CN114477123B

CN114477123B - Carbon-doped material, platinum-carbon catalyst, and preparation methods and applications thereof

Info

Publication number: CN114477123B
Application number: CN202011151997.2A
Authority: CN
Inventors: 荣峻峰; 赵红; 顾贤睿; 彭茜; 张家康; 王厚朋; 谢南宏; 张云阁
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-10-26
Filing date: 2020-10-26
Publication date: 2023-09-05
Anticipated expiration: 2040-10-26
Also published as: CN114477123A

Abstract

The invention relates to a carbon-doped material, a platinum-carbon catalyst, and a preparation method and application thereof. In XPS analysis of the carbon material, a characteristic peak was found at 135.8.+ -. 0.5 ev. The platinum carbon catalyst prepared from the carbon material has excellent catalytic performance and carbon corrosion resistance when catalyzing oxygen reduction reaction.

Description

Carbon-doped material, platinum-carbon catalyst, and preparation methods and applications thereof

Technical Field

The invention relates to a carbon-doped material, a platinum-carbon catalyst, and a preparation method and application thereof. In particular to a phosphorus-doped carbon material, a platinum-carbon catalyst using the phosphorus-doped carbon material as a carrier, and a preparation method and application of the phosphorus-doped carbon material and the platinum-carbon catalyst.

Background

In the chemical field, carbon materials are both important supports and commonly used catalysts. The bonding mode of the carbon element is rich, and the carbon material can be modified in various modes so as to obtain more suitable performance.

Oxygen Reduction Reactions (ORR) are key reactions in the electrochemical field, such as in fuel cells and metal-air cells, and are a major factor affecting cell performance. The atomic doped carbon material can be used directly as a catalyst for the oxygen reduction reaction. When used as an oxygen reduction catalyst, it has been reported in the literature that elements such as nitrogen, phosphorus, boron, sulfur, fluorine, chlorine, bromine, iodine and the like are incorporated into a carbon material. Although there are many reports of carbon doped materials directly as fuel cell catalysts and some research results show better activity, there are large differences compared to platinum carbon catalysts and far from commercial applications. On the one hand, the knowledge of the combination mode of the hetero atoms and the carbon materials and the interaction between the hetero atoms and the catalysis mechanism is insufficient in the field; on the other hand, each heteroatom has multiple bonding modes with the carbon material, and multiple roles exist among the heteroatoms, so that the situation is very complex when doping multiple heteroatoms, and therefore, how to control the bonding modes of the heteroatoms and the carbon material and the interaction among the heteroatoms is a difficulty of doping atoms. In addition, such catalysts are generally not suitable for use in acidic environments, particularly Proton Exchange Membrane Fuel Cells (PEMFCs), which are important.

Up to now, the most effective oxygen reduction catalysts are platinum carbon catalysts, but for large scale commercial applications platinum carbon catalysts have been deficient. On the one hand, platinum resources are scarce and expensive, and the cost thereof is about 40% of the total cost of the fuel cell. On the other hand, the dispersion degree of platinum metal in the currently used commercial platinum-carbon catalyst is not ideal and is easy to agglomerate and deactivate, and the dissolution and agglomeration of platinum at the cathode of the hydrogen fuel cell lead to obvious reduction of the surface area of the platinum with time, thus influencing the service life of the fuel cell. The art is urgent to greatly improve the utilization rate of platinum metal, and improve the catalytic activity and stability of the platinum metal, so as to promote the large-scale commercial application of the platinum metal. Many factors and complications affect the activity and stability of the platinum carbon catalyst, and some documents believe that the activity and stability of the platinum carbon catalyst are related to the particle size, morphology, structure of the platinum, as well as the type, nature and platinum loading of the support. The prior art mainly improves the performance of the platinum-carbon catalyst by controlling the particle size, morphology, structure and specific surface area of the carrier and pore structure of the platinum; there are also reports of improving the performance of platinum carbon catalysts by modifying the carbon support.

The carbon carrier can improve the specific surface area of the catalyst, reduce the agglomeration of metal particles and improve the metal utilization rate. The increase of the platinum carrying capacity of the carbon carrier is beneficial to manufacturing thinner membrane electrodes with better performance, but the increase of the platinum carrying capacity greatly is easier to cause accumulation among platinum metal particles, so that the utilization rate of active sites is greatly reduced. How to more effectively utilize the catalytic active sites of platinum metal particles and increase the accessible three-phase catalytic reaction interface, thereby improving the utilization rate of platinum and the comprehensive performance of fuel cells and metal-air cells is a key problem to be solved in the art. In addition, the platinum loading of the practically applied hydrogen fuel cell platinum carbon catalyst is at least more than 20wt%, which is much more difficult to manufacture than chemical platinum carbon catalysts (platinum loading is lower than 5 wt%).

The problem of deactivation of platinum carbon catalysts in proton exchange membrane fuel cells caused by carbon corrosion has raised a great deal of attention in the art. It is reported in the literature that, theoretically, when the potential is greater than 0.2V, corrosion of the carbon support occurs. In practice, the problem of carbon corrosion is only evident when the potential is greater than 1.2V. The cathode potential can be higher than 0.9V when the cell is operated in open circuit, and the local interface potential of the cathode can even reach 1.6V during the starting/stopping process of the cell, which greatly accelerates the carbon corrosion reaction, resulting in the drastic reduction of the performance of the platinum carbon catalyst. In addition, platinum accelerates the carbon corrosion rate, and the larger the platinum carrying amount, the faster the carbon corrosion. The conductive carbon black has low price and is a platinum-carbon catalyst carrier used in industry, but the conductive carbon black has poor corrosion resistance. On the one hand, the defect sites of the carbon carrier are more beneficial to increasing the platinum carrying capacity, but at the same time, the carbon corrosion is aggravated. On the other hand, increasing the graphitization degree can alleviate carbon corrosion, but also makes the surface of the carbon carrier chemically inert, and it is difficult to uniformly disperse platinum on the carbon carrier.

The chemical reduction method is a common method for manufacturing platinum-carbon catalyst, and has the advantages of simple process, low utilization rate of platinum and low catalytic activity. The reason for this may be that the irregular pore structure of the carbon support causes uneven dispersion of the platinum nanoparticles.

The information disclosed in the foregoing background section is only for enhancement of understanding of the background of the invention and may include information that is not already known to those of ordinary skill in the art.

Disclosure of Invention

It is a first object of the present invention to provide a carbon material having unique properties and a simple method for preparing the same. A second object of the present invention is to improve the resistance of platinum carbon catalysts to carbon corrosion on the basis of the carbon material. A third object of the present invention is to provide a platinum carbon catalyst having more excellent overall properties and a simple process for producing the same, in addition to the foregoing objects. A fourth object of the present invention is to provide a platinum carbon catalyst with a higher platinum-carrying amount in addition to the foregoing object.

In order to achieve the above object, the present invention provides the following technical solutions.

1. A carbon-doped material characterized by P analyzed by XPS _2P Of the spectral peaks, there was a characteristic peak at 135.8.+ -. 0.5 ev.

