Modulating the microenvironment structure of single Zn atom: ZnN4P/C active site for boosted oxygen reduction reaction

The electronic structure of catalytic active sites can be influenced by modulating the coordination bonding of the central single metal atom, but it is difficult to achieve. Herein, we reported the single Zn-atom incorporated dual doped P, N carbon framework (Zn-N4P/C) for ORR via engineering the surrounding coordination environment of active centers. The Zn-N4P/C catalyst exhibited comparable ORR activity (E1/2 = 0.86 V) and significantly better ORR stability than that of Pt/C catalyst. It also shows respectable performance in terms of maximum peak power density (249.6 mW cm−2), specific capacitance (779 mAh g−1), and charge-discharge cycling stability for 150 hours in Zn-air battery. The high catalytic activity is attributed to the uniform active sites, tunable electronic/geometric configuration, optimized intrinsic activity, and faster mass transfer during ORR-pathway. Further, theoretical results exposed that the Zn-N4P configuration is more electrochemically active as compared to Zn-N4 structure for the oxygen reduction reaction.