Systematical synthesis of magnetic-layered core@shell supports for metalloporphyrin immobilization aiming catalysis

Abstract

Bioinspired catalytic systems based on metalloporphyrins have been extensively researched in recent years and, in many cases, have played a key role in the development of more efficient and selective catalysts. The immobilization of this family of catalyst species in robust supports can permit the preparation of recoverable and reusable catalyst solids. In this work, we present the systematic and comprehensive preparation of core@shell-like solids for catalyst immobilization based on magnetic particle, using microwave-assisted synthesis of magnetite, coated with a shell composed of two distinct LDH formulations: Mg₃Al and Ni₃Al, evaluating different LDH/magnetite molar ratios. Four different tetra-anionic metalloporphyrins (Na₄[M(TDFSPP)], M = iron(III), manganese(III), zinc(II), or magnesium(II) ions) (MP) were immobilized in both prepared LDHs. The eight resulting solids were evaluated as catalysts in the model oxidation reaction of cyclooctene to cis-cyclooctene oxide, using iodosylbenzene (PhIO) as the oxidant.