Then, the incorporated N atom is not directly the ORR active site, but it provides a way to modify the electronic structure of the graphitic network. Similarly, the presence of intrinsic defects can alter the charge distribution along the graphitic . network. This has been extensively studied in the case of edges exposure,16-21] showing even a synergy effect between the edges and the nitrogen presence[19-23]; and more recently with topological (non hexagonal carbon rings) defects,[19,24-27] especially the pentagon carbon ring,[12,17,28]