Oxidação do glicerol sobre catalisadores de nanotubos de carbono decorados com ouro e platina

Abstract

Glycerol is a polyalcohol that via its oxidation can be transformed in products with a large range of chemical applications, in many sectors like foods, pharmacy, polymers, among others. Nowadays is produced in large scale as a coproduct in the transesterification of triglycerides in vegetable oils and animal fat to product biodiesel. In this work was realized the liquid phase selective oxidation of glycerol over heterogeneous catalysts made of multiwalled carbon nanotubes (MWNT) and gold , Au, and/or platinum, Pt, synthesized through the reduction of its ions by the sodium citrate in the presence of the MWNTs. It were obtained the catalysts Au0,5, 3,0, 7,4; Pt4,0 and PtAu4,7 /MWNT (1:1), in mass, characterized by thermogravimetric analysis (TGA), RAMAN spectroscopy, X-ray diffraction powder method (XRPD), and transmission electron microscopy (MET). After the catalytic tests the catalytic activity and selectivity were determined by high precision liquid chromatography. It was achieved a catalytic activity, in glycerol conversion, of 33-97%, being the bimetallic catalyst more active than the monometallic. The catalysts containing only Au are selective to glyceraldehyde, at higher temperature and pH, and are reusable, while the one which contains Pt also are selective to form organic acids (acetic, formic, glycolic, lactic and tartonic).