Electrochemical preparation and characterization of thin deposits of Pd-noble metal alloys

The procedures of Pd-noble metal alloy (Pd-Au, Pd-Pt, Pd-Rh, Pd-Pt-Rh) preparation by electrochemical deposition from chloride solutions are described. The influence of deposition conditions on alloy composition is presented. The deposits were characterized electrochemically in acidic solutions (H2SO4 aq) by cyclic voltammetry. The surface morphology of the alloys was examined by scanning electron microscopy and scanning tunneling microscopy. The alloy surface composition was investigated in situ by the electrochemical method and ex situ by Auger electron spectroscopy, while the bulk composition was determined by energy dispersive analysis of X-rays and atomic absorption spectroscopy. The electrochemical methods of the real surface area determination were compared and discussed. (C) 2009 Elsevier B.V. All rights reserved.