ATOMIC AND MACROSCOPIC REACTION-RATES OF A SURFACE-CATALYZED REACTION

The catalytic oxidation of carbon monoxide (CO) on a platinum (111) su rface was studied by scanning tunneling microscopy. The adsorbed oxyge n atoms and CO molecules were imaged with atomic resolution, and their reactions to carbon dioxide (CO2) were monitored as functions of time . The results allowed the formulation of a rate law that takes the dis tribution of the reactants in separate domains into account. From temp erature-dependent measurements, the kinetic parameters were obtained. Their values agree well with data from macroscopic measurements. In th is way, a kinetic description of a chemical reaction was achieved that is based solely on the statistics of the underlying atomic processes.