Solution combustion synthesis of Nb-Al and W-Al oxide catalysts for direct production of 5-HMF from glucose

Abstract

In this work, niobium- and tungsten- promoted aluminas were syntheses by solution combustion synthesis using mixture fuel (1, 3, 5, and 10% metal loadings and 0, 5, and 10% ammonium acetate in mixture fuel). The catalysts were characterized by X-ray diffraction, N2-physisorption, scanning electron microscopy, pyridine-IR, and NH3-TPD. The XRD showed the peaks of γ-Al2O3 at 36.9, 45.3, and 67.7o for all samples and α-Al2O3 at 25.62, 35.29, 37.80, 43.33, 52.52, and 57.46 o for 1W-Al 5AA and 1W-Al 10AA. The BET result showed the surface of all catalysts is around 290 m2/g. The SEM images showed that amount of ammonium acetate affected the surface morphologies of the catalysts. The NH3-TPD results showed that the increase of metal increased the amount of strong acid site and ammonium acetate reduced the amount of strong acid. The highest 5-HMF yield at 41.46% was obtained for 5W-Al 10AA.

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