High-activity / stability nitrogen-phosphorus-modified platinum-based fuel cell catalyst and preparation method therefor

Abstract

Disclosed in the present invention are a high-activity / stability nitrogen-phosphorus-modified platinum-based fuel cell catalyst and a preparation method therefor. The method comprises: dissolving a platinum source and a transition metal source compound in water or a water-alcohol mixed solvent, and subjecting the mixture to an ultrasonic treatment to obtain a metal precursor solution; impregnating a pretreated carbon carrier with the metal precursor solution, and performing an ultrasonic treatment and drying thereon; then, impregnating the carbon carrier containing a metal precursor with a solution containing a nitrogen source and a phosphorus source to obtain a carbon carrier containing nitrogen, phosphorus and the metal precursor; and subjecting same to freeze drying, and then reducing same in a high-temperature reducing atmosphere to obtain a nitrogen-phosphorus-modified platinum-based carbon catalyst or a platinum-based intermetallic compound catalyst. The activity and durability of the nitrogen-phosphorus-modified platinum-cobalt intermetallic compound catalyst are higher than those of an unmodified catalyst by several times. A nitrogen-phosphorus modification method provided in the present invention has important significance for improving the activity and durability of the current fuel cell catalyst.

Description

A high-activity / stable nitrogen-phosphorus-modified platinum-based fuel cell catalyst and its preparation method Technical Field

[0001] The present invention belongs to the technical field of new energy materials, and specifically relates to a high-activity and high-stability nitrogen-phosphorus modified carbon-supported platinum-based metal catalyst and a preparation method thereof. Background Art

[0002] Catalysts are one of the most core materials of fuel cells and play a decisive role in the performance of fuel cells. Developing high-performance fuel cell catalysts, reducing the use of precious metal platinum, and improving the performance of fuel cells have always been the most important research topics in the fuel cell field.

[0003] Currently, the most widely used fuel cell catalysts are carbon-supported platinum catalysts (Pt / C) or carbon-supported platinum alloy catalysts (such as PtRu / C), which use conductive carbon black as a carrier and platinum as an important active component. The activity and durability of the catalysts are in urgent need of improvement. In recent years, the platinum-based intermetallic compound low-platinum catalysts (such as Umicore's Pt3Co / C catalyst) developed have significantly improved the platinum mass activity compared to JM Pt / C catalysts, and the amount of platinum used has also been reduced accordingly. However, with the rapid development of fuel cell technology and the continuous improvement of cost and performance requirements, the activity and durability of current catalysts still need to be greatly improved. The development of fuel cell cathode oxygen reduction catalysts with higher activity and stability remains an important research topic in the fuel cell field.

[0004] To improve the activity and stability of catalysts, elemental modification has been widely studied. Chinese invention patent CN201110421469.9 reports the preparation and application of a Pt / Au / PdCo / C catalyst. The applicant discovered that Au-modified PtPdCo / C significantly improved its activity and stability. However, using expensive gold-modified catalysts further increases catalyst costs, and the modification effect also falls short of expectations.

[0005] Chinese invention patent CN201310410537.0 proposes a method for modifying a Pt / C catalyst with polyaniline. The polyaniline modification effectively improves the stability and durability of the catalyst. However, this modification method does not improve the activity of the catalyst, but instead results in a certain degree of decrease in activity.

[0006] Although element modification can improve the activity or stability of catalysts, the currently reported element modification methods or modified platinum-based catalysts cannot meet the requirements of the commercialization of proton exchange membrane fuel cells for continuously improving catalyst performance.

[0007] Summary of the Invention

[0008] The present invention aims to provide a type of high-activity / stability nitrogen-phosphorus modified platinum-based fuel cell catalyst and a preparation method thereof. The method first adopts impregnation of a metal precursor solution and a nitrogen-phosphorus precursor solution on a carbon support, freeze-drying to obtain a dry carbon support material containing nitrogen, phosphorus and metal precursors, and then high-temperature heat treatment under a reducing atmosphere to obtain a high-activity / stability nitrogen-phosphorus modified platinum-based and platinum-based intermetallic compound fuel cell catalyst. The nitrogen-phosphorus modification method can also be directly used to modify carbon-supported platinum or carbon-supported platinum-based intermetallic compound catalyst. The platinum-carbon or intermetallic compound catalyst is impregnated with a nitrogen-phosphorus precursor solution, freeze-dried, and then high-temperature heat treatment is performed in a reducing atmosphere to obtain a high-performance nitrogen-phosphorus modified platinum-based or platinum-based intermetallic compound catalyst.

