Insights into the alkylation of benzene with olefins: effect of chain length of the olefins

摘要

Structure–reactivity relationships are a hot topic in the catalytic field, wherein the effect of the catalyst structure on the reactivity has been extensively investigated. However, the structure–reactivity relationship based on different reactants has been rarely reported. Herein, three representative olefins, viz., ethene, propylene and 1-dodecene, were selected to get insights into the effect of the chain length on the reactivity of the alkylation of benzene with olefins from a theoretical aspect. Both stepwise and concerted mechanisms were all considered, of which the concerted mechanism was demonstrated to be the dominant route for all the three olefins. The increased activity as the chain length increases was confirmed from both the energy barrier and energetic span. Kinetics analysis revealed that temperature has a more significant effect on the activity than pressure and the variation of activity at different temperatures is mainly contributed by the entropy part. The increased contribution of the stepwise mechanism to the overall reaction rate can also be observed as temperature increases.