Preparation And Electrocatalytic Behavior Of Tungsten Carbide/MultiWalled Carbon Nanotube Composite

Tungsten carbide has an analogy of the catalytic capability of noble metal, e.g. Pt, and higher ability to resist catalytic poisons, but its catalytic activity is much lower than that of noble metal. How to improve its catalytic activity is one of the difficult and hot points in recent years. In order to solve this problem, tungsten carbide/multiwalled carbonnanotube composite was prepared through surface decoration, reduction-loading in liquid phase and carbonization, the electrocatalytic behaviors of the reducion of p-methylnitrobenzen and the oxydation of methanol on tungsten carbide multiwalled carbonnanotube composite was investigated by powder-microelectrode approach.In the first chapter, the structure and preparation of WC and its composite with carbon nanotube, the application of WC in catalytic field, were simply stated, the reaserch advance of the anode material in DMFC was summarized and so on. In the second chapter, the experimental process and epuipments was introduced simply.In the third chapter, using the oxidants, we modified the multiwalled carbonnanotube with carboxyl in liquid phase, and optimized the processing parameters.In the fourth chapters, the preparation of tungsten carbide/ multiwalled carbon nanotube composite was investigated. The results of XRD, SEM, TEM,BET and so on show that the sample is composed of MWNTs、WC、W and W₁₇O₅₀ mainly, and the morphology of the particles of tungsten carbide is nanoscale irregular, with a diameter of samller than 30nm, and WC granules distribute on the surface of multiwall carbon nanotube through chemical bond.In the fifth chapter, the electrocatalytic behavior of the p-methyl nitrobenzen reduction and methanol oxidation on the composite in micro-powder electrode was study.The results imply that the electrocatalytic activity of the composite for p-methylnitrobenzen reduction and methanol oxidation is higher than that of MWNTs and WC. The improvement of the electrocatalytic activity of the sample can be attributed to its components and composite structure. Base on the experimental results, the mechanism of the electro-reaction was proposed. At last, we summrized the thesis and prospected the post work.