Liquid-phase dehydration of 1-phenylethanol over HZSM-5: Kinetic modeling

The liquid-phase dehydration of 1-phenylethanol over HZSM-5 zeolite (Si/Al = 20), at 353–373 K and using cyclohexane as solvent, was studied. Varying initial reactant concentration, a negative order respect to 1-phenylethanol was determined. In all cases, HZSM-5 resulted highly selective to styrene. Experimental data were fitted using LHHW-like kinetic models. Both physical and statistical criteria were applied to discriminate the best heterogeneous kinetic model. The most satisfactory fitting was obtained assuming that styrene is formed from 1-phenylethanol interacting simultaneously with two active sites. This mechanism explains the negative order respect to 1-phenylethanol.