Abstract
Single-atom catalysts (SACs) within carbon matrix became one of the most promising alternatives to noble metal-based catalysts for oxygen reduction reaction (ORR). Although SACs have significant benefits in reducing the total catalyst cost, it also has the disadvantages of weak interaction between atoms and poor stability. Hence, there is still much room for improvement for the catalyst activity. In response, we designed a Fe-Co-Pt ternary metal single atom catalyst anchored on covalent organic framework (COF)-derived N-doped carbon nanospheres (Pt, Fe, Co/N-C). Due to effective charge transfer between Pt single atom and neighboring Fe-Co components, an intense electron interaction can be established within the Pt, Fe, Co/N-C catalyst. This is beneficial for enhancing charge transfer efficiency, modulating d electronic structure of Pt center and weakening oxygen intermediate adsorption, thus distinctly accelerating ORR catalytic kinetics. As expected, the half-wave potential of Pt, Fe, Co/N-C was 0.845 V, much higher than those of commercial 20 wt% Pt/C (0.835 V), Pt/N-C (0.79 V) and Fe, Co/N-C (0.81 V) counterparts. Moreover, the Pt, Fe, Co/N-C catalyst demonstrated much-improved cycling stability and methanol tolerance.