Structural investigation of the initial stages of copper electrodeposition on polycrystalline and single crystal palladium electrodes

The Influence of Iodide Adsorption on Copper Underpotential Deposition on Polycrystalline Palladium Electrodes in Mildly Acidic Solutions

“…Cu UPD on noble metals is a relatively slow process and the electrochemical spectra of the interfaces are strongly dependent on the potentiodynamic perturbation used in the experiments, specially on Pd surfaces because of the less noble characteristics of this metal (19). On the other hand, the deposition of small amounts of Cu on Pt enhances the adsorption of halides present in solution, as it was confirmed by in-situ surface EXAFS and X-ray standing wave spectroscopy (23)(24)(25)(26).…”

“…However, the evaluation of the real surface electrode area was accomplished by voltammetric profiles only up to 1.27 V vs NHE where a full PdO monolayer is formed (27). An electropolishing procedure was also assayed in a nonaqueous bath, as it has been previously suggested by Chierche et al (19). However, this preparation procedure leads to the development of defined crystallographic planes on the pc surface after a number of trials, characterized by single voltammetric peaks.…”

“…0.2 cm 2 , which were pretreated according to different procedures (19,22). Since this work was conducted with a pc Pd electrode, the activation (cleaning) of the surface was achieved by potential cycling in the electrochemical region of the oxide formation and reduction in 0.05 M H 2 SO 4 , until well-defined voltammograms were obtained.…”

“…Cu UPD on polycrystalline (pc) Pd electrodes has been firstly investigated by Chierche et al (19,20). They have found that Cu UPD takes place at different energetic sites of Pd, and their contributions respond to the different low Miller index crystallographic planes of the substrate.…”

“…They also proposed that Cu UPD on pc Pd obeys a Temkin-type isotherm with a mean saturation charge density of ca. 400 C cm Ϫ2 for a 1:1 ratio of Cu and Pd atoms (19).…”