Preparation method and application of hollow carbon-based oxygen reduction electrocatalyst

Abstract

The invention discloses a preparation method and application of a hollow carbon-based oxygen reduction electrocatalyst. According to the preparation method, a Prussian blue analogue coated with a metal-polyphenol chelate is adopted as a precursor, and the metal-polyphenol chelate is carbonized to form a framework matrix of the catalyst; ionic-state zinc elements in the Prussian blue analogue can be reduced into elemental zinc by carbon at high temperature, metal zinc is further heated to be melted until the metal zinc is completely evaporated to form a hollow structure, and the high temperature is not only the key for forming the hollow structure, but also enables a carbon framework to be rich in defects, so that the conductivity is improved; however, the carbon loss is increased, the hollow structure collapses, a mass transfer channel is blocked, active sites cannot be exposed, and the catalytic performance is reduced due to over-high temperature; and iron, cobalt or nickel elements are finally attached to the inner surface of the carbon framework in the form of simple substances and carbides, so that carbon atoms on the surface layer can be further activated, the oxygen reduction electrocatalytic activity is improved, and therefore, the obtained catalyst has a good application prospect in the technical field of electrocatalytic oxygen reduction.

Description

technical field [0001] The invention belongs to the technical field of electrocatalytic oxygen reduction, and in particular relates to a preparation method and application of a hollow carbon-based oxygen reduction electrocatalyst. Background technique [0002] The widespread use of traditional fossil fuels is one of the main reasons for the increase in carbon dioxide emissions and the energy crisis, and fuel cells and metal-air batteries, as a promising alternative, play an important role in reducing the consumption of fossil fuels. In the practical application of fuel cells and metal-air batteries, the electrochemical oxygen reduction reaction plays a vital role, but the kinetics of this reaction is very slow, which seriously affects the performance of the battery device. Efficient and cheap carbon-based cathode catalysts can speed up the reaction kinetics process while reducing production costs. Under this strategy, cathode catalysts based on hollow carbon structures have ...

AI Technical Summary

Problems solved by technology

Hollow carbon nanospheres can be directly obtained by using some carbon source molecular hydrothermal methods. For example, Chinese patent document CN109378490A discloses a preparation method of transition metal / nitrogen co-doped hollow carbon nanomaterials. Molecular hydrothermal preparation of hollow carbon nanomaterials, and then grinding and mixing with nitrogen source molecules and metal salts, and calcination to obtain the target material. Although the preparation of hollow carbon materials in this patent is a one-step method, in order to load metal compounds, impregnation is still required. Grinding and calcining steps

[0005] At present, there are very few reports on the construction of hollow carbon nano-electrocatalysts using the self-template method. Therefore, the study of a simple and efficient self-template preparation method can greatly optimize the process flow of catalyst preparation.

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