Investigation of precipitation kinetics of FeCO3 by EQCM
By Ma, Zheng; Yang, Yang; Brown, Bruce; Nesic, Srdjan; Singer, Marc
Published in Corrosion Science
2018
Abstract
Iron carbonate (FeCO3) is the most common corrosion product in aqueous CO2 corrosion of mild steel. When it forms, the FeCO3 corrosion product layer may be protective, by serving as a diffusion barrier and by affecting the rate of electrochemical reactions at the surface. In the present study, an Electrochemical Quartz Crystal Microbalance (EQCM) was used to investigate the kinetics of precipitation of FeCO3 from an aqueous CO2 corrosion environment. EQCM is a technique providing very accurate in-situ measurement of surface mass change, enabling also simultaneous electrochemical measurements. Three different substrates were used to conduct the FeCO3 precipitation experiments: a cathodically polarized gold-coated quartz crystal, a freely corroding iron-coated quartz crystal and a cathodically polarized iron-coated quartz crystal, at varied temperatures (50