ELECTRIC CATALYTIC DISCHARGE OF METAL-IONS ON MERCURY-ELECTRODES UNDER CATALYSIS BY LIGANDS

In this review the mechanism of electrocatalysis has been analysed on the basis of the occurrence at the electrode of bulk (one-step and a two-step sequence) and surface (parallel) reactions of the formation of electroactive complexes (EACs). The following have been explained quantitatively: the role of ligand-induced EAC adsorption, the role of catalytically inactive ligands, the maximum on the catalytic current-metal ion concentration curve, and splitting of the catalytic prewave. The methods of determination and a summary of the constants of EAC formation rates, complex stability constants and acid dissociation constants of ligands obtained from the catalytic current have been reported. The constants are similar to those obtained by non-electrochemical methods. The analytical application of the catalytic current has been considered.