A generalized Langmuir-Hinshelwood mechanism was analyzed to explain the multiple steady state in the CO oxidation on the surface (110) of platinum single crystal catalyst.
It is believed that the multiplicity is due to the interactions between the adsorbed species. The lattice-gas model with the absolute rate theory was applied to elucidate the interactions.
The simulation by the proposed model was in good correlation with the experimental rate data obtained in continuously pumped vacuum system. It is rather interesting that both the clockwise and the counterclockwise hysteresis can be predicted with the same values of the kinetic parameters. Discussions have also been made on the physical meanings of the hystereses.