Electrocatalytic Properties of Core - Shell Structure Tungsten Carbide Reinforced

Tungsten carbide can be used as a catalyst in the field of chemical catalysis and electrocatalysis because of its platinum like catalysis, and it will not cause CO, H₂S and other gas pollution reactions during the catalytic reaction. But the existing research shows that the catalytic activity of tungsten carbide is less than platinum and other precious metals, thus improve the catalytic activity of tungsten carbide is one of the key issues in the study of WC hot and catalytic materials for industrial applications.

The surface structure of metal is the reason why tungsten carbide has platinum catalytic performance, if can control the surface electronic structure of tungsten carbide, tungsten carbide can be catalytic activity regulation, based on this understanding, many experts and scholars at home and abroad to carry out a targeted research.

Chen Hui, a scholar, found that carbon nanotubes were loaded on the nitrated carbon nanotubes after the reduction of carbon nanotubes, and the tungsten carbide and carbon nanotubes composites were obtained after the reduction and carbonization. Secondly, the nanocomposite of tungsten carbide and natural zeolite was prepared by using the natural zeolite with three dimensional channel structure as the carrier. Thirdly, using the unique properties of Ti⁴⁺'s empty D orbits, tungsten carbide and rutile nanocomposites were prepared with rutile nano titanium dioxide as the carrier. Finally, the iron-tungsten as carrier and ammonium metatungstate as tungsten source were combined with surface-coating method and in-situ reduction carbonization technology to prepare tungsten carbide and tungsten carbide nanocomposites with core-shell structure. Taking methanol fuel cell as an example, the above composite materials improve the electrocatalytic activity of tungsten carbide to some extent, but also face some problems. Although carbon nanotubes have excellent electronic properties and tubular structure, they will be oxidized under the electrochemical environment. Thus, the structure and properties of the composites are changed.

In order to improve the above problems, the scholars using coating technology of ammonium metatungstate uniformly adsorbed on the outer surface, and the use of iron in iron doped Fe₃W₃C formation of tungsten carbide can in reduction carbonization process, to enhance the characteristics of conductive composite material, the Fe₃W₃C and WC composites with core-shell structure were prepared by combining the surface coating with in situ reduction carbonization technology. The new core shell composite exhibits better catalytic performance.

This is due to the good electrocatalytic activity of Fe₃W₃C and WC itself. Moreover, Fe₃W₃C has good electrical conductivity. More importantly, core-shell structure composite material can control the properties of materials by using the characteristics of core and shell, which can significantly enhance the catalytic performance of composite materials.

Therefore, using iron yellow large surface area and superior adsorption properties and other characteristics, and using coating technology to uniformly adsorbed ammonium metatungstate on its outer surface, and the use of iron yellow iron in the process of reduction and carbonation can be incorporated into tungsten carbide to form Fe₃W₃C. In order to enhance the conductivity of composite materials, the core shell structure of Fe₃W₃C/WC composite prepared by the combination of surface coating and in situ reduction carbonization technology is an upgrading solution to improve the catalytic activity of tungsten carbide.

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