Complexos metálicos (ferro, níquel e cobalto) em sistemas de oxidação do tipo Fenton: reações e mecanismos

Abstract

Fenton-like reactions using transition metal complexes in the decomposition of hydrogen peroxide to hydroxyl radical generation have received special attention due to its advantages over classical homogeneous process involving soluble salts of iron. The objective of this study was to investigate the use of transition metal complexes (Ni, Co and Fe) with the ligand dipicolinic acid (PDC) as a homogeneous catalyst for the degradation of organic compounds. The complexes have been characterized and tested in the oxidation of methylene blue model. The iron complex was more efficient and was also used in the oxidation of quinoline and desethylatrazine. The tests were monitored by UV-Vis spectroscopy and mass spectrometry. Moreover, in order to shed some light on the formation of hydroxyl radicals and the overall reaction mechanism, some theoretical calculations at the DFT level were performed. The results of this study demonstrated that the complex of iron and dipicolinic acid solid and synthesized in situ are good catalysts for the oxidation of organic contaminants through a Fenton-like mechanism. All theoretical data indicated good agreement with experimental results.