Covalent attachment of Mn-porphyrin onto functionalized activated carbon for green oxidation of olefins

Complexes of first row transition metals are a promising class of inexpensive catalysts for oxidation reactions. In this work, we studied the influence of covalent immobilization of Mn-porphyrin onto the surface of activated carbon in the green oxidation of various olefins. meso-tetrakis(4-carboxyphenyl)porphyrinatomanganese(III) acetate (MnTCPP) immobilized onto hydroxylated activated carbon (AC-OH). The anchored catalyst was characterized using FTIR, UV–VIS, atomic absorption and EDX spectroscopies. TGA analysis and BET-BJH method were employed to determine thermal behavior and surface properties of complex respectively. Then, catalytic performance of MnTCPP@AC-OH was investigated in the green oxidation of olefins with molecular oxygen and hydrogen peroxide. A comparison between two green oxidants (molecular oxygen and hydrogen peroxide) shows that although more product is obtained with hydrogen peroxide, more recyclability is obtained with molecular oxygen. The separation and recovery of the nanocatalyst was simple, effective and economical in this green oxidation method and the supported catalyst can be reused at least five times without significant loss of activity.