Computational studies on surface reaction mechanisms: ethylene hydrogenation on platinum catalysts

A new computational approach that combines kinetic and thermodynamic met:hods to mimic surface reactions is reported. Thermodynamics is mainly used to calculate, from experimental and/or quantum chemistry data, the parameters to be used in kinetic studies performed by Monte Carlo simulations. Monte Carlo algorithms are formulated in terms of the time dependent version. An innovative statistical approach is presented for cutting down the computational time required for the simulations. The reported discontinuity in the Arrhenius plot for the hydrogenation of ethylene on Pt/silica catalysts, and other peculiar properties of the above reaction on platinum catalysts, are extensively discussed as an example of reliability of the method. A new approach to metal catalysts and their role in catalytic reactions is also presented.