Isomerização da glicose empregando catalisadores homogêneos e heterogêneos em meio aquoso

Abstract

Biomass has become a research object for the development of technologies that can help improve our dependence on fossils fuels. The crescent interest in convert the chemical inputs, sustainable way together with the principles of green chemistry, attract attention to the carbohydrates that are abundant in lignocellulosic biomass, and are promising building blocks for the synthesis of a variety of products of industrial interest and of high added value, through large synthetic routes with the use of chemical and / or enzymatic catalysts. Among these routes, isomerization of glucose to fructose is an important one with some applications in terms of biomass valorization. Thus, the present work has the objective to study the isomerization of glucose in fructose in the aqueous medium and to evaluate the heterogeneous catalysts as oxides and mixed oxides based on Sn(IV) and Mo(VI) compared to the homogeneous dibutyl tin oxide catalyst (DBTO) and the reactions without the use of catalysts to investigate their catalytic activities in terms of conversion and yield at temperature of 70º C in times of variation ranging from 0,25 to 6 h. The catalysts were characterized as absorption spectroscopy in the infrared region (FTIR), thermogravimetric analysis (TG/DTA) and X-ray diffraction (XRD). The results demonstrate that it is the main reason for the influence of the glucose on conversion are the acid sites present in the catalytic systems, already reported in the literature. With this study it can be verified that molybdenum oxide and mixed oxide obtained high conversions, but the molybdenum oxide of presented better results in terms of yield terms to fructose. In addition, minority products such as glyceraldehyde and pyruvate were found and quantified.