Topological dynamics in a catalysis experiment

A time series of the catalytical reaction of CO and ${\mathrm{O}}_2$ on a Pt(110) surface is used to model the topological features of the underlying attractor by reconstructing unstable periodic orbits in a three-dimensional imbedding space. The orbits reveal that the template supporting the dynamics cannot be that of a Smale’s horseshoe. Some of the computed orbits imply positive topological entropy, showing that the time series is chaotic. © 1996 The American Physical Society.