2. The carbon-doped material according to any one of the preceding claims, characterized by S in XPS analysis thereof _2P In the spectral peak, the ratio of the characteristic peak area of the thiophene-type sulfur to the characteristic peak area at 168.+ -.1 ev is more than 2, preferably more than 4.

3. The carbon-doped material according to any one of the preceding claims, characterized in that B is analyzed by XPS _1s The spectrum peak has a characteristic peak between 190.3ev and 191.3 ev.

4. The carbon-doped material according to any one of the preceding claims, characterized in that B is analyzed by XPS _1s Among the spectral peaks, there are four characteristic peaks between 190ev and 195 ev.

5. The carbon-doped material according to any one of the preceding claims, characterized by P analyzed by XPS _2P There are two characteristic peaks between 134.5ev and 136.5ev in the spectrum peak.

6. The carbon-doped material according to any one of the preceding claims, wherein the carbon-doped material is a sulfur-phosphorus-boron-doped carbon material.

7. The carbon-doped material according to any one of the above, characterized in that in XPS analysis, the mass fraction of sulfur is 0.01% to 4%, the mass fraction of phosphorus is 0.01% to 4%, and the mass fraction of boron is 0.01% to 4%; preferably, the mass fraction of sulfur is 0.1-2%, the mass fraction of phosphorus is 0.02-2%, and the mass fraction of boron is 0.05-3%.

8. The carbon-doped material according to any of the preceding claims, characterized in that its resistivity is <10Ω·m, preferably <5Ω·m, more preferably <3Ω·m.

9. The carbon-doped material according to any one of the preceding claims, characterized in that the specific surface area thereof is 10m ² /g～2000m ² /g, preferably 200m ² /g～2000m ² /g; the pore volume is 0.02mL/g to 6.0mL/g, preferably 0.2mL/g to 3.0mL/g.

10. The doped carbon material according to any one of the preceding claims, characterized in that the doped carbon material is a sulfur phosphorus boron doped graphene, a sulfur phosphorus boron doped carbon nanotube or a sulfur phosphorus boron doped conductive carbon black; the conductive carbon Black is preferably EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

11. A method of doping a carbon material, comprising: (1) Firstly, contacting a carbon material with a phosphorus source and a boron source, and treating the carbon material in an inert gas at 300-800 ℃ for 0.5-10 h; (2) Then contacts with sulfur source and is treated for 0.5 to 10 hours at 400 to 1000 ℃ in inert gas.

12. The method for doping a carbon material according to any one of the above, wherein the sulfur source is elemental sulfur.

13. The method for doping a carbon material according to any one of the above, wherein the mass ratio of the carbon material to the sulfur source is 20: 1-2: 1, a step of; preferably 10:1 to 4:1, a step of; more preferably 8:1 to 4:1.

14. the doping method of the carbon material according to any one of the preceding claims, wherein the phosphorus source is one or more of phosphoric acid, phosphate, pyrophosphate, polyphosphate, hydrogen phosphate, dihydrogen phosphate, phosphite and hypophosphite.

15. The doping method of a carbon material according to any one of the above, wherein the mass ratio of the carbon material to the phosphorus source is 10000, based on the mass of phosphorus contained in the carbon material: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

16. the method for doping a carbon material according to any one of the above, wherein the boron source is one or more of boric acid and a borate.

17. The doping method of a carbon material according to any one of the above, characterized in that the mass ratio of the carbon material to the boron source is 10000, based on the mass of boron contained therein: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

18. the method for doping a carbon material according to any one of the above, wherein in (1) and (2), the treatment time is 1 to 5 hours, preferably 2 to 4 hours, independently of each other.

19. The method for doping a carbon material according to any one of the above, wherein in (1), the temperature is 450 to 700 ℃.

20. The method for doping a carbon material according to any one of the above, wherein in (2), the temperature is 400 to 700 ℃.

21. The doping method of the carbon material according to any one of the above, wherein the carbon material is graphene, carbon nanotubes or conductive carbon black; the conductive carbon Black is preferably EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

22. The method for doping a carbon material according to any one of the above, wherein the mass fraction of oxygen in XPS analysis of the carbon material is greater than 4%, preferably 4% to 15%.

23. The method for doping a carbon material according to any one of the above, wherein the carbon material has a resistivity of <10Ω·m, preferably <5Ω·m, more preferably <2Ω·m.

24. The method for doping a carbon material according to any one of the above, wherein the specific surface area of the carbon material is 10m ² /g～2000m ² /g, preferably 200m ² /g～2000m ² /g; the pore volume is 0.02mL/g to 6mL/g, preferably 0.2mL/g to 3mL/g.

25. A doped carbon material produced by the doping method of any one of the foregoing carbon materials.

26. The use of any of the foregoing doped carbon materials as electrode materials in electrochemistry.

27. A platinum carbon catalyst comprising a carbon support and a platinum metal supported thereon, wherein the carbon support is any one of the doped carbon materials described above.

28. The platinum carbon catalyst according to any one of the preceding claims, characterized in that the platinum carbon catalyst has S analyzed by XPS _2P In the spectral peak, the ratio of the characteristic peak area of the thiophene-type sulfur to the characteristic peak area at 168.+ -.1 ev is more than 1, preferably more than 2.

29. The platinum carbon catalyst according to any one of the preceding claims, wherein in XPS analysis thereof, there is no B between 185ev and 200ev _1s And no P between 125ev and 145ev _2p Is a characteristic peak of (2).

30. The platinum carbon catalyst according to any one of the preceding claims, characterized in that the carbon carrier is a sulfur phosphorus boron doped graphene, a sulfur phosphorus boron doped carbon nanotube or a sulfur phosphorus boron doped conductive carbon black; the conductive carbon Black is preferably EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

31. The platinum carbon catalyst according to any one of the preceding claims, characterized in that the platinum carbon catalyst has a resistivity of <10 Ω -m, preferably <2 Ω -m.

32. A method for preparing a platinum carbon catalyst, comprising:

(1) A step of manufacturing a carbon carrier: firstly, contacting a carbon material with a phosphorus source and a boron source, and treating the carbon material in an inert gas at 300-800 ℃ for 0.5-10 h; then contacting with a sulfur source, and treating for 0.5-10 hours at 400-1000 ℃ in inert gas to obtain the carbon carrier;

(2) A step of supporting platinum with the carbon support obtained in (1).

33. The method for producing a platinum carbon catalyst according to any one of the above (1), wherein the sulfur source is elemental sulfur.

34. The method for producing a platinum carbon catalyst according to any one of the preceding claims, wherein in (1), the mass ratio of the carbon material to the sulfur source is 20, based on the mass of sulfur contained therein: 1-2: 1, a step of; preferably 10:1 to 4:1, a step of; preferably 8:1 to 4:1.

35. The method for preparing a platinum carbon catalyst according to any one of the above (1), wherein the phosphorus source is one or more of phosphoric acid, phosphate, pyrophosphate, polyphosphate, hydrogen phosphate, dihydrogen phosphate, phosphite and hypophosphite.

