Adsorption of CO on W(110) as studied using electron-stimulated desorption and thermal desorption

Abstract

The chemisorption of CO on the (110) face of W at room temperature is studied using a combined technique consisting of electron-stimulated desorption (ESD) and thermal desorption. Measurements of the ESD ion energy distribution as a function of CO exposure, crystal temperature, and incident electron energy are presented in conjunction with a comparison with the corresponding thermal-desorption spectra. The correlation between the presence of the binding states in the thermal-desorption spectra and the liberation of ions in ESD is discussed in detail. An interesting result is the observation that ${\mathrm{O}}^{+}$ and C${\mathrm{O}}^{+}$ are due to ${\ensuremath{\beta}}_{1}$ and virgin states of CO, respectively. In conjunction with data acquired from other surface techniques, the present results are used to discuss and propose the bonding geometry of the various binding states of CO on W(110).