[0009] The technical solutions for achieving the purpose of the present invention are as follows:

[0010] A preparation method and application of a highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst, comprising the following steps:

[0011] The following steps are involved:

[0012] (1) dissolving a platinum source compound and a transition metal source compound in water or a water-alcohol mixed solvent to obtain a metal precursor solution; dissolving a phosphorus-containing compound and a nitrogen-containing compound in a solvent to obtain a nitrogen-phosphorus precursor solution;

[0013] (2) impregnating the pretreated carbon support with the metal precursor solution obtained in step (1), and ultrasonically impregnating the precursor evenly into the carbon support to obtain carbon containing the metal precursor; after drying, impregnating the carbon support with the nitrogen and phosphorus solution prepared in step (1) for a second time;

[0014] (3) drying the carbon support containing nitrogen, phosphorus and metal precursors obtained in step (2) to obtain a dried carbon support containing nitrogen, phosphorus and metal precursors;

[0015] (4) placing the dried carbon support containing nitrogen, phosphorus and metal precursors obtained in step (3) in a tubular furnace in a reducing atmosphere and subjecting it to high-temperature thermal reduction to obtain a nitrogen-phosphorus modified platinum-based intermetallic compound;

[0016] (5) In parallel, a nitrogen-phosphorus-modified platinum-based catalyst can also be prepared by directly using the nitrogen-phosphorus precursor solution prepared in step (1) to impregnate a carbon-supported platinum catalyst (Pt / C) or a carbon-supported platinum-cobalt intermetallic compound catalyst (PtCo / C), followed by drying and high-temperature heat treatment in a reducing atmosphere.

[0017] In the present invention, a platinum-carbon catalyst or a carbon-supported platinum-cobalt intermetallic compound catalyst is directly impregnated with a solution containing nitrogen and phosphorus compounds. After freeze-drying and high-temperature treatment under a reducing atmosphere, the performance of the obtained nitrogen-phosphorus-modified platinum-carbon and platinum-cobalt intermetallic compound catalysts is also improved exponentially.

[0018] Preferably, in step (1), the platinum source is an inorganic platinum salt or an organic platinum salt, the transition metal is an inorganic compound or an organic compound containing one or more of Co, Ni, Cu, Mn and Fe, and the molar ratio of platinum to transition metal is in the range of 3-1.

[0019] Preferably, in step (1), the platinum source is one or more of chloroplatinic acid, potassium chloroplatinate, potassium chloroplatinite or platinum acetylacetonate; and the transition metal source is one or more of chloride, nitrate, acetate and acetylacetonate.

[0020] Preferably, the nitrogen-containing compound is any one selected from 2-methylimidazole, melamine, dopamine, and ammonium bicarbonate; the mass percentage of nitrogen to catalyst is 0.5-2wt%; the phosphorus-containing compound is any one selected from diamine hydrogen phosphate, ammonium dihydrogen phosphate, phosphoric acid, ammonium phosphite, ammonium hypophosphite, and organic phosphate, and the mass percentage of phosphorus to catalyst is 1-8wt%.

[0021] Preferably, in step (1), the alcohol comprises ethanol, n-propanol and isopropanol, the volume ratio of water to alcohol is 1:3 to 3:1, and the solution concentration is 10-30 wt%.

[0022] Preferably, in step (2), the carbon carrier is one of XC-72R carbon black (Cabot, USA), Ketjen Black (Ketjen, Japan), and Black Pearls (Cabot, USA); and the carbon carrier pretreatment method is heat treatment at 300°C for 3 hours.

[0023] Preferably, in step (2), the ultrasonic time is 30-60 min.

[0024] Preferably, the drying in step (3) includes freeze drying and vacuum drying, the preferred method is freeze drying, and the drying time ranges from 10 to 16 hours.

[0025] Preferably, in step (4), the reducing atmosphere is any one of H2 / Ar, H2 / N2, H2 / He mixed gas, and ammonia; the heat treatment temperature is 650-850°C, and the time is 1-4h.

