Preparation Of Nanometer Tungsten Carbide By Template Method And Its Electrochemical Performance

Tungsten carbide has the class platinum catalytic performance and stronger ability to resist poisoning, but its catalytic activity is far lower than the platinum and other precious metal catalysts.To look for the technology ways to improve the catalytic performance of tungsten carbide, this paper use the template Method to prepare the precursors of nano-sized tungsten carbide, using mixed liquid of ethanol/methanol as the reducing agent and carbon source, Successfully prepared the nano-sized tungsten carbide and tungsten carbide/carbon nanotubes nanocomposites, and their electric catalytic performance was also evaluated.This paper mainly studies the preparation methods and process conditions of the tungsten carbide and tungsten carbide/carbon nanotubes.First of all, from the perspective of the purification and dispersion of carbon nanotubes, heat treatment and pickling is helpful to remove the impurities in the carbon nanotubes, ultrasonic dispersion using ethylene glycol as dispersant can quickly and better dispersed carbon nanotubes.Next,based on the purified and dispersed of carbon nanotubes,using carbon nanotubes as template precursor to prepare tungsten acid/carbon nanotubes, optimization of process parameters as follows: the temperature is 100 o C, the molar mass ratio of carbon nanotubes and sodium tungstate is 1:14.the last step is reduction carbonization, the temperature of this step is 600 oC, the ethanol concentration in the carbon source is 10 %,the heating rate is 0.2 m L/min to 1000 o C and heat preservation for 1 hour.Using SEM,XRD, differential thermal and analytical means such as HRTAM to characterize the samples,the results show that this process can prepared pure WC, WC particle and their size were both less than 300 nm.On the basis of the above experiment, with ethylene glycol reduction of WC/Pt and WC/CNTs/Pt catalyst for methanol electric catalytic material, compared the two materials electrochemical performance.The experimental results show that both of the catalyst materials have similar electric catalytic oxidation properties with Pt and Pt electrode, the electric catalytic and oxidation of methanol is produced by dissociation adsorption and reaction intermediates two-way mechanism.Two kinds of catalyst materials both have good catalytic activity, but under the acidic system, composite materials has slightly higher electric catalytic activity on methanol.