Abstract
The corrosion behavior and hydrogen generation on aluminum in NaOH solutions are followed up using different techniques. The rates of Al
2
O
3
film destruction, metal dissolution, and hydrogen gas production are dependent on the alkali amount and the solution temperature. The existence of two capacitive semicircles at high and low frequencies confirm the charge transfer process on the metal surface. The existence of an inductive loop at intermediate frequencies emphasizes the surface charge due to the building up of oxide film at the Al/Al
2
O
3
interface. Low values of free energy of activation of these processes
E
a
indicate that these processes are controlled by a diffusion step. The positive values of Δ
H
a
reflect the endothermic nature of the activation processes, while the negative values of Δ
S
a
indicate a decreased disordering of a dissociation step.