In the negative-going scan, the COOR current increases again in this potential region for the Pt-1 electrode, while for the Pt-3 electrode, it remains about constant. The constant COOR current on the Pt-3 electrode indicates that the slight decline of the COOR rate due to the further accumulation of OH/O species on the surface in the positive-going scan, in addition to the amount formed in the peak A1, is not reversed, but also not continued. Thus, during the reaction, the coverage of these species remains constant in this potential range. Their amount can only be reduced at lower potential. In this case, the kinetic limitations remain present in the negative-going scan in this potential range. This also means that the difference in COOR rates between the positive-going and the negative-going scan increases with increasing UPL. For the Pt-1 electrode, the reasons for the pronounced decay in COOR rate at potentials positive of peak A1 are largely, though not completely, removed in this potential range, leading to only small differences in the COOR current between the positive-going and negative-going scans at the potential directly above the peak A1. Furthermore, different from the Pt-3 electrode, this removal of the kinetic limitations always leads to the same current at about 0.95 V, independent of the UPL. Therefore, for this electrode, most of the more pronounced COOR current decay in the positive-going scan in this potential range must be due to reversible processes such as reversible accumulation and replenishment of additional adsorbed OH/O species or the reversible buckling of Pt surface atoms due to insertion of oxygen atoms underneath, which was described as reversible extraction during the oxidation of Pt(111). Only a small part of this decay in activity is caused by processes that cannot be reversed in this potential range.