[0026] Preferably, in step (5), the Pt / C catalyst is one of the commercial Pt / C catalysts, and the PtCo / C catalyst is the Pt3Co / C catalyst from Umicore; and the heat treatment temperature in the reducing atmosphere is 300-800°C.

[0027] The present invention also provides the use of the high-activity / stability nitrogen-phosphorus modified platinum-based fuel cell catalyst prepared by the above preparation method in fuel cell cathode oxygen reduction.

[0028] Compared with existing catalysts and modification technologies, the present invention has the following advantages:

[0029] (1) The activity and stability of the nitrogen-phosphorus modified catalyst prepared by the present invention can be significantly improved at the same time, or the improvement can be several times; it is expected to achieve a significant improvement in the performance of fuel cell catalysts and has great practical application prospects;

[0030] (2) The method proposed in the present invention does not require the use of expensive reagents and complex equipment, the process is simple, and the modification effect is extremely significant. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is an XRD diagram of the PtCo / C and NP-PtCo / C intermetallic compounds prepared in Comparative Example 1 and Example 3.

[0032] FIG2 is a polarization curve diagram of the PtCo / C and NP-PtCo / C intermetallic compounds prepared in Comparative Example 1 and Example 3 before and after the oxygen reduction stability test.

[0033] FIG3 is a polarization curve diagram of NP-JM Pt / C and JM Pt / C prepared in Example 6 before and after the oxygen reduction stability test.

[0034] FIG4 is a polarization curve diagram of NP-Umicore PtCo / C and Umicore PtCo / C prepared in Example 7 before and after the oxygen reduction stability test. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to the accompanying drawings and specific examples. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are commercially available unless otherwise specified.

[0036] Comparative Example 1

[0037] Chloroplatinic acid and cobalt chloride were dissolved in a water-alcohol mixed solvent (water: ethanol = 4:1 (volume ratio)) to obtain a metal precursor solution. The concentrations of chloroplatinic acid and cobalt chloride were both 0.386 mol L -1265 μL of chloroplatinic acid solution and 265 μL of cobalt chloride solution were ultrasonically mixed and then added dropwise to 80 mg of pretreated Ketjen Black. After ultrasonication for 60 minutes, the mixture was freeze-dried for 12 hours. The dried product was calcined at 750°C in an H2 / Ar atmosphere (H2 volume fraction range: 8%) for 2 hours to obtain the Pt1Co1 / C intermetallic compound fuel cell catalyst.

[0038] Example 1

[0039] Chloroplatinic acid and cobalt chloride were dissolved in a water-alcohol mixed solvent (water: ethanol = 4:1 (volume ratio)) to obtain a metal precursor solution. The concentrations of chloroplatinic acid and cobalt chloride were both 0.386 mol L -1 Take 265uL of the solution with a concentration of 0.386mol L -1 Chloroplatinic acid and 265 μL of 0.386 mol L -1 After the cobalt chloride solution was ultrasonically mixed, it was evenly added drop by drop into 80 mg of pretreated Ketjen black, ultrasonicated for 30 min, and then 500 μL of 440 mg mL -1 A 2-methylimidazole solution was added dropwise to a carbon support containing a metal precursor solution, ultrasonicated for 30 minutes, and freeze-dried for 12 hours. The dried product was calcined at 750°C for 2 hours in a H2 / Ar atmosphere (H2 volume fraction range: 8%) to obtain an N-Pt1Co1 / C intermetallic compound fuel cell catalyst.

[0040] Example 2

[0041] In addition to using 22.5uL 92mg mL -1 The other steps and methods were the same as those in Example 1, except that the 500 μL 440 mg mL −1 2-methylimidazole solution in Example 1 was replaced with the ammonium dihydrogen phosphate solution. The obtained catalyst was a phosphorus-modified platinum-cobalt intermetallic compound catalyst (P-Pt1Co1 / C).

