Cobalt or Nickel Doped SiC Nanocages as Efficient Electrocatalyst for Oxygen Reduction Reaction: A Computational Prediction

In this paper, the oxygen reduction reaction (ORR) activities and mechanisms on pristine and doped Si 60 C 60 nanocages were predicted by DFT methods. The calculation results indicate that pristine Si 60 C 60 has a relatively low ORR activity due to its excessive adsorption energies of ORR species when compared with Pt(111) catalyst. However, doping Si 60 C 60 with Co or Ni elements can largely reduce the adsorption energies of ORR species, indicating the enhancement of the catalytic activity. At the same time, all of the changes on reaction energy of ORR steps become downhill in the relative energy landscapes, indicating the spontaneous nature of the ORR. Furthermore, both Co 1 Si 59 C 60 and Ni 1 Si 59 C 60 nanocages can catalyze ORR through two main reaction pathways: one is initiated by the end-on adsorption of O 2 on the top of doped metal site, and will be completed via a H 2 OO dissociation pathway; the other is initiated by the bridge adsorption of O 2 molecule, and will be completed via an OOH dissociation pathway. Based on the calculated data, we conclude that Ni 1 Si 59 C 60 possesses higher ORR activity than Co 1 Si 59 C 60 catalyst.