In other words, once O2 -is adsorbed on Au(100), it would be consumed by ORR. The standard potential for R9 is around -0.28 V, and at pH=13 it would be 0.5 V (RHE). When the electrode potential is raised above 0.5 V, the ORR current does not drop to zero due to the irreversible nature of R10, although the amount of O2 -in the outer sphere should decay exponentially with the increasing overpotential and so should the ORR current. By +0.9 V (RHE), there is only a small amount of O2 -produced, and R9 should indeed be the RDS. Such an exponential decay implies a linear Tafel plot with a slope around 120 mV/decade for the one electron transfer reaction R9, in agreement with recently reported experimental value. This decay could further extend to E > 1.0 V (RHE), although in this region there are other complicating factors. The adsorption sites on Au(100) would be partially blocked due to the enhanced presence of OH* and O* at high potential, which would hinder R10. When E is close to 1.2 V, OH* desorption would also slow down. Such factors could have impacts on the rather low O2 -concentration in this potential region and cause significant shifts in the equilibrium R9. The decay in ORR current would be faster than that expected from an exponential function. But, as long as OH* desorption remains active, which is the case up to 1.2 V (RHE), there would still be ORR current. It explains the small ORR current in the corrected j-E curve for E > 1.0 V (RHE), up to 1.18 V (RHE), which is close to the equilibrium potential for the overall ORR at 1.23 V.