CN113285080B - Nitrogen-phosphorus co-doped FeW/N, P-C composite material derived from phytic acid and preparation and application thereof - Google Patents

Abstract

The invention relates to a nitrogen and phosphorus co-doped FeW/N, P-C composite material derived from phytic acid and a preparation method and application thereof, wherein the preparation method specifically comprises the following steps: (a) Taking an acidic solution A containing aniline, phytic acid and a tungsten source and an acidic solution B containing ammonium persulfate and an iron source, dropwise adding the acidic solution B into the acidic solution A for reaction, and carrying out post-treatment to obtain a FeW/N, P-C precursor; (b) Uniformly mixing the FeW/N, P-C precursor obtained in the step (a) with NaCl and KCl, and sequentially carrying out primary annealing, acid washing and secondary annealing to obtain the FeW/N, P-C composite material. Compared with the prior art, the composite material prepared by the invention has good catalytic activity, stability and methanol tolerance, can be used as a cathode oxygen reduction catalyst of a fuel cell, and is simple to operate in the preparation process.

Description

Nitrogen and phosphorus co-doped FeW/N,P-C composites derived from phytic acid and their preparation and application application

technical field

The invention belongs to the field of fuel cells, in particular to a FeW/N,P-C composite material derived from phytic acid and co-doped with nitrogen and phosphorus, and its preparation and application.

Background technique

Energy shortage and environmental pollution are two major problems faced by human society since the 21st century. Therefore, finding clean and renewable energy and developing efficient energy storage and conversion technologies are the top priorities. Fuel cells have attracted extensive attention as a new energy technology that is most likely to be commercialized on a large scale, and the electroreduction of oxygen is one of the most important electrocatalytic reactions, which are widely used in fuel cells and metal-air batteries. field. However, the oxygen reduction reaction of the fuel cell cathode requires a catalyst, and the commonly used catalysts are platinum or platinum-based catalysts. The disadvantages of platinum metal, such as high price, limited reserves, easy poisoning and serious performance loss during long-term operation, limit its practical application and hinder its practical application. The development of fuel cells and other related fields.

In view of the deficiencies of platinum-based catalysts, carbon materials doped with some non-metallic elements (such as nitrogen, sulfur, boron, and phosphorus) have shown certain oxygen reduction performance in recent years, but element doping involves harsh conditions and has poor performance. Compared with commercial platinum catalysts, the performance is relatively poor, and the oxygen reduction overpotential is relatively large. Therefore, the main task at this stage is to develop low-cost, high-activity, and high-stability cathode non-precious metal catalysts, thereby promoting the large-scale commercial application of fuel cells.

Previously, patent CN103920519B disclosed a preparation method of an oxygen reduction electrocatalyst based on iron-tungsten bimetallic oxides reinforced nitrogen-doped graphene, comprising the following steps: 1) oxidizing graphite powder to prepare graphite oxide; 2) oxidizing graphite powder; 1) the prepared graphite oxide is subjected to ultrasonic treatment to prepare graphene oxide; 3) the graphene oxide prepared in step 2) is diluted with water and mixed with a nitrogen source for hydrothermal reaction to obtain nitrogen-doped graphene; 4) the Step 3) The nitrogen-doped graphene prepared in step 3) is dispersed in water and then added with iron source and tungsten source, and heated for hydrolysis reaction; 5) The reaction product of step 4) is washed and dried, and then heat treated under the condition of protective gas. Although the patent discloses a preparation method of an oxygen reduction electrocatalyst based on iron-tungsten bimetallic oxides to enhance nitrogen-doped graphene, the experimental method is relatively dangerous and the reaction conditions are relatively harsh. The conditions are mild, the safety factor is high, the operability is strong, and the method is simpler and faster.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a nitrogen and phosphorus co-doped FeW/N, P-C composite material derived from phytic acid and its preparation and application, which solves the problem that the Pt/C catalyst has a large amount of precious metal and a low catalyst utilization rate in the prior art. , low catalytic activity and other technical problems, the prepared composite material has good catalytic activity, stability and methanol tolerance, can be used as a fuel cell cathode oxygen reduction catalyst, and the preparation process is simple to operate.

