Theoretical insights into the activation of O2 by Pt single atom and Pt4 nanocluster on functionalized graphene support: Critical role of Pt positive polarized charges

Density functional theory calculations were performed to cast insight into the mechanism of the activation of O2 by Pt single atom and Pt4 nanocluster deposited on single vacancy and different pyridinic N-doped graphene. It is found that the graphene by introducing pyridinic N can make supported Pt single atom and Pt4 nanocluster accumulate more positive polarized charges, which upshift the d-band centers of the supported Pt single atom and Pt4 nanocluster toward the Fermi level. It is also observed that the more pyridinic N in grapheme is, the more positive polarized charges is accumulated by supported Pt single atom and Pt4 nanocluster. The positive charged sites is favour the dissociation of O2. We find that the energy barrier of O2 dissociation almost decrease linearly with the increase Pt positive polarized charges. Our work reveals that the Pt positive polarized charges can act as microscopic driving force for O2 dissociation.

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