Tungsten oxides dispersed on Al2O3, ZrO2, and SiO2 supports were investigated for catalytic dehydration of glycerol (GL) to form acrolein (AC) in the gas phase at 315 degrees C with aqueous GL (GL concentration: 36.2 wt% or 10 mol%, molar GL/H2O = 1/9) as the feed (GHSVGL= 400 h(-1)). The WO3 /Al-2 03 and WO3/ZrO2 catalysts are found much more effective than WO3/SiO2 in catalyzing the reaction in terms of the selectivity (ca. 70 mol% vs. 60 mol%) and yield (49-58% vs. 11-32%) for AC production. Optimization of the WO3 loading (5-40 wt%) and calcination temperature (550-900 degrees C) of the WO3/Al2O3 and WO3/ZrO2 catalysts identifies that the calcination at 800 degrees C of a 30 wt%WO3/Al2O3 sample would generate the most efficient catalyst that offers an AC yield as high as 61% AC for longer than 10 h (AC selectivity: 69 mol%). Correlating the catalytic performance with the density of W atoms at the surfaces of WO3/Al2O3 and WO3/ZrO2 samples discloses that those catalysts having the intermediate numbers for the surface density of W atoms (3.5-7.6 W nm(-2) or 0.5-1.0 monolayer), either on Al2O3 or on ZrO2, would offer the highest AC selectivity (69-72 mol%). The catalytic results obtained in the temperature range of 280-400 degrees C uncover 315 degrees C as the optimum reaction temperature; significant derivation from this temperature would lead to faster catalyst deactivation and lower AC selectivity. (C) 2014 Elsevier B.V. All rights reserved.