The object of the present invention is achieved through the following technical solutions:

A preparation method of a nitrogen-phosphorus co-doped FeW/N,P-C composite material derived from phytic acid, the preparation method specifically comprises the following steps:

(a) take the acidic solution A containing aniline, phytic acid and tungsten source and the acidic solution B containing ammonium persulfate and iron source, add the acidic solution B dropwise to the acidic solution A to react, and obtain FeW/N through post-processing , P-C precursor, the FeW/N, P-C precursor is dark green. Among them, aniline can be used as carbon source and nitrogen source at the same time, phytic acid can be used as carbon source and phosphorus source at the same time, aniline and phytic acid together form a carbon carrier, and ammonium persulfate can be used as an initiator to induce the occurrence of aniline self-polymerization reaction;

(b) The FeW/N,P-C precursor obtained in step (a) is mixed uniformly with NaCl and KCl, and the FeW/N,P-C composite material is obtained by one annealing, pickling and second annealing in sequence.

In step (a), the acidic solution A is prepared by H ₂ SO ₄ solution with a concentration of 0.5M and ultrapure water in a volume ratio of 1:(0.5-1), the volume is 15-30 mL, and contains aniline, phytochemicals acid and tungsten sources;

The acidic solution B is prepared from H ₂ SO ₄ with a concentration of 0.5M and ultrapure water in a volume ratio of 1:(0.5-1), and contains ammonium persulfate and iron source. The purpose of using an acidic solution is that aniline has better conductivity when polymerized under acidic conditions.

In step (a), phosphotungstic acid is used as the tungsten source, and iron acetylacetonate is used as the iron source, and these two organic compounds are more easily reacted with aniline and phytic acid as the tungsten source and the iron source.

In step (a), the molar ratio of aniline, phytic acid, ammonium persulfate and iron source is (1-2):(0.1-0.3):(0.5-1):(0.01-0.1), preferably 1:0.125 : 0.75: 0.05, and the molar ratio of the iron source to the tungsten source is (20-40): 1, preferably 20: 1.

In step (a), the initial temperature of the reaction is 0-5°C, preferably 0°C, an ice-water bath can be used in the initial stage of the reaction, and after the low-temperature reaction for 1-4h (preferably 2h), the temperature is raised to room temperature and the reaction is continued for 20-24h, preferably For 22h, the reaction was carried out while stirring. The aniline self-polymerization reaction is induced at a low temperature first, and the initial reaction rate is controlled to effectively adjust the reaction process, and then the temperature is raised to room temperature to accelerate the reaction.

In the step (a), the post-processing process is specifically as follows: the reaction solution after the reaction is subjected to suction filtration, the obtained filter residue is washed with water to neutrality, then washed with an organic solvent for several times, and then vacuum-dried, and the drying temperature is 50-70°C, preferably 60°C, and the drying time is 10-12h, preferably 10h.

In step (b), the mass ratio of FeW/N, P-C precursor, NaCl and KCl is 1:(5-20):(5-20), preferably 1:10:10. As template compounds, NaCl and KCl gradually melt into liquid state with the increase of temperature during the annealing process, so that the carbonization reaction of each part of the composite material is complete at high temperature.

In step (b), the temperature of one annealing is 800-950°C, preferably 850°C, the time of one annealing is 1-4h, preferably 2h, and the heating rate is 1-5°C/min, preferably 3°C/min , annealing process in an inert atmosphere

and then cooled to room temperature naturally. The inert atmosphere can be nitrogen or argon, which does not react with the catalyst as a protective gas. If the annealing temperature is low, the degree of graphitization of the material is poor, and the conductivity of the material is not good; if the annealing temperature is too high, the material will collapse to a certain extent and the active sites will aggregate, which will affect the overall performance of the material, including catalytic performance.

In step (b), the pickling process is specifically as follows: dispersing the intermediate product after one annealing in a H ₂ SO ₄ solution with a concentration of 0.5M, and stirring at 50-80° C. (preferably 60° C.) for 10-12 h (preferably 12h), then suction filtration to obtain the filter residue, the filter residue is washed with water until neutral, and washed several times with an organic solvent, and then vacuum dried at 50-70°C (preferably 60°C) for 10-12h, preferably 10h. Pickling can remove nanoparticles, clusters and excess NaCl and KCl compounds aggregated at high temperature.

In step (b), the temperature of the secondary annealing is 800-950°C, preferably 850°C, the secondary annealing time is 1-4h, preferably 2h, and the heating rate is 1-5°C/min, preferably 5°C /min, the annealing process was carried out in an inert atmosphere, and then naturally cooled to room temperature. The inert atmosphere can be nitrogen or argon. As a protective gas, it does not react with the composite material. Pickling will destroy the structure of the carbon skeleton, and the secondary annealing treatment stabilizes the carbon skeleton.

