Spatial Self-Organization of Surface Structure during an Oscillating Catalytic Reaction

Under appropriate conditions, the rate of catalytic CO oxidation on a Pt(100) surface exhibits sustained temporal oscillations which are associated with a periodic surface-structural transformation from the reconstructed (hex) to the nonreconstructed (1×1) phase and back again. By use of a newly developed scanning low-energy electron-diffraction technique it is demonstrated that spatial self-organization in the oscillations involves a wavelike propagation of alternating bands of the two surface-structural modifications across the entire scanned area. These features can be modeled by numerical solution of a set of coupled differential equations.