Abstract: The binding strength of coinage metal (IB group) single and double atoms clusters on perfect or N-doped graphene has been studied with the periodic slab model using generalized gradient approximation (GGA). The calculated results indicated that N-doped graphene showed metallic electron properties rather than semimetallic ones of perfect graphene. Physical or weak chemical adsorption was got on perfect or graphite N-doped graphene with the binding energy around 0.5 eV. Chemical adsorption happened on pyridine N-doped graphene and pyrrole N-doped graphene with binding energy above 1 eV. Pyrrole N-doped graphene was less stable than graphite N-doped graphene or pyridine N-doped graphene. When adsorbates interacted with pyrrole N-doped graphene, it carried out the transition from pyrrole N-doped graphene to pyridine N-doped graphene, and the most stable adsorption structure based on pyridine N-doped graphene was obtained finally. The analysis of Mulliken population indicated that metal single atoms had positive charge while double atom clusters had negative charge after adsorbing on pyridine N-doped graphene. The density of states and orbital analysis demonstrated that Cu atom bonded with three atoms with dangling bonds while Au atom bonded with two of them in pyridine N-doped graphene.

Key words: density functional theory, coinage metal, N-doping, graphene, adsorption