organic framework material. the

3) Preparation of metal-organic framework material loaded with phytic acid: Weigh 1.5 g of the purified metal-organic framework material prepared in the above step 2) into a 100 mL Schrank tube, and heat and degas under vacuum at 120° C. for 12 hours. Subsequently, the temperature of the system was lowered to 80° C., and 30 mL of pure water was added under vacuum. Then connect to the atmosphere, stir for 6 hours, centrifuge, wash until the pH of the supernatant liquid is neutral, and dry to obtain a pure metal organic framework material. the

4) Preparation of casting solution: at room temperature, weigh 0.052 g of the pure metal organic framework material prepared in the above step 3) and ultrasonically disperse it into 6.5 mL of nitrogen nitrogen dimethylacetamide, add 0.65 g of 117 resin, stirred at room temperature for 24 hours to obtain a casting solution.

5) Preparation of composite film: at room temperature, cast the casting solution prepared in step 4) on a glass plate, and place it in an oven to dry, and then heat-treat at 120°C for 2 hours, then peel off the film and place it in a Treat in 2M sulfuric acid for 24h, then rinse with deionized water until the washing solution is neutral, and dry the wet film under vacuum at 50°C to obtain 117 - Phytic acid-loaded metal organic framework material composite membrane (corresponding membrane 5 in Table 1), the methanol permeability and proton conductivity of the composite membrane are as membrane 5 shown in Table 1.

Comparative example:

0.65g Added to 6mL nitrogen nitrogen dimethylacetamide, stirred for 24h to obtain casting solution. At room temperature, the casting solution was cast on a glass plate, dried in an oven, and then heat-treated at 120°C for 2 hours, then the film was peeled off and treated in 2M sulfuric acid for 24 hours, and then rinsed with deionized water until washed Until the solution is neutral, the wet film is vacuum-dried at 50°C to obtain a recast Membrane (corresponding to Membrane 6 in Table 1), the methanol permeability and proton conductivity of the composite membrane are as Membrane 6 shown in Table 1.

Proton conductivity tests were performed on the products prepared in the above-mentioned Examples 1-5 and Comparative Examples. the

The horizontal impedance of the membrane was measured by the two-electrode method and calculated from the membrane impedance. The membrane was placed between two electrodes and a pressure of 200 g was applied to make good contact with the electrodes. The test conditions are: the oscillation voltage is 20mV, the frequency is 10Hz-100kHz, the electrode is a platinum (Pt) metal wire with a diameter of 1mm and a purity of 99.95%. The calculation formula of proton conductivity is: proton conductivity = distance between two electrodes/membrane thickness/membrane horizontal impedance/membrane width. Table 1 shows the methanol permeability and proton conductivity of Membrane 1, Membrane 2, Membrane 3, Membrane 4, Membrane 5 prepared in Examples 1-5 and Membrane 6 prepared in Comparative Example. the

In Table 1, ^a is the proton conductivity at 80°C and 100% relative humidity, ^b is the proton conductivity at 80°C and 10% relative humidity. Severe coagulation occurs in the filling of ^c -film 4, as shown in Figure 3.

It can be seen from Figure 1 to Figure 3 and Table 1 that the addition of metal organic framework materials loaded with phytic acid can improve the proton conductivity of sulfonated polyetheretherketone because the added modified metal organic framework materials have the following effects :

1) Cr ³⁺ , as a Lewis acid, effectively constructs a hydrogen bond network in the structural framework as a path for proton transfer, enabling protons to be transported by a hopping mechanism;

2) A large amount of phosphoric acid-rich phytic acid is loaded inside. On the one hand, these phosphate radicals serve as efficient proton transfer sites, which can make protons jump and transfer faster; on the other hand, the high-density phosphate radicals around phytic acid have Facilitate the formation of hydrogen bond network and promote the high-speed conduction of protons along the hydrogen bond network;

3) The interface between organic polymers and inorganic substances can form phase separation channels, which can allow protons to pass through efficiently through the transport mechanism. the

In terms of low humidity, due to the lack of water, Cr ³⁺ will not be able to hydrolyze to form -OH and donate protons. However, due to the addition of phytic acid, there are a large number of phosphate groups in the membrane. These phosphate groups have low water dependence and self-dissociation characteristics, so that they can still build hydrogen bond networks and provide proton transfer sites under low humidity conditions.

