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CN-121983598-A - Catalyst for direct methanol fuel cell and preparation method thereof

CN121983598ACN 121983598 ACN121983598 ACN 121983598ACN-121983598-A

Abstract

The invention discloses a catalyst of a direct methanol fuel cell and a preparation method thereof, wherein a structural unit of the catalyst takes a vertically oriented carbon nano tube as a conductive network, platinum iron cobalt nickel copper high-entropy alloy is loaded on the conductive network, and the preparation method comprises the following steps that S1 prepares the vertically oriented carbon nano tube; S2, carrying out hydrothermal reaction to load iron cobalt nickel copper nano-sheets to obtain iron cobalt nickel copper hydroxide@vertical orientation carbon nano-tubes, S3, putting the obtained iron cobalt nickel copper hydroxide@vertical orientation carbon nano-tubes into a chloroplatinic acid solution to be soaked to load platinum ions, and S4, carrying out plasma reduction treatment on the iron cobalt nickel copper hydroxide@vertical orientation nano-tubes soaked in the chloroplatinic acid solution in an argon-hydrogen atmosphere by utilizing a radio frequency plasma technology to obtain the direct methanol fuel cell catalyst, wherein the direct methanol fuel cell catalyst has the characteristics of high specific surface area, more active sites, excellent performance, low cost and long-term stability.

Inventors

  • JIANG ZHONGQING
  • REN XIAORUI

Assignees

  • 浙江理工大学

Dates

Publication Date
20260505
Application Date
20251222

Claims (10)

