For the Pt-3 electrode, such kind of restructuring induced increase of the COOR at around the onset potential is hardly visible in the COOR-CV upon extending the UPL up to 1.35 V (see inset of Fig. ). The remaining subtle changes in the current density (one order of magnitude lower than for Pt-1) are tentatively associated with a slight restructuring of the electrode, possibly in the small fraction of mono-and bilayer Pt areas (see Fig. ) present on the Pt-3 electrode, although this could not be resolved by STM imaging. The magnitude of peak A1 remains almost unchanged during potential cycling for the Pt-3 electrode, different from the decrease for the Pt-1 electrode.