Graphene with an intrinsic sp2-conjugated carbon framework is inactive to the oxygen reduction reaction (ORR) because of the weak adsorption of oxygenated species at the electroneutral carbon site. The heteroatom doping such as N into graphene is an efficient strategy to facilitate it, but most N-doped electrocatalysts are still inferior to transition metal-based catalysts because it is difficult endowing them with enough electrons to achieve a superb performance. Herein, we successfully tune carbon atoms into near-optimal adsorption sites for ORR by injection of extra electrons from a combined electron-rich source to change the π electron occupancy at carbon sites in a rationally designed core–shell structure. Ag nanoparticles encapsulated in N-doped graphitized carbon shells exhibit an excellent performance of a half-wave potential of 906 mV and limited current density of 6.10 mA cm–2 in alkaline media, which is superior to most N-doped electrocatalysts. Density functional theory calculation shows that ...