Potential transients on a renewed electrode as a source of information on the surface concentration of catalytically active adatoms

Abstract

Potential transients on renewable gold and silver electrodes in cyanide solutions containing catalytically active ions of lead and thallium are measured. The transients are recorded both on freshly renewed electrodes and on renewed electrodes kept in solution for specified time periods Δt. The behavior of transients following a change in the concentration of lead and thallium ions, current density, and Δt qualitatively conforms to regularities that could be expected if the catalytically active adatoms were inserted into the deposit similarly to the admixtures. Methods for determining coefficients of capture of such adatoms by the growing metal deposit are suggested. Factors that hamper determination of these coefficients and make it worthwhile to select a method for their determination that would use potential transients are considered. The capture coefficient for the incorporation of lead adatoms in the growing silver deposit is nearly 20 times that for gold.