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CN-116093350-B - Platinum-carrying nitrogen-doped graphene and preparation method and application thereof

CN116093350BCN 116093350 BCN116093350 BCN 116093350BCN-116093350-B

Abstract

The application relates to the technical field of graphene, in particular to platinum-carrying nitrogen-doped graphene, and a preparation method and application thereof. The preparation method of the platinum-carrying nitrogen-doped graphene comprises the steps of mixing graphene oxide, platinum salt and a solvent to form a mixed solution, performing hydrothermal reaction to prepare graphene oxide-platinum salt composite powder, mixing the graphene oxide-platinum salt composite powder with an amino compound, performing ball milling to prepare amino-modified graphene oxide-platinum salt composite powder, and performing microwave irradiation on the amino-modified graphene oxide-platinum salt composite powder to prepare the platinum-carrying nitrogen-doped graphene. The preparation process is simple, and the prepared platinum-carrying nitrogen-doped graphene has good oxygen reduction catalytic activity.

Inventors

  • WANG JING
  • DU ZHENZHEN
  • YU FAN
  • WANG JUN
  • LI JIONGLI
  • WANG XUDONG

Assignees

  • 北京石墨烯技术研究院有限公司

Dates

Publication Date
20260508
Application Date
20221207

Claims (14)

  1. 1. The preparation method of the platinum-carrying nitrogen-doped graphene is characterized by comprising the following steps of: mixing graphene oxide, platinum salt and a solvent to form a mixed solution, and performing hydrothermal reaction to prepare graphene oxide-platinum salt composite powder; mixing the graphene oxide-platinum salt composite powder with an amino compound, ball milling to prepare amino modified graphene oxide-platinum salt composite powder, and Performing microwave irradiation on the amino-modified graphene oxide-platinum salt composite powder to prepare platinum-carrying nitrogen-doped graphene; wherein the amino compound comprises ammonia water and/or urea; in the prepared platinum-carrying nitrogen-doped graphene, the particle size of the carried metal platinum is 2 nm-10 nm.
  2. 2. The method of claim 1, wherein the platinum salt comprises chloroplatinic acid and/or platinum acetate.
  3. 3. The preparation method of claim 1, wherein the number of layers of the graphene oxide is 1-10, and the oxygen content is 30 at% -60 at%.
  4. 4. The method according to claim 1, wherein the mass ratio of carbon atoms in the graphene oxide to platinum atoms in the platinum salt is (0.5 to 3): 1.
  5. 5. The method according to claim 4, wherein the mass ratio of carbon atoms in the graphene oxide-platinum salt composite powder to nitrogen atoms in the amino compound is (1-10): 1.
  6. 6. The method according to any one of claims 1 to 5, wherein the hydrothermal reaction is carried out at a temperature of 80 ℃ to 120 ℃ for a time of 0.5 h to 3h.
  7. 7. The method according to any one of claims 1 to 5, wherein the power of the microwave irradiation is 1 kW to 15 kW for 5 s to 300 s.
  8. 8. The method according to any one of claims 1 to 5, wherein the rotation speed of the ball mill is 200 rpm to 500 rpm for 0.5 h to 3 h.
  9. 9. The method of any one of claims 1 to 5, wherein the method of forming the mixed liquor comprises: dispersing the graphene oxide in water to form graphene oxide dispersion liquid; dissolving the platinum salt in an organic solvent to form a platinum salt solution, and The dispersion is mixed with the platinum salt solution to form the mixed solution.
  10. 10. The method of claim 9, wherein the organic solvent comprises ethanol and/or ethylene glycol.
  11. 11. The platinum-carrying nitrogen-doped graphene prepared by the preparation method according to any one of claims 1 to 10.
  12. 12. Use of the platinum-carrying nitrogen-doped graphene according to claim 11 as a fuel cell catalyst.
  13. 13. A membrane electrode comprising a proton exchange membrane and a catalyst layer disposed adjacent to the proton exchange membrane, the catalyst layer comprising the platinum-carrying nitrogen-doped graphene of claim 11.
  14. 14. A proton exchange membrane fuel cell comprising the membrane electrode of claim 13.

