Using high resolution X-ray photoelectron spectroscopy and scanning tunneling microscopy
we study the intercalation of hydrogen under graphene/Ir (111). The hydrogen intercalated
graphene is characterized by a component in C 1 s that is shifted− 0.10 to− 0.18 eV with
respect to pristine graphene and a component in Ir 4f at 60.54 eV. The position of this Ir 4f
component is identical to that of the Ir (111) surface layer with hydrogen atoms adsorbed,
indicating that the atomic hydrogen adsorption site on bare Ir (111) and beneath graphene is …