Modifying hydrogen binding strength of graphene

Abstract

The effect of the substrate on the binding strength of hydrogen on single layer graphene grown on Pt(111) surfaces has been investigated via determining its desorption activation energy. We showed that subsurface alloys on Pt(111) can dramatical modify the C-H bond strength in hydrogenated graphene. Various 3d metals, vanadium, iron, cobalt, and nickel were deposited in the subsurface layer to modify the chemical and electronical properties of the substrate. Analysis of the temperature programmed desorption data shows that subsurface alloys reduce the hydrogen desorption activation energy by weakening C-H bond energy in graphene, down to 57 kJ/mol in the case of Pt/Co/Pt(111) as compared to similar to 111 kJ/mol obtained from hydrogenated graphene grown on a bare Pt(111).