Platinum Metals Rev., 1957, 1, (1), 19
Electrodeposition of Ruthenium
Very little work has been carried out on the electrodeposition of ruthenium although it is known that deposits have been obtained from dilute solutions of ruthenium nitroso salts. An investigation recently completed at the Atomic Energy Research Establishment, Harwell, by A. C. Littlejohn (A.E.R.E. C/R 1892, 1956) shows that, under certain conditions, uniform deposits of ruthenium may be obtained on copper cathodes from solutions of ruthenium nitroso trichloride in dilute hydrochloric acid.
Numerous runs were carried out, using a platinum anode, at constant potential, but it was found in all cases that once an initial coating of ruthenium had been deposited at low current density, the current gradually increased to very high values and brittle deposits were obtained. Constant potential electrolysis was therefore dropped in favour of constant current electrolysis. In these experiments current densities up to 20 mA/cm2 were used, and the deposits were considerably improved.
Conditions finally recommended for successful deposition include a solution of 5×10−3 M Ru(NO)Cl3 + 0.5N HCl, and a current density between 2 and 5 mA/cm2.