Oxygen reduction on a ruthenium electrode in acid electrolytes

✍ Scribed by N.A. Anastasijević; Z.M. Dimitrijević; R.R. Adžić

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 468 KB
• Volume: 31
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(86)80124-4

✦ Synopsis

The kinetics and mechanism of O2 reduction on an Ru electrode in acid electrolytes have been measured by using a disc-ring method. The reaction proceeds through a "parallel" mechanism with the exchange of approximately four electrons. It shows a pronounced dependence on the oxidation state of the Ru surface. A catalytic decomposition of H,OZ does not occur on the surface obtained at potentials E > 0.0 V. Tafel slopes, some rate constants and reaction orders for 02 and Hz02 reduction have been determined. Calculated rate constant for a direct reduction of 02 (k,) is higher than k2, the reduction with the HZOZ intermediate. The experimental value ofk3, the H202 reduction, is lower thank, and k2 at E r 0.05 V.

The Tafel slope for O2 reduction with the value higher than 120 mV has been obtained.