Conversion of levulinic acid using CuO/WO3(x)-Al2O3 catalysts

Abstract

The CuO/WO3(x)-Al2O3 catalysts were tested for the conversion of levulinic acid into chemicals of high added-value compounds. The WO3(x)-Al2O3 modified supports with 5 different WO3 contents (2, 4, 6, 8, and 10%wt) were prepared by the wet impregnation method, consequently 5%wt CuO was impregnated on the modified supports. The optimum catalytic activity was obtained with CuO/WO3(6%)-Al2O3 catalyst, which was directly related to the highest acidity of the catalyst showed by NH3-TPD and acid strength by titration analysis. The distribution of products observed on CuO/WO3(x)-Al2O3, was correlated with a change in acid site type and acid strength. The changes in the acidity by the addition of CuO over modified support was attributed to structural changes (distortions) stabilizing the active phase. This distortion is increasing the acidity strength, and favoring a higher catalytic activity with changes in the selectivity in function of CuO content over WO3(x)-Al2O3 modified support, obtaining the maximum formation of 2-MTHF and possibly other higher value-added chemicals from GVL such as: 1,4-pentanediol, pentenoic acid, pentanoic acid, 2-pentanol, and gaseous products were on CuO/WO3(6%)-Al2O3 catalyst.