Metal-Embedded Graphene: A Possible Catalyst with High Activity

The catalytic activity of Au-embedded graphene is investigated by the first-principle method using the CO oxidation as a benchmark probe. The first step of CO oxidation catalyzed by the Au-embedded graphene is most likely to proceed with the Langmuir-Hinshelwood reaction (CO + O-2 -> OOCO -> CO2 + O), and the energy barrier is as low as 0.31 eV. The second step or the oxidation would be the Eley-Rideal reaction (CO + O -> CO2) with a much smaller energy barrier (0.18 eV). The partially filled d states of Au are localized around the Fermi level due to the interactions between Au and the neighboring carbon atoms. The high activity of Au-embedded graphene may be attributed to the electronic resonance among electronic states of CO, O-2, and the Au atom, particularly, among the d states of the ALL atom and the antibonding 2 pi* states of CO and O-2 This opens a new avenue to fabricate low cost and high activity carbon-based catalyst.