Search

CN-122025677-A - Carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt4PdFeCoNi, and preparation method and application thereof

CN122025677ACN 122025677 ACN122025677 ACN 122025677ACN-122025677-A

Abstract

The invention discloses a carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi and a preparation method and application thereof, wherein the method comprises the steps of (1) uniformly mixing a platinum-containing precursor, a palladium-containing precursor, an iron-containing precursor, a cobalt-containing precursor, a nickel-containing precursor and a carbon carrier in a solvent, removing the solvent and drying to obtain a mixture; and (2) reducing and preserving heat of the mixture in a reducing atmosphere to obtain the carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi. The high-entropy platinum-based intermetallic compound HEI-Pt 4 PdFeCoNi provided by the invention has an optimal d-band center, and simultaneously achieves high oxygen reduction activity and high durability stability by utilizing the combined action of the cocktail effect of a high-entropy structure and the ordered structure of the intermetallic compound.

Inventors

  • ZHOU WEI
  • CHEN DUO
  • LI CHANG
  • MAO YIYANG
  • MIAO JIE

Assignees

  • 南京工业大学

Dates

Publication Date
20260512
Application Date
20260210

Claims (10)

  1. 1. The preparation method of the carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi is characterized by comprising the following steps of: (1) Uniformly mixing a platinum-containing precursor, a palladium-containing precursor, an iron-containing precursor, a cobalt-containing precursor, a nickel-containing precursor and a carbon carrier in a solvent, removing the solvent and drying to obtain a mixture; (2) And reducing and preserving heat of the obtained mixture in a reducing atmosphere to obtain the carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi.
  2. 2. The preparation method of the nickel-containing precursor composition according to claim 1, wherein in the step (1), the platinum-containing precursor is one or more of platinum dichloride, platinum (II) nitrate, potassium chloroplatinite, platinum acetylacetonate and chloroplatinic acid hexahydrate, the palladium-containing precursor is one or more of palladium dichloride, palladium tetraammine dichloride monohydrate, palladium (II) nitrate, ammonium chloropalladate, potassium chloropalladate, palladium acetylacetonate and palladium (II) acetate, the iron-containing precursor is one or two of ferric nitrate and ferric chloride, the cobalt-containing precursor is one or two of cobalt nitrate and cobalt chloride, and the nickel-containing precursor is one or two of nickel nitrate and nickel chloride.
  3. 3. The method of claim 1, wherein in step (1), the amount of platinum-containing precursor, palladium-containing precursor, iron-containing precursor, cobalt-containing precursor, nickel-containing precursor is controlled such that the molar ratio Pt, pd, fe, co, ni is 4 (0.8-1.2): 0.8-1.2: (0.8-1.2), optionally 4:1:1:1.
  4. 4. The method of claim 1, wherein in step (1), the carbon support comprises carbon black.
  5. 5. The method according to claim 1, wherein in the step (1), the amount of the carbon support is controlled so that the total mass of the metal in the platinum-containing precursor, the palladium-containing precursor, the iron-containing precursor, the cobalt-containing precursor, and the nickel-containing precursor is 15 to 45% in terms of the ratio of the total mass of the metal to the total mass of the carbon support.
  6. 6. The method according to claim 1, wherein in the step (2), the reduction and heat preservation is carried out by reducing at 930-970 ℃, and then cooling to 580-620 ℃ and preserving heat.
  7. 7. The method of claim 6, wherein the time for the reduction is 1-3 h.
  8. 8. The method of claim 6, wherein the incubation time is 4-8 h.
  9. 9. The carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi prepared by the method of any one of claims 1 to 8.
  10. 10. Use of the carbon-supported platinum-based high entropy intermetallic compound HEI-Pt 4 PdFeCoNi as claimed in claim 9 as a cathode catalyst in proton exchange membrane fuel cells.

