Oxygen reduction reaction (ORR) is an important reaction in many energy conversion systems, but it is severely restricted by its slow kinetics. Developing efficient non-noble-metal catalysts for ORR has attracted extended interests, but still remains a great challenge. Herein, an efficient catalysts consisting of Co₃O₄@Co nanoparticles embedded in N-rich mesoporous carbon matrix is developed by the carbonization of Co-containing zeolitic imidazolate framework precursor. The derived matrix exhibits outstanding catalytic activity with onset potential of 0.97 V vs. RHE, half-wave potential of 0.88 V vs. RHE, and good catalytic durability when tested with the rotation speed of 1600 rpm. Carbinization under NH₃ introduces extra elemental N, which subsequently enhances the limiting current densities. This study provides insight into the rational design of highly active ORR catalysts.