Catalysts for heterogeneous oxidation reaction based on metalloporphyrins immobilized on kaolinite modified with triethanolamine

Raw kaolinite was modified with triethanolamine (TEA), in an attempt to create a new support for the immobilization of metalloporphyrins. Anionic metalloporphyrins containing Fe(3+) or Mn(3+) as metallic centers were immobilized on the prepared support, and the obtained solids were characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRPD), thermal analysis (thermogravimetric and differential thermal analyses--TGA/DTA), and scanning electron microscopy (SEM). The solids were used in heterogeneous oxidation catalysis of cyclooctene and cyclohexane. The yields from the oxidation of cyclooctene depended on the amount of TEA and/or water present in the solids. Good reaction yields were obtained for the oxidation of cyclohexane, with selectivity for the alcohol. In one specific case, a possible co-catalytic activity was verified for TEA during the oxidation of cyclohexane.