CN-121983600-A - Platinum-based catalyst based on molybdenum carbide nanofiber and preparation method and application thereof

Abstract

The invention discloses a platinum-based catalyst based on molybdenum carbide nanofibers, and a preparation method and application thereof. Through an electrostatic spinning process, preparing a [ CH 3 COCH=C(O-)CH 3 ] 2 MoO 2 /C nanofiber material in advance, carrying out high Wen Tanre treatment to obtain a Mo 2 C@CNFs nanofiber carrier, and carrying platinum nanoparticles on the carrier by using a mode of physical adsorption and then thermal adsorption to obtain the Pt/Mo 2 C@CNFs catalyst material. According to the invention, platinum nano particles are loaded on a molybdenum carbide nanofiber carrier, the adsorption effect of an acid HOR reaction intermediate is coordinated and optimized by utilizing the high activity effect of the platinum nano particles and the corrosion resistance and efficient charge transfer effect of molybdenum carbide, and the CO poisoning resistance and the phosphoric acid poisoning resistance of the material are improved, so that the improvement of the catalytic activity of the acid HOR is finally realized.

Inventors

• LI TONGFEI
• ZHOU XI
• QIAN TAO
• ZHANG JINGWEN
• LU WENKANG
• LIU MENGJIAO
• SUN LINBO

Assignees

• 南通大学

Dates

Publication Date

20260505

Application Date

20251230

Claims (10)

1. 1. A method for preparing a platinum-based catalyst based on molybdenum carbide nanofibers, comprising the steps of: s1, preparing [ CH 3 COCH=C(O-)CH 3 ] 2 MoO 2 /C nanofiber material Adding molybdenum acetylacetonate, polyacrylonitrile and zinc acetate dihydrate into N, N-dimethylformamide solvent respectively, stirring at normal temperature for 12 h, transferring into an injector, collecting spinning fibers by using an electrostatic spinning machine and an aluminum foil as a collector, and collecting to obtain a [ CH 3 COCH=C(O-)CH 3 ] 2 MoO 2 /C nanofiber material; S2, preparing Mo 2 C@CNFs The [ CH 3 COCH=C(O-)CH 3 ] 2 MoO 2 /C nanofiber material is placed in a muffle furnace for pre-oxidation, and then is subjected to high-temperature heat treatment to obtain Mo 2 C@CNFs; s3, preparing Pt/Mo 2 C@CNFs Dissolving Mo 2 C@CNFs and chloroplatinic acid (H 2 PtCl 6 ) in glycol (C 2 H 6 O 2 ), stirring, adding KOH aqueous solution to adjust pH, carrying out oil bath reaction, centrifugally washing and drying to obtain the platinum-based catalyst based on molybdenum carbide nano fibers, which is marked as Pt/Mo 2 C@CNFs.
2. 2. The method for preparing a platinum-based catalyst based on molybdenum carbide nanofibers according to claim 1, wherein the mass ratio of the molybdenum acetylacetonate to zinc acetate dihydrate in step S1 is 1:2-2:1, and the polyacrylonitrile is used in an amount of 0.5-1.5g.
3. 3. The preparation method of the platinum-based catalyst based on the molybdenum carbide nanofiber, according to claim 1, wherein the volume of DMF in the step S1 is 5-15 mL.
4. 4. The method for preparing the platinum-based catalyst based on the molybdenum carbide nanofiber according to claim 1, wherein parameters of the electrostatic spinning machine in the step S1 are set to be that the flow rate is 0.04-0.12 mm min -1 , the applied voltage is 10-25 kV, and the distance from the tip of the nozzle to the receiving plate is 8-20 cm.
5. 5. The method for preparing a platinum-based catalyst based on molybdenum carbide nanofibers according to claim 1, wherein the pre-oxidation in step S2 is performed by heating to 100-300 ℃ at a heating rate of 1-4 ℃ per minute, and maintaining the temperature at 1-4 h.
6. 6. The method for preparing a platinum-based catalyst based on molybdenum carbide nanofibers according to claim 1, wherein the high temperature heat treatment in step S2 is to raise the temperature to 600-1000 ℃ at a heating rate of 2-10 ℃ per minute, and keep the temperature at 1-5 h.
7. 7. The preparation method of the platinum-based catalyst based on the molybdenum carbide nanofiber, which is characterized in that in the step S3, the consumption of Mo 2 C@CNFs is 5-50mg, the consumption of H 2 PtCl 6 is 2-10mg, the consumption of ethylene glycol is 2-20mL, the mass ratio of chloroplatinic acid to Mo 2 C@CNFs is 1:3.72, the oil bath reaction is 2-10 h, the drying temperature is 50-80 ℃, and the drying time is 8-12 h.
8. 8. A platinum-based catalyst based on molybdenum carbide nanofibers prepared by the preparation method of any one of claims 1 to 7.
9. 9. The molybdenum carbide nanofiber-based platinum-based catalyst of claim 8, wherein the molybdenum carbide nanofiber-based platinum-based catalyst is a long nanofiber structure composed of Mo 2 C nanoparticles, the Pt nanoparticles being uniformly embedded in the nanofiber surface.
10. 10. The platinum-based catalyst based on the molybdenum carbide nanofiber prepared by the preparation method of claim 8 is used as an acidic HOR catalyst in an acidic hydrogen oxidation reaction.