  1. 1. The catalyst for direct methanol fuel cell features that its structure unit has vertically oriented carbon nanotube as conducting network and Pt-Fe-Co-Ni-Cu alloy with high entropy is loaded onto the conducting network.
  2. 2. A method for preparing the catalyst for direct methanol fuel cells as claimed in claim 1, comprising the steps of: S1, preparing a carbon nano tube which grows vertically and directionally; S1.1, carrying out hydrolytic pyrolysis treatment on carbon cloth, and loading a silica thin layer on the surface of the carbon cloth; S1.2, growing carbon nano tubes on the surface of the carbon cloth material in situ by adopting a chemical vapor deposition process on the carbon cloth treated in the step S1.1, introducing a carbon source solution through a microinjection pump in a high-temperature tube furnace at the temperature of 800-900 ℃ under an inert atmosphere to prepare a hybrid material, wherein the hybrid material is marked as VACNTs@CC; S2, carrying out hydrothermal reaction to load an iron cobalt nickel copper nano-sheet to obtain an iron cobalt nickel copper hydroxide@vertical orientation carbon nano-tube, which is marked as FeCoNiCu LDH/VACNTs@CC; S3, putting the obtained iron cobalt nickel copper hydroxide@vertical orientation carbon nanotube into a chloroplatinic acid solution to be soaked so as to load platinum ions, and marking the platinum ions as PtFeCoNiCu@VACNTs@CC. S4, performing plasma reduction treatment on the iron cobalt nickel copper hydroxide@vertical orientation nanotube soaked in the chloroplatinic acid solution by utilizing a radio frequency plasma technology in an argon-hydrogen atmosphere to obtain the direct methanol fuel cell catalyst, wherein the direct methanol fuel cell catalyst is named as P-PtFeCoNiCu@VACNTs@CC.
  3. 3. The method for preparing a catalyst for direct methanol fuel cells according to claim 2, wherein before the carbon cloth is subjected to hydrolytic pyrolysis treatment, carbon is placed in an inert atmosphere, and after the temperature is raised to 800-900 ℃ at a heating rate of 4-6 DEG Cmin -1 , the carbon cloth is subjected to heat preservation for 25-35min to remove the polymer film on the surface of the carbon cloth.
  4. 4. The preparation method of the direct methanol fuel cell catalyst according to claim 2, wherein the hydrolytic pyrolysis treatment in the step S1.1 is specifically that toluene is firstly measured, then the same amount of tetraethyl orthosilicate and silicon tetrachloride are added, then ultrasound is carried out for 25-35min, namely a precursor solution, carbon cloth is soaked in the precursor solution for 1h, taken out and dried, kept for 60min at 150-250 ℃, then kept for 55-65min at 800-900 ℃, and a silicon dioxide thin layer is loaded on the surface of the carbon cloth.
  5. 5. The preparation method of the direct methanol fuel cell catalyst according to claim 2, wherein the preparation method of the carbon source solution in the step S1.2 is characterized in that ferrocene is weighed, then absolute ethyl alcohol and dimethylbenzene are weighed, finally ethylenediamine is extracted and stirred uniformly to obtain the carbon source solution, wherein the ferrocene is 600mg, the absolute ethyl alcohol is 9.8ml, the dimethylbenzene is 9.8ml and the ethylenediamine is 0.4ml.
  6. 6. The method for preparing the direct methanol fuel cell catalyst according to claim 2, wherein the preparation process of the step S2 comprises dissolving iron transition metal salt, cobalt transition metal salt, nickel transition metal salt, copper transition metal salt, urea and ammonium fluoride in deionized water, stirring thoroughly to dissolve, putting into a vertically oriented carbon nanotube, reacting at 110-130 ℃ for 5-7h, taking out after cooling, washing with deionized water and ethanol, and drying for 6-24h.
  7. 7. The method for preparing a catalyst for a direct methanol fuel cell according to claim 6, wherein one or more of FeSO 4 、FeCl 3 、FeCl 2 、Fe(NH 2 SO 3 ) 3 , one or more of Co(NO 3 ) 2 ·6H 2 O、CoCl 2 ·6H 2 O、Co(CH 3 COO) 2 ·4H 2 O、CoSO 4 ·6H 2 O、CoCl 2 , one or more of NiC 10 H 14 O 4 、NiCl 2 ·6H 2 O、Ni(NO 3 ) 2 ·6H 2 O、NiC 4 H 6 O 4 ·4H 2 O、NiCO 3 , and one or more of CuCl 2 ·2H 2 O、CuSO 4 ·5H 2 O、Cu(CH 3 COO) 2 ·H 2 O、Cu(NO 3 ) 2 ·3H 2 O are used as the iron transition metal salt, the cobalt transition metal salt, and the copper transition metal salt.
  8. 8. The method for preparing a catalyst for a direct methanol fuel cell as in claim 6, wherein the FeCl 3 ·3H 2 O:Co(NO 3 ) 2 ·6H 2 O:Ni(NO 3 ) 2 ·6H 2 O:Cu(NO 3 ) 2 ·3H 2 O molar ratio is 1:1:1:1.
  9. 9. The method for preparing a catalyst for a direct methanol fuel cell according to claim 2, wherein the concentration of chloroplatinic acid solution in the step S3 is 0.1mol/L chloroplatinic acid, and the soaking time is 10 to 14 hours.
  10. 10. The method for preparing the direct methanol catalyst according to claim 2, wherein the step S4 is specifically that the iron cobalt nickel copper hydroxide @ vertically oriented carbon nanotubes loaded with platinum ions are placed into a porcelain boat, the porcelain boat is placed into a plasma enhanced chemical vapor deposition device, argon hydrogen is introduced for plasma reduction, the temperature of the heat preservation in the tube is 500 ℃, the pressure in the tube is 20Pa, the discharge power is 100W, and the discharge time is 30-90min.

