Kinetics of Electrode Reactions in Liquid Ammonia: Part 3.—The Silver Electrode in Acid Solution

Abstract

The behaviour of the silver electrode in acid solutions of liquid ammonia has been studied by steady and non-steady state electrochemical measurements and electron microscopy. The apparent rate constant and standard potential have been determined. The rate-determining step in silver deposition and dissolution is the charge transfer reaction which is probably coupled with an adatom diffusion mechanism. Oxidised species originating from the solvent are adsorbed on silver except at cathodic values of electrode potential. The anodic behaviour of silver is complicated by the formation of anodic deposits, probably silver nitride, in parallel with the metal dissolution reaction. By making comparisons with silver electro-deposition from simple and cyanide aqueous baths it is concluded that the adsorbed solvent decomposition products are responsible for the poor quality of deposits from ammoniacal electrolytes.