We investigate the dynamics of the CO oxidation on Pt(100) by means of
a master equation approach. Adsorption, diffusion and the reaction ar
e modelled as a stochastic birth and death process. The transformation
from the hexagonal phase to the (1 x 1)-phase is described by a Glaub
er dynamics. The stochastic simulation performed for the one-dimension
al case shows qualitative agreement with the experimental results. Mor
eover, equations for the averaged densities are derived, discussed and
numerically solved. Our investigation shows that the oscillatory beha
viour is generated by stochastic ignitions of fronts and pulses in an
excitable and in a bistable regime.