Designed oscillations of the Fe/H2SO4 system with the flow injection in a partially-closed environment

The flow injection (FI) method is used for the first time in a partially-closed environment (PCE) to study the electrodissolution of iron in 0.5 mol dm−3 H2SO4 solution. With the precise control of the amount of the solution injected, the physicochemical microenvironment at the electrode/electrolyte interface is manipulated, thus the mechanism of anodic dissolution is examined in detail. At the beginning stage of the passive region, when 0.5 mol dm−3 H2SO4 solution or distilled water is injected quantitatively into the PCE periodically, current oscillations are induced. Unlike the spontaneous oscillations, the periods of the artificial oscillations can be changed as designed. The local perturbation caused by the FI offers valuable information about the onset of the current oscillations. This method will have some potential applications in the study of the anodic dissolution mechanism of the metallic materials.