Nonlinear Time Series Analysis of Nickel in Sulfuric Acid

Abstract

Nickel is one of the most important passive metals used in electrodeposition processes in the world. These processes alone consume several million metric tons of nickel yearly. Nickel is well known for its corrosion resistant properties. However, nickel does corrode in H2SO4 and can produce current or potential oscillations in potentiostatic or galvanostatic experiments. Traditional electrochemical studies on Ni oscillating systems are performed by applying applied potential or current during the electrodissolution (corrosion) of single wire electrodes in highly concentrated solutions. External forcing, in which perturbations are applied to systems by an external source, have provided a better understanding of oscillating systems. However, little attention has been given to performing electrochemical studies on electrodeposited metals that produce oscillating systems in lower concentrations of acidic solutions (0.1 M – 1.0 M) and no attention has been given to the possibility for external forcing of these unique systems via concentration change and local heating at the electrode surface until now. The presented work examines the changes in frequency, magnitude, and shape of periodic oscillations and the change in kinetics from temperature changes due to electrical heating and external forcing by independently changing the proton concentration at a nickel electrode. This work improves the understanding of the relationship between periodic oscillation phenomena and the corrosion process of the nickel system in H2SO4.