As discussed in this paper, if the upper voltage is controlled at 0.925V or lower, the LVL where almost full reduction of the Pt-oxide occurs , such as 0.60 V (vs RHE) used in this work, can be of particular importance to enable alloy cathodes. Of course, the voltage at which full Pt-oxide reduction occurs depends on the T, RH and p used in addition to the composition of the cathode catalyst layer. The observations derived from this work lean towards the hypothesis that Pt-alloys are particularly prone to faster degradation compared pure Pt, if exposed to voltage windows where almost all the Pt-oxide and OHad is removed and grown again using a dynamic profileleading to the depletion of the less noble metal in the first three or four atomic layers and presence of leached metal ions in the ionomer. The explanation is based on the hypothesis that oxygen diffusion into the subsurface is an important step in the formation of the surface oxide, and for the subsequent Pt dissolution. For a detailed discussion on this topic, the reader is directed to the elegant work by Balbuena and co-workers on the mechanism of subsurface oxygen formation, surface segregation and Pt dissolution for Pt and Pt-alloys. Considering that the less noble metal composition in the second and third atomic layer of a Pt-alloy is usually in the range of Pt:X (3:1) X=Ni, Co or Cu, from the voltage windows provided in this work, one could easily explain the fast depletion of the less noble metal in the subsurface if exposed to the (0.6-0.925) V voltage window. Dissolution of the less noble metal is influenced by the reactions that occur at the vicinity of the Pt-oxide growth and reduction. On the other hand, if the catalyst surface is left slightly oxidized, such as with the use of narrower voltage windows (0.70-0.925) V then the depletion of the less noble metal in the subsurface is inhibited under the protocol and conditions used in this work. One would also have to acknowledge that the onset of the oxide growth is shifted to higher voltages/potentials for the case of Pt-alloys compared to Pt . This is of particular relevance for industrial application in MEAs because by preventing the segregation of the less noble metal the negative impact of dissolved metal ions is avoided. This is often overlooked in wet electrochemical cells where dissolved metal ions in the electrolyte do not lead to a decrease in ORR activity. However, in MEAs, it is well known that metal ions can diffuse from the cathode layer to the membrane and back again being the flux of ions back and forwards from the cathode layer to the membrane, proportional to the flux of protons and hence the load. As a consequence proton and oxygen transport can be severely decreased in the presence of dissolved metal ions, which are two of the main reasons for the decrease in performance at high current densities after cycling Pt-alloys, among other factors, as reported by Ramaswamy and co-workers .