| Autor: |
Christensen, So\ren V., Nerlov, Jesper, Godowski, P. Jan, Onsgaard, Jens |
| Předmět: |
|
| Zdroj: |
Journal of Chemical Physics; 6/15/1996, Vol. 104 Issue 23, p9613, 7p |
| Abstrakt: |
Adsorption of CO on the Cu(110) surface modified with a low (near the work function minimum) potassium precoverage has been investigated by use of low energy electron diffraction, photoelectron spectroscopy based on synchrotron radiation, work function measurements (Δ[uppercase_phi_synonym]), and high resolution electron energy loss spectroscopy (HREELS). During potassium adsorption at 118 K the binding energy (BE) of the K 3p peak shifts -0.3 eV. For a thick potassium overlayer both a surface and a bulk K 3p peak, with a 0.9 eV difference in BE, are observed. The work function results at ΘK∼0.5 ML show after saturation with CO an increase of 1.11 eV. An electrostatic interaction energy between CO and K equal to 0.23 eV is determined. This energy indicates a moderate attractive interaction between CO and K. A CO overlayer on K/Cu(110) shows the 4σ satellite, the 4σ orbital, and the 5σ/1π joint feature. No observable change in the BE separation between the 4σ and the 5σ/1π band (3.1 eV) was found, thereby indicating a negligible CO–CO interaction. From the 4σ to the 5σ/1π intensity ratio (∼2) a weakening of the CO–metal binding with increasing CO coverage is deduced. In the HREEL spectrum, an intense feature at 1731 cm-1 besides the fundamental stretching frequency at 2030 cm-1 implies a substantial potassium induced weakening of the C–O bond. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
