Influence of adsorption phenomena upon the mechanism and kinetics of oxygen reduction at a gold electrode in (Li-Na)CO3 melt

The reduction of oxygen at a gold flag electrode fully immersed in (53 + 47 ) mol % (Li-Na)CO3 was investigated at different temperatures (600 similar to 750 degrees C) using cyclic voltammetry and the semi-integral method. It was found that the electrode reaction mechanism depends critically on the scan rate and temperature. The overall mechanism is complicated by adsorpti on phenomena. This was identified via semi-integral analysis by the appeara nce of a peak-shaped semi-integrated voltammetric response. An electron tra nsfer number equal to 2 was determined by the simultaneous use of the volta mmetric peak and the maximum value of the semi-integral curve. Both the ini tial surface excess, Gamma*, and the mass-transfer parameter CD1/2 could be determined from the semi-integration of a single voltammogram. (C) 2000 Th e Electrochemical Society. S0013-4651(99)06-048-6 All rights reserved.