Ternary single atom catalysts for effective oxygen reduction and evolution reactions

Synergistic effects have been demonstrated for binary single-atom catalysts (SACs), while it is still challenging to investigate the activity and performance of ternary SACs due to the lack of robust method to synthesize these materials. Herein, we provide a general approach for the preparation of ternary SACs, and the features of single atoms highly dispersed on the support have been identified and verified. As an illustration, trace platinum decorated iron-cobalt ternary single atom catalysts (PtFeCo/NC) possess an obviously enhanced bifunctional activity of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), as well as high stability. The density functional theory calculations reveal that the synergistic effects induced by the introduction of Pt enable modulating the adsorption strength of reaction intermediates both on the Fe-N4 and Co-N4 sites, thus enhancing the ORR and OER activity, respectively. In addition, the PtFeCo/NC-based Zn-air battery delivers a higher power density than that of commercial Pt/C-RuO2, and can be steadily operated over 188 h.