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CN-121983596-A - Dual-function electrocatalyst prepared by utilizing Joule heat and preparation method and application thereof

CN121983596ACN 121983596 ACN121983596 ACN 121983596ACN-121983596-A

Abstract

The invention provides a dual-function electrocatalyst prepared by utilizing Joule heat, and a preparation method and application thereof, and belongs to the technical field of new energy materials. The invention synthesizes an organic framework compound by adopting transition metal salts of dimethyl imidazole, zinc nitrate and cobalt (Co), then prepares a cobalt-nitrogen doped carbon material with oxygen reduction (ORR) activity by pyrolysis, mixes the cobalt-nitrogen doped carbon material with nickel and iron compounds respectively, reduces the nickel and iron compounds into alloy nano particles by utilizing Joule heat in extremely short time to directly load the alloy nano particles on the surface of the cobalt-nitrogen doped carbon material, and obtains a high-performance bifunctional (ORR and OER) electrocatalyst which can be used as a cathode catalyst for metal-air batteries.

Inventors

  • TAN FENG
  • LIU JIAN

Assignees

  • 昆明贵研催化剂有限责任公司
  • 云南贵金属实验室有限公司
  • 昆明理工大学

Dates

Publication Date
20260505
Application Date
20260209

Claims (10)

  1. 1. A method for preparing a dual-function electrocatalyst by using joule heat, comprising the steps of: 1) Mixing dimethyl imidazole, zinc salt and cobalt-containing transition metal salt with an organic solvent, and performing self-assembly to obtain an organic framework compound; 2) Carrying out heat treatment on the organic framework compound in a protective atmosphere to obtain a cobalt-nitrogen doped carbon material; 3) Mixing cobalt-nitrogen doped carbon material, iron-containing compound and nickel-containing compound in ethanol, evaporating at a certain temperature to obtain dry mixed material, grinding the mixed material, placing the ground mixed material between conducting electrodes, applying pulse current under inert gas atmosphere to enable the mixed material to generate instant Joule heat under the action of self resistance, and performing rapid heat treatment to obtain the dual-function electrocatalyst.
  2. 2. The method for preparing a bifunctional electrocatalyst by using joule heat according to claim 1, wherein a molar ratio of the dimethylimidazole, the zinc salt, and the cobalt-containing transition metal salt is 35 to 50:10:2 to 5.
  3. 3. The method for preparing a bifunctional electrocatalyst by using joule heat according to claim 1 or 2, wherein the cobalt-containing transition metal salt comprises cobalt acetate and/or cobalt nitrate hexahydrate, the zinc salt is zinc nitrate hexahydrate, and the organic solvent is methanol.
  4. 4. The method for preparing a dual-function electrocatalyst by using joule heat according to claim 3, wherein the self-assembling temperature is 5 to 15 ℃ and the self-assembling time is 24 to 48 hours.
  5. 5. The method for preparing a dual-function electrocatalyst by using joule heat according to claim 1, wherein the temperature of the heat treatment is 900 to 1000 ℃, the time of the heat treatment is 1 to 3 hours, and the gas of the protective atmosphere is argon or nitrogen.
  6. 6. The method for producing a bifunctional electrocatalyst using joule heat as recited in claim 5, wherein the iron-containing compound comprises iron acetylacetonate and/or iron dichloride, and the nickel-containing compound comprises nickel acetylacetonate and/or nickel dichloride.
  7. 7. The method for preparing a bifunctional electrocatalyst using joule heat as claimed in claim 6, wherein the cobalt-nitrogen doped carbon material, the iron-containing compound, and the nickel-containing compound are used in an amount ratio of 30mg:0.03 to 0.15mm:0.09 to 0.5mm.
  8. 8. The method for preparing a dual-function electrocatalyst using joule heat according to claim 1, 6 or 7, wherein the condition for generating instantaneous joule heat is that the temperature of heating by a single pulse is 800 to 1500 ℃, the number of pulses is 2 to 5, and the inert gas is nitrogen or argon.
  9. 9. The bifunctional electrocatalyst prepared by the method of any one of claims 1 to 8.
  10. 10. Use of the bifunctional electrocatalyst according to claim 9 as cathode material for metal-air batteries.

