Effect of Adsorbed Arsenic on the Decomposition Rate of Nickel Hydride.

摘要

The decomposition rate of nickel hydride was studied using x-ray, Auger spectroscopy, and SIMS techniques. In high purity nickel, which was cathodically charged with hydrogen, deposition of arsenic on the nickel surface considerably decreased the decomposition rate of nickel hydride. This effect of arsenic on the egress of hydrogen from nickel is related to the influence of adsorbed arsenic on the entry of hydrogen into nickel during cathodic charging. Both effects result from inhibition of the recombination of hydrogen atoms at the surface thus resulting in a higher effective hydrogen fugacity at the surface. The effects of adsorbed arsenic on the decomposition of nickel hydride was influenced by alloying elements such as carbon and sulfur in the nickel, with the arsenic effect being greater in Ni-S alloys and smaller in Ni-C alloys than in high purity nickel. Keywords: Hydrogen; Hydrides; Cathodic charging; Electrolysis. (kt)