Journal of Catalysis, Vol.161, No.2, 798-809, 1996
Kinetic Modeling of N-Hexane Oxyfunctionalization by Hydrogen-Peroxide on Titanium Silicalites of Mel Structure (Ts-2)
Catalytic oxyfunctionalization of n-hexane by aqueous H2O2 is a complex multiphase reaction. The kinetic modeling of a set of catalytic reaction experiments performed in a batch reactor in the presence of various solvents was achieved. In the present report, a two-phase kinetic model describing the influence of these cosolvents (methanol, acetone, and water) on the initial rates as well as rates at varying catalytic reaction times, observed in the presence of titanium silicalites of MEL structure (TS-2), was proposed. The solubility of n-hexane in the aqueous phase was estimated using liquid-liquid equilibrium concentrations calculated by the standard UNIQUAC model. The model is based on a simple description of the selective oxidation reaction mechanism of n-hexane on TS-2. The kinetic, derived assuming pseudo-steady-state conditions and no mass transfer limitations, showed second-order reaction rates with respect to H2O2 concentration in the aqueous phase. The complete absence of activation of the primary carbon was also discussed.
Keywords:SILICATE MOLECULAR-SIEVE;CATALYTIC PROPERTIES;SELECTIVE OXIDATION;ORGANIC-COMPOUNDS;ALKANES;COMPLEXES;METAL;SPECTROSCOPY;IONS