Metal phthalocyanine (MPC) catalysts are commonly used in olefin epoxidation reactions but tend to deactivate quickly in solution. Depositing MPCs on the external surface of a support can prevent deactivation by physically isolating complexes. Here, we examine the effects of MPC metal identity, support, solvent, and oxidant on the reaction rate and product selectivity in the liquid phase batch oxidation of cyclohexene. We prepare and characterize a series of MPC catalysts. We measure rates over supports without metal active sites and in uncatalyzed reactions and subtract these from the reaction rates with metal containing catalysts. The relative reactivity of each catalyst is determined by calculating the per metal atom turnover frequency (TOF). The reactivity of MPC on faujasite (MPC/FAU), silica (MPC/Si-Xerogel), and carbon black pearl (MPC/C) supports is compared to unsupported MPC and the structurally similar metal nitrogen-doped carbon (M-N-C). Of the metals tested, MPCs with Fe metal active centers have the highest reactivity. The products cyclohexene oxide, 2-cyclohexen-1-ol, and 2-cyclohexen-1-one form at short reaction times. We compare the selectivity for cyclohexene oxide formation in methanol and acetonitrile solvents. The side products 2-cyclohexen-1-ol and 2-cyclohexen-1-one preferentially form in acetonitrile solvent. In methanol solvent, unsupported FePC and FePC/Si-Xerogel demonstrate high selectivity for epoxidation, while other catalysts tested do not. We investigate the reactivity of each catalyst with hydrogen peroxide (H2O2) and iodosylbenzene (PhIO) oxidants. The reaction with PhIO has a higher rate and selectivity for cyclohexene oxide formation than the reaction with H2O2. With these results, we hope to further study the kinetics of cyclohexene oxidation with supported MPC catalysts.
