Reduction of oxygen from electrolyte emulsions with high oxygen contents

The kinetics of oxygen reduction from electrolyte emulsions containing oxyg en carriers was studied with respect: to fuel cell applications. Electroche mical experiments including stationary and nonstationary measurements under defined hydrodynamic conditions at a rotating platinum disk electrode reve aled that diffusion-controlled limiting currents can be increased significa ntly at high oxygen concentrations. Additionally, the limiting currents sho w a strong correlation with the composition and the structure of the emulsi ons. In particular, the average droplet size of the organic phase and its d istribution depends on the nature of the emulsifying agents used for stabil isation. The complex hydrodynamic behaviour of two-phase electrolyte emulsi ons and the influence of different surfactants seem to outweigh the; effect of the total oxygen concentration on the transport kinetics of oxygen. (C) 2000 Elsevier Science S.A. All rights reserved.