Electrodissolution Kinetics of Iron in Chloride Solutions: IX . Effect of Benzotriazole on Potential Oscillations

This study examined the effect of the organic inhibitor, benzotriazole (BTA), on the oscillatory behavior of high‐rate Fe electrodissolution in concentrated chloride media. Linear sweep experiments with rotating disk electrodes showed well‐defined limiting currents for both uninhibited and inhibited iron. In the presence of BTA, the inhibition of Fe dissolution was observed in the entire potential region examined, with the onset of the limiting diffusion current occurring at lower potentials. Galvanostatic experiments showed that potential oscillations for both uninhibited and inhibited Fe occurred at applied current densities within and above the limiting diffusion current; the potential oscillations exhibited a variety of waveforms. The chaotic oscillations were characterized by power spectral densities, phase portraits, Poincaré sections, correlation dimensions, and Lyapunov exponents. The effect of BTA on the oscillatory behavior of Fe in concentrated chloride solutions was interpreted in terms of a duplex inner nonporous layer‐outer porous salt film model.