For the voltage window experiments the benchmark d-Pt-Ni/C-JM cathode catalyst was tested for durability under H2/N2 with the UPL fixed at 0.925 V whilst the LVL was changed to 0.5, 0.6 or 0.7 V. At both LVL and UVL, the voltage was held for 3 seconds whilst the rise time in between the voltage window of (LVL -0.925) V was below 0.5 s. The durability protocol was applied for a total of 1000 cycles, at 80°C, 100% RH and ambient pressure at the cell outlet. Afterward, the cell voltage was measured at 1.2 A cm -2 at different temperatures as described in the text. The Pt-alloy NIC electrocatalysts were synthesized in a three-step process. In the first step (Figure ), Pt-based NPs were deposited on the M/C composites using our previously reported proprietary double passivation method. In the second step (Figure ), the obtained Pt-containing composites were subjected to a high-temperature thermal annealing in order to form a Pt-alloy structure . In the last step (Figure ), for the purpose of this study, both Pt-M alloys (M = Cu or Ni) have been de-alloyed by using two different chemical activation (in other words acid washing) protocols. In one case, we have employed a rather mild previously reported de-alloying protocol (4x 1 M acetic acid + COg ) that uses mild conditions such as acetic acid, but in combination with an adsorptive gas such as COg. The adsorptive gas binds to the Pt-surface and inhibits any possible re-adsorption of re-deposition of M ions (M = Cu, Ni or possibly other less noble metals) onto Pt surface. This improves the ability to wash the de-alloyed M out of the carbon matrix during the process of acid washing . Hereinafter we will refer to this acid washing activation as protocol 'A' and the electrocatalysts d-Pt-Ni/C-NIC-A and d-Pt-Cu/C-NIC-A. On the other hand, the second de-alloying activation protocol included the use of a stronger acid such as sulfuric acid (H2SO4) also reported by others as part of previous DoE projects (0.5 M H2SO4, 24 hours, 80 o C) .