Description

Dual-function electrocatalyst prepared by utilizing Joule heat and preparation method and application thereof Technical Field The invention relates to the technical field of new energy materials, in particular to a difunctional electrocatalyst prepared by utilizing Joule heat, a preparation method and application thereof. Background The rechargeable air battery has important application value in the fields of clean energy utilization and energy storage because of high theoretical energy density, environmental friendliness, safety and low cost. Oxygen Reduction Reactions (ORR) and Oxygen Evolution Reactions (OER) are key reactions for charging and discharging the cathode of rechargeable metal-air batteries, however the ORR reactions and OER reaction kinetics are slow to require catalysts to promote their reaction kinetics. Thus, ORR catalysts and OER catalysts are key materials for rechargeable metal-air cell cathodes. At present, commercial noble metal Pt/C catalysts and RuO 2 catalysts are regarded as optimal heterogeneous ORR and OER catalysts, and noble metal Pt and Ru resources are scarce and high in price, so that commercial application of metal-air batteries is affected. Therefore, the development of a low-cost and high-efficiency bifunctional catalyst to replace noble metal Pt and Ru-based catalysts has important significance for promoting the commercialization process and practical application of air batteries. In recent years, transition metal nitrogen-doped carbon materials have excellent ORR activity under alkaline conditions, and are widely focused, and NiFe alloys have higher OER activity. Therefore, the NiFe alloy nano particles are directly loaded on the surface of the transition metal nitrogen doped carbon material to prepare the double-function catalyst with ORR and OER activities, so that the catalyst required by the ORR and OER reactions can be synthesized on one catalyst, and meanwhile, a non-noble metal material with wide sources can be used for replacing expensive noble metal, the cost of the catalyst is reduced, and the catalyst has remarkable economic benefit. Disclosure of Invention The invention aims to provide a dual-function electrocatalyst prepared by utilizing Joule heat, and a preparation method and application thereof, which are used for solving the technical problems. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a preparation method for preparing a dual-function electrocatalyst by utilizing Joule heat, which comprises the following steps: 1) Mixing dimethyl imidazole, zinc salt and cobalt-containing transition metal salt with an organic solvent, and performing self-assembly to obtain an organic framework compound; 2) Carrying out heat treatment on the organic framework compound in a protective atmosphere to obtain a cobalt-nitrogen doped carbon material; 3) Mixing cobalt-nitrogen doped carbon material, iron-containing compound and nickel-containing compound in ethanol, evaporating at a certain temperature to obtain dry mixed material, grinding the mixed material, placing the ground mixed material between conducting electrodes, applying pulse current under inert gas atmosphere to enable the mixed material to generate instant Joule heat under the action of self resistance, and performing ultra-rapid heat treatment to obtain the dual-function electrocatalyst. Further, the molar ratio of the dimethylimidazole to the zinc salt to the cobalt-containing transition metal salt is 35-50:10:2-5. Further, the cobalt-containing transition metal salt comprises cobalt acetate and/or cobalt nitrate hexahydrate, the zinc salt is zinc nitrate hexahydrate, and the organic solvent is methanol. Further, the self-assembly temperature is 5-15 ℃, and the self-assembly time is 24-48 h. Further, the temperature of the heat treatment is 900-1000 ℃, the time of the heat treatment is 1-3 hours, and the gas of the protective atmosphere is argon or nitrogen. Further, the iron-containing compound comprises ferric acetylacetonate and/or ferric dichloride, and the nickel-containing compound comprises nickel acetylacetonate and/or nickel dichloride. Further, the dosage ratio of the cobalt-nitrogen doped carbon material, the iron-containing compound and the nickel-containing compound is 30 mg:0.03-0.15 mM:0.09-0.5 mM. Further, the condition for generating the instant Joule heat is that the temperature of single pulse heating is 800-1700 ℃, the pulse times are 2-5, and the inert gas is nitrogen or argon. The invention also provides the difunctional electrocatalyst prepared by the preparation method. The invention also provides application of the bifunctional electrocatalyst as a cathode material of a metal-air battery. The invention has the beneficial effects that: The invention utilizes simple Joule heating technology to prepare high-activity bifunctional catalyst for metal-air battery. The invention is that nickel and iron compo