Abstract
Glucose is the most available hexose as it can be obtained from the most abundant and renewable biomass on Earth, cellulose. In addition, glucose can be catalytically transformed into furan derivates such as hydroxymethyl furfural (HMF) and furan dicarboxylic acid (FDCA) which are potential compounds to prepare polymeric materials and biofuels. The catalytic conversion of glucose can proceed via three chemical routes. Firstly, glucose isomerization can produce fructose. Secondly, the dehydration process of glucose to obtain 1,6-anhydroglucose and finally, the dehydration of fructose and small fragments such as glycolaldehyde and dihydroxyacetone through a retro-aldol condensation to obtain HMF [1,2]. It has been shown that basic catalysts are more efficient to convert glucose into fructose. However, acidic properties are also needed to facilitate the dehydration process in order to obtain furan derivates. Titanium oxide catalysts appear to be an appropriate catalyst for an industrial process whereby glucose is converted due to both its acidic and basic properties and its low synthesis cost. Based on this, glucose conversion was studied with a TiO2 catalyst obtained by a sol-gel method. The reactions were performed as a function of reaction time (2, 4, 6, and 8 h)and temperature (393, 403, 413 and 423 K). N2 physisorption analysis revealed a mesoporous structure for the titania with a pore diameter range from 10 to 110 Å, superficial area of 128 m2/g and total pore volume of the 1.7x10-7 m3/g. The structural characterization by XRD showed that the titania was present in the anatasepolymorph. The catalytic results showed that the lower temperature and reaction time increases the fructose yield. However, significant amounts of HMF were detected at higher temperatures and reaction time.
