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KR-20260062705-A - METHOD FOR PRODUCING PLATINUM ALLOY CATALYST

KR20260062705AKR 20260062705 AKR20260062705 AKR 20260062705AKR-20260062705-A

Abstract

The present invention relates to a method for manufacturing a platinum-based alloy catalyst, characterized by using a solution combustion synthesis method, wherein a metal to form an alloy with platinum is first supported on a carrier, and then platinum is supported.

Inventors

  • 강우람

Assignees

  • 현대자동차주식회사
  • 기아 주식회사

Dates

Publication Date
20260507
Application Date
20241029

Claims (11)

  1. Step (S1) of preparing a primary precursor composition comprising a metal salt, a carrier salt, and a first reducing agent; Step (S2) of obtaining a first particle by first combusting the above first precursor composition; Step (S3) of preparing a secondary precursor composition comprising the first particle, platinum salt, and second reducing agent; A step (S4) of obtaining a second particle by secondarily combusting the above second precursor composition; and A method for manufacturing a platinum-based alloy catalyst comprising the step (S5) of reducing the second particle.
  2. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the metal salt comprises one or more metals selected from the group consisting of Ni, Cu, Fe, Co, Mo, Mn, and Ag.
  3. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the metal salt is one or more selected from the group consisting of metal nitrates, sulfur oxides, chloride oxides, superoxide, ammonides, halides, and hydrates thereof.
  4. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the above-mentioned carrier salt comprises a metal-based carrier or a carbon-based carrier.
  5. In paragraph 1, A method for preparing a platinum-based alloy catalyst in which the first reducing agent and the second reducing agent are each independently selected from the group consisting of urea, glycine, sucrose, glucose, citric acid, hydrazine monohydrate, carbohydrazide, oxalyl dihydrazide, hexamethylenetetraamine, and acetylacetone.
  6. In paragraph 1, A method for preparing a platinum-based alloy catalyst in which the molar ratio between the metal salt and the first reducing agent in the above-mentioned primary precursor composition is 1:1.5 to 1:3.
  7. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the above primary combustion is initiated at a temperature of 250 to 450°C.
  8. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the platinum salt is one or more selected from the group consisting of platinum nitrates, sulfur oxides, chloride oxides, superoxide oxides, ammonides, halides, and hydrates thereof.
  9. In paragraph 1, A method for preparing a platinum-based alloy catalyst in which the molar ratio between the platinum salt and the second reducing agent in the above secondary precursor composition is 1:20 to 1:40.
  10. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the molar ratio between the metal salt in the primary precursor composition and the platinum salt in the secondary precursor composition is 30:70 to 70:30.
  11. In paragraph 1, A method for manufacturing a platinum-based alloy catalyst in which the secondary combustion is initiated at a temperature of 250 to 450°C.

Description

Method for producing platinum alloy catalyst The present invention relates to a method that can increase the platinum concentration on the catalyst surface by using a two-step solution combustion synthesis method, thereby enabling the production of a platinum-based alloy catalyst having excellent catalytic activity at a low cost. Platinum is evaluated as a material exhibiting excellent catalytic activity in various chemical reactions, such as automobile exhaust gas treatment, fuel cells, crude oil refining, organic compound synthesis, and hydrogen production, due to its unique electronic structure. However, the high cost of platinum is the biggest obstacle to the commercialization of platinum-based catalysts, and various studies are actively underway to enhance catalytic activity while minimizing platinum usage. As a means to reduce platinum usage and enhance catalytic activity, there are attempts to maximize the active surface area for reaction participation by reducing platinum particles to the nanoscale, or to expand the active surface area by increasing the degree of platinum dispersion through the loading of platinum particles onto porous support materials. Additionally, research has been conducted to improve catalytic activity while relatively reducing platinum usage by alloying platinum with low-cost metal materials that exhibit catalytic synergy. In particular, catalysts alloyed with platinum and other metals are known to demonstrate excellent catalytic performance for reforming reactions that produce hydrogen from various hydrocarbons. However, synthesis methods used to manufacture such platinum-based alloy catalysts, such as impregnation, precipitation, or ion exchange, have problems including difficulty in forming nano-sized catalyst particles, a wide particle size distribution, and complex and time-consuming catalyst fabrication. Therefore, the solution combustion synthesis method is being newly researched as an alternative to the aforementioned manufacturing methods. The solution combustion synthesis method is a method for producing a catalyst by inducing a combustion reaction in a state where a metal salt is mixed with a reducing agent to produce metal oxide powder, and then reducing it. When two or more metals are used as the metal salts, alloy catalysts can be produced, and when a precursor for a support is used together, supported catalysts can also be produced. Since the combustion reaction is completed within a few seconds to minutes, the solution combustion synthesis method has the advantage of being able to rapidly produce a catalyst with a simple process, and has the advantage of being able to produce a porous catalyst due to the rapid gas ejection that occurs during the combustion process. However, the aforementioned solution combustion synthesis method is known to be unsuitable for the manufacture of platinum-based alloy catalysts. This is because, during the high-temperature combustion reaction, platinum particles migrate and become embedded within the support, resulting in a reduced number of platinum particles distributed on the surface of the catalyst particles. Consequently, the performance of the catalyst is insufficient relative to the amount of platinum used, or the amount of platinum used must be significantly increased to achieve sufficient performance. Therefore, a new manufacturing method is required that can be applied to the production of platinum-based alloy catalysts while retaining the advantages of the solution combustion synthesis method described earlier. Figure 1 is a diagram showing the manufacturing process of the platinum-based alloy catalyst of the present invention. Figure 2 is a figure showing the XPS analysis results for the catalyst of Example 1 and the catalyst of the comparative example. Figure 3 shows the HADDF-STEM analysis results and energy dispersive spectral analysis results for the catalyst of Example 2. Figure 4 is a figure comparing the catalytic activity of the catalyst of Example 1 and the catalyst of the comparative example for the hydrazine decomposition reaction. The present invention will be described in more detail below. Terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. The present invention provides a method for manufacturing a platinum-based alloy catalyst comprising the steps of: preparing a primary precursor composition comprising a metal salt, a carrier salt, and a first reducing agent (S1); obtaining a first particle by first combusting the primary precursor composition (S2); preparing a secondary precursor composition comprising the first particle, a platinum salt, and a second reducing agent (S3); obtaining a second