Article,
Vibration spectroscopy of benzene adsorbed on Pt(111) and Ni(111)
Surface Science, 78 (3): 577 - 590 (1978)
DOI: DOI: 10.1016/0039-6028(78)90234-0
Abstract
High resolution electron energy loss spectroscopy has been applied
to study the adsorption of benzene (C6H6 and C6D6) on Pt(111) and
Ni(111) single crystal surfaces between 140 and 320 K. The vibrational
spectra provide evidence that benzene is chemisorbed with its ring
parallel to the surface, predominantly pi bonded to the platinum
and nickel surface respectively. A significant frequency increase
of the CH-out-of-plane bending mode, largest in the case of platinum,
is observed compared to the free molecule. On both metals two phases
of benzene exist simultaneously, characterized by a different frequency
shift. The shifts are explained by electronic interaction between
the metal d-orbitals and molecules adsorbed in on top and threefold
hollow sites respectively. The vibrational spectra of the multilayer
condensed phase of benzene exhibit the infrared active modes of the
gasphase molecule as expected.
