Dehydration of Glucose to 5-Hydroxymethylfurfural Using LaOCl/Nb2O5 Catalysts in Hot Compressed Water Conditions

Abstract

The dehydration of fructose and glucose to 5-hydroxymethylfurfural was studied using LaOCl/Nb2O5 in hot compressed water conditions. The catalysts were prepared by impregnation of LaCl3 on Nb2O5 with different loadings. The solids were characterized by EDX, XRD, TGA and N2 physisorption at 77 K and pyridine and CO2 adsorption followed by FTIR; the strength of acidity and basicity was determined by NH3- TPD and CO2- TPD, respectively. The use of acid–base systems for HMF production mainly from glucose requires weak basic sites and moderate acidity condition that is reached with LaOCl/ Nb2O5 as was confirmed by acidity and basicity analyses. The presence of Nb2O5 increase HMF yield (>50%) and prevented the formation of undesirable products in hot compressed water conditions, similar results could be obtained with DMSO.