Bursting Oscillations during Metal Electrodissolution:  Experiments and Model

Abstract

Experiments were carried out on bursting oscillations in an electrochemical system, the dissolution of iron in sulfuric acid. Bursting characteristics were investigated as functions of the parameters applied potential and external resistance. We develop a model that incorporates the effects of oxide and salt films. This model reproduces all the important features of the dynamics seen in experiments including both the slow activepassive oscillations and the faster oscillations on the mass-transfer-limited plateau as well as the bursting phenomena. During this bursting, two time scales are important: the slow variation of the salt-film thickness and the faster dynamics of a three-variable (potential drop and proton and iron(II) concentrations) subsystem.

On the onset of current oscillations at the limiting current region emerged during iron electrodissolution in sulfuric acid solutions

“…Periodic current oscillations of a relaxational character appear across the passive-active transition region, close to the Flade potential (E F ) where the iron oxide film is formed [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Current oscillations, often chaotic, appear across the transition from the active state (dissolution of a film-free Fe surface) to a partially passive state where the formation of a ferrous salt layer leads to a mass-transfer controlled limiting current region (LCR) [23][24][25][26][27][28][29][30][31].…”

“…Thus only few models treat these current oscillations. These models [27,30,31], developed either to describe the essential dynamical features or to explain the origin of the oscillations at the LCR, adopt different approaches due to a poor understanding of the conditions, which lead to the onset of oscillations [29].…”

Application of recurrence plots as a new tool in the analysis of electrochemical oscillations of copper

“…Such oscillations contain information of the corrosion process under study, finding an important application in the industry [1] and also as a tool of basic research in electrochemistry [2][3][4].…”

Influence of metal ions on oscillatory behavior of zinc anode in nitric acid-potassium dichromate media

“…Dynamic behavior of some metals at the transition region from the active state to the passive state, from steady state to simple, double or chaotic oscillations, affords a large area of research interest in corrosion and protection of metals as well as understanding the oscillatory phenomena which occur at the solid/liquid interface processes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16].…”

“…Most frequently studied electrochemical system, from the point of view of the dynamic behavior, is iron anodization in sulfuric acid media [2,4,6,9]. Besides iron, there are many other metals which present current or potential oscillations (Ni, Cu, Co, Pb, Ag, Zn, alloys) in certain media (acid, alkaline or salts solutions).…”