Effect of solvent on the liquid phase epoxidation of 1-hexene with titanium silicalite-1 catalyst

Titanium silicalite-1 (TS-1) catalyst is active and highly selective in the liquid phase epoxidation of 1-hexene using aqueous hydrogen peroxide as the oxidant, but the observed reaction kinetics are dependent on the choice of the solvent used. In this study, the effect of-the solvent on (1) the intrinsic kinetics, (2) the partitioning of species between the fluid phase and the adsorbed phase, and (3) the rates of diffusion for reagents was explored. Three different solvents were examined: methanol, acetonitrile and acetone.; TS-1 catalyst was synthesized hydrothermally and characterized by several spectroscopic and microscopic methods. Kinetic data obtained through batch reaction experiments have yielded reliable and more accurate initial rates than those reported in the literature, and the dependence of the rates on the various reactants were determined. The diffusivity of 1-hexene in TS-1 was estimated from PFG NMR studies, and it was shown that the reaction is not diffusion limited. The adsorption behavior of the system was determined by batch sorption experiments as well as grand canonical Monte Carlo simulations. Results showed that the solvent has a significant effect on the adsorption of the various species.; Based on the data from the various independent studies, a kinetics model was proposed based on an Eley-Rideal type mechanism. The model was solved using parameter estimation techniques, and it was shown that the differences in the observed reaction kinetics may be attributed mostly, if not entirely to, adsorption effects.