Electro-oxidation behavior of tungsten carbide
electrode in different electrolytes①
electrode in different electrolytes①
(1. Department of Applied Chemistry, Zhejiang University of Technology, Hangzhou 310014, China;
2. Department of Materials Science and Technology, Shanghai University, Shanghai 200072, China)
2. Department of Materials Science and Technology, Shanghai University, Shanghai 200072, China)
Abstract: The electrochemical activity and stability of tungsten carbide gas diffusion electrode in different electrolytes were determined by galvanostatic charge method. It is shown that WC exhibits good electrocatalytic activity and stability for hydrogen oxidation in acidic solutions when the electrode potential is below about 800 mV(vs DHE), WC is firstly oxidized to an unstable blue tungsten oxides at 800 900 mV which are closed to a composite stoichiometry of W2O5in H2SO4solution and W8O23in HCl solution calculated by charge consumed . Furthermore, the generated intermediate tungsten oxides can be further oxidized into WO3at higher potentials. While in alkali solution, WC can not be used as anodic catalyst for its poor stability and catalytic activity due to the fact that WC will be directly oxidized into WO3.
Key words: tungsten carbide; electrocatalyst; electrochemical behavior