A FeW/N,PC composite material prepared by the above-mentioned preparation method and prepared by phytic acid-derived nitrogen and phosphorus co-doped, the FeW/N,PC composite material has a porous lamellar structure, and the pore volume is 0.693 cm ³ /g, the specific surface area was 737.93 m ² /g. The FeW/N,PC composites contain nitrogen-phosphorus co-doped carbon supports and Fe and W supported on the carbon supports in the form of highly dispersed atoms.

A kind of FeW/N, P-C composite material with nitrogen and phosphorus co-doped from phytic acid as described above is used in fuel cell, the composite material can catalyze 4e-oxygen reduction reaction efficiently, and has good catalytic activity , stability and methanol tolerance, can be used as a fuel cell cathode oxygen reduction catalyst.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention increases the density of active sites by precisely controlling the coordination environment and/or the pore volume of the structure, and prepares a nitrogen-phosphorus-doped FeW/N, PC sheet-like composite material, which can promote O ₂ and The diffusion of water, the transport of protons, and the transfer of electrons in the carbon skeleton can improve the catalytic performance. The composite material has high catalytic activity, good stability and methanol tolerance, exhibits excellent catalytic activity for ORR, and can be used as a cathode material for fuel cells.

2. Compared with commercial Pt-based catalysts, the ORR catalytic activity of the FeW/N,P-C composites of the present invention in alkaline medium exceeds that of commercial 20% Pt/C catalysts, and has higher stability and methanol resistance. .

3. The raw materials used in the present invention are low in price, rich in sources, simple in preparation process, favorable for large-scale production, and have high practical value.

4. The catalyst of the present invention can overcome the technical problems of the traditional Pt/C catalyst, such as large amount of precious metal, low catalyst utilization efficiency and low catalytic activity.

Description of drawings

Fig. 1 is the transmission electron microscope (TEM) of FeW/N, P-C composite material prepared in Example 1;

Fig. 2 is the XRD pattern of FeW/N, P-C composite material prepared in Example 1;

Fig. 3 is the XPS diagram of FeW/N, P-C composite material prepared in Example 1;

Fig. 4 is the linear polarization curve test comparison diagram of the catalysts of Example 1, Comparative Example 1 and Comparative Example 2 in 0.1M KOH solution;

Fig. 5 is a chronoamperometry comparison diagram of the catalysts of Example 1 and Comparative Example 1 in 0.1M KOH solution;

FIG. 6 is a comparison chart of the methanol tolerance test of the catalysts of Example 1 and Comparative Example 1 in 0.1M KOH solution.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

A nitrogen and phosphorus co-doped FeW/N, P-C composite material derived from phytic acid, the composite material has a porous sheet-like structure, and is prepared by the following steps:

(1) Preparation of FeW/N, P-C precursors

2mmol of aniline, 0.25mmol of phytic acid and 0.0025mmol of phosphotungstic acid were uniformly dissolved and dispersed in 20mL of acidic solution (the H ₂ SO ₄ solution with a concentration of 0.5M and ultrapure water in a volume ratio of 1:1), denoted as solution A; 1.5mmol of ammonium persulfate and 0.05mmol of ferric acetylacetonate are uniformly dissolved and dispersed in an acidic solution (a 0.5M H ₂ SO ₄ solution and ultrapure water in a volume ratio of 1:1), which is designated as solution B. Under the reaction conditions of an ice-water bath (0°C), solution B was slowly added dropwise to solution A, and after 2 hours of reaction, the temperature was raised to room temperature and continued to stir for 20 hours. to neutrality, then washed with organic solvent for several times, and then vacuum-dried at 60 °C for 12 h to obtain dark green FeW/N, PC precursor.

(2) Preparation of FeW/N, P-C composites

According to the mass ratio of 1:10:10, take 50 mg of FeW/N obtained in step (a), and mix the PC precursor with 500 mg of NaCl and 500 mg of KCl, and then undergo post-treatment such as primary annealing, pickling, and secondary annealing in turn. During the process, FeW/N, PC composite material was obtained with a pore volume of 0.693 cm ³ /g and a specific surface area of 737.93 m ² /g. Among them: the temperature of one annealing is 850℃, the time of one annealing is 2h, the heating rate is 3℃/min, and the annealing process is carried out under inert atmosphere nitrogen as protective gas; The product was dispersed in H ₂ SO ₄ solution with a concentration of 0.5M, stirred at 60°C for 10h, and then suction filtered to obtain a filter residue. The filter residue was washed with water until neutral, washed with organic solvent for several times, and then vacuum-dried at 60°C for 12h ; The temperature of the secondary annealing is 850°C, the annealing time is 2h, the heating rate of the secondary annealing is 5°C/min, and the annealing process is carried out in an inert atmosphere of nitrogen.

