Oxidação do glicerol empregando catalisadores bidentados de paládio

Abstract

The following work describes the synthesis of palladium β-diimines and their applications like catalysts in glycerol oxidation reactions. The first part consisted on the synthesis of the β-diimines ligands, varying the different substituents of the aromatic rings which were characterized by Infrared, TGA and FT-IR. The palladium complexes were characterized like homogeneous catalysts in glycerol oxidation reactions using a stainless steel reactor. Their performance as catalysts was evaluated by varying several conditions: temperature, reaction time, catalytic precursor quantity, catalytic precursor structure. The catalysts showed activity for homogenous-media glycerol oxidation reactions. Several observations were made: the catalysts were very selective in some reactions, glycerol was transformed into chemicals of higher market value, and glycerol conversions between 39 and 82% were attained. The 2,6-diisopropyl and 2,6-dimethyl catalysts have high selectivity for the production of oxalic acid; in contrast to other catalysts with selectivity for different products. It must be noted that the different substituents on the aromatic rings of the β-diimines have a strong effect on the activity and selectivity of the catalytic system.