Abstract: Copper p-toluenesulfonate was synthesized and has been applied to the electrochemical test for the first time. This salt can lose all its hydrated water easily and the dehydrated salt does not deliquesce in air. Hence, the copper p-toluenesulfonate is suitable to the electrochemical studies in organic solvents. The cyclic voltammetry, chronoamperometry and potential-time curve after galvanostatic electrolysis were used to study the electro-reduction of Cu(II) on Pt electrode in Cu (p-CH3C6H4SO3)2＋TBAP＋DMSO. The electro-reduction of Cu (II) to Cu proceeds by two steps: Cu (II)＋e = Cu (I), Cu (I)＋e = Cu. The first step is reversible. The diffusion coefficient of Cu(II) in DMSO is determined as 1.0×10－6 cm2•s－1 at 301 K.

Key words: Copper p-toluenesulfonate, DMSO, Cu (II), Electroreduction, Diffusion coefficient