During the MOR, we observed a shift of the decrease in X-ray intensity to more positive potentials compared to the measurements in the methanol-free electrolyte. This effect was rationalized by a potential dependent lowering of the OH/O adsorbate coverage and thus by a similar up-shift of the O insertion and Pt extraction in the presence of methanol or reaction intermediates formed during the MOR. We suggest that a similar shift of the decrease in X-ray intensity to more positive potentials, as observed in the SXRD measurements in the MOR, will occur also during the COOR. In that case, the effect might be even more pronounced since CO oxidation also occurs up to the OER. CO can readily adsorb and react on the electrode surface, even by chemical reaction with Pt surface oxides. In contrast, active interme-diates can only be formed in the MOR by splitting MeOH, which is increasingly hindered at high potentials. Therefore, we assume that CO in the CO-saturated solution can efficiently remove OH/O species from the surface even at a potential where the MOR is inhibited and thus shift the potential for partial Pt extraction and reversible surface restructuring to even more positive potentials. Accordingly, also the potential for irreversible restructuring may be up-shifted.