MATHEMATICAL-MODELING OF THE NO-2(H)PT(100) REACTION - SURFACE EXPLOSION, KINETIC OSCILLATIONS, AND CHAOS/

A mathematical model, consisting of six ordinary differential equation s and taking into account the lateral interactions in the adlayer, has been developed for simulating the NO+H-2/Pt(100)-(1 x 1) reaction. Th is-model provides a good theoretical description of temperature progra mmed desorption and temperature programmed reaction (TPR) experiments, including the occurrence of a ''surface explosion'' in TPR studies. I n addition, the model is capable of reproducing many kinds of nonlinea r behavior observed in the experiments such as kinetic oscillations an d the transition to chaos through period-doubling bifurcations followe d by a period-3 or period-5 limit cycle. The simulation results sugges t that the (1 X 1)double left right arrow hex surface phase transition of Pt(100) is not essential to describe the kinetic oscillations and chaos in the NO+H-2/Pt(100) system. The most important step in the osc illation mechanism is the autocatalytic increase in the number of vaca nt sites for NO dissociation. (C) 1998 American Institute of Physics.