(color online) Atomic-scale STEM analysis of graphene-based catalysts for ORR. (a) STEM-HAADF image of individual Fe atoms in few-layered graphene. (b) The EEL spectra of N K-edge and Fe L-edge from the three points indicated in panel (a). (c) Simultaneously acquired STEM-HAADF image and EELS mapping of Fe (d) and N (e).^[29]