Regulation of Interfacial Chemistry by Coupled Reaction-Diffusion Processes in the Electrolyte: A Stiff Solution Dynamics Model for Corrosion and Passivity of Metals

TL;DR

This paper develops a stiff solution dynamics model to analyze how coupled reaction and diffusion processes in electrolytes influence metal corrosion and passivity, providing detailed insights into local chemistry regulation.

Contribution

It introduces a novel SSD model that captures detailed space-time dynamics of ionic concentrations near corroding metals, advancing understanding of corrosion mechanisms.

Findings

Onset of passivity varies with corrosion conditions.

Model predicts concentration profiles near metals.

Insights support spectro-electrochemical studies.

Abstract

In this paper we advance a stiff solution dynamics [SSD] model to study the regulation of local chemistry near a corroding metal by reaction and diffusion processes in the electrolyte. Using this model we compute the detailed space-time dynamics of the concentrations of metal ions, its hydroxy complexes, H+ and OH- ions near the corroding metal. The time for the onset of passivity for Fe and Zn is presented for free corrosion condition, different impressed currents and initial pH values. The theory advanced provides much physical insight into corrosion and passivity of metals and motivate spectro-electrochemical studies.