Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride ionic liquid

• Published in: Electrochimica acta Vol. 54; no. 26; pp. 6747 - 6755
• Main Authors: Jayakumar, M., Venkatesan, K.A., Srinivasan, T.G., Vasudeva Rao, P.R.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2009; Elsevier
• Subjects: 1-Butyl-3-methylimidazolium chloride; Applied sciences; Chemistry; Electrochemistry; Electrodeposition; Exact sciences and technology; General and physical chemistry; Hydrometallurgy; Metals. Metallurgy; Nucleation; Palladium; Production of metals; Production of non ferrous metals. Process materials; Rhodium; Room temperature ionic liquid; Ruthenium; Study of interfaces; Voltammetry; Ruthenium; Nucleation; Rhodium; Voltammetry; Electrodeposition; Palladium; 1-Butyl-3-methylimidazolium chloride; Room temperature ionic liquid; Electrochemical characteristic; Ionic liquid; Electrodes; Fission product; Electrochemical reaction; Platinoid; Ruthenium III Chlorides; Hydrometallurgy; Transition metal; Carbon; Electrolytic separation; Palladium II Ions; Rhodium III Ions; Stainless steel; By product; Room temperature; Glassy state
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2009.06.043

Electrochemical behavior of ruthenium (III), rhodium (III) and palladium (II) in 1-butyl-3-methylimidazolium chloride (bmimCl) and their ternary and binary solutions in bmimCl was studied at various working electrodes at 373 K by cyclic voltammetry and chronoamperometry. Ruthenium (III) chloride forms a stable solution with bmimCl and the cyclic voltammogram of ruthenium (III) in bmimCl recorded at glassy carbon electrode consisted of several redox waves due to the complex nature of ruthenium to exist in several oxidation states. Electrolysis of ruthenium (III) chloride in bmimCl at the cathodic limit of bmimCl (−1.8 V (vs. Pd)) did not result in ruthenium metal deposition. However, it was deposited from bmimPF 6 and bmimNTf 2 room temperature ionic liquids at −0.8 V (vs. Pd). The electrochemical behavior of ruthenium (III) in bmimCl in the presence of palladium (II) and rhodium (III) was studied by cyclic voltammetry. The presence of palladium (II) in bmimCl favors underpotential deposition of ruthenium metal. The nuclear loop at −0.5 V (vs. Pd) was observed in all solutions when palladium (II) co-existed with other two metal ions. Nucleation and growth of the metal on glassy carbon working electrode was investigated by chronoamperometry. The growth and decay of chronocurrents has been found to follow the instantaneous nucleation model with three-dimensional growth of nuclei.