Description

Platinum-based catalyst based on molybdenum carbide nanofiber and preparation method and application thereof Technical Field The invention belongs to the field of proton exchange membrane fuel cells, and relates to a platinum-based catalyst based on molybdenum carbide nanofibers, and a preparation method and application thereof. Background The proton exchange membrane fuel cell (Proton Exchange Membrane Fuel Cells, PEMFC) is a novel energy source for directly converting chemical energy stored in hydrogen molecules into electric energy through electrochemical reaction, has the advantages of zero emission, high energy conversion efficiency, high response speed and the like, and is widely applied to the fields of automobiles, submarines, unmanned aerial vehicles and the like. The carbon-supported platinum-based catalyst is a universal anode catalyst, and under the working condition of PEMFC (0.6-0.8V and pH < 1), the carbon carrier of Pt nano particles is easy to corrode, so that CO is generated and the structure is damaged. In addition, during the start-up and stop operation of the PEMFC, the local potential of the cathode reaches 1.5V due to the existence of reverse current, which greatly aggravates the further oxidation of the carbon carrier. Previous studies have shown that after a potentiostatic test of 4000 min at a potential of 1.5V, the weight loss of carbon due to corrosion is about 19%. After carbon corrosion, pt nanoparticles on the carbon support surface tend to dissolve and migrate, resulting in a decrease in catalytic performance. Meanwhile, the weak interaction between Pt and carbon support makes Pt particles also easy to migrate and aggregate, and in view of this, it is an urgent need for the development of PEMFC technology to find an electrochemically stable and conductive support material having stronger interaction with Pt nanoparticles to replace carbon. Molybdenum carbide (Mo 2 C) has high chemical and mechanical stability, rich metal active sites, and has attracted great attention in the oxidation and reduction reactions due to its d-electron structure and similar catalytic properties to noble metal-based cocatalysts. Notably, combining Mo 2 C with non-metallic elements (such as nitrogen, phosphorus, carbon, and sulfur) has been demonstrated to be effective in forming active sites and reducing the number of unoccupied d orbitals of Mo, thereby further increasing catalytic activity. The Mo 2 C materials currently studied, usually in the form of low specific surface area, are unfavorable for charge transfer, and thus methods of forming Mo 2 C nanostructures such as nanotubes, nanofibers, nanoplates, etc. have been developed to increase their surface area. For example, wei et al explored the HOR catalytic process of Ir/O, ir/Mo and Ir/MoO 2, and found through DFT calculation that the surface electronic structure of the catalyst can be well regulated by constructing chemical bonds with different interfaces, thereby affecting the catalytic activity. Because of the low localization of the interface electrons, ir/O-MoO 2 transfers charge from the surface to the interface through the interface Ir-O bonds, thereby lowering the d-band center of the surface, which makes the adsorption of H and OH weaker and shows higher theoretical activity. And Ir/Mo-MoO 2, on the contrary, shows lower HOR theoretical activity. In addition to the synergistic effect between the support and the metal, recent studies have been carried out to find that monoatomic metals can also regulate the activity of the catalyst. Zheng et al propose a single-atom Mo modified Pt catalyst loaded on N-doped C, which greatly improves the catalytic activity and exhibits a strong resistance to CO poisoning. Disclosure of Invention In order to overcome the defects of the prior art, the invention aims to provide a platinum-based catalyst based on molybdenum carbide nanofibers, and a preparation method and application thereof. The invention relates to a preparation technology of a Pt nano particle loaded Mo 2 C nanofiber with improved hydrogen oxidation performance as a proton exchange membrane fuel cell anode electrocatalyst, and the prepared Pt /Mo2 C@CNFs shows excellent activity and stability as an acidic hydrogen oxidation electrocatalyst material. Meanwhile, the method fully utilizes the stability of the structure and the excellent electronic conductivity of Mo 2 C, cooperates with Pt nano particles, fully plays a role in reasonably adsorbing and desorbing active sites and reaction intermediates, and resists poisoning of CO and phosphoric acid on the active sites. In order to solve the problems in the prior art, the invention adopts the following technical scheme: A method for preparing a platinum-based catalyst based on molybdenum carbide nanofibers, comprising the following steps: S1, preparing a [ CH 3COCH=C(O-)CH3]2MoO2/C nanofiber material; Adding molybdenum acetylacetonate ([ CH 3COCH=C(O-)CH3]2MoO2), polyacrylonitrile (PAN) and