关键词: Pt单晶电极, Cu, 欠电位沉积, 台阶修饰

Abstract: The underpotential deposition of Cu on platinum stepped surfaces composed of (100) terraces and (110) monoatomic steps has been studied in different acidic solutions. It has been found that the initial stage of copper deposition on the surface takes place simultaneously on terrace and step sites, irrespective of the nature of the adsorbing anion. During the voltammetric deposition of a full monolayer, several peaks can be observed. The analysis of the dependence of the peak charge with the step density allows assigning the different peaks to different deposition sites. The peak appearing at most positive potentials corresponds to the deposition of Cu on the terrace sites, whereas deposition on the step sites gives rise to different voltammetric contributions depending on the anion present in solution. Additionally, it has been found that the charge transferred upon Cu deposition is very close to 2e and that the anion coverage does not change during this process from that initially present on the platinum substrate.

Key words: Pt single crystal electrodes, copper, underpotential deposition, step decoration