The transmission electron microscope (TEM) image of the FeW/N,P-C composite material is shown in Figure 1 (the left picture is 200 nm), it can be seen that the prepared FeW/N,P-C composite material has obvious sheet-like structure, and no The existence of Fe and W nanoparticles was observed, indicating that the two elements Fe and W may not form clusters or particles, but may exist in the form of highly dispersed atoms. The small image on the right shows that the composite material is polycrystalline material, which also shows the reliability of the synthesis method of the present invention.

The XRD pattern of the FeW/N,P-C composite material is shown in Figure 3. It can be seen that no crystal particles such as Fe and W are formed in the composite material, but only the peaks of graphitized carbon, indicating that Fe and W may be doped with The form exists in the catalyst, and the material obtained is indeed FeW/N, P-C with reference to Figures 2 and 3.

The FeW/N, PC composite was used as an oxygen reduction catalyst for linear polarization test. The test conditions were as follows: KOH solution with a concentration of 0.1M was used. 1600rpm (the same below), the results are shown in Figure 4, it can be seen that the initial potential of FeW/N, PC composite material is 0.995V (vs.RHE), the half-wave potential is 0.877V (vs.RHE), The limiting current density at 0.85V is -3.36mA cm ^-2 .

The FeW/N, PC composite material was tested by chronoamperometry, and the test conditions were as follows: in a solution with a concentration of 0.1M KOH saturated with _O2 , the test parameters were -0.15V, the rotating speed was 1600rpm, and the test time was 50000s (the same below). ), the results are shown in Figure 5. It can be seen that the stability of FeW/N, PC composites gradually decreases with the passage of test time, but the rate of decline is very slow. After 50000s test, FeW/N, PC The composite material can maintain 93.92% of the initial current density.

The FeW/N, PC composites were tested for methanol resistance. The test conditions were as follows: KOH solution with a concentration of 0.1M saturated with O ₂ was used, the test parameters were -0.15V, the rotation speed was 1600rpm, and the test time was 5000s. At the beginning of the test for 1000s, 3M methanol (the same below) was rapidly added to the KOH solution. The results are shown in Figure 6. It can be seen that after the addition of methanol, the current of FeW/N, PC composites only changed slightly .

Comparative Example 1

A commercial catalyst JM 20%Pt/C, purchased from Johnson-Matthery, was tested for its linear polarization curve in an alkaline solution. The results are shown in Figure 4. It can be seen that JM 20%Pt/C The initial potential of : 0.990V; the half-wave potential: 0.861V; the limiting current density at 0.85V: -3.01mAcm ^-2 . Chronoamperometry was performed on the commercial catalyst, and the results are shown in Figure 5. It can be seen that the stability of JM20%Pt/C gradually decreases with the passage of test time, but the rate of decline is very fast. The current density of JM20%Pt/C remains only 44.57% of the initial current density. The methanol resistance test of the commercial catalyst is carried out, and the results are shown in Figure 6. It can be seen that after adding methanol, the current of the JM 20% Pt/C catalyst has an obvious change, that is, the JM 20% Pt/C catalyst contains methanol. Violent oxidation reaction occurred in the alkaline solution.

Figure 4 shows that the prepared FeW/N,P-C composites have high catalytic activity for the oxygen reduction reaction, which is comparable to that of commercial catalysts.

It can be seen in Fig. 5 that the current decay rate of FeW/N,P-C composite is significantly slower than that of commercial JM 20%Pt/C, indicating that the stability of FeW/N,P-C composite under the above conditions is much better than that of commercial JM 20% Pt/C.

Figure 6 illustrates that the methanol tolerance of FeW/N,P-C composite is better than that of JM 20%Pt/C catalyst.

To sum up, the present invention provides a method for preparing a FeW/N,P-C composite material derived from phytic acid, which is co-doped with nitrogen and phosphorus. The process exhibits significantly enhanced electrochemical performance.

