SOLITONS IN A SURFACE-REACTION

The catalytic oxidation of CO on Pt(110) exhibits, for certain sets of control parameters, oscillatory kinetics and spatiotemporal pattern formation which may be followed by photoemission electron microscopy. Within a very narrow range of conditions, these patterns consist of solitary waves with bell-shaped profiles which propagate with a constant velocity of about 3-mu-m/s along the crystallographic [001] axis of the surface. Collision of pulses traveling in opposite directions leads mostly to annihilation, but in some cases the two waves emerge again with unchanged shapes and velocities, as characteristic for solitons.