Use of ac admittance voltammetry to study very fast electron-transfer reactions. The [Ru(NH3)6]3+/2+ system in water.

The kinetics of electroreduction of Ru(NH3)6(3+) has been studied at a polycrystalline gold electrode using high-frequency ac admittance voltammetry. It is shown that precise kinetic data may be obtained for a very fast electron-transfer reaction using this technique. The kinetic data show a small double layer effect when the concentration of HClO4 used as background electrolyte is varied. This is discussed in terms of the point of zero charge, which is very close to the standard potential for the studied reaction.