Engineering the coordination environment of Ni and Pd dual active sites for promoting the oxygen reduction reaction.

Precisely regulating active sites is vital for promoting the oxygen reduction reaction (ORR) activity. Here we reported highly active Ni-Pd co-doped N-coordinated graphene towards ORR achieved by edge termination and O doping. Our first-principles calculations demonstrated that edge termination effectively boost the ORR activity, and armchair-edge termination was energetically more favorable than zigzag-edge termination. Notably, after O doping Ni-Pd active center, armchair edge-terminated Ni-Pd active site exhibited better ORR activity, and the lowest overpotential was only 0.31 V. This improvement in activity was attributed to the shift of the d-band center of Ni atom toward the Fermi-level and the shift of the d-band center of Pd atom away from the Fermi-level, thus regulating the *OH adsorption strength. This work paves the way for developing highly active graphene-based dual-atom catalysts for ORR through edge and doping engineering.