Monte Carlo simulations combined with UHV-atmospheric pressure reaction studies on CO hydrogenation on cobalt

Abstract

We show that useful information on catalytic reactions can be obtained using Monte Carlo simulations combined with experimental data from model catalysts. The experimental rate dependencies of CO hydrogenation on the partial pressures were used to guide the selection of different parameter values used in the simulations. The results give the following picture of the reaction conditions on the surface: hydrogen and carbon monoxide occupy different adsorption sites, the diffusion of hydrogen and the growth of hydrocarbon chains are fast processes, and the rate-limiting elementary reaction step is the termination of the hydrocarbon chains (α-hydrogenation). The formation of longer chain hydrocarbons falls onto the line defined by the Anderson-Flory-Schulz distribution but the value of the chain growth parameter α, obtained in the simulations, is higher than the experimental value.