MONTE-CARLO SIMULATION OF ETHYLENE HYDROGENATION ON PT CATALYSTS

The catalytic hydrogenation of ethylene on Pt catalysts was simulated by a Monte Carlo model. Elementary events such as adsorption, diffusio n, and desorption of the species involved (hydrogen, ethylene, and eth ane) and reaction on the surface were considered. Based on comparison between experimental and calculated data no distinction has to be made between competitive and noncompetitive hydrogen adsorption sites nor has adsorbed hydrogen activation to be taken into consideration. Howev er, steric hindrance caused by adsorbed ethylene and ethane has been i ncluded in the model. Not only was the basic physical and chemical beh avior reproduced by this very simple model, but also important experim ental findings such as the trend of the turnover frequency versus hydr ogen pressure (P-H2) and the magnitudes of reaction orders for hydroge n and ethylene. In addition this model can predict some aspects of hyd rocarbon hydrogenation not investigated experimentally so far. (C) 199 6 Academic Press, Inc.