36. The method for preparing a platinum carbon catalyst according to any one of the preceding claims, wherein in (1), the mass ratio of the carbon material to the phosphorus source is 10000, based on the mass of phosphorus contained in the phosphorus source: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

37. the method for preparing a platinum carbon catalyst according to any one of the above (1), wherein the boron source is one or more of boric acid and a borate.

38. The method for preparing a platinum carbon catalyst according to any one of the preceding methods, wherein in (1), the mass ratio of the carbon material to the boron source is 10000, based on the mass of boron contained in the boron source: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

39. the method for preparing the platinum-carbon catalyst according to any one of the above methods, wherein the temperature is 450 ℃ to 700 ℃ in the phosphorus-boron doping operation.

40. The method for preparing a platinum carbon catalyst according to any one of the preceding claims, wherein the temperature is 400 ℃ to 1000 ℃ in the sulfur-doped operation.

41. The method for preparing a platinum-carbon catalyst according to any one of the above methods, wherein the treatment time is 1 to 5 hours, preferably 2 to 4 hours, independently of each other in the phosphorus-boron doping operation and the sulfur-doping operation.

42. The preparation method of any one of the platinum carbon catalysts is characterized in that in the step (1), the carbon material is graphene, carbon nano tube or conductive carbon black; the conductive carbon Black is preferably EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

43. The method for producing a platinum carbon catalyst according to any one of the above (1), wherein in the XPS analysis of the carbon material, the mass fraction of oxygen is more than 4%, preferably 4% to 15%.

44. The method for producing a platinum carbon catalyst according to any one of the above (1), wherein in (1), the specific resistance of the carbon material is <10Ω·m, preferably <5Ω·m, and more preferably <2Ω·m.

45. The process for producing a platinum carbon catalyst according to any one of the preceding (1), wherein in (1), the specific surface area of the carbon material is 10m ² /g～2000m ² /g, preferably 200m ² /g～2000m ² /g; the pore volume is 0.02mL/g to 6mL/g, preferably 0.2mL/g to 3mL/g.

46. The method for preparing a platinum carbon catalyst according to any one of the preceding claims, wherein the step (2) of supporting platinum comprises:

(a) Dispersing the carbon carrier obtained in the step (1) and a platinum precursor in an aqueous phase, and adjusting the pH to 8-12 (preferably adjusting the pH to 10+/-0.5);

(b) Reducing agent is added for reduction;

(c) Separating out solid, and post-treating to obtain the platinum carbon catalyst.

47. The method for preparing the platinum carbon catalyst according to any one of the preceding methods, wherein in (a), the platinum precursor is chloroplatinic acid, potassium chloroplatinate or sodium chloroplatinate; the concentration of the platinum precursor is 0.5 mol/L-5 mol/L.

48. The preparation method of any platinum-carbon catalyst is characterized in that in the step (b), the reducing agent is one or more of citric acid, ascorbic acid, formaldehyde, formic acid, ethylene glycol, sodium citrate, hydrazine hydrate, sodium borohydride or glycerol; the mol ratio of the reducing agent to the platinum is 2-100; the reduction temperature is 60-90 ℃; the reduction time is 4-15 h.

49. A platinum carbon catalyst, characterized by being prepared by any one of the aforementioned platinum carbon catalyst preparation methods.

50. A hydrogen fuel cell characterized in that any one of the platinum carbon catalysts described above is used for an anode and/or a cathode of the hydrogen fuel cell.

The hetero atoms and the carbon materials have various combination modes, the hetero atoms have various interactions, the preparation method and the raw materials are different, and the operation steps and the conditions of the doping process are different, so that the combination modes of the hetero atoms and the carbon materials and the interactions among the hetero atoms can be influenced, the property differences of the hetero atoms and the carbon materials are caused, and the functions of the hetero atoms and the carbon materials are changed. In the art, how to control the binding mode of heteroatoms to carbon materials and the interactions between heteroatoms are difficulties in doping atoms. Controlling the manner in which heteroatoms are bound to the carbon material and the interactions between the heteroatoms may result in a carbon material that is uniquely characterized, thereby rendering it suitable for a particular application. The research of the invention finds that the multi-element co-doping of the carbon carrier is beneficial to improving the carbon corrosion resistance of the platinum-carbon catalyst. After the carbon material is subjected to sulfur, phosphorus and boron triple doping by a relatively simple method, a unique doped carbon material can be obtained, and an XPS analysis map of the carbon material shows that the surface doped phosphorus has a characteristic peak between 135.3ev and 136.3ev, and the surface doped sulfur of the carbon material mainly exists in a thiophene sulfur form and has a characteristic peak between 190.3ev and 191.3 ev.

Compared with the prior art, the invention can realize the following beneficial technical effects.

1. Compared with the existing carbon material, the surface doped phosphorus of the carbon material has a characteristic peak between 135.3ev and 136.3ev, the surface doped sulfur mainly exists in the form of thiophene sulfur, and the surface doped boron has a characteristic peak between 190.3ev and 191.3ev, which is beneficial to improving the catalytic performance of the fuel cell platinum-carbon catalyst.

2. The carbon material is suitable for manufacturing platinum-carbon catalysts with high platinum loading, and has excellent comprehensive catalytic performance and carbon corrosion resistance when the platinum loading is up to 70 wt%.

3. The platinum-carrying amount of the practically applied platinum-carbon catalyst of the hydrogen fuel cell is generally more than 20 weight percent, and the difficulty in manufacturing the high-platinum-carrying catalyst with excellent performance is great. The chemical reduction method has simple process, but the utilization rate of platinum is low and the catalytic activity is low. However, the carbon material produced by the present invention is used as a carrier, and a high-platinum-carrying catalyst having excellent mass specific activity and stability can be easily produced by a chemical reduction method using an aqueous phase.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

Fig. 1 is an XPS spectrum of sulfur of the sulfur phosphorus boron doped carbon material of example 1.

Fig. 2 is an XPS spectrum of phosphorus of the sulfur phosphorus boron doped carbon material of example 1.

Fig. 3 is an XPS spectrum of boron of the sulfur phosphorus boron doped carbon material of example 1.

Fig. 4 is an XPS spectrum of sulfur of the sulfur phosphorus boron doped carbon material of example 2.

Fig. 5 is an XPS spectrum of phosphorus of the sulfur phosphorus boron doped carbon material of example 2.

Fig. 6 is an XPS spectrum of boron of the sulfur phosphorus boron doped carbon material of example 2.

Fig. 7 is an XPS spectrum of sulfur of the platinum carbon catalyst of example 3.

Fig. 8 is an XPS spectrum of sulfur of the platinum carbon catalyst of example 5.

Fig. 9 is a TEM image of the platinum carbon catalyst of example 5.

Fig. 10 is an XPS spectrum of phosphorus of the phosphorus-doped carbon material of comparative example 4.

Fig. 11 is an XPS spectrum of boron of the boron doped carbon material of comparative example 5.

Detailed Description

The invention is described in detail below in connection with the embodiments, but it should be noted that the scope of the invention is not limited by these embodiments and the principle explanation, but is defined by the claims.

