Size Control to a Sub-Nanometer Scale in Platinum Catalysts on Graphene

Size controlled Pt catalysts supported by graphene nanosheets (GNS) are successfully prepared by changing the loading of Pt at 10-70 wt % using an impregnation method. It is found that Pt sub-nanoclusters (0.8 nm) with an extremely large surface area (170 m(2) g(-1)) are formed on the GNS support in a 10 wt % Pt/GNS catalyst. An increase in loading of Pt leads to an increase in the particle sizes of Pt, which results in lower activities for electro-oxidation of adsorbed CO. A core level shift of Pt 4f in XPS indicates that Pt is chemically interacted with graphene. The modification of catalytic properties and the electronic structure is ascribed to the interface interaction between Pt and graphene via pi-d hybridization.