MONTE-CARLO SIMULATION OF KINETIC DISCONTINUITIES IN HYDROCARBON HYDROGENATION REACTIONS

Recent experimental studies of alkene and alkyne hydrogenation reactio ns have shown the presence of a transition between a reactive regime a t low hydrocarbon surface coverage and a less reactive regime in which the catalyst surface is saturated with the hydrocarbon. This transiti on is discontinuous but reversible. Langmuir-Hinshelwood rate expressi ons cannot account for this discontinuity between the two regimes, ind icating that the origin of the transition is related to the non-random distribution of reactants on the catalyst surface. Time-dependent Mon te Carlo simulations of ethylene hydrogenation have been used to predi ct the presence of this transition and investigate the complex dynamic s of the reaction.