Nisrine Benzbiria
University of Chouaib Doukkali, Morocco
Title: Determination of the kinetic parameters of oxygen reduction on copper using a rotating disk electrode in neutral medium
Biography
Biography: Nisrine Benzbiria
Abstract
Regarding their excellent mechanical properties associated to a corrosion resistance quite satisfactory, the passivated metals occupy a prominent place in several industries. However, these materials undergo corrosion in some media especially those containing chloride. Consequently, to understand the phenomena taking place into their surface, some electrochemical investigations should be done. The majority of the previous studies concerned only anodic dissolution of the metal while the cathodic reaction, which is least studied, can provide relevant information. Oxygen reduction assumes importance in corrosion processes since in neutral solutions and in the absence of any other depolarizer the corrosion rate is controlled by the kinetics of oxygen reduction reaction. Our interest is to outline the significant role of oxygen reaction reduction (ORR) on copper. For this purpose, we have used the rotating disc electrode (RDE) to obtain cathodic polarization curves in neutral Na2SO4 solution containing different O2 concentrations. Three types of copper surfaces were investigated: pre-reduced electrodes, copper pre-oxidized to Cu/Cu2O and pre-oxidized to the duplex Cu/Cu2O/CuO layer. This will allow us to elucidate the influence of film and dissolved oxygen concentration on the kinetics of the cathodic reaction. Parameters, such as reaction order, kinetic current, Tafel slopes as well as the number of electrons transferred are determined.