[0042] Example 3

[0043] Chloroplatinic acid and cobalt chloride were dissolved in a water-alcohol mixed solvent (water: ethanol = 4:1 (volume ratio)) to obtain a metal precursor solution. The concentrations of chloroplatinic acid and cobalt chloride were both 0.386 mol L -1 Take 265uL of chloroplatinic acid and 265uL of cobalt chloride solution and mix them evenly by ultrasonic. Then add them drop by drop evenly into 80mg of pretreated Ketjen black. Ultrasonicate for 30min. Then add 500uL of 440mg mL -1 2-Methylimidazole solution with 22.5 μL of 92 mg mL -1After ultrasonic mixing, the ammonium dihydrogen phosphate solution was added dropwise to the carbon support containing the metal precursor solution. After ultrasonication for 30 minutes, the product was freeze-dried for 12 hours. The dried product was calcined at 750°C for 2 hours in a H2 / Ar atmosphere (H2 volume fraction range of 8%) to obtain the NP-Pt1Co1 / C intermetallic compound fuel cell catalyst.

[0044] Example 4

[0045] Chloroplatinic acid and cobalt chloride were dissolved in a water-alcohol mixed solvent (water: ethanol = 4:1 (volume ratio)) to obtain a metal precursor solution. The concentrations of chloroplatinic acid and cobalt chloride were both 0.386 mol L -1 Take 275uL of chloroplatinic acid and 91.8uL of cobalt chloride solution and mix them evenly by ultrasonic. Then add them drop by drop evenly into the pretreated XC-72R, Ketjen Black or Black pearls Carbon. Ultrasonicate for 30 minutes. Then add 500uL of 440mg mL -1 2-Methylimidazole solution with 22.5 μL of 92 mg mL -1 A solution of ammonium dihydrogen phosphate (20 vol% isopropanol + 80 vol% water) was ultrasonically mixed and then added dropwise to the carbon support containing the metal precursor solution. After ultrasonication for 30 minutes, the solution was freeze-dried. The dried product was calcined at 750°C for 2 hours in an H2 / Ar atmosphere (H2 volume fraction range: 8%) to obtain the NP-Pt3Co / C intermetallic compound fuel cell catalyst.

[0046] Example 5

[0047] Tetraammine dichloroplatinum, cobalt acetate, and ferrous chloride were dissolved in dehydrated alcohol solvent (water: isopropanol = 3:2 (volume ratio) to obtain a metal precursor solution. The concentrations of chloroplatinic acid, cobalt chloride, and ferrous chloride were all 0.386 mol L-1. 265 uL of chloroplatinic acid, 84.8 uL of cobalt chloride, and 21.2 uL of ferrous chloride solution were ultrasonically mixed and then evenly added dropwise to 80 mg of pretreated XC-72R carbon black. Ultrasonication was performed for 30 minutes, and then 500 uL of 440 mg mL -1 2-Methylimidazole solution with 22.5 μL of 92 mg mL -1 The ammonium dihydrogen phosphate solution was ultrasonically mixed and then added dropwise to the carbon support containing the metal precursor solution. After ultrasonication for 30 minutes, it was further freeze-dried. The dried product was calcined at 750 ° C for 2 hours in a H2 / N2 atmosphere (the volume fraction of H2 was 10%) to obtain NP-PtCo 0.8 Fe 0.2 / C intermetallic compound fuel cell catalyst.

[0048] Example 6

[0049] 500 μL of 440 mg mL -1 2-Methylimidazole solution (solvent is aqueous solution containing 20% ​​ethanol) and 22.5uL of 92mg mL -1 After ultrasonic mixing, a solution of ammonium dihydrogen phosphate (ADP) was added dropwise to 100 mg of JM Pt / C (Hispec 3000, 20 wt%) catalyst. After ultrasonication for 30 minutes, the mixture was freeze-dried for 12 hours. The dried product was calcined at 750°C for 2 hours in a H2 / He atmosphere (H2 volume fraction range: 10%) to obtain the NP-JM Pt / C intermetallic fuel cell catalyst.

[0050] Example 7

[0051] 500 μL of 440 mg mL -1 2-Methylimidazole solution with 22.5 μL of 92 mg mL -1 After ultrasonic mixing, the ammonium dihydrogen phosphate solution was added dropwise to 100 mg of Umicore PtCo / C (Pt30-0690, 30 wt%) catalyst. After ultrasonication for 30 minutes, the catalyst was freeze-dried for 12 hours. The dried product was calcined at 750°C for 2 hours in a H2 / Ar atmosphere (H2 volume fraction range: 10%) to obtain the NP-Umicore PtCo / C intermetallic compound fuel cell catalyst.

