PATTERN-FORMATION DURING THE CO OXIDATION ON PT(110) SURFACES UNDER GLOBAL COUPLING

A reaction-diffusion model for CO oxidation on Pt(110) single crystals proposed by Krischer, Eiswirth, and Ertl is supplemented by an equati on for the balance of CO partial pressure in the gas phase. This allow s us to study the interaction of local and global coupling with the dy namics of the reaction in the oscillatory regime. In absence of global coupling a stability analysis of the homogeneous oscillatory state pr edicts parameter regions with negative values of the phase diffusion c oefficient indicating the possibility of phase turbulence. In the glob ally coupled system without diffusion we observe the formation of phas e-locked clusters of oscillators and irregular behavior. If both surfa ce diffusion and global coupling through the gas phase are taken into account depending on the range of external parameters we get the follo wing types of structures: phase flips, standing waves, spatially irreg ular coverage pattern, and the uniformly oscillating surface.