In Fig. , the evolution of ELF attractors for the SV and the reactive methanol atoms going from structure I to IV, from reactants to products are reported. The attractors are local maxima of the ELF and allow an identifica-tion of localized bond electrons and lone pairs. The population of each attractor, highlighted in bold in Fig. , is obtained by integrating the electron density over the associated basin, defined as the region of space from which the gradient path leads to the attractor. At the reactant state (structure I), our analysis identifies three attractors (0.8 ELF value) located in the SV: attr2 and attr3 lying in the Graphene plane close to C u2 and C u3 atoms, and attr1 located slightly out-of-plane in the proximity of C u1 . These attractors correspond to one electron pair shared between the three undercoordinated carbon atoms. The electronic pair has been identified from the corresponding maximally localized Wannier function and associated center (in green), reported in Panel B of Fig. ). It should be mentioned that, in apparent contradiction with the Wannier function analysis, the total ELF basins population is close to 3. This is due to the inclusion of a π-delocalized electron pair in the ELF integration (see Supplementary Information, Fig. ).