Where e is the elementary charge, k 0 is the rate constant taken to be 200/s/site, 5 N site is the total number of sites and A is the surface area (both calculated from the alpha shape technique), giving j0 to be 121 mA/cm 2 . ∆G ‡ ORR (0) is the activation energy of the RDS on the oxide-free catalyst at the equilibrium potential U • ORR . This value is difficult to obtain experimentally, since at this potential the catalyst is fully oxidized. Instead, we perform an educated guess based on the theoretical literature and the expectation that the value will significantly grow as the oxide coverage increases due to Equation .