Comparative Example 2

A nitrogen-doped FeW/NC composite material was prepared by the same steps as in Example 1 except that phytic acid was not added during the preparation process. The linear polarization curve test in alkaline solution was carried out. The results are shown in Figure 4. It can be seen that the initial potential of FeW/NC composite material: 0.893V; half-wave potential: 0.799V; at 0.85V Time limiting current density: -0.50mAcm ^-2 . Figure 4 can illustrate that the prepared FeW/N, PC composites have higher catalytic activity than FeW/NC composites.

Example 2

A nitrogen and phosphorus co-doped FeW/N, P-C composite material derived from phytic acid, the composite material has a porous sheet-like structure, and is prepared by the following steps:

(1) Preparation of FeW/N, P-C precursors

1mmol of aniline, 0.1mmol of phytic acid and 0.0005mmol of phosphotungstic acid were uniformly dissolved and dispersed in 20mL of acidic solution (the H ₂ SO ₄ solution with a concentration of 0.5M and ultrapure water in a volume ratio of 1:0.5), denoted as solution A; 0.5 mmol ammonium persulfate and 0.01 mmol iron acetylacetonate are uniformly dissolved and dispersed in an acidic solution (from H ₂ SO ₄ solution with a concentration of 0.5 M to ultrapure water in a volume ratio of 1:0.5), which is designated as solution B. Under the reaction conditions of 5 °C, solution B was slowly added dropwise to solution A. After reacting for 1 hour, the temperature was raised to room temperature and the reaction was continued for 20 hours. After that, it was washed several times with an organic solvent, and then vacuum-dried at 50 °C for 12 h to obtain a dark green FeW/N, PC precursor.

(2) Preparation of FeW/N, P-C composites

According to the mass ratio of 1:5:5, take 50 mg of FeW/N obtained in step (a), and mix the PC precursor with 250 mg of NaCl and 250 mg of KCl, and then undergo post-processing such as primary annealing, pickling, and secondary annealing in turn. process to obtain FeW/N, PC composites. Among them: the temperature of one annealing is 800℃, the time of one annealing is 4h, the heating rate is 3℃/min, and the annealing process is carried out under inert atmosphere nitrogen as protective gas; The product was dispersed in H ₂ SO ₄ solution with a concentration of 0.5M, stirred at 80°C for 10h, and then suction filtered to obtain a filter residue. The filter residue was washed with water until neutral, washed with organic solvent for several times, and then vacuum-dried at 70°C for 10h ; The temperature of the secondary annealing is 800°C, the annealing time is 4h, the heating rate of the secondary annealing is 5°C/min, and the annealing process is carried out in an inert atmosphere nitrogen.

Example 3

A nitrogen and phosphorus co-doped FeW/N, P-C composite material derived from phytic acid, the composite material has a porous sheet-like structure, and is prepared by the following steps:

(1) Preparation of FeW/N, P-C precursors

2mmol of aniline, 0.3mmol of phytic acid and 0.0025mmol of phosphotungstic acid were uniformly dissolved and dispersed in 20mL of acidic solution (the H ₂ SO ₄ solution with a concentration of 0.5M and ultrapure water in a volume ratio of 1:0.75), denoted as solution A; 1 mmol ammonium persulfate and 0.1 mmol ferric acetylacetonate are uniformly dissolved and dispersed in an acidic solution (a 0.5 M H ₂ SO ₄ solution and ultrapure water in a volume ratio of 1:0.75), which is designated as solution B. Under the reaction conditions of an ice-water bath (0°C), solution B was slowly added dropwise to solution A, and after 4 hours of reaction, the temperature was raised to room temperature and the reaction was continued for 24 hours. to neutrality, then washed with organic solvent for several times, and then vacuum-dried at 70 °C for 10 h to obtain a dark green FeW/N, PC precursor.

(2) Preparation of FeW/N, P-C composites

According to the mass ratio of 1:20:20, take 50 mg of FeW/N obtained in step (a), the PC precursor is mixed with 1000 mg of NaCl and 1000 mg of KCl, and then undergoes a post-treatment such as annealing, pickling, and secondary annealing. process to obtain FeW/N, PC composites. Among them: the temperature of one annealing is 950℃, the time of one annealing is 1h, the heating rate is 3℃/min, and the annealing process is carried out in an inert atmosphere with argon as protective gas; The intermediate product was dispersed in H ₂ SO ₄ solution with a concentration of 0.5M, stirred at 50 °C for 12 h, and then suction filtered to obtain a filter residue. The filter residue was washed with water until neutral, washed with organic solvent for several times, and then vacuum-dried at 50 °C 10h; the temperature of the secondary annealing is 950°C, the annealing time is 1h, the heating rate of the secondary annealing is 5°C/min, and the annealing process is carried out in an inert atmosphere of argon.

