Effect of Acid-Basic Sites Ratio on the Catalytic Activity to Obtain 5-HMF from Glucose Using Al2O3-TiO2-W Catalysts

A series of Al2O3-TiO2-W materials with variation in W composition was prepared using an innocuous and easy sol-gel method, under both acid and basic pH conditions. The morphology and composition of W in the materials were studied by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDS), respectively, Density of basic and acid sites by CO2 and NH3 temperature programmed desorption (TPD) technique, and physicochemical properties by N-2 physisorption studies, X-ray diffraction (XRD), and UV-Vis spectroscopy. The catalytic properties of Al2O3-TiO2-W were examined for the conversion of glucose to produce 5-hydroxymethylfurfural (5-HMF) and the best yield of 5-HMFobtained with the catalyst of 5 w% W load. This high yield level was achieved when the catalyst with 2.35 acid-basic sites molar ratio was probed.