Theoretical investigation of gold clusters supported on graphene sheets

The structure and stabilization of a series of gold (Au-n) clusters (where n = 1, 5, 6, 19 and 39) supported on the perfect and defective (vacancy and/or N-doped) graphene sheets were investigated using a periodic DFT model. Much stronger interaction was found between a gold atom and the graphene sheet with a defective structure that is comparable to interaction energies reported for different transition metal oxide supports. Increasing gold particle size does not weaken the interaction with the single vacancy graphene sheet, where the gold clusters are anchored to the carbon surface through only one gold atom and the cluster shape is preserved. Catalytic performance of Au(100) facets in the isolated and graphene-supported Au-39 nanoparticle (mean size similar to 1 nm) for the O-2 dissociation reaction was investigated. Structure of the involved species along the reaction pathway and energy profile were found very much alike, regardless the reaction takes place on the isolated or graphene-supported gold nanoparticle.