Datensatz

Zusammenfassung

A kinetics investigation of ethylbenzene disproportionation over zeolite catalysts has revealed several novel catalytic features. With large pore zeolites at low temperatures, the reaction rate is strongly but reversibly retarded by the product diethylbenzene, a result of its large physical adsorption constant. By contrast, no product inhibition occurs with the medium pore zeolite, ZSM-5. With the latter, the reaction rate is independent of the crystal size. However, the para-selectivity of the diethylbenzene produced increases strongly with crystal size and also with reaction temperature, yielding 100% p-diethylbenzene as the primary disproportionation product. This strongly suggests diffusion control of the product selectivit