Description

Catalyst for direct methanol fuel cell and preparation method thereof Technical Field The invention relates to the technical field of methanol fuel cell catalysts, in particular to a direct methanol fuel cell catalyst and a preparation method thereof. Background The demand for energy by humans is increasing and is becoming increasingly difficult to meet. Currently, the global great demand for energy is mainly dependent on fossil fuels that are not renewable and have a negative impact on the environment. However, with the gradual proliferation of world economy, how to reduce fossil fuel consumption and solve the environmental problems caused by the fossil fuel consumption has become a problem to be solved in the current society. Filling the gap between the energy demand and the supply, searching a large amount of unconventional energy resources becomes an urgent task in the modern society. Fuel cells are becoming an emerging clean and efficient energy conversion technology as a substitute for fossil fuels. Among the various types of fuel cells, a direct methanol fuel cell is an ideal choice because of its characteristics for use in light vehicles and portable devices. One key strategy to achieve sustainable energy is to develop efficient, economical and environmentally friendly catalysts to improve the performance of energy storage and energy conversion devices. To date, extensive research has been conducted to improve the efficiency of methanol oxidation reactions using platinum (Pt) and its modified electrocatalysts. Platinum-based nanocubes, nanorods, nanoflower, and other structures, as well as composites of platinum with metal oxides (e.g., fe 2O3、TiO2、SnO2、MnO、Cu2 O, znO) and conductive polymers, have been widely used in acidic and alkaline media. In addition, palladium-based materials, transition metal-based materials, metal Organic Frameworks (MOFs) and their derivatives have also become hot spots of current research. Among the different types of fuel cells, direct methanol fuel cells are an excellent choice for light vehicles and portable devices. The energy storage and conversion equipment produces highly mature, economical and green catalysts that can realize sustainable energy development. ORR has been developed relatively well as a key reaction in fuel cells and metal-air cells. In contrast, poor stability and slow kinetics make MOR the bottleneck of DMFCs, limiting its commercialization. Disclosure of Invention The invention aims to solve the technical problem of providing a direct methanol fuel cell catalyst and a preparation method thereof, and the catalyst has the characteristics of high specific surface area, more active sites, excellent performance, low cost and long-term stability. The application provides a direct methanol fuel cell catalyst, wherein a structural unit of the catalyst is formed by taking a vertically oriented carbon nano tube as a conductive network, and platinum iron cobalt nickel copper high-entropy alloy is loaded on the conductive network. The application also provides a preparation method of the direct methanol fuel cell catalyst, which specifically comprises the following steps: S1, preparing a carbon nano tube which grows vertically and directionally; S1.1, carrying out hydrolytic pyrolysis treatment on carbon cloth, and loading a silica thin layer on the surface of the carbon cloth; S1.2, growing carbon nanotubes on the surface of the carbon cloth material in situ by adopting a chemical vapor deposition process on the carbon cloth treated in the step S1.1, and introducing a carbon source solution through a microinjection pump in an inert atmosphere at the temperature of 800-900 ℃ in a high-temperature tube furnace to prepare a hybrid material, wherein the hybrid material is marked as VACNTs@CC; S2, carrying out hydrothermal reaction to load an iron cobalt nickel copper nano-sheet to obtain an iron cobalt nickel copper hydroxide@vertical orientation carbon nano-tube, which is marked as FeCoNiCu LDH/VACNTs@CC; S3, putting the obtained iron cobalt nickel copper hydroxide@vertical orientation carbon nanotube into a chloroplatinic acid solution to be soaked so as to load platinum ions, and marking the platinum ions as PtFeCoNiCu@VACNTs@CC. S4, performing plasma reduction treatment on the iron cobalt nickel copper hydroxide@vertical orientation nanotube soaked in the chloroplatinic acid solution by utilizing a radio frequency plasma technology in an argon-hydrogen atmosphere to obtain the direct methanol fuel cell catalyst, wherein the direct methanol fuel cell catalyst is named as P-PtFeCoNiCu@VACNTs@CC. Preferably, before the carbon cloth is subjected to hydrolytic pyrolysis treatment, the carbon is arranged in an inert atmosphere, and after the temperature rising rate of 4-6 DEG Cmin -1 is increased to 800-900 ℃, the carbon cloth is kept for 25-35min to remove the polymer film on the surface of the carbon cloth. Preferably, the hydrolytic pyrolysis treatment in the s