Immobilization of iron porphyrins in tubular kaolinite obtained by an intercalation/delamination procedure

This paper describes the synthesis of a first-generation iron porphyrin catalyst immobilized in a tubular/delaminated kaolinite. Kaolinite was mechanochemically intercalated with urea followed by n-hexylamine, and the catalyst was prepared by submitting the kaolinite/hexylamine intercalation compound to a sonication procedure in the presence of two different iron porphyrin solutions. The materials thus obtained were characterized by UV–vis and IR spectroscopies, XRD, and TEM. The procedure delaminated part of the kaolinite, yielding scroll-like nanotubes, with the metalloporphyrins immobilized in the mixture. The catalytic activity of the materials for cyclohexane and n-heptane oxidation was investigated using iodosylbenzene as the oxygen donor and the products were analyzed by gas chromatography. The results show a promising catalytic system for selective oxidation reactions.