Operando kinetics of hydrogen evolution and elemental dissolution I: The dissolution of galvanized steel in hydrochloric acid

A new approach to the simultaneous measurement of the hydrogen evolution reaction (HER) and elemental dissolution rates is presented and applied to the reaction of galvanized steel coatings with HCl solution. Disso-lution profiles revealed several kinetic regimes including the dissolution of the intact coating, the dissolution of the nanometric Fe2Al5 intermetallic layer, and the corrosion of the steel substrate. The HER and Zn dissolution rates were in excellent agreement, and the quantities of interfacial Fe and Al were consistent with the predicted 50 nm thick Fe2Al5 intermetallic film, demonstrating the analytical capabilities of the atomic emission spec-troelectrochemistry (AESEC) technique.

Automated summary

A new approach using atomic emission spectroelectrochemistry (AESEC) was applied to simultaneously measure the hydrogen evolution reaction (HER) and elemental dissolution rates in the reaction of galvanized steel coatings with HCl solution. The dissolution profiles revealed different kinetic regimes including the dissolution of the intact coating, the dissolution of the nanometric Fe2Al5 intermetallic layer, and the corrosion of the steel substrate. The HER and Zn dissolution rates showed excellent agreement, and the amount of interfacial Fe and Al matched the predicted thickness of the Fe2Al5 intermetallic film, demonstrating the analytical capabilities of the AESEC technique.