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

Thin layers (0.1–5 μm) of Pd-rich Pd-Ru alloys were prepared by potentiostatic electodeposition from baths containing aqueous solutions of RuCl3 and PdCl2 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 H2SO4 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.