W(110) 표면에 CO의 흡착 = Chemisorption of CO on W(110) Surface

다국어 초록 (Multilingual Abstract)

The interaction of CO with W(110) surface was investigated through LEED, TDS, and photoelectron spectroscopy using synchrotron radiation under UHV condition. After CO saturation at RT, two desorption states, called α and β , were observed at about 400 and 1150 K in thermal desorption spectra, respectively. The kinetics of 3-CO followed the first order kinetics, indicating the existence of molecular CO on W(110) surface. This is contrary to the previous results. The O 1s BE(binding energy) of CO adsorbed on W(110) surface at room temperature was 529.9 eV. On the other hand, the O 1s BE of β-CO after heating to 900 K was different from that of oxygen adsorbed W(110) surface, suggesting a different adsorption state. According to the UP valence band spectra, we observed two peaks at near -10.7 eV (4σ) and -7.0 eV (5σ+1π), indicating the molecular adsorption of CO at room temperature. Furthermore we could see the 4σ peak at the various photon energy and elevated temperatures. Comparing the energy separation, Δ(4σ-1π) , between 4σ and 1π UP peaks of chemisorbed CO, we found that an increased separation reflects an decreased C-O bond strength. Therefore on the basis of TDS and photoelectron spectroscopy, we could suggest that β state of CO on W(110) may not be dissociated and has an adsorption geometry of lying-down mode.