Oxygen reduction reaction (ORR) plays a crucial role in both the chemical and energy industries. Despite substantial advancements in theoretical, computational, and experimental studies, identifying both the in situ activity and selectivity in ORR electrocatalysis remains a major challenge. Here, using a suite of correlative operando scanning electrochemical probe and electrochemiluminescence microscopy techniques, we establish a link between the morphological structure and the local ORR activity and selectivity of single Au and Au@Pt platelets at the subparticle level. It is clearly shown that the edge facets of Au and Au@Pt platelets exhibit higher activity for 4e