Composite material of nitrogen-doped porous carbon-wrapped carbon nano tube as well as preparation method and application of material

Abstract

The invention relates to a composite material of a nitrogen-doped porous carbon-wrapped carbon nano tube as well as a preparation method and an application of the composite material. The preparation method comprises the following steps: dispersing the carbon nano tube in water, adding a carbon source to obtain a reaction system, subsequently performing hydrothermal reaction, performing thermal treatment on the carbon nano tube wrapped with a carbon layer on the surface, and a nitrogen source at the high temperature so as to obtain the composite material of the nitrogen-doped porous carbon-wrapped carbon nano tube. According to the preparation method, the carbon source is polymerized under a hydrothermal reaction condition so as to obtain the carbon layer, the outer surface of the carbon nano tube is wrapped with the carbon layer, subsequently the carbon layer is carbonized and decomposed to generate a porous structure under high temperature treatment, and at the same time, the gasified nitrogen source is diffused to the carbon layer through ducts to be subjected to in-situ doping. The composite material provided by the invention can be used as a cathode oxidation reduction catalyst of a fuel battery, is excellent in catalysis, and is high in oxidation activity when being compared with other nitrogen-doped materials reported in documents. The preparation method provided by the invention is simple and economic in process, convenient to operate and easy to achieve the large-scale production.

Description

technical field [0001] The invention relates to a composite material of nitrogen-doped porous carbon-coated carbon nanotube, a preparation method thereof, and an application of the composite material as an oxygen reduction catalyst. Background technique [0002] Fuel cell is a clean and non-polluting power generation device with extremely high energy conversion efficiency, which plays a pivotal role in solving major energy problems. However, the key cathode oxygen reduction reaction has slow kinetics and requires rare noble metals as catalysts, which seriously hinders the wide application of fuel cells. Many people have begun to use precious metals and other transition metals to form alloys or special structures such as core-shell to increase the utilization rate of precious metals and reduce their loading, but this still cannot get rid of the limitations of precious metals themselves. Therefore, the development of non-noble metal catalysts with high catalytic activity for ...

AI Technical Summary

Problems solved by technology

At present, there are three main methods for preparing nitrogen-doped carbon materials: one is the in-situ doping method, that is, doping while growing the carbon skeleton, such as chemical vapor deposition, this preparation method can often be doped with a high content of heteroatoms , but its expensive equipment and sensitive preparation conditions are not conducive to large-scale production of catalysts

The second is the post-treatment doping method. Generally, conductive graphitized carbon materials and compounds containing heteroatoms are treated and doped at high temperature. Since the graphitized structure brings resistance to doping, the content of heteroatoms is usually relatively low. , the ideal catalytic activity cannot be obtained

However, how to properly combine carbon nanotubes with nitrogen-containing carbon materials to improve the utilization of heteroatoms still remains a big challenge.

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