Self‐assembled metalloporphyrins–inorganic hybrid flowers and their application to efficient epoxidation of olefins

BACKGROUND Various proteins or enzymes were employed as organic components to form hybrid flowers, and they exhibited excellent properties in catalysis, adsorption, and sensing. However, there is no previous report of metalloporphyrins-based hybrid flowers. Based on the importance of metalloporphyrins in catalytic reactions, metalloporphyrins–copper phosphate hybrid flowers were prepared and their catalytic performance in epoxidation reactions was evaluated. RESULTS The composition, morphology, and crystallite structure of the hybrid flowers strongly depended on the incubation time (0.1–72 h) and concentration of metalloporphyrins in the mother liquor (0–47 µg mL−1). In comparison with the free metalloporphyrins, the hybrid flowers exhibited enhanced stability without any decrease in the catalytic activity. Moreover, the activity was linearly correlated with the surface content of metalloporphyrins which indicated that the metalloporphyrins on the surface were the key active species. Furthermore, the hybrid flowers showed good compatibility with a wide range of solvents and substrates. CONCLUSION The mechanism of formation of the hybrid flowers was proposed that involves four major successive steps: coordination, nucleation, formation, and growth. The catalytic results suggest that well-designed hybrid materials with hierarchical nano-structures and metalloporphyrins as organic component would be potential candidates for industrial catalysis applications. © 2017 Society of Chemical Industry