Influence of time delayed global feedback on pattern formation in oscillatory CO oxidation on Pt(110)

Spatiotemporal pattern formation in the catalytic CO oxidation on Pt(1 1 0) is controlled by means of global delayed feedback applied through the gas phase. Using photoemission electron microscopy we have investigated the dyn amical response of the system to a change of feedback intensity and time de lay. Well defined synchronization and desynchronization regimes alternate w hen the delay is varied. In the case of synchronization the surface shows s patial homogeneous oscillations whereas in the case of desynchronization. n on-uniform patterns are observed. Furthermore two-phase clusters with perio d doubled local oscillations are studied. Phase balance between single clus ter areas and breathing cluster modes are observed. (C) 2001 Elsevier Scien ce B.V. All rights reserved.