Dehydration of Sugar Mixture to HMF and Furfural over SO42-/ZrO2-TiO2 Catalyst

A series of sulfated zirconia-titanium dioxide (SO4 2-/ZrO2-TiO2) catalysts with different Zr-Ti molar ratios were prepared by a precipitation and impregnation method and characterized by ammonia adsorption/ temperature programmed desorption (NH3-TPD), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques.The catalysts were used in the catalytic conversion of a sugar mixture (glucose and xylose) to 5-hydroxymethylfurfural and furfural in a water/n-butanol reaction system.An optimized yield of 26.0 mol% for 5hydroxymethylfurfural and 47.5 mol% for furfural was obtained within 2 h at 170 °C over the SO4 2-/ZrO2-TiO2 catalyst with a Zr-Al molar ratio of 7:3.Catalysts with higher acidity and moderate basicity were more favorable for the formation of the target product.