As a part of this work, the stability of an experimental state-of-the-art de-alloyed Pt-Co/C electrocatalyst from ReCatalyst has been comprehensively investigated. The paper has had two goals: 1) to provide the stability guidelines to the PEMFC scientific community for testing of Pt-based electrocatalysts in liquid half-cells using RDE, which are based on the Degradation protocol for fuel cells and fuel cell components proposed by the US DoE; 2) to provide novel insights into the significant effects of both the LPL and UPL limits on the dissolution of metals (Pt and M) to understand also on how to minimize it during PEMFC operation as much as possible. To achieve these goals, two previously reported advanced electrochemical methodologies have been used: (i) a high-temperature disc electrode (HT-DE) setup, which enables ADT to be performed in a liquid electrolyte half-cell by utilization of a standard rotating disc electrode (RDE) at elevated temperatures; (ii) an electrochemical flow cell coupled to an inductively coupled plasma mass spectrometer (EFC-ICP-MS), which allows for precise, highly sensitive (ppb range) time-temperature-and-potential resolved measurements of dissolution of metals, as well as direct monitoring of the dissolution mechanisms at close-toreal operational conditions. EXPERIMENTAL Synthesis of the experimental de-alloyed Pt-Co/C electrocatalyst.