[0052] Example 8

[0053] The performance of the catalyst was studied using a three-electrode system. A glassy carbon electrode with a diameter of 5 mm was used as the working electrode, a carbon rod was used as the counter electrode, and the sodium chloride concentration was 3 mol L -1 The Ag / AgCl electrode was used as the reference electrode.

[0054] Working electrode preparation method: Weigh 4 mg of the catalyst material prepared in each example and disperse it into a mixed solution of 400 μL of 0.5 wt% Nafion solution (solvent is isopropanol) and 400 μL of deionized water. After ultrasonic dispersion, use a pipette to transfer 5 μL of catalyst slurry and drop it on the surface of the glassy carbon electrode. After natural drying, test its oxygen reduction catalytic activity in an oxygen-saturated 0.1 M HClO4 solution.

[0055] FIG1 is the XRD test result of the catalyst; FIG2 to FIG5 are the results of the oxygen reduction activity and durability test of the catalyst.

[0056] The XRD comparison diagrams of the PtCo / C and NP-PtCo / C intermetallic compound catalysts prepared in Comparative Example 1 and Example 1 are shown in Figure 1. It can be seen that the XRD spectra of the PtCo / C and NP-PtCo / C catalysts perfectly match the PDF#43-1358 card of the standard ordered PtCo, that is, this method can effectively prepare ordered PtCo intermetallic compounds.

[0057] Figure 2 shows the oxygen reduction curves of PtCo / C and NP-PtCo / C intermetallic compound catalysts prepared in Comparative Example 1 and Example 3, as well as the polarization curves before and after the catalytic stability test. The half-wave potential and mass activity of the nitrogen-phosphorus modified NP-PtCo / C catalyst are 0.969 V vs. RHE and 1.82 A mg, respectively. Pt -1 The half-wave potential and mass activity of the unmodified PtCo / C intermetallic compound catalyst are 0.914 V vs. RHE and 0.38 A mg Pt -1 ; The mass activity increased 5 times after nitrogen and phosphorus modification.

[0058] After 5000 cycles of cycling stability testing, the half-wave potential of the PtCo / C intermetallic compound catalyst was 0.900 V vs. RHE, a decrease of 14 mV, while the half-wave potential of the NP-PtCo / C intermetallic compound catalyst was 0.966 V vs. RHE, a decrease of only 3 mV. Nitrogen and phosphorus modification reduced the attenuation of the catalyst by more than 80%.

[0059] As shown in Figure 3, the half-wave potential and mass activity of the commercial Pt / C catalyst (JM Pt / C) after nitrogen and phosphorus modification are 0.916 V (vs. RHE) and 0.47 A mg Pt -1 The mass activity was 3 times that of the unmodified catalyst (0.893 V vs. RHE and 0.18 A mg Pt -1 ); after 5,000 cycles of cycling stability testing, the half-wave potential of the nitrogen-phosphorus modified catalyst (NP-JM Pt / C) was 0.913 V (vs. RHE), a decrease of only 3 mV, while the half-wave potential of the unmodified JM Pt / C was 0.864 V vs. RHE, a decrease of as much as 29 mV; the decline in the modified catalyst was reduced by 90%.

[0060] Figure 4 shows the test results of the Umicore PtCo / C catalyst and the nitrogen-phosphorus modified catalyst (NP-Umicore PtCo / C). The half-wave potential and mass activity of the nitrogen-phosphorus modified NP-Umicore PtCo / C catalyst are 0.952 V (vs. RHE) and 1.46 A mg Pt -1 The mass activity is about doubled (Umicore PtCo / C catalyst is 0.935V vs.RHE and 0.85A mg Pt -1 ); After 5000 cycles of stability testing, the half-wave potential of the NP-Umicore PtCo / C catalyst did not decrease and remained at 0.952 V (vs. RHE), while the half-wave potential of the Umicore PtCo / C was 0.916 V (vs. RHE), a decrease of 19 mV. This shows that nitrogen and phosphorus modification can significantly improve the stability of PtCo intermetallic compounds.