Therefore, due to the lack of phytic acid in Example 5, its proton conductivity is lower than the Nafion membrane of the comparative example at low humidity; the proton conductivity of Examples 1, 2, and 3 is higher than the Nafion membrane of the comparative example, and as the load plant The increase in the amount of acid metal organic framework material increases. However, the addition of too much metal-organic framework material loaded with phytic acid will seriously interfere with the molecular chain arrangement of Nafion, thereby destroying the structure of the membrane, and the metal-frame organic material and the polymer are severely separated into two phases, as shown in the figure 3. the

The composite membrane prepared by the preparation method of the invention still has good proton conduction properties under low humidity, and the composite membrane can be used for low-humidity hydrogen-oxygen fuel cells and direct methanol fuel cells under saturated humidity. Its proton conductivity is 0.17-0.23 S/cm at saturated humidity at 80°C; at 10% relative humidity, its proton conductivity can reach 1.47-7.63×10 ^-4 S/cm at 80°C. (In both environments, The proton conductivities of 117 are 0.16 and 0.64×10 ^-4 S/cm, respectively).

Although the present invention has been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, and the above-mentioned specific embodiments are only illustrative, rather than restrictive. Under the enlightenment of the present invention, many modifications can be made without departing from the gist of the present invention, and these all belong to the protection of the present invention. the

Claims (3)

1. macromolecule-load phytic acid metal organic frame Material cladding film, is characterized in that, is that to take macromolecule loading phytic acid metal organic frame material be material of preparing; Wherein, macromolecule is perfluorinated sulfonic acid polyelectrolyte.

2. a preparation method for macromolecule-load phytic acid metal organic frame Material cladding film as claimed in claim 1, is characterized in that, comprises the following steps:

1) prepare metal organic frame material: take terephthalic acids, nine water chromic nitrates, hydrofluoric acid and water is raw material, and by obtaining after trifluoromethyl sulfonic acid anhydride, concentrated sulfuric acid modification, concrete steps are: the mixed in molar ratio by phthalic acid, nine water chromic nitrates, hydrofluoric acid, water with 1:1:0.825:266, at 220 ℃, corresponding saturated steam is depressed reaction 8h, with the speed of 10-20 ℃/min, lower the temperature until 40 ℃, the metal organic frame material that at centrifuge washing, 50-80 ℃, vacuumize 24h call number is MIL101;

2) purifying to metal organic frame material: take metal organic frame material and join in flask, nitrogen nitrogen-dimethyl formamide, 1wt% ammonium fluoride aqueous solution, ethanol, carrene 200 times of quality boils successively one by one 11-13h under solvent boiling point respectively, centrifugal drying, obtains the metal organic frame material of purifying;

3) prepare load phytic acid metal organic frame material: the metal organic frame material of purifying step 2) obtaining joins in reactor, the degassed 11-13h of heating in vacuum at 80-120 ℃; Subsequently, system cools to 60-80 ℃, and under vacuum, adding mass fraction is the plant acid solution of 0-50wt%, and the metal organic frame material of purifying is 5g/100mL in the concentration of this plant acid solution; Connect subsequently atmosphere, stir 5.5h-6.5h, centrifugation, wash to supernatant pH as neutral, dry, obtain load phytic acid metal organic frame material.

4) prepare casting solution: under room temperature, take a certain amount of step 3) ultrasonic being distributed in nitrogen nitrogen-dimethylacetylamide of load phytic acid metal organic frame material that prepare, disperse to add macromolecule after (8-10) h, under room temperature, stir 10-24h, obtain casting solution.Wherein, in above-mentioned solution, the amount ratio of metal organic frame material, macromolecule and nitrogen nitrogen-dimethylacetylamide is 0.04:1:6.5-0.16:1:6.5, and unit is respectively quality: quality: volume.；

5) preparation of composite membrane:

Under room temperature, by step 4) casting solution curtain coating on glass plate of making, and it is dry to be placed in baking oven, then after temperature is 110-120 ℃ of heat treatment 1-2h, film is taken and is placed in off 2M sulfuric acid and process 10-24h, afterwards with deionized water rinsing until cleaning solution is neutrality, be placed in vacuumize at 50-60 ℃ and obtain macromolecule-load phytic acid metal organic frame material.

One kind as claimed in claim 1 macromolecule-load phytic acid metal organic frame Material cladding film as the purposes of direct methanol fuel cell film.