Effect of La Addition on the Kinetics of the Oxygen Reduction Reaction in Li/Na Molten Carbonate

Abstract

The effect of lanthanum addition to the Li/Na eutectic carbonate on the oxygen reduction reaction has been investigated using a meniscus electrode made of a gold ring. This electrode could reduce the effect of the gas diffusion to the reaction. Therefore, this is the good electrode for a model of a porous gas diffusion electrode. The apparent standard exchange current density due to the lanthanum addition that is determined by a quasi-steady state voltammogram around the open circuit potential increased five times that without the additive. The reduction peak potential of the cyclic voltammogram decreased, and the reduction current density increased due to the lanthanum addition. The diffusion process of the oxygen species in the molten carbonate would affect these behaviors. Therefore, the charge transfer and the diffusion process should be enhanced by the lanthanum.