AVS 47th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP23
The Adsorption and Trimerization of Acetylene to Benzene on Cu(110) Monitored by X-ray Spectroscopies

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: H. Öström, Uppsala University, Sweden
Authors: H. Öström, Uppsala University, Sweden
K. Weiss, Uppsala University, Sweden
L. Triguero, Uppsala University, Sweden
A. Nilsson, Uppsala University, Sweden
Correspondent: Click to Email
We have studied the adsorption of acetylene on Cu(110) and its trimerization reaction to benzene by high resolution X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure (NEXAFS) spectroscopy and temperature programmed desorption (TPD). At liquid nitrogen temperature the XP spectra show two different C 1s peaks which correspond to two nonequivalent adsorbed acetylene species. By heating the sample one species transforms into the other. This species disappears above room temperature due to the trimerization of acetylene to benzene. The reaction has been followed by time resolved XP spectroscopy. We have been able to monitor the reaction in real time, finding that benzene leaves the surface as soon as it is formed. The adsorption geometry of the different adsorbate species has been determined by polarization dependent NEXAFS spectra and the experimental results are completed by ab-initio cluster model calculations performed in the framework of density functional theory (DFT).