Description

Carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi, and preparation method and application thereof Technical Field The invention relates to the technical field of nano materials, in particular to a preparation method and practical application of a carbon-supported platinum-based high-entropy intermetallic compound HEI-Pt 4 PdFeCoNi serving as an oxygen reduction electrocatalyst on a cathode side of a proton exchange membrane fuel cell for element composition screening based on d-band center optimization. Background This section provides merely background information related to the present disclosure and is not necessarily prior art. Carbon supported platinum based catalysts are the most widely used oxygen reduction electrocatalyst on the cathode side of proton exchange membrane fuel cells today due to their optimal adsorption energy for oxygen. However, since the carbon-supported platinum-based catalyst is expensive and the carbon-supported platinum-based alloy catalyst is very easy to cause agglomeration of particles and dissolution of metals due to carbon corrosion generated by start-up and shut-down of the battery or water management after long-time operation of the battery. For this reason, it is a great difficulty to reduce the cost of the carbon-supported platinum-based catalyst and to improve its durability, so that the proton exchange membrane fuel cell has a long life. The use cost of the metal platinum is reduced by alloying with non-noble metals (iron, cobalt, nickel and the like), and the d-band center of the metal platinum is regulated by adopting an alloying effect, so that the adsorption energy of oxygen is reduced, and the oxygen reduction activity of the metal platinum is improved. The alloy composition of the traditional carbon-supported platinum-based alloy mainly comprises a non-noble metal or two non-noble metal components and noble metal platinum in a disordered structure, and the structure can easily produce non-noble metal dissolution in long-term operation of a proton exchange membrane fuel cell, so that the activity and durability of the catalyst are reduced. The intermetallic compound has the structural characteristic of ordered arrangement of atoms, and the strong d-d orbit interaction between atoms ensures that the alloy has high stability and can make up for the characteristic of lack of stability of disordered alloy. However, although the stability of the alloy catalyst is improved by the single intermetallic compound, the oxygen reduction activity of the platinum metal is not greatly improved due to the isolation of the active site, and in addition, the optimal combination cannot be obtained quickly due to excessive screenable elements, meanwhile, the metal particle size of the catalyst which is theoretically suitable for an electrocatalytic system is less than 5nm, and the intermetallic compound with small size is difficult to prepare, so that the wide application of the platinum-based metal compound as the oxygen reduction electrocatalyst in proton exchange membrane fuel cells is further limited. Disclosure of Invention The invention aims to solve the technical problem of providing a method for screening a carbon-supported platinum-based intermetallic catalyst, a high-performance platinum-based high-entropy intermetallic compound catalyst, and a preparation method and application thereof. In order to solve the technical problems, the invention discloses the following technical scheme: in the technical scheme of the invention, the d-band center theory is adopted to screen a plurality of high-entropy element combinations. Specifically, based on the density functional theory, elements Pt, pd, fe, co, ni and Cu are selected for element combination, and screening is performed in classical theoretical calculation software VASP. Wherein the cut-off energy of the structural model is set to 450eV, and the K point is set to 2×2×1 for state density calculation and other calculations. The atomic structure is fully relaxed until the force on each atom is 0.05eV a -1. To ensure the rationality of the calculation result, a dispersion corrected DFT-D3 method is set for the adsorption model. The calculated data was analyzed using the vaspkit program. Wherein, the selected element composition is HEI-Pt5PdFeCoNiCu,HEI-Pt4PdFeCoNi,HEI-Pt4FeCoNiCu,HEI-Pt4PdFeCoCu,HEI-Pt4PdFeNiCu,HEI-Pt4PdCoNiCu,, all structural models are (111) crystal face models, HEI-Pt 4 PdFeCoNi obtained by various combinations has the optimal d-band center and theoretically has the optimal oxygen reduction activity. In a second aspect, the present invention provides novel high entropy platinum-based intermetallic compounds HEI-Pt 4 PdFeCoNi and methods of making the same. In some embodiments, the method comprises the steps of: (1) Uniformly mixing a platinum-containing precursor, a palladium-containing precursor, an iron-containing precursor, a cobalt-containing precursor, a nickel-contai