and correspondingly MA loss (Figure ) has been observed. This significant decrease in degradation can be explained by the lower Pt dissolution and the consequent Ostwald ripening. The substantially lower loss of SA is also a consequence of additionally lower Co dissolution, which is already known to always follow Pt dissolution. Thus, narrowing the potential window to only 0.7-0.85 VRHE has a dramatic effect on the durability of Pt-alloy cathodesdrastically decreasing the loss of ECSACO, SA. Lastly, it also results in a lower loss of Co. since it is very well-known that the SA of Pt-nanoalloys is dependent on the ligand, strain, coordination number and surface disorder effects provided by the presence of less noble metal. To gain additional mechanistic insights and understand the influence of the trapezoid degradation ADT protocols on the dissolution of metals, an on-line analysis of metal dissolution has been performed using the previously already widely described EFC-ICP-MS methodology. However, to ensure adequate resolution between the cathodic and anodic Pt and Co dissolution peaks, we have adjusted the protocol by prolonging the potential hold periods (Scheme 1). Specifically, three trapezoid-wave protocols of 10 cycles each have been performed in accordance with Table . The most important is, however, that for both the DoE potential window (0.6-0.95 V) as well as the narrower potential window (0.7-0.85 V), different UPL potential holds have been investigated to evaluate the impact of both parameters on the amount of Pt and Co dissolution. This number of cycles has been sufficient