In the present invention, any matters or matters not mentioned are directly applicable to those known in the art without modification except for those explicitly stated. Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or ideas thus formed are all considered as part of the original disclosure or description of the present invention, and should not be considered as new matters not disclosed or contemplated herein unless such combination would obviously be unreasonable to one skilled in the art.

All of the features disclosed in this invention may be combined in any combination which is known or described in the present invention and should be interpreted as specifically disclosed and described in the present invention unless the combination is obviously unreasonable by those skilled in the art. The numerical points disclosed in the present specification include not only the numerical points specifically disclosed in the embodiments but also the end points of each numerical range in the specification, and any combination of these numerical points should be considered as a disclosed or described range of the present invention.

Technical and scientific terms used in the present invention are defined to have their meanings, and are not defined to have their ordinary meanings in the art.

The "doping element" in the present invention means nitrogen, phosphorus, boron, sulfur, fluorine, chlorine, bromine and iodine.

The numerical ranges defined in the present invention include the endpoints of the numerical ranges.

In the present invention, reference to "carbon material" refers to carbon material that does not contain a doping element, except that it may be uniquely determined to be "carbon material containing a doping element" depending on the context or definition itself. The same is true of the underlying concept of carbon materials.

In the present invention, "carbon black" and "carbon black" are interchangeable terms of art.

The "inert gas" in the present invention refers to a gas that does not cause any appreciable influence on the properties of the boron-parathion-doped carbon material in the preparation method of the present invention. The same is true of the underlying concept of carbon materials.

In the present invention, other references to "pore volume" refer to P/P unless otherwise clear from context or definition of the same ₀ The single point adsorption total pore volume at maximum.

The invention provides a carbon-doped material, P analyzed in XPS _2P Of the spectral peaks, there was a characteristic peak at 135.8.+ -. 0.5ev.

According to the carbon-doped material of the present invention, sulfur, phosphorus and boron are chemically bonded to the carbon material.

The doped carbon material according to the present invention is free of other doping elements than sulfur, phosphorus and boron.

The carbon-doped material according to the present invention is free of metal elements.

The carbon-doped material according to the inventionS in XPS analysis thereof _2P In the spectral peak, the ratio of the characteristic peak area of the thiophene-type sulfur to the characteristic peak area at 168.+ -.1 ev is more than 2, preferably more than 4.

According to the carbon-doped material of the present invention, the characteristic peak of the thiophene-type sulfur is located between 162ev and 166 ev.

According to the carbon-doped material, the characteristic peaks of the thiophene sulfur are bimodal and are respectively located at 163.6+/-0.5 ev and 164.8+/-0.5 ev.

The carbon-doped material according to the present invention, in B of XPS analysis thereof _1s The spectrum peak has a characteristic peak between 190.3ev and 191.3 ev.

The carbon-doped material according to the present invention, in B of XPS analysis thereof _1s Four characteristic peaks between 190ev and 195ev, and no other characteristic peaks between 185ev and 200ev are present in the spectrum peaks.

According to the carbon-doped material of the present invention, P is analyzed in XPS thereof _2P Of the spectral peaks, there are two characteristic peaks between 134.5ev and 136.5ev, and there are no other characteristic peaks between 125ev and 145 ev.

In XPS analysis, the carbon doped material comprises 0.01-4% of sulfur, 0.01-4% of phosphorus and 0.01-4% of boron; preferably, the mass fraction of sulfur is 0.1-2%, the mass fraction of phosphorus is 0.02-2%, and the mass fraction of boron is 0.05-3%.

According to the carbon-doped material of the present invention, in some embodiments, the mass fraction of sulfur in the XPS analysis is 0.1% to 1.5%, the mass fraction of phosphorus is 0.02% to 1.5%, and the mass fraction of boron is 0.1% to 3%.

The carbon-doped material according to the invention has a resistivity of <10Ω·m, preferably <5Ω·m, more preferably <3Ω·m.

The oxygen content of the carbon-doped material according to the present invention is not particularly limited. Generally, the mass fraction of oxygen analyzed by XPS is 2% -15%.

The specific surface area and the pore volume of the carbon-doped material according to the invention can vary within a large range, for example the specific surface area can be 10m ² /g～2000m ² The pore volume may be 0.02mL/g to 6.0mL/g. In one embodiment, the specific surface area is 200m ² /g～2000m ² Per gram, the pore volume is 0.2 mL/g-3.0 mL/g.

The carbon-doped material according to the present invention may be a sulfur phosphorus boron doped graphene, a sulfur phosphorus boron doped carbon nanotube or a sulfur phosphorus boron doped conductive carbon black. The conductive carbon black can be common conductive carbon black (Conductive Blacks), super conductive carbon black (Super Conductive Blacks) or special conductive carbon black (Extra Conductive Blacks), for example, the conductive carbon black can be one or more of Ketjen black series super conductive carbon black, cabot series conductive carbon black and series conductive carbon black produced by Yingchang solid Saint Co; preferably Ketjen Black EC-300J, ketjen Black EC-600JD, ketjen Black ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

The carbon-doped material of the present invention is not limited in the production method and source of the conductive carbon black. The conductive carbon black can be acetylene black, furnace black and the like.

According to the carbon-doped material of the invention, the carbon nanotube or the graphene can be oxidized carbon nanotube or graphene or non-oxidized carbon nanotube or graphene.

The invention also provides a doping method of the carbon material, which comprises the following steps: (1) Firstly, contacting a carbon material with a phosphorus source and a boron source, and treating (preferably, carrying out constant temperature treatment) in an inert gas at 300-800 ℃ for 0.5-10 h to obtain a phosphorus-boron doped carbon material (intermediate product); (2) Then contacts with sulfur source and is treated for 0.5 to 10 hours at 400 to 1000 ℃ in inert gas to obtain the carbon doped material.

According to the doping method of the carbon material of the present invention, the carbon material may be graphene, carbon nanotubes or conductive carbon black. The conductive carbon black can be one or more of Ketjen black series superconducting carbon black, cabot series conductive carbon black and series conductive carbon black produced by Yingchang solid Saint Co; preferably EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

According to the doping method of the carbon material, the carbon nanotube or the graphene can be oxidized carbon nanotube or graphene or non-oxidized carbon nanotube or graphene.

According to the doping method of the carbon material of the present invention, there is no limitation on the preparation method and source of the conductive carbon black. The conductive carbon black can be acetylene black, furnace black and the like.

According to the doping method of the carbon material of the invention, the carbon material is I _D /I _G The value is generally from 0.8 to 5, preferably from 1 to 4. In Raman spectrum, at 1320cm ^-1 The nearby peak is D peak, which is located at 1580cm ^-1 The nearby peak is G peak, I _D Representing the intensity of the D peak, I _G Representing the intensity of the G peak.

