Microscopic CO Diffusion on Pt(111) by Time-Resolved Surface Infrared Spectroscopy
03 October 1988
Adsorbate mobilities directly reflect adsorbate-substrate and adsorbate- adsorbate interactions. They also serve as the delimiting factor to many surface chemical processes. Previously field emission and helium scattering have investigated CO diffusion on Pt(111) and have reported activation barriers to diffusion of 14 kcal/mole and 7 kcal/mole, respectively. Such differing values are presumably due to the discrepant experimental conditions employed, ie. variable coverages, defect densities, and presence of an external electric field. An experimental approach that is microscopic, nondestructive, and fully quantifiable is necessary to resolve this controversy.