[0061] The half-wave potentials and initial mass specific activities of the PtCo / C, NP-PtCo / C, NP-JM Pt / C and NP-Umicore Pt / C catalysts prepared in Comparative Example 1 and several examples are shown in Table 1;

[0062] Table 1

[0063] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms should not be understood as necessarily referring to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0064] The above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst, characterized in that: The following steps are involved: (1) dissolving a platinum source compound and a transition metal source compound in water or a water-alcohol mixed solvent to obtain a metal precursor solution; dissolving a phosphorus-containing compound and a nitrogen-containing compound in a solvent to obtain a nitrogen-phosphorus precursor solution; (2) using the metal precursor solution obtained in step (1) to impregnate the pretreated carbon carrier, and ultrasonically impregnate the precursor evenly into the carbon carrier to obtain carbon containing the metal precursor; after drying, using the nitrogen and phosphorus precursor prepared in step (1) for a second impregnation; (3) drying the carbon support containing nitrogen, phosphorus and metal precursors obtained in step (2) to obtain a dried carbon support containing nitrogen, phosphorus and metal precursors; (4) placing the dried carbon support containing nitrogen, phosphorus and metal precursor obtained in step (3) in a tubular furnace in a reducing atmosphere for high-temperature thermal reduction to obtain a nitrogen-phosphorus modified platinum-based intermetallic compound; (5) In parallel, a nitrogen-phosphorus-modified platinum-based catalyst can also be prepared by directly using the nitrogen-phosphorus precursor solution prepared in step (1) to impregnate a carbon-supported platinum catalyst (Pt / C) or a carbon-supported platinum-cobalt intermetallic compound catalyst (PtCo / C), followed by drying and high-temperature heat treatment in a reducing atmosphere.

2. The method for preparing the high activity / stability nitrogen-phosphorus modified platinum-based intermetallic compound catalyst according to claim 1, characterized in that: In step (1), the platinum source is an inorganic platinum salt or an organic platinum salt, the transition metal is an inorganic compound or an organic compound containing one or more of Co, Ni, Cu, Mn and Fe, and the molar ratio of platinum to transition metal is in the range of 3-1.

3. The method for preparing the high activity / stability nitrogen-phosphorus modified platinum-based intermetallic compound catalyst according to claim 1, characterized in that: In step (1), the platinum source is one or more of chloroplatinic acid, potassium chloroplatinate, potassium chloroplatinite or platinum acetylacetonate; the transition metal source is one or more of chloride, nitrate, acetate and acetylacetonate; The nitrogen-containing compound is any one selected from 2-methylimidazole, melamine, dopamine, and ammonium bicarbonate; the mass percentage of nitrogen to the catalyst is 0.5-2wt%; the phosphorus-containing compound is any one selected from diamine hydrogen phosphate, ammonium dihydrogen phosphate, phosphoric acid, ammonium phosphite, ammonium hypophosphite and organic phosphate, and the mass percentage of phosphorus to the catalyst is 1-8wt%.

4. The method for preparing the high activity / stability nitrogen-phosphorus modified platinum-based intermetallic compound catalyst according to claim 1, characterized in that: In step (1), the alcohol includes ethanol, n-propanol and isopropanol, the volume ratio of water to alcohol is 1:3 to 3:1; and the solution concentration is 10-30wt%.

5. The method for preparing the high activity / stability nitrogen-phosphorus modified platinum-based intermetallic compound catalyst according to claim 1, characterized in that: In step (2), the carbon carrier is one of XC-72R carbon black (Cabot, USA), Ketjen black (Ketjen, Japan), and Black Pearls (Cabot, USA); the carbon carrier pretreatment method is heat treatment at 300°C for 3 hours.

6. The method for preparing the highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst according to claim 1, characterized in that: In step (2), the ultrasonic time is 30-60 min.

7. The method for preparing the highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst according to claim 1, characterized in that: The drying in step (3) includes freeze drying and vacuum drying, and the drying time ranges from 10 to 16 hours.

8. The method for preparing the highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst according to claim 1, characterized in that: In step (4), the reducing atmosphere is any one of H2 / Ar, H2 / N2, H2 / He mixed gas, and ammonia; the heat treatment temperature is 650-850°C, and the time is 1-4h.

9. The method for preparing the highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst according to claim 1, characterized in that: In step (5), the Pt / C catalyst is one of the commercial Pt / C catalysts, and the PtCo / C catalyst is the Pt3Co / C catalyst of Umicore; and the heat treatment temperature in the reducing atmosphere is 300-800°C.

10. A highly active / stable nitrogen-phosphorus modified platinum-based fuel cell catalyst prepared by the preparation method according to any one of claims 1 to 9.

Images