DISPERSION-RELATION AND SPIRAL ROTATION IN AN EXCITABLE SURFACE-REACTION

A kinetic model of the catalytic CO oxidation on a Pt(110) surface is used to describe effects of spatiotemporal self-organization, which have been observed experimentally with this system. After some simplification and taking advantage of the strong separation of fast and slow variables the model can be used to obtain analytical expressions for front and pulse velocities, pulse width and the dispersion relation. as well as for the dependency of pinned spiral rotation on the core size. Comparison with experimentally observed wave velocities and spiral rotation allows to draw conclusions about defects on the surface. Possible extensions of the model in order to explain more complex spatiotemporal behavior are briefly discussed.