A Kinetic Study of the Thermal and Photochemical Partial Oxidation of Cyclohexane with Molecular Oxygen in Zeolite Y

The kinetics of the thermal and photochemical oxidation of cyclohexane in zeolite Y were investigated using ex situ GC product analysis and in situ FTIR and solid state NMR spectroscopies. The results show that cyclohexyl hydroperoxide, cyclohexanone, and cyclohexanol (and water) are formed during the thermal and photochemical oxidation of cyclohexane in BaY. The overall percent conversion of cyclohexane decreases dramatically at cyclohexane loadings of greater than 3 cyclohexane molecules per supercage. Pronounced deuterium kinetic isotope effects were observed for both the thermal and photochemical cyclohexane oxidation reactions, indicating that a proton transfer step is a rate-limiting step in the reaction mechanism. For the thermal oxidation of cyclohexane in BaY and NaY, activation energies of 62 (±9) and 85 (±3) kJ/mol, respectively, were measured.