The electrochemical reduction of oxygen on cobalt-cemented tungsten carbide

✍ Scribed by Ashok K. Vijh; R. Jacques; G. Bélanger

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 594 KB
• Volume: 9
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/0378-7753(83)87010-4

✦ Synopsis

The electrochemical reduction of oxygen has been examined on cobaltcemented tungsten carbide and on WC electrodes in alkaline solutions. The kinetics have been studied on a rotating disk electrode and the variation of reaction rate with electrode potential, temperature, oxygen concentration, solution pH and the rotation has been investigated. Rather high "Tafel slopes", low apparent heats of activation, negligible pH effect, unity reaction order with respect to oxygen and only a slight dependence on the rate of rotation (and that only at higher current densities) are the principal kinetic features. A chemical ratedetermining4ep (r.d.s.) has been concluded to be consistent with these data.

A comparison of the electroactivity of these electrodes for O2 and HzOz reduction

shows that, at a given electrode potential, reduction of HzOz proceeds at much higher rates than the reduction of Oz.