Selective Gas-Phase Conversion of Glycerol to Acetol Over Promoted Zirconia Solid Acid Catalysts

The vapour phase selective conversion of glycerol to acetol at normal atmospheric pressure in a fixed-bed micro reactor was investigated over SO4 2� and WOx promoted ZrO2 and M-ZrO2 (M = Al2O3 or TiO2) solid acid catalysts. The investigated sulfate and tungstate ion promoted zirconia-based catalysts were prepared by both coprecipitation and impregnation methods and calcined at 923 K. The synthesized catalysts were characterized by means of X-ray powder diffraction, X-ray photoelectron spectroscopy, BET surface area and ammonia temperature-programmed desorption methods. Characterization results suggest that SO4 2� promoter strongly influences the physicochemical properties of the support oxides than WOx. However, the WOx promoted catalysts exhibited better catalytic activity than SO4 2� promoted catalysts. Among various catalysts investigated, the WOx/Al2O3-ZrO2 catalyst exhibited stable catalytic activity with the highest glycerol conversion of 99% and acetol selectivity of 74%.