FT-IRAS STUDY OF CO ADSORPTION, DESORPTION AND DISPLACEMENT REACTION BY NO ON NI(100)

The CO adsorption, desorption and displacement by NO on Ni(100) have b een studied by Fourier transform infrared reflection absorption spectr oscopy (FT-IRAS). The adsorption and desorption processes are studied by time-resolved IRAS. The reversible site-conversion of adsorbed CO b etween the terminal site and the bridged site at low coverage are stud ied between 80 K and 220 K, where the binding energy difference is det ermined to be 11 meV. The displacement reaction of CO by NO at room te mperature occurs predominantly from the terminal CO and all the adsorb ed CO species are removed finally. The main driving force of the displ acement is attributed to the dissociative adsorption of NO on Ni(100) at room temperature.