The manner in which the carbon material is contacted with the phosphorus source and the boron source is not limited by the present invention, and those skilled in the art can select an appropriate manner based on the teachings and/or prior knowledge of the present invention. The carbon material is preferably contacted with a phosphorus source and a boron source in a mixed manner. The order and manner of mixing the carbon material with the phosphorus source and the boron source is also not limited by the present invention, and may be readily selected by one of ordinary skill in the art based on the teachings and/or prior knowledge of the present invention. The invention provides a preferred mixing mode: the carbon material is mixed with a phosphorus source and a boron source solution (preferably an aqueous solution), impregnated and dried.

The manner in which the phosphorus-boron doped carbon material (intermediate product) is contacted with the sulfur source is not limited by the present invention, and one skilled in the art can select an appropriate manner based on the teachings and/or prior knowledge of the present invention. According to the doping method of the carbon material of the present invention, the intermediate product is preferably contacted with a sulfur source (such as elemental sulfur) in a mixed manner.

According to the doping method of the carbon material, if the temperature is required to be raised, the temperature raising rate is 3 ℃/min-7 ℃/min when the phosphorus and the boron are doped, and the temperature raising rate is 3 ℃/min-7 ℃/min when the sulfur is doped.

According to the doping method of a carbon material of the present invention, in (1) and (2), the time of the treatment is each independently 1 to 5 hours, preferably 2 to 4 hours.

According to the doping method of a carbon material of the present invention, in (1), the temperature is 450 to 700 ℃.

According to the doping method of a carbon material of the present invention, in (2), the temperature is 400 to 700 ℃.

According to the doping method of the carbon material, the sulfur source is elemental sulfur.

According to the doping method of the carbon material, the mass ratio of the carbon material to the sulfur source is 20, wherein the mass ratio of the sulfur source to the sulfur source is calculated according to the mass of sulfur contained in the sulfur source: 1-2: 1, a step of; preferably 10:1 to 4:1, a step of; more preferably 8:1 to 4:1.

according to the doping method of the carbon material, the phosphorus source is one or more of phosphoric acid, phosphate, pyrophosphates, polyphosphates, hydrogen phosphate, dihydrogen phosphate, phosphite and hypophosphite.

According to the doping method of the carbon material, the mass ratio of the carbon material to the phosphorus source is 10000, based on the mass of phosphorus contained in the carbon material: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

According to the doping method of the carbon material, the boron source is one or more of boric acid and borate.

According to the doping method of the carbon material, the mass ratio of the carbon material to the boron source is 10000, based on the mass of boron contained in the carbon material: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

according to the doping method of the carbon material, the inert gas is nitrogen or argon.

According to the doping method of the carbon material, in XPS analysis of the carbon material, the mass fraction of oxygen is generally more than 4%, preferably 4% -15%.

According to the doping method of the carbon material of the present invention, the resistivity of the carbon material is <10Ω·m, preferably <5Ω·m, more preferably <2Ω·m.

According to the doping method of the carbon material of the present invention, the specific surface area of the carbon material may vary within a wide range. Generally, the specific surface area is 10m ² /g～2000m ² /g; pore volume is 0.02 mL/g-6 mL/g。

According to the doping method of the carbon material of the present invention, in one embodiment, (1) the carbon material impregnated with the phosphorus source and the boron source in the aqueous solution is dried, placed in a tube furnace, and the tube furnace is heated to 300 ℃ to 800 ℃ (preferably 450 ℃ to 700 ℃) at a rate of 3 ℃/min to 7 ℃/min in an inert gas, and then is subjected to constant temperature treatment for 0.5h to 10h, thereby obtaining a phosphorus-boron doped carbon material (intermediate product); (2) Mixing the intermediate product with sulfur powder, placing the mixture in a tube furnace, heating the tube furnace to 400-1000 ℃ at a speed of 3-7 ℃/min in inert gas (preferably 400-700 ℃), and then performing constant temperature treatment for 0.5-10 hours to obtain the carbon-doped material.

The inert gas is nitrogen or argon.

According to the doping method of the carbon material of the present invention, a metal-containing catalyst is not used in the process of doping the carbon material.

The invention also provides the carbon-doped material prepared by any one of the methods.

The use of the carbon-doped material according to the invention as an electrode material in electrochemistry.

The invention provides a platinum-carbon catalyst, which comprises a carbon carrier and platinum metal loaded on the carbon carrier, wherein the carbon carrier is a sulfur-phosphorus-boron doped carbon material.

The invention provides another platinum-carbon catalyst comprising a carbon carrier and a platinum metal supported thereon, wherein the carbon carrier is any one of the carbon-doped materials of the invention.

According to the platinum carbon catalyst of the present invention, the platinum carbon catalyst is analyzed by XPS _2P In the spectral peak, the ratio of the characteristic peak area of the thiophene-type sulfur to the characteristic peak area at 168.+ -.1 ev is more than 1, preferably more than 2.

According to the platinum carbon catalyst of the present invention, the characteristic peak of the thiophene-type sulfur is located between 162ev and 166 ev.

According to the platinum carbon catalyst of the present invention, the characteristic peaks of the thiophene sulfur are bimodal, and are located at 163.2.+ -. 0.5ev and 164.5.+ -. 0.5ev, respectively.

According to the platinum carbon catalyst of the invention, in In XPS analysis, there is no B between 185ev and 200ev _1s And no P between 125ev and 145ev _2p Is a characteristic peak of (2).

According to the platinum carbon catalyst of the present invention, P was detected in TG-MS (thermogravimetric-mass spectrometry) test ₂ O ₃ And P ₂ O ₅ Is a signal of (a).

According to the platinum carbon catalyst of the present invention, boron signals (B and B) were detected in TG-MS (thermogravimetric-mass spectrometry) test ₂ O ₃ )。

The platinum carbon catalyst according to the present invention does not contain other doping elements except sulfur, phosphorus and boron.

The platinum carbon catalyst according to the present invention does not contain other metal elements than platinum.

The platinum carbon catalyst according to the present invention, wherein sulfur, phosphorus and boron are chemically bonded to a carbon material.

According to the platinum carbon catalyst, the sulfur-phosphorus-boron doped carbon material can be sulfur-phosphorus-boron doped graphene, sulfur-phosphorus-boron doped carbon nano tube or sulfur-phosphorus-boron doped conductive carbon black. The conductive carbon black can be one or more of Ketjen black series superconducting carbon black, cabot series conductive carbon black and series conductive carbon black produced by Yingchang solid Saint Co; preferably Ketjen Black EC-300J, ketjen Black EC-600JD, ketjen Black ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

The platinum carbon catalyst according to the present invention has a mass fraction of platinum of 0.1 to 80%, preferably 20 to 70%, more preferably 40 to 70%, based on the mass of the catalyst.

The platinum carbon catalyst according to the invention has a resistivity of <10.0 Ω -m, preferably <2.0 Ω -m.

According to the platinum carbon catalyst of the present invention, the specific surface area of the platinum carbon catalyst is 80m ² /g～1500m ² /g, preferably 100m ² /g～200m ² /g。

The invention provides a preparation method of a platinum-carbon catalyst, which comprises the following steps:

(2) A step of supporting platinum with the carbon support obtained in (1).

According to the preparation method of the platinum carbon catalyst of the present invention, in (1), the "contact mode of the carbon material with the sulfur source, the phosphorus source and the boron source" is the same as the corresponding parts in the foregoing, and the present invention will not be repeated.

