Fig. 4
From: Substrate engineering of graphene reactivity: towards high-performance graphene-based catalysts
O2 (in red) adsorption on graphene@Ru (0001) with an Au impurity: a fcc-top, b hcp-top, and c intermediate. Isosurfaces of the charge redistribution caused by O2 adsorption is superimposed. The charge redistribution is defined as \({\mathrm{\delta \rho = \rho }}_{{\mathrm{O}}{_2}@{\mathrm{{\rm G}}@{\mathrm{Ru}}}} - \left( {{\mathrm{\rho }}_{{\mathrm{{\rm G}}@{\mathrm{Ru}}}}{\mathrm{ + \rho }}_{{\mathrm{O}}{_2}}} \right)\). Note that O2 does not bind onto graphene for the fcc-hcp case. Partial density of states of O2 p orbital before/after adsorption for fcc-top configuration is shown in d. The upper (lower) panel in d is for the case of before (after) adsorption. Energy profile along the reaction path for two steps of CO oxidation catalyzed by fcc-top Graphene@Ru (0001) with Au in ER mechanism: e CO + O2 ⇒ CO2 + O* and (f) CO + O* ⇒ CO2. Atomic structures of the initial state (IS), the transition state (TS), and the final state (FS) are also shown. Calculations are done with cNEB method.Color scheme is the same as before
