Cobalt-based oxygen reduction electro-catalytic material and preparation method thereof

An electrocatalytic material, cobalt-based technology, used in circuits, electrical components, battery electrodes, etc., can solve the problems of cumbersome preparation, low catalytic activity, and low utilization of active sites.

Pending Publication Date: 2022-07-08
UNIV OF SCI & TECH BEIJING
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The present invention proposes a cobalt-based oxygen reduction electrocatalytic material and its preparation method. Using ZIF-67 as a precursor, the coordination environment of the carbon-supported cobalt-based catalyst is precisely regulated through the process parameters of the carbonization and vulcanization pr

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  • Cobalt-based oxygen reduction electro-catalytic material and preparation method thereof
  • Cobalt-based oxygen reduction electro-catalytic material and preparation method thereof
  • Cobalt-based oxygen reduction electro-catalytic material and preparation method thereof

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Embodiment 1

[0020] (1) The ZIF-67 was placed in a quartz boat, and placed in a vacuum tube furnace with nitrogen, heated to 800°C at a heating rate of 10°C / min, kept for 2 hours, and then cooled to room temperature with the furnace to obtain the intermediate product;

[0021] (2) After fully mixing the intermediate product with the sulfur powder (the mass ratio is 1:3), place it in a quartz boat, and place it in a tube furnace with nitrogen, and heat it up to 155°C at a heating rate of 10°C / min , kept for 30 min; then heated to 300 °C at a heating rate of 10 °C / min, held for 2 h, and cooled to room temperature with the furnace to obtain a cobalt-based oxygen reduction electrocatalytic material.

[0022] XRD analysis of the cobalt-based electrocatalytic material for oxygen reduction reaction synthesized in Example 1 shows that the phase composition of the material is Co 1-x S@C, such as figure 1 shown; and then using ICP analysis to obtain that the cobalt-sulfur atomic molar ratio of the...

Embodiment 2

[0031] (1) The ZIF-67 was placed in a quartz boat, placed in a vacuum tube furnace with nitrogen, heated to 750°C at a heating rate of 8°C / min, kept for 1.5h, and then cooled to room temperature with the furnace to obtain mid product;

[0032] (2) After fully mixing the intermediate product with the sulfur powder (mass ratio is 1:2.5), place it in a quartz boat, and place it in a tube furnace with nitrogen, and heat it up to 145°C at a heating rate of 8°C / min , kept for 20 min; then heated to 290 °C at a heating rate of 8 °C / min, kept for 1 h, and cooled to room temperature with the furnace to obtain a cobalt-based oxygen reduction electrocatalytic material.

[0033] Using ICP analysis, the cobalt-sulfur atomic molar ratio of the material prepared in Example 2 was 0.46, that is, Co 1-x x=0.54 in S. Figure 5 For the pore and specific surface area diagram of the synthetic material in Example 2, the specific surface area of ​​the material is 97.19m 2 g -1 , with an average ...

Embodiment 3

[0035] (1) The ZIF-67 was placed in a quartz boat, and placed in a vacuum tube furnace with nitrogen, heated to 820°C at a heating rate of 10°C / min, kept for 3 hours, and then cooled to room temperature with the furnace to obtain the intermediate product;

[0036] (2) After fully mixing the intermediate product with the sulfur powder (the mass ratio is 1:4), place it in a quartz boat, and place it in a tube furnace with nitrogen, and heat it up to 165°C at a heating rate of 10°C / min , kept for 45 min; then heated to 320 °C at a heating rate of 8 °C / min, kept for 3 h, and cooled to room temperature with the furnace to obtain a cobalt-based oxygen reduction electrocatalytic material.

[0037] Using ICP analysis, the cobalt-sulfur atomic molar ratio of the material prepared in Example 3 was 0.43, that is, Co 1-x x=0.57 in S.

[0038] In order to evaluate the oxygen reduction catalytic ability of the material, a lithium-oxygen battery was assembled with the cobalt-based oxygen r...

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Abstract

The invention relates to a cobalt-based oxygen reduction electro-catalytic material and a preparation method thereof, and solves the problems of low catalytic activity, small catalytic active site density, low active site utilization rate, complicated preparation, high cost and the like of the existing non-noble metal ORR catalyst. ZIF-67 is used as a precursor, the coordination environment of a carbon-supported cobalt-based catalyst is accurately regulated and controlled through process parameters of carbonization and vulcanization processes, an electro-catalytic material which is mainly composed of Co-S-C, coexists with Co-N-C and Co-C and has a phase composition of Co1-xS is obtained, and the electro-catalytic activity of a single active site is remarkably enhanced. Moreover, cobalt atoms of the material are uniformly distributed in a carbon skeleton at high density, so that the density of active sites is improved; meanwhile, the material has a larger average pore size on the basis of high specific surface area, and the utilization rate of active sites is improved. The preparation method of the cobalt-based electrocatalyst is easy and convenient to operate, the consistency of synthetic materials is high, and the cobalt-based electrocatalyst has application and popularization value.

Description

Technical field: [0001] The invention belongs to the technical field of electrocatalytic materials, and more particularly relates to an oxygen reduction electrocatalytic material and a preparation method thereof. Background technique [0002] The oxygen reduction reaction (ORR) is a key reaction in metal-air batteries and fuel cells. Platinum (Pt)-based electrocatalysts have high ORR kinetic activity, but due to high price and scarce resources, it is urgent to find alternative materials with high catalytic activity to promote practical applications in metal-air batteries and fuel cells. At present, there are still the following technical difficulties in the design, development and preparation of non-precious metal ORR electrocatalysts: First, the catalytic activity is low. CeO was prepared by Lefan Yuan et al. (Electrochimica Acta, 2021 368, 137645) 2 Decorated Fe 2 O 3 Nanorods (Fe 2 O 3 / CeO 2 @CC) ORR catalyst, which has the advantage of being self-supporting witho...

Claims

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Application Information

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IPC IPC(8): H01M4/92
CPCH01M4/92H01M4/926Y02E60/50
Inventor 连芳冯云薛杉杉
Owner UNIV OF SCI & TECH BEIJING
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