The foregoing description of the embodiments is provided to facilitate understanding and use of the invention by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (8)

1. a preparation method of FeW/N, P-C composite material by phytic acid-derived nitrogen and phosphorus co-doped, is characterized in that, described preparation method specifically comprises the following steps: (a) take the acidic solution A containing aniline, phytic acid and tungsten source and the acidic solution B containing ammonium persulfate and iron source, add the acidic solution B dropwise to the acidic solution A for reaction, and obtain FeW/N through post-processing , P-C precursor; (b) Take the FeW/N, P-C precursor obtained in step (a) and mix it with NaCl and KCl uniformly, and then undergo one annealing, pickling and second annealing in turn to obtain FeW/N, P-C composite material, the FeW/N , The P-C composite material has a porous lamellar structure, and the FeW/N, P-C composite material comprises a carbon support co-doped with nitrogen and phosphorus, and Fe and W supported on the carbon support and in the form of highly dispersed atoms; In step (a), the acidic solution A is prepared from H ₂ SO ₄ solution with a concentration of 0.5 M and ultrapure water in a volume ratio of 1:(0.5-1), and contains aniline, phytic acid and tungsten source; The acidic solution B is prepared from H ₂ SO ₄ with a concentration of 0.5 M and ultrapure water in a volume ratio of 1: (0.5-1), and contains ammonium persulfate and iron source; In step (a), the tungsten source adopts phosphotungstic acid, and the iron source adopts iron acetylacetonate; The molar ratio of aniline, phytic acid, ammonium persulfate and iron source is (1-2):(0.1-0.3):(0.5-1):(0.01-0.1), and the molar ratio of iron source and tungsten source is (20 -40):1. 2. a kind of preparation method of FeW/N, P-C composite material by phytic acid-derived nitrogen and phosphorus co-doped according to claim 1, is characterized in that, in step (a), the initial temperature of reaction is 0- After reacting at 5°C for 1-4 hours at a low temperature, the temperature was raised to room temperature and the reaction was continued for 20-24 hours, and stirring was carried out during the reaction. 3. a kind of preparation method of FeW/N, P-C composite material by the nitrogen and phosphorus co-doped of phytic acid-derived according to claim 1, is characterized in that, in step (a), described post-processing process is specifically: : Perform suction filtration on the reaction solution after the reaction is completed, and the obtained filter residue is washed with water until neutral, then washed with organic solvent for several times, and then dried in vacuum. The drying temperature is 50-70 ℃, and the drying time is 10-12h. 4. the preparation method of a kind of FeW/N, P-C composite material by the nitrogen and phosphorus co-doped of phytic acid-derived according to claim 1, is characterized in that, in step (b), FeW/N, P-C precursor The mass ratio of , NaCl and KCl is 1:(5-20):(5-20). 5. a kind of preparation method of FeW/N, P-C composite material by phytic acid-derived nitrogen and phosphorus co-doped according to claim 1, is characterized in that, in step (b), the temperature of one annealing is 800- 950℃, the time of one annealing is 1-4 h, the annealing process is carried out in an inert atmosphere, and then naturally cooled to room temperature; In step (b), the temperature of the secondary annealing is 800-950° C., the time of the secondary annealing is 1-4 h, and the annealing process is carried out in an inert atmosphere, and then naturally cooled to room temperature. 6. the preparation method of a kind of FeW/N, PC composite material by phytic acid-derived nitrogen and phosphorus co-doped according to claim 1, is characterized in that, in step (b), the pickling process is specially: The intermediate product after one annealing was dispersed in a H ₂ SO ₄ solution with a concentration of 0.5 M, stirred at 50-80 °C for 10-12 h, and then suction filtered to obtain a filter residue, which was washed with water until neutral, and washed with an organic solvent several times, and then vacuum-dried at 50-70 °C for 10-12 h. 7. a FeW/N, P-C composite material prepared by the preparation method of any one of claims 1-6 by phytic acid-derived nitrogen and phosphorus co-doped, is characterized in that, the FeW/N, The P-C composite has a porous lamellar structure. 8. The application of the FeW/N,P-C composite material of phytic acid-derived nitrogen-phosphorus co-doped FeW/N,P-C in a fuel cell as claimed in claim 7.

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