The Effect of Sulfur on the Anodic H 2 ( Ni ) Electrode in Fused Li2 CO 3 ‐ K 2 CO 3 at 650°C

Abstract

Steady‐state polarization curves for rotating Ni wires in (62 m/o Li) at 650°C are reported for gas of different contents. In the absence of sulfur, the diffusion‐limiting currents are only slightly larger than the observed limiting currents. A reduction in the observed limiting currents by the presence of is interpreted as a decrease of the reaction‐limiting current, i.e., as poisoning of the Tafel reaction. The sulfur effect levels off at which suggests that the sulfur coverage approaches a saturation value, and that a sulfur‐saturated Ni surface retains a finite activity for oxidation. is not oxidized at a significant rate at potentials below that of Ni sulfide formation. An approximate rate equation for oxidation is derived for small sulfur coverages.