Influence of surface configurations of adsorbed cyanide ions to anodic dissolution of silver and gold in cyanide electrolytes

The low coverage adsorption of CN^- ions on Ag and Au have been studied by means of density functional theory and cluster model. Geometry and adsorption energy of one- and two-coordination associations of cyanide with surface silver and gold atoms have been computed. It was founded on the base of comparison of surface configuration energies that the part of surface gold atoms on which is adsorbed two CN^- ions considerably less than such for atoms of silver. This phenomenon can motive the passivation of gold dissolution in the cyanide electrolytes.