“…Figure 1) is the active surface configuration in the potential range of the CER and OER. [10] While in the corresponding surface stability diagrams in heterogeneous catalysis [58,59] or in battery research [60,61] surface energies, γ, are used in order to comprehend on the stability range of the respective electrode material, Pourbaix diagrams are commonly constructed based on free energies, ΔG, rather than on surface energies, γ. [10,17,18,21,24,28,[54][55][56][57] This finding triggers to expand the Pourbaix approach by adopting the concept of surface energies from the neighboring research communities: [57] the electrode material is unstable, if in a certain (U, pH) range the surface energy γ(U, pH) of a surface phase falls below zero.…”