Figure 2.

Gibbs free energy and overpotential. a) Linear relationship of ∆G _H*, ∆G _OH*, ∆G _O*, ∆G _OOH*, and ∆G _OO* vs. a) ∆G _OH* and b) new descriptor (φ) for FeCoNiRu‐HESAC, indicating that the new descriptor effectively establishes a linear relationship with Gibbs free energies. c) The counter plot of ORR overpotential vs. ∆G _OOH* and ∆G _O*‐∆G _OH*. d) Volcano plot of ORR overpotential vs. ∆G _OH*, indicating Fe active site with D = 6.11 Å at the summit.