Respirometric Techniques for Real-Time Monitoring of Corrosion Reactions

Abstract

Recently, we have introduced novel respirometric methods for real-time monitoring of corrosion, both for atmospheric corrosion [1,2] and immersion conditions [3]. The approach is based on monitoring the rate of the cathodic reactions with help of different types of sensors; this enables to track the O2 reduction reaction and the H2 evolution reaction simultaneously. Different experimental setups have been developed, from static to flow cell scenarios. Moreover, combining respirometry with time-lapse microscopy reveals interesting details on initiation and propagation of corrosion. Most recently, the respirometric setups were coupled with electrochemistry [4], enlarging the corrosion cases to be studied from open-circuit conditions to potential-controlled systems. With this, it is possible for instance to follow and quantify the amount of oxygen evolving during transpassive dissolution of stainless steels at potentials above the water stability region (i.e., the net electrical current/charge can be assigned into partial currents for oxygen evolution and for metal dissolution). Examples will be presented, to illustrate the potential of these techniques to reveal new insights into corrosion mechanisms of active and passive metals and alloys.References M. Strebl, S. Virtanen, Real-Time Monitoring of Atmospheric Magnesium Alloy Corrosion, Journal of The Electrochemical Society 166 (2019) C3001-C3009M. Strebl, M. Bruns, S. Virtanen, Editors’ Choice—Respirometric in Situ Methods for Real-Time Monitoring of Corrosion Rates: Part I. Atmospheric Corrosion, J. Electrochem. Soc. 167 (2020) 21510M.G. Strebl, M.P. Bruns, G. Schulze, S. Virtanen, Respirometric In Situ Methods for Real-Time Monitoring of Corrosion Rates: Part II. Immersion, J. Electrochem. Soc. 168 (2021) 11502M.G. Strebl, M.P. Bruns, S. Virtanen, Coupling Respirometric HER and ORR Monitoring with Electrochemical Measurements, Electrochimica Acta 412 (2022) 140152