  The kinetics of a 2A + B2 = 2AB reaction on supported metal catalyst with
spillover effects is investigated using Dynamic Monte Carlo simulations. In the
presented model A particles can adsorb reversibly on both metal clusters and
the support whereas B2 particles can adsorb dissociatively only on metal
clusters. Particles A can diffuse from the support to metal clusters and vice
versa. The model describes CO oxidation on Pd/Al2O3 catalyst. Steady-state
reaction rates and surface coverages are investigated as functions of partial
pressures of reactants in the gas phase. Simulations show that spillover
effects change the reaction rate dramatically by increasing it and widening the
pressure window of the reaction. In systems with spillover the reaction driven
by an adsorption channel, in addition to a spillover channel, is observed. The
character of the dependence of the reaction rate on reactants' partial
pressures can be controlled by changes of spillover and adsorption channel
contributions.