Description

Platinum-carrying nitrogen-doped graphene and preparation method and application thereof Technical Field The application relates to the technical field of graphene, in particular to platinum-carrying nitrogen-doped graphene, and a preparation method and application thereof. Background Proton exchange membrane fuel cells are becoming increasingly important as a new clean energy source for research. The membrane electrode is called the heart of a proton exchange membrane fuel cell, and is a core link of the proton exchange membrane fuel cell technology, wherein an anode-cathode catalyst is important for improving the performance of the membrane electrode. Platinum carbon catalysts are the most widely used catalysts in the current proton exchange membrane fuel cells and are the most commercially mature catalysts. The platinum metal particles loaded by the traditional platinum-carbon catalyst are larger, agglomeration easily occurs among the particles in the use process, and the service life and catalytic activity of the catalyst can be reduced. In order to enhance the catalytic activity and reduce the production cost, researchers choose to modify the platinum carbon catalyst. The current novel platinum carbon catalyst is mainly prepared by two paths of alloying platinum metal particles and modifying a matrix material loaded with the platinum metal particles. Alloying platinum metal particles means that platinum forms a Pt-M alloy with the transition metal supported on a carbon matrix. Modification of the support is generally focused on improving the specific surface area, conductivity and chemical stability of the support. The modification method is usually a liquid phase synthesis process or a solid phase synthesis process, for example, three-position graphene is used as a template, platinum nano particles are electrodeposited on the surface by electric pulse, platinum silver alloy nano particles are chemically deposited on the surface of the graphene by utilizing different oxidation-reduction potentials, or platinum particles are grown on a carbon nano tube carrier by combining a dipping method and a thermal reduction method. However, these methods are generally complicated to prepare and take a long time. In addition, the liquid phase preparation process generally uses a large amount of organic solvent and surfactant, which is difficult to thoroughly remove and can lead to the introduction of impurities. The use of a large amount of organic solvent also increases the cost of subsequent treatments. The solid phase preparation process generally requires high temperature sintering and has high energy consumption. And long-time thermal reflux is needed when small-size platinum metal particles are prepared, the reaction period is long, and the production cost is increased. Disclosure of Invention Based on the above, it is necessary to provide a platinum-carrying nitrogen-doped graphene, and a preparation method and application thereof, wherein the preparation method is simple, no impurity is introduced, and the prepared platinum-carrying nitrogen-doped graphene can improve the oxygen reduction catalytic activity of the platinum-carrying nitrogen-doped graphene serving as a fuel cell catalyst. In a first aspect, the application provides a preparation method of platinum-carrying nitrogen-doped graphene, which comprises the following steps: mixing graphene oxide, platinum salt and a solvent to form a mixed solution, and performing hydrothermal reaction to prepare graphene oxide-platinum salt composite powder; mixing the graphene oxide-platinum salt composite powder with an amino compound, ball milling to prepare amino modified graphene oxide-platinum salt composite powder, and And carrying out microwave irradiation on the amino-modified graphene oxide-platinum salt composite powder to prepare the platinum-carrying nitrogen-doped graphene. In some embodiments, the platinum salt comprises chloroplatinic acid and/or platinum acetate. In some embodiments, the amino compound comprises ammonia and/or urea. In some embodiments, the number of layers of the graphene oxide is 1-10, and the oxygen content is 30at% to 60at%. In some embodiments, the mass ratio of carbon atoms in the graphene oxide to platinum atoms in the platinum salt is (0.5-3): 1. In some embodiments, the mass ratio of carbon atoms in the graphene oxide-platinum salt composite powder to nitrogen atoms in the amino compound is (1-10): 1. In some embodiments, the hydrothermal reaction is at a temperature of 80 ℃ to 120 ℃ for 0.5h to 3h. In some embodiments, the microwave irradiation has a power of 1kW to 15kW for 5s to 300s. In some embodiments, the rotational speed of the ball mill is 200rpm to 500rpm for 0.5h to 3h. In some embodiments, the method of forming a mixture comprises: dispersing the graphene oxide in water to form graphene oxide dispersion liquid; dissolving the platinum salt in an organic solvent to form a platinum salt solution, and Mixing the