Local Chemical Reactions Involving Fluorine Atoms on the Pt(111) Surface

The adsorption of fluorine atoms on the Pt(111) surface was studied using ultrahigh-vacuum scanning tunnelling microscopy (UHV STM) and X-ray photoelectron spectroscopy (XPS). Fluorofullerene molecules were chosen as fluorine sources. When deposited on Pt(111), fluorine atoms are cleaved from the carbon backbone, forming new surface structures. Varying the stoichiometric composition, as well as the number of deposited fluorofullerene molecules, makes it possible to obtain different fluorine atom concentrations on the surface. Using C $${}_{60}$$ F $${}_{18}$$ molecules, the formation of a fluorine-induced surface structure was observed. The observed structure was unstable and completely disappeared within 3–4 days of continuous STM monitoring. Deposition of C $${}_{60}$$ F $${}_{48}$$ molecules on Pt(111) also resulted in the formation of unstable structures on the surface. XPS spectra clearly demonstrated the absence of chemical interaction between platinum and fluorine. The presence of hydrogen on the platinum surface and its interaction with fluorine to form volatile hydrogen fluoride explains the disappearance of the observed structures over time.