CN-122025678-A - Preparation method of platinum-carbon catalyst

Abstract

The invention relates to the technical field of platinum-carbon catalysts, in particular to a preparation method of a platinum-carbon catalyst. Adding a carbon carrier into a polyalcohol solvent, adding an acidic auxiliary dispersing agent, dispersing to obtain a carbon carrier dispersion liquid, adding a platinum precursor solution into the carbon carrier dispersion liquid, dispersing to obtain a mixed liquid, adding an alkaline regulator into the mixed liquid, regulating the pH of a system to be alkaline, dispersing in an inert atmosphere to obtain a liquid mixture, heating the liquid mixture for a reduction reaction, then cooling, regulating the pH of a cooled product solution to be acidic, carrying out post-treatment to obtain a solid substance, heating the solid substance in the inert atmosphere for heat preservation, cooling and grinding to obtain the platinum-carbon catalyst. The invention prepares the carbon carrier dispersion liquid by mixing the acid dispersion aid agent with the carbon carrier and the polyalcohol solvent, realizes the uniform dispersion and the surface property optimization of the carbon carrier, and lays a foundation for the subsequent uniform loading of platinum particles.

Inventors

• LIU HAITAO
• WANG YUNQIANG
• DUAN YUTING
• ZHANG YUHANG
• SHI YAN
• Pei Guanru
• YI YAFEI
• MA FANGFANG
• LI PENG
• SHI BINGJIE

Assignees

• 北京亿华通科技股份有限公司

Dates

Publication Date

20260512

Application Date

20260211

Claims (10)

1. 1.A preparation method of a platinum-carbon catalyst is characterized by comprising the steps of mixing a carbon carrier, a polyalcohol solvent and an acidic auxiliary dispersing agent, dispersing to obtain a carbon carrier dispersion liquid, adding a platinum precursor solution into the carbon carrier dispersion liquid, dispersing to obtain a mixed liquid, adding an alkaline regulator into the mixed liquid, regulating the pH value of a system to be alkaline, dispersing in an inert atmosphere to obtain a liquid mixture, heating the liquid mixture for a reduction reaction, cooling after the reaction is finished, regulating the pH value of a cooled product solution to be acidic, carrying out post treatment to obtain a solid substance, heating the solid substance under the inert atmosphere for heat preservation, and grinding after cooling to obtain the platinum-carbon catalyst.
2. 2. The method for preparing a platinum carbon catalyst according to claim 1, wherein the acidic dispersion aid agent comprises at least one of acetic acid, formic acid, perchloric acid, hydrochloric acid, nitric acid, sulfuric acid, phytic acid and oxalic acid.
3. 3. The method for preparing a platinum carbon catalyst according to claim 1, wherein the polyhydric alcohol solvent comprises at least one of ethylene glycol, propylene glycol, glycerol, 1, 4-butanediol, diethylene glycol, triethylene glycol.
4. 4. The method for preparing a platinum carbon catalyst according to claim 1, wherein the platinum precursor comprises at least one of chloroplatinic acid hexahydrate, ammonium chloroplatinate, potassium tetrachloroplatinate, dinitroso diammine platinum, and platinum acetylacetonate.
5. 5. The method for producing a platinum carbon catalyst according to any one of claims 1 to 4, wherein the concentration of the acidic auxiliary dispersant is 0.1 to 20mol/L.
6. 6. The method for preparing a platinum carbon catalyst according to claim 5, wherein the concentration of the platinum precursor in the platinum precursor solution is 10 to 50mg/mL.
7. 7. The method for producing a platinum carbon catalyst according to claim 6, wherein the mass ratio of the carbon support to the platinum precursor is (0.2 to 8): 1.
8. 8. The method for producing a platinum carbon catalyst according to claim 7, wherein the mass ratio of the carbon support to the platinum precursor is (0.5 to 6): 1.
9. 9. The method for preparing a platinum carbon catalyst according to claim 1, wherein the temperature of the reduction reaction is 100 to 150 ℃ for 2 to 5 hours.
10. 10. The method for preparing a platinum carbon catalyst according to claim 9, wherein the temperature of the heat preservation is 400-700 ℃ for 2-6 hours.

