Breaking the Limitation of Scaling Relationship By Dual Functions of Adsorbed O Atom on Non-Metal-Element-Doped Single Atom Catalyst

Abstract

Carbon-based single atom catalysts (SACs) are considered as one of potential catalysts of oxygen reduction reaction (ORR) because of their low cost, high metal atom availability and good CO or methanol tolerance.[ 1] The structure of M-N4 (M is transition metal, such as Fe and Co) has been proved as main active structure of carbon-based N-doped SACs. The efficient strategies on improving their activity are still in short except changing the kind of metal atom. In this DFT work, the influences of non-metal-elements doping (B, N, Si, P, S) on their ORR catalytic activity are studied by density functional theory (DFT). Previous studies simply owed the improved activity to the changing of electronic structure of metal atom, which is not inaccurate. It is revealed that the B doping leads to metal site losing more electrons and N doping works on the contrary. But limited by the scaling relationship, the ORR performance changes little. Interestingly, we find that the Si/P/S site is preferred to be oxidized during ORR. The P/S site would be taken up by O atom and Si sites would be occupied by OH in oxidization process. We find that the local collaborative structures have a great influence on SACs’ ORR performance, which is ignored for a long time. The results not only help understanding the origin and effect of the local collaborative structure on carbon-based SACs, but also provide a guide to the synthesis of carbon-based SACs. Reference [1] C. Zhu, S. Fu, Q. Shi, D. Du, Y. Lin. Angew. Chem. Int. Ed., 2017, 56, 13944. Acknowledgements This work was supported in part by National Natural Science Foundation of China (21975157) and the National Key Research and Development Program of China (2016YFB0101201 and 2016YFB0101312).