Mass‐Transport Study for the Electrodissolution of Copper in 1M Hydrochloric Acid Solution by Impedance

Abstract

The dissolution of copper in 1M chloride solution was studied by steady‐state (current‐voltage curves for various disk rotation rates) and transient [frequency analysis of the electrochemical and electrohydrodynamical (EHD) impedance] measurements. The anodic polarization curves have presented one region of mixed kinetic and another of mass‐transport control characterized by a current plateau. The limiting current is a Ω1/2 function throughout the whole range of rotation rates. From the EHD impedance diagrams observed below the anodic plateau, it was shown that the limitation by mass transport is due to CuCl2− . On the current plateau, the presence of two time constants on the EHD impedance diagram and the reductibility of the curves have been attributed to the existence of a salt layer covering the surface, the rate of formation of this layer being identical to the rate of dissolution. A layer model has been developed.

Influence of extracellular polymeric substances (EPS) from Pseudomonas NCIMB 2021 on the corrosion behaviour of 70Cu–30Ni alloy in seawater

“…An effect of the rotation speed on the anodic polarisation curves plotted with a rotating ring electrode was evidenced below 0.3 V vs SCE (results not shown here). However, the curves exhibit no anodic plateau unlike pure copper in acidic and neutral chloride solution for which a limiting-current region can be observed around 0 V vs SCE [50,51]. These results show partial mass transport limitation i.e.…”

Protection of copper against corrosion in simulated urban rain by the combined action of benzotriazole, 2-mercaptobenzimidazole and stearic acid

“…12a). The semicircle reflects the relaxation time constant of the charge-transfer resistance, which is approximately equal to the diameter of the capacitive loop, and the double layer capacitance at the copper/electrolyte interface [32]. Similar to the EIS response for Cu in chloride solution [33][34][35][36], Warburg impedance observed in simulated urban rain reflects the anodic diffusion process of soluble copper species from the surface to the bulk solution as well as the cathodic diffusion of dissolved oxygen in the opposite direction.…”

Investigation of the first stages of the localized corrosion of pure copper combining EIS, FE-SEM and FE-AES

“…As a result of the contact with the chloride containing solution, layers of corrosion products are formed. Sometimes porous Cu 2 O layers are mentioned [41,[60][61][62][63], also CuCl is found [1,2,34,[60][61][62]64,65], sometimes as a layer [13,14,21,43], possibly formed from an intermediate CuCl − [65,66]. Some mention the transformation of CuCl into Cu 2 O [5,50,61,67].…”

“…Upon immersion a double layer appears on the surface [80]. Because of the corrosion reaction there also exists a diffusion of reagents towards the surface: (O 2 , Cl − ) and a diffusion of reaction products (CuCl x− ions) away from the active zones [5,21,23,42,43,50,62,65,66,69,77]. This diffusion can occur through the solution as well as in a formed surface film.…”