Importance of the hydrogen evolution reaction in magnesium chloride solutions on stainless steel
By Katona, R. M.; Carpenter, J. C.; Knight, A. W.; Bryan, C. R.; Schaller, R. F.; Kelly, R. G.; Schindelholz, E. J.
Published in Corrosion Science
Corrosion Science
2020
Abstract
Cathodic kinetics in magnesium chloride (MgCl2) solutions were investigated on platinum (Pt) and stainless steel 304 L (SS304 L). Density, viscosity, and dissolved oxygen concentration for MgCl2 solutions were also measured. A 2-electron transfer for oxygen reduction reaction (ORR) on Pt was determined using a rotating disk electrode. SS304 L displayed non-Levich behavior for ORR and, due to ORR suppression and buffering of near surface pH by Mg-species precipitation, the primary cathodic reaction was the hydrogen evolution reaction (HER) in saturated MgCl2. Furthermore, non-carbonate precipitates were found to be kinetically favored. Implications of HER are discussed through atmospheric corrosion and stress corrosion cracking.