According to the preparation method of the platinum carbon catalyst, the sulfur source is elemental sulfur.

According to the preparation method of the platinum carbon catalyst, in (1), the mass ratio of the carbon material to the sulfur source is 20: 1-2: 1, a step of; preferably 10:1 to 4:1, a step of; preferably 8:1 to 4:1.

According to the preparation method of the platinum carbon catalyst, the phosphorus source is one or more of phosphoric acid, phosphate, pyrophosphate, polyphosphate, hydrogen phosphate, dihydrogen phosphate, phosphite and hypophosphite.

According to the preparation method of the platinum carbon catalyst, in the (1), the mass ratio of the carbon material to the phosphorus source is 10000 based on the mass of phosphorus contained in the phosphorus source: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

according to the preparation method of the platinum carbon catalyst, the boron source is one or more of boric acid and borate.

According to the preparation method of the platinum carbon catalyst, in (1), the mass ratio of the carbon material to the boron source is 10000 based on the mass of boron contained in the boron source: 1 to 10:1, a step of; preferably 2000: 1-20: 1.

according to the preparation method of the platinum-carbon catalyst, if the temperature is required to be raised in the step (1), the temperature rise rate is 3 ℃/min-7 ℃/min when phosphorus and boron are doped, and the temperature rise rate is 3 ℃/min-7 ℃/min when sulfur is doped.

According to the preparation method of the platinum carbon catalyst, in the phosphorus-boron doped operation in the step (1), the temperature is 450-700 ℃.

According to the preparation method of the platinum carbon catalyst, in the sulfur doping operation in the step (1), the temperature is 400-700 DEG C

According to the preparation method of the platinum carbon catalyst, in the phosphorus-boron doping operation in the step (1), the treatment time is 1 to 5 hours, preferably 2 to 4 hours.

According to the method for preparing a platinum carbon catalyst of the present invention, in the sulfur-doping operation in (2), the treatment time is 1 to 5 hours, preferably 2 to 4 hours.

According to the preparation method of the platinum carbon catalyst, in the (1), the carbon material can be graphene, carbon nano tube or conductive carbon black; the conductive carbon Black is preferably EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

According to the preparation method of the platinum carbon catalyst, the sulfur-phosphorus-boron doped carbon material prepared in the step (1) can be easily dispersed in an aqueous phase. For some carbon materials, such as ketjen black, it is difficult to disperse directly in the aqueous phase.

According to the preparation method of the platinum carbon catalyst, in (1), the mass fraction of oxygen in XPS analysis of the carbon material is more than 4%, preferably 4% -15%.

According to the method for producing a platinum carbon catalyst of the present invention, in (1), the specific resistance of the carbon material is <10Ω·m, preferably <5Ω·m, more preferably <2Ω·m.

According to the method for producing a platinum carbon catalyst of the present invention, (1) the specific surface area of the carbon material is 10m ² /g～2000m ² /g, preferably 200m ² /g～2000m ² /g; the pore volume is 0.02mL/g to 6mL/g, preferably 0.2mL/g to 3mL/g.

According to the preparation method of the platinum carbon catalyst, a TEM image of the platinum carbon catalyst shows that platinum metal particles are uniformly dispersed on a carbon carrier.

A platinum carbon catalyst prepared by any one of the methods for preparing a platinum carbon catalyst described above.

A hydrogen fuel cell uses any one of the platinum carbon catalysts described above in the anode and/or cathode of the hydrogen fuel cell.

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way.

Reagents, instruments and tests

Unless otherwise specified, all reagents used in the present invention are analytically pure and commercially available.

The invention detects the elements on the surface of the material by an X-ray photoelectron spectroscopy (XPS). The X-ray photoelectron spectroscopy analyzer used was an ESCALab220i-XL type radiation electron spectroscopy manufactured by VG scientific company and equipped with Avantage V5.926 software, and the X-ray photoelectron spectroscopy analysis test conditions were: the excitation source is monochromized A1K alpha X-ray with power of 330W and basic vacuum of 3X 10 during analysis and test ^-9 mbar. In addition, the electron binding energy was corrected by the C1s peak (284.3 eV) of elemental carbon, and the post-peak splitting treatment software was XPSPEAK. Characteristic peaks of thiophene sulfur, phosphorus and boron in the spectrogram are characteristic peaks after peak separation.

Instrument and method for elemental analysis, conditions: elemental analyzer (Vario EL Cube), reaction temperature 1150 ℃, 5mg of sample, reduction temperature 850 ℃, carrier gas helium flow rate 200mL/min, oxygen flow rate 30mL/min, and oxygen introduction time 70s.

Apparatus, method, conditions for testing mass fraction of platinum in platinum carbon catalyst: 30mg of the prepared Pt/C catalyst is taken, 30mL of aqua regia is added, the mixture is condensed and refluxed for 12 hours at 120 ℃, cooled to room temperature, and the supernatant is taken for dilution, and then the content of Pt in the mixture is tested by ICP-AES.

The model of the high-resolution transmission electron microscope (HRTEM) adopted by the invention is JEM-2100 (HRTEM) (Japanese electronics Co., ltd.) and the test conditions of the high-resolution transmission electron microscope are as follows: the acceleration voltage was 200kV. The particle size of the nano particles in the sample is measured by an electron microscope picture.

BET test method: in the invention, the pore structure property of a sample is measured by a Quantachrome AS-6B type analyzer, the specific surface area and the pore volume of the catalyst are obtained by a Brunauer-Emmett-Taller (BET) method, and the pore distribution curve is obtained by calculating a desorption curve according to a Barrett-Joyner-Halenda (BJH) method.

The Raman detection of the invention adopts a LabRAM HR UV-NIR laser confocal Raman spectrometer manufactured by HORIBA company of Japan, and the laser wavelength is 532nm.

Electrochemical performance testing, instrument models Solartron analytical EnergyLab and Princeton Applied Research (Model 636A), methods and test conditions: polarization curve LSV of catalyst O at 1600rpm ₂ Saturated 0.1M HClO ₄ CV Curve 0.1M HClO under Ar atmosphere ₄ The electrochemically active area ECSA was calculated therefrom. Stability test at O ₂ Saturated 0.1M HClO ₄ After 5000 cycles of scanning in the range of 1.0V to 1.5V, LSV and ECSA were tested as described above. The catalyst is prepared into slurry which is uniformly dispersed during the test, and the slurry is coated on a glassy carbon electrode with the diameter of 5mm, wherein the platinum content of the catalyst on the electrode is 3-4 mug.

Resistivity test four-probe resistivity tester, instrument model KDY-1, method and test conditions: the applied pressure was 3.9.+ -. 0.03MPa and the current was 500.+ -. 0.1mA.

TG-MS test method: testing by using a German relaxation-resistant STA449F5-QMS403D type thermogravimetric-mass spectrometer, wherein an ion source is an EI source, a four-stage rod mass spectrometer is in an MID mode, a transmission pipeline is a 3-meter long capillary, and the temperature is 260 ℃; the temperature is 55-1000 ℃ and the heating rate is 10 ℃/min.

