Characterization and electrochemical behavior of Pd-rich Pd-Ru alloys

Abstract Thin layers (0.1–5 μm) of Pd-rich Pd-Ru alloys were prepared by potentiostatic electodeposition from baths containing aqueous solutions of RuCl 3 and PdCl 2 with HCl. Alloy bulk compositions were determined by atomic emission spectroscopy and energy dispersive analysis of X-rays. The crystal structure of the deposits was examined by X-ray diffraction. Alloy surface morphology was characterized by scanning electron microscopy and atomic force microscopy. Surface compositions were determined by X-ray photoelectron spectroscopy. General electrochemical behavior of Pd-Ru deposits was investigated using cyclic voltammetry. The processes of alloy surface oxidation and hydrogen adsorption/absorption were studied in 0.5 M H 2 SO 4 solutions at 298 K. It was found that homogeneous fcc alloys were formed by Pd and Ru with the lattice parameter smaller than that of pure Pd.