As further evidence on the importance of the results in the present study, revealing data published by Argonne National Laboratory with a detailed investigation of the operated Mirai stack showed that under system-controlled operation the voltage window was kept within the range (0.65-0.85) V. Analysis of MEAs showed no Co dissolution into the membrane under system-controlled operation, but that a large amount of Co had dissolved after the application of the ADT for catalyst durability defined by the US-DoE (0.60-0.95) V voltage window. The reported cathode loading for the Mirai MEAs under study were circa 0.30 mgPt cm -2 and under the operating conditions used, this loading was enough to prevent exposure to aggressive upper and lower voltages (i.e. <0.65 or >0.95V). It is plausible that this benign voltage window leads to low Pt dissolution and is probably one of the causes that prevented significant dissolution of cobalt. Clearly, this is a solid evidence that the voltage window used to determine the durability of Pt-alloys is extremely important. In addition to the d-Pt-Ni/C-JM benchmark, we have also tested all four A and Sactivated Pt-alloy catalysts (Figures ) using the exact same protocol presented in Figure (see also, SI Figure for the II. LPL part of the EFC-ICP-MS protocol). First and foremost, we observe the exact same effect (in other words, increase the less noble metal dissolution upon the decrease of LPL) as in the case of d-Pt-Ni/C-JM benchmark (Figure ). Also importantly, analogously to the comparison of metal dissolution in the WPW cycles for the A and S-activated Pt-alloy electrocatalysts (Figures ), both A-activated catalysts exhibit a dramatically higher amount of less noble metal dissolution (Figures and) in contrast to the S-activated catalysts (Figures and). We wish to remind the reader, that upon TF-RDE characterization (Figures and SI, Figures ), the only noticeable difference between the A and S-activated catalysts for both Pt-Ni and Pt-Cu catalysts was observed in the shift of the CO-electrooxidation peak maximum measured before and after PCA. However, following also the additional comparison of the metal dissolution trends (Figure ) as well as single-cell performances (Figure ), it is now rather clear that depending on the choice of the de-alloying (activation) protocol, the electrochemical behavior is influenced substantially.