Description

Preparation method of platinum-carbon catalyst Technical Field The invention relates to the technical field of platinum-carbon catalysts, in particular to a preparation method of a platinum-carbon catalyst. Background The proton exchange membrane fuel cell is used as an important direction of clean energy technology, the core performance of the proton exchange membrane fuel cell depends on the efficiency of a catalyst layer, and a platinum-carbon catalyst is a current mainstream electrode material due to the fact that the platinum-carbon catalyst has high specific surface area and excellent catalytic activity. In commercial applications, platinum carbon catalysts are typically designed with high loadings of 20-60wt% for balanced activity and durability, requiring platinum particle size control at 3-5nm and uniform dispersion on the carbon support surface, which presents a stringent challenge to the platinum loading process. The polyol reduction method is a conventional technology for preparing the platinum-carbon catalyst, and the size of platinum particles can be regulated and controlled by adjusting the parameters of a reaction system, but under a high-load condition, the problems of platinum particle agglomeration, uneven dispersion of the surface of a carbon carrier and the like are outstanding, and the performance improvement of the catalyst is restricted. The prior art has been developed around the optimization of polyol reduction processes, but all suffer from significant drawbacks. The Chinese patent application CN119092724A discloses a method for preparing platinum-carbon catalysts with different particle diameters by adjusting the addition amount of a polyol alkali solution, although the regulation and control of the platinum particle size are realized, the problems of agglomeration and uneven dispersion under high load cannot be solved, and the scheme of adopting water to adjust the carbon dispersion liquid can only realize low-load preparation of 20wt percent, so that the technical applicability is limited. The Chinese patent application CN119230850A proposes a preparation scheme of a polyol-water mixed solvent system, chloroplatinic acid is dispersed in an ethylene glycol-water mixed solvent and then added into a carbon carrier, no auxiliary dispersing agent is needed, but the chloroplatinic acid is easy to hydrolyze in an aqueous solution to form platinum oxide nanoclusters, so that platinum is sparsely loaded on the surface of the carbon carrier, and the actual loading is lower than expected. The Chinese patent application CN117790826A adopts a preparation technology of the microwave reaction of the polyaminobenzene auxiliary polyol, the microwave reaction energy is limited, the macro preparation requirement is difficult to meet, the triaminobenzene is easy to be adsorbed on the surface of the catalyst and difficult to be removed, and the catalyst is easy to poison to influence the catalytic activity. In summary, the technical scheme for preparing the platinum-carbon catalyst by the existing polyol reduction method has the defects in the aspects of uniform dispersion control of high-load platinum particles, residual poisoning of dispersing agents, suitability for mass preparation and the like, and cannot meet the performance and preparation requirements of commercial-grade high-load platinum-carbon catalysts, and development of a preparation technology which can realize uniform load of high load, easy removal of dispersing agents and simple process is needed. Disclosure of Invention The first aspect of the invention provides a preparation method of a platinum-carbon catalyst, which comprises the steps of adding a carbon carrier into a polyalcohol solvent, adding an acidic auxiliary dispersing agent, dispersing to obtain a carbon carrier dispersion liquid, adding a platinum precursor solution into the carbon carrier dispersion liquid, dispersing to obtain a mixed liquid, adding an alkaline regulator into the mixed liquid, regulating the pH of a system to be alkaline, dispersing in an inert atmosphere to obtain a liquid mixture, heating the liquid mixture for reduction reaction, then cooling, regulating the pH of a cooled product solution to be acidic, performing post-treatment to obtain a solid substance, heating the solid substance under the inert atmosphere for heat preservation, and grinding after cooling to obtain the platinum-carbon catalyst. The carbon carrier has strong hydrophobicity, and agglomerates are easily formed due to the difference of surface tension after the polyalcohol solvent is directly added. In the prior art, no targeted modification means is introduced in the carbon carrier dispersing stage, and only the subsequent mixing of the platinum precursor and the solvent is relied on, so that the platinum precursor can only be attached to the outer surface of the carbon carrier aggregate, cannot permeate into the aggregate or be uniformly adsorbed on the surface of a single ca