Highly active and durable WO(3)/Al(2)O(3) catalysts for gas-phase dehydration of polyols

Gas-phase glycerol dehydration over WO(3)/Al(2)O(3) catalysts was investigated. WO(3) loading on γ-Al(2)O(3) significantly affected the yield of acrolein and the catalyst with 20 wt% WO(3) loading showed the highest activity. The WO(3)/Al(2)O(3) catalyst with 20 wt% WO(3) loading showed higher activity and durability than the other supported WO(3) catalysts and zeolites. The number of Brønsted acid sites and mesopores of the WO(3)/Al(2)O(3) catalyst did not decrease after the reaction, suggesting that glycerol has continuous access to Brønsted acid sites inside the mesopores of WO(3)/Al(2)O(3), thereby sustaining a high rate of formation of acrolein. Dehydration under O(2) flow further