▎ 摘　　要

We present the density functional calculations for the adsorption of a single platinum (Pt) atom on the 2-fold bridged-oxygen (O-b) covered graphene (graphene oxide, GO). We found the incoming Pt at low kinetic energies prefers to interact with only one O-b and the reaction weakens the coupling of the O-b with the underlying two carbon atoms to give rise to an upward tilted Pt-O-a configuration with the O-a singly connected to one of the underlying carbon (C-IL) and leaving a semifilled and lone-paired orbital on the other carbon (C*). The highly reactive and long-lived C* plays an important role determining the energy barriers and branching nature of the subsequent reaction pathways. By being long-lived, reactions of the C* spilt into the early- and late-C* pathways depending when the long-lived C* is participated in the reaction. The early-C* pathways involve direct reactions of the C* with either the Pt or the neighboring carbons with low energy barriers (E-a < 0.3 eV) and give rise to stable local minimum states. In contrast, the C* in the late-C* pathways remains a radical such that the product states are less stable and the reactions that follows can again split into the early- and late-C' manifolds. This bifurcation stops when the C* quenches. To our surprise, we found the C*, via a rehybridization from sp(3) to sp(2) with E-a = 0.23 eV, can attack the C-IL that is singly connected to the Pt-O-a on the O-a end to give rise to the ejection of the Pt-O molecule from the GO surface. This self-cleaning mechanism indicates that a molecule chemisorbed on the carbon-based surface can be removed with an E-a approximately equal to that for the sp(3)-to-sp(2) rehybridization of the carbon lattice.