▎ 摘　　要

Based on first principles method, the catalytic property of nitrogen-doped graphene is investigated for cathode oxygen reduction reaction. It is revealed that nitrogen clusters other than the isolated one are the most efficient catalytic sites for oxygen reduction. Codoping boron (or Fe, Co) can effectively stabilize these otherwise high energy clusters while keeping the cluster's high activity. Clusters with three or four nitrogens are found to be optimal. Theoretically, catalytic properties similar to or even superior to platinum can be obtained. The results can act as guiding principles for designing new functional materials via codoping.