RESEARCH RELATING TO FUEL CELLS. THE OXYGEN REACTION ON PLATINUM AND GOLD IN ACID SOLUTIONS
Abstract
The electrode kinetics of the oxygen reaction were studied on smooth platinum and gold electrodes in acid solutions (H2SO4 and HClO4) and at room temperature. Polarization curves were obtained both galvanostatically and at controlled potentials. The electrode coverage by absorbed oxygen and the extent of oxide formation were determined using chronopotentiometry and potentiostatic sweep methods. The kinetics of the electrochemical reduction and oxidation of hydrogen peroxide, an intermediate found in solution during the reduction of oxygen, were also studied. Platinum forms a thin oxide at potentials where oxygen evolution takes place. The rate-determining reaction in oxygen evolution is the discharge of a water molecule which occurs with a Tafel slope of 0.086 V. On cathodized (reduced) Pt surfaces, the discharge of water occurs at a higher rate than on superficially oxidized surfaces. The transfer coefficient on cathodized surfaces corresponds to a nearly symmetrical energy barrier.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1963
- Accession Number
- AD0414800
Entities
People
- A. K. Shamsul Huq