碳化钨催化剂电化学氧化机理的研究

RESEARCH ON THE MECHANISM OF ELECTRO CHECAL OXIDATION OF TUNGSTEN CARBIDE CATALYST

本文采用理论计算与实验数据相结合的方法探索了碳化钨(WC)催化剂在三种不同电解液中的电氧化机理。研究表明;在2.0mol.L^(-1)H_2SO_4电解液中,若电极电势大于800mv(vs.DHE),则电极表面上的碳化钨催化剂被氧化成W_2O_5,电氧化过程属1电子反应;在3.5mol.L^(-1)HCl中,电极表面上生成的产物为W_8O_(23),属1.75电子反应。在2.5mol.L^(-1)KOH电解液中,WC粉末的电氧化过程未经中间氧化态的变化一步就氧化成WO_3,为2电子氧化反应。

In this paper, the mec'hanism of electrochemical oxidation of tungsten carbide catalyst in three different electrolytes is explored by using the method in which the theoretical calculation is combined with the experimental data. The research shows that if potential greater than 800mv (vs.DHJS) the catalyst of tungsten carbide(WC)on the surface of electrode can be oxidized into W2O3 in 2.0 mol.L-1 H2SO4, which is considered as an oxidizing reaction of 1 electron. This catalyst also forms W8O23 oxide in 3.5 mol.L-1 HC1, which is regarded as an oxidizing reaction of 1.75 electron. But, the catalyst can be oxidized in one step into WO3 in 2.5 mol.L-1 KOH which is known as an oxidizing reaction of 2 electron.