Green-hydrogen generation has become a focus for research due to its promising future as an energy vector. In this regard, one topic that has not been explored in depth, is the corrosion of catalytic layers under on/off operation in alkaline media during oxygen evolution reaction (OER) on the anode. Here, we studied the corrosion of, and changes to, the catalytic layer on stainless steel (SS) electrodes under different surface treatments. The results showed that there was formation of a passive and catalytic layer of NiOOH during the anodic polarization concomitantly with iron dissolution.