The mechanism of the activation process of the tungsten carbide electrode

✍ Scribed by P. Zoltowski

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 726 KB
• Volume: 31
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(86)80069-x

✦ Synopsis

The nature of the activation of tungsten carbide (WC) electrodes for the hydrogen ionization reaction (hir) as a result of prolonged treatment of the electrode at a potential of + 0.7 V/&e was investigated on smooth samples in 0.5 h4 sulfate electrolytes of pH 0.3 and 1.85, at 80°C. by potentiostatic, potentiodynamic and small-signal ac methods. The results have suggested that even at low anodic potentials an adsorption-desorption process takes place, reducing the activity of the electrode for hir down to about zero at about + 0.55 Vlrhe. At higher potentials a deep corrosion of the electrode surface takes place. As a result of the corrosion, after dissolution of its products, a higher activity is attained by the electrode, with an almost unchanged real surface arca and an inmased total capacity. It was demonstrated that for the description of the processes taking place at the electrode at + 0.25 V/r& a three time-constants equivalent circuit should be used.