CO Diffusion on Pt(111) by Time-Resolved Surface Infrared Spectroscopy.

The mobility of CO chemisorbed on Pt(111) has been measured using a technique that synchronizes pulsed molecular beam dosing with fast scanning infrared interferometry. The method is based on the observation that molecules are generally more tightly bound at defects (e.g. steps) where they exhibit a different internal vibrational frequency to that associated with the same molecule adsorbed on the low index terrace site.