Electrochemistry of copper in aqueous ethylenediamine solutions

Potential-pH equilibria and potentiodynamic polarization studies were used to examine the electrochemical behavior of copper in aqueous ethylenediamine solutions. Potential-pH diagrams for the copper-water-ethylenediamine system were derived at different total copper {Cu sub T } and ethylenediamine {En sub T } activities. The diagrams show that the solubility range of copper is significantly extended in the presence of ethylenediamine. Polarization experiments were conducted in deaerated and aerated aqueous solutions of 10 exp 2 M ethylenediamine with 10 exp -3 M cupric sulfate, and 10 exp -4 M ethylenediamine with 10 exp -5 M cupric sulfate over a wide pH range. The results of these experiments are discussed in terms of relevant potential-pH diagrams. Good correlations were observed.