Highly efficient aerobic epoxidation of olefins catalyzed by cationic meso-tetrakis-(1-methyl-4-pyridyl) (TM4PyP) metalloporphyrins immobilized into montmorillonite (MT) interlayer was achieved. The heterogeneous catalysts were characterized by diffuse reflectance UV spectra, infrared, X-ray diffraction, nitrogen adsorption isotherm and scanning electron microscopy. Manganese porphyrin (MnTM4PyP-MT) showed excellent activity and selectivity for the aerobic epoxidation of olefins under ambient conditions, in which more 90% yields of epoxides were obtained. The clay basal spacing played significant role in the catalytic efficiency and selectivity for different olefins. The catalyst could be reused consecutively five times without significant loss of activity.
Carbon nitride nanotubes with in situ grafted hydroxyl groups for highly efficient spontaneous H2O2 production