ELECTRODEPOSITION AND ELECTROCATALYSIS - THE DEPOSITION AND DISSOLUTION OF SINGLE CATALYST CENTERS

It is confirmed that it is possible to obtain a mathematical solution to the problem of the nucleation and three-dimensional growth at const ant potential of single growth centres of a new phase on a microelectr ode substrate under all conditions ranging from kinetic to diffusion c ontrol of the growth process under the assumption that diffusion is in a quasi-steady state. The results are extended to double-potential-st ep experiments and it is shown that similar complete descriptions can be derived for experiments where the growth centre acts as a catalyst site for an electrocatalytic reaction. Cyclic voltammetry of the two t ypes of processes is discussed for a more restricted range of conditio ns, namely pure kinetic or diffusion control of the growth of the cata lyst centre. It is shown that it should be possible to detect catalyti c reactions at a single atom of the new phase.