Copper corrosion mitigation by binary inhibitor compositions of potassium sorbate and benzotriazole

This work presents the combined effect of two inhibitors, potassium sorbate (2,4-hexadienoic acid potassium salt) and 1,2,3-benzotriazole, on the corrosion behavior of copper in sulfate based solutions. Individual and combined characteristics of copper corrosion inhibition in sulfate solution in the presence of potassium sorbate (K-sorbate) and benzotriazole (BTAH) were studied with the use of electrochemical, microscopic and spectroscopic methods. Whereas, BTAH alone protects copper from corrosion attack in sulfate solutions only in a limited potential range below 0.4V vs. saturated calomel electrode (SCE), the presence of K-sorbate combined with BTAH in such solutions enables the protection of the copper surface at potentials above 0.4 V_SCE. The mixture of both inhibitors provides supplementary and robust corrosion protection of Cu over a wide potential range.