VXC72 (Vulcan XC72, manufactured by cabot corporation, usa) is available from energy technologies limited in wing Long, su. The test by the instrument method shows that: specific surface area 258m ² Per gram, pore volume 0.388mL/g, oxygen mass fraction 8.72% by XPS analysis, I _D /I _G The resistivity was 1.02. Omega. M, which was 1.22. Omega. M.

Ketjenback ECP600JD (Ketjen Black, manufactured by Lion corporation, japan) was purchased from Suzhou wing Long energy technologies Co. The test by the instrument method shows that: specific surface area 1362m ² Per gram, pore volume 2.29mL/g, oxygen mass fraction 6.9% by XPS analysis, I _D /I _G 1.25, and the resistivity was 1.31. Omega. M.

Black Pearls 2000 (U.S. card)Bott corporation) from the energy technology company of Suzhou wing Long. The test by the instrument method shows that: specific surface area 1479m ² Oxygen mass fraction of XPS analysis of 9.13% per gram, I _D /I _G The resistivity was 1.14 and 1.19Ω·m.

Commercial platinum carbon catalyst (trade name HISPEC4000, manufactured by Johnson Matthey Co.) was purchased from Alfa Aesar. The test results show that: the mass fraction of platinum was 40.2%.

Example 1

This example is used to illustrate the preparation of the sulfur phosphorus boron doped carbon material of the present invention.

1g of Vulcan XC72 is immersed for 24 hours in 15mL of aqueous solution with the concentration of sodium borate of 2.0wt% and the concentration of phosphoric acid of 0.5 wt%; drying in an oven at 100 ℃; then placing the mixture into a tube furnace, heating the tube furnace to 450 ℃ at a speed of 5 ℃/min, and carrying out constant temperature treatment for 2 hours; naturally cooling to obtain the boron-phosphorus doped carbon material.

Uniformly mixing the boron-phosphorus doped carbon material with 0.167g of elemental sulfur, placing the mixture into a tube furnace, heating the tube furnace to 700 ℃ at a speed of 5 ℃/min, and carrying out constant temperature treatment for 3 hours; naturally cooling to obtain the sulfur-boron-phosphorus doped carbon material, wherein the number of the carbon carrier A.

Sample characterization and testing

The mass fraction of sulfur analyzed by XPS is 0.8%; the mass fraction of phosphorus analyzed by XPS is 0.7%; the mass fraction of boron analyzed by XPS is 2.6%; a specific surface area of 237m ² /g; the resistivity was 1.30Ω·m.

In FIG. 1, the ratio of the characteristic peak area of thiophene-type sulfur to the characteristic peak area at 168.+ -. 1ev was 4.1.

Example 2

10mL of absolute ethanol was added to 1g Ketjenblack ECP600JD, followed by soaking in 25mL of an aqueous solution having a boric acid concentration of 0.4wt% and a sodium phosphate concentration of 2.0wt% for 24 hours; drying in an oven at 100 ℃; then placing the mixture into a tube furnace, heating the tube furnace to 700 ℃ at a speed of 5 ℃/min, and carrying out constant temperature treatment for 2 hours; naturally cooling to obtain the boron-phosphorus doped carbon material.

Uniformly mixing the boron-phosphorus doped carbon material with 0.25g of elemental sulfur, placing the mixture into a tube furnace, heating the tube furnace to 400 ℃ at a speed of 5 ℃/min, and carrying out constant temperature treatment for 3 hours; naturally cooling to obtain the sulfur-boron-phosphorus doped carbon material, wherein the number of the carbon carrier B is the number of the carbon carrier B.

Sample characterization and testing

The mass fraction of sulfur analyzed by XPS is 0.4%; the mass fraction of phosphorus analyzed by XPS is 0.02%; the mass fraction of boron analyzed by XPS is 0.3%; a specific surface area of 1296m ² /g; the resistivity was 1.36. Omega. M.

In FIG. 4, the ratio of the characteristic peak area of thiophene-type sulfur to the characteristic peak area at 168.+ -. 1ev is 4.1.

Example 3

This example illustrates the preparation of the platinum carbon catalyst of the present invention.

Dispersing the carbon carrier A in deionized water according to the proportion of 250mL of water used per gram of carbon carrier, adding 3.4mmol of chloroplatinic acid per gram of carbon carrier, performing ultrasonic dispersion to form suspension, and adding 1mol/L of sodium carbonate aqueous solution to enable the pH value of the system to be 10; heating the suspension to 80 ℃, adding formic acid under stirring to perform reduction reaction, wherein the molar ratio of the formic acid to the chloroplatinic acid is 50:1, and continuously maintaining the reaction for 10 hours; filtering the reacted mixture, washing the mixture with deionized water until the pH value of the filtrate is neutral, filtering the mixture, and then drying the mixture at 100 ℃ to obtain the platinum-carbon catalyst.

Sample characterization and testing

The platinum mass fraction of the platinum carbon catalyst was 40.4%.

In FIG. 7, the ratio of the characteristic peak area of thiophene-type sulfur to the characteristic peak area at 168.+ -. 1ev is 1.7.

In XPS analysis of the Pt-C catalyst, there was no P between 125ev and 145ev _2p Is a characteristic peak of (2).

P, P was detected in TG-MS test of platinum carbon catalyst ₂ O ₃ And P ₂ O ₅ Is a signal of (a).

In XPS analysis of the platinum carbon catalyst, there was no B between 185ev and 200ev _1s Is a characteristic peak of (2).

B and B were detected in TG-MS test of platinum carbon catalyst ₂ O ₃ Is a signal of (a).

The results of the performance test of the platinum carbon catalyst are shown in table 1.

Example 4

This example illustrates the preparation of a platinum carbon catalyst.

A platinum carbon catalyst was prepared according to the method of example 3, except that: 1.3mmol of chloroplatinic acid per gram of carbon support are added.

Sample characterization and testing

The platinum mass fraction of the platinum carbon catalyst was 20.2%.

Example 5

Dispersing a carbon carrier B in a solution according to the proportion of 600mL of water and 600mL of ethylene glycol used for each gram of carbon carrier, adding 12mmol of chloroplatinic acid into each gram of carbon carrier, adding sodium acetate into the solution according to the molar ratio of sodium acetate to chloroplatinic acid being 2:1, performing ultrasonic dispersion to form a suspension, and adding 1mol/L of sodium carbonate aqueous solution to enable the pH value of the system to be 10; heating the suspension to 80 ℃, adding sodium borohydride under stirring to perform reduction reaction, wherein the molar ratio of the sodium borohydride to chloroplatinic acid is 5:1, and continuously maintaining the reaction for 10 hours; filtering the reacted mixture, washing the mixture with deionized water until the pH value of the filtrate is neutral, filtering the mixture, and drying the mixture at 100 ℃ to obtain the platinum-carbon catalyst.

Sample characterization and testing

The platinum mass fraction of the platinum carbon catalyst was 69.6%.

In FIG. 8, the ratio of the characteristic peak area of thiophene-type sulfur to the characteristic peak area at 168.+ -. 1ev is 2.4.

Fig. 9 is a TEM image of the platinum carbon catalyst of example 5.

Comparative example 1

Dispersing Vulcan XC72 in deionized water according to the proportion of 250mL of water used for each gram of carbon carrier, adding 3.4mmol of chloroplatinic acid for each gram of carbon carrier, performing ultrasonic dispersion to form suspension, and adding 1mol/L of sodium carbonate aqueous solution to enable the pH value of the system to be 10; heating the suspension to 80 ℃, adding formic acid under stirring to perform reduction reaction, wherein the molar ratio of the formic acid to the chloroplatinic acid is 50:1, and continuously maintaining the reaction for 10 hours; filtering the reacted mixture, washing the mixture with deionized water until the pH value of the filtrate is neutral, filtering the mixture, and then drying the mixture at 100 ℃ to obtain the platinum-carbon catalyst.

Sample characterization and testing

The platinum mass fraction of the platinum carbon catalyst was 40.1%.

The results of the platinum carbon catalyst performance test are shown in table 1.

Comparative example 2

Dispersing Ketjenback ECP600JD in a solution according to the proportion of 600mL of water and 600mL of ethylene glycol used for each gram of carbon carrier, adding 12mmol of chloroplatinic acid into each gram of carbon carrier, adding sodium acetate into the solution according to the molar ratio of sodium acetate to chloroplatinic acid being 2:1, performing ultrasonic dispersion to form a suspension, and adding 1mol/L of sodium carbonate aqueous solution to enable the pH value of the system to be 10; heating the suspension to 80 ℃, adding sodium borohydride under stirring to perform reduction reaction, wherein the molar ratio of the sodium borohydride to chloroplatinic acid is 5:1, and continuously maintaining the reaction for 10 hours; filtering the reacted mixture, washing the mixture with deionized water until the pH value of the filtrate is neutral, filtering the mixture, and drying the mixture at 100 ℃ to obtain the platinum-carbon catalyst.

Sample characterization and testing

The platinum mass fraction of the platinum carbon catalyst was 69.9%.

Comparative example 3

The platinum carbon catalyst is a commercially available catalyst, under the trade designation HISPEC4000.

Sample characterization and testing

The platinum mass fraction of the platinum carbon catalyst was 40.2%.

Comparative example 4

This comparative example is used to illustrate the preparation of phosphorus doped carbon materials.

1g Vulcan XC72 is immersed in 15mL of 0.8wt% phosphoric acid aqueous solution for 16h; drying in an oven at 100 ℃; then placing the mixture into a tube furnace, heating the tube furnace to 400 ℃ at the speed of 8 ℃/min, and carrying out constant temperature treatment for 2 hours; naturally cooling to obtain the phosphorus-doped carbon material.

Sample characterization and testing

Comparative example 5

This comparative example is used to illustrate the preparation of boron doped carbon materials.

1g of Vulcan XC72 is immersed in 15mL of 4.5wt% sodium borate aqueous solution for 16h; drying in an oven at 100 ℃; then placing the mixture into a tube furnace, heating the tube furnace to 400 ℃ at a speed of 10 ℃/min, and carrying out constant temperature treatment for 3 hours; naturally cooling to obtain the boron doped carbon material.

Sample characterization and testing

TABLE 1

/>

Claims

1. A platinum carbon catalyst comprising a carbon support and a platinum metal supported thereon, wherein the carbon support is prepared by a process comprising: (1) Drying the conductive carbon black which is immersed with the phosphorus source and the boron source in the aqueous solution, placing the conductive carbon black in a tube furnace, heating the tube furnace to 450-700 ℃ at the speed of 3-7 ℃/min in inert gas, and then performing constant temperature treatment for 0.5-10 h to obtain an intermediate product; (2) Mixing the intermediate product with sulfur powder, placing the mixture in a tube furnace, heating the tube furnace to 400-700 ℃ in inert gas at the speed of 3-7 ℃/min, and then performing constant temperature treatment for 0.5-10 h to obtain the carbon carrier; the mass ratio of the conductive carbon black to the sulfur powder is 8:1 to 4:1, a step of; the phosphorus source is one or more of phosphoric acid, phosphate, pyrophosphates, polyphosphates, hydrogen phosphate, dihydrogen phosphate, phosphite and hypophosphite, the mass of the phosphorus source is calculated by the mass of phosphorus contained in the phosphorus source, and the mass ratio of the conductive carbon black to the phosphorus source is 2000: 1-20: 1, a step of; the boron source is one or more of boric acid and borate; the mass ratio of the conductive carbon black to the boron source is 2000: 1-20: 1, a step of; the carbon carrier does not contain other doping elements except sulfur, phosphorus and boron, and the doping elements are nitrogen, phosphorus, boron, sulfur, fluorine, chlorine, bromine and iodine;

XPS analysis of the carbon Carrier _2P In the spectrum peak, thiophene type sulfurThe ratio of the characteristic peak area to the characteristic peak area at 168 + -1 ev is greater than 4; p of the carbon support _2P Two characteristic peaks exist between 134.5ev and 136.5ev, and no other characteristic peaks exist between 125ev and 145 ev; XPS analysis of the carbon Carrier B _1s Four characteristic peaks exist between 190ev and 195ev, and no other characteristic peaks exist between 185ev and 200 ev;

in the platinum-carbon catalyst, the mass fraction of platinum is 40% -70% based on the mass of the catalyst.

2. The platinum carbon catalyst according to claim 1, wherein the conductive carbon Black is EC-300J, EC-600JD, ECP-600JD, VXC72, black pears 2000, PRINTEX XE2-B, PRINTEX L6 or HIBLAXK 40B2.

3. The method for preparing a platinum carbon catalyst according to claim 1, comprising: (1) the step of producing a carbon support as described in claim 1; (2) a step of supporting platinum with the carbon support obtained in (1).

4. A method of preparing a platinum carbon catalyst according to claim 3, wherein said step (2) of supporting platinum comprises:

(a) Dispersing the carbon carrier and the platinum precursor obtained in the step (1) in a water phase, and regulating the pH to 8-12;

(b) Reducing agent is added for reduction;

5. The method of preparing a platinum carbon catalyst according to claim 4, wherein in (a), the platinum precursor is chloroplatinic acid, potassium chloroplatinate, or sodium chloroplatinate; the concentration of the platinum precursor is 0.5 mol/L-5 mol/L.

6. The method for preparing a platinum carbon catalyst according to claim 4, wherein in (b), the reducing agent is one or more of citric acid, ascorbic acid, formaldehyde, formic acid, ethylene glycol, sodium citrate, hydrazine hydrate, sodium borohydride or glycerol; the mol ratio of the reducing agent to the platinum is 2-100; the reduction temperature is 60-90 ℃; the reduction time is 4-15 h.

7. A hydrogen fuel cell, wherein the platinum carbon catalyst according to any one of claims 1 to 2 is used in an anode and/or a cathode of the hydrogen fuel cell.