Global coupling in the presence of defects: Synchronization in an oscillatory surface reaction

Abstract
The transition from a spatially uniformly oscillating surface to the formation of chemical wave patterns has been investigated in the NO+CO reaction on Pt(100) using photoemission electron microscopy. This transition is associated with a discontinuous jump in the local oscillation frequency and can be described as a breakdown of global coupling caused by the presence of defects in the oscillating medium.