Pt₃₈ cluster on OH- and COOH-functionalised graphene as a model for Pt/C-catalysts

The binding of a Pt₃₈-cluster on pristine graphene, mono-vacancy graphene, OH- and COOH-functionalised graphene has been investigated using DFT-calculations. Graphene containing a mono-vacancy site or OH and COOH functional groups on graphene anchor the Pt₃₈-cluster more strongly than pristine graphene. The most favoured adsorption geometry for the cluster depends on the number of Pt-C bonds generated and the required distortion of the interacting facet. Adsorption of the cluster is associated with charge transfer between (functionalised) graphene and the Pt₃₈-cluster, a localised charge re-distribution within the cluster and shift in the d-band centre. The modified electronic properties of the supported Pt₃₈-cluster would imply a change in the reactivity of these supported Pt₃₈-clusters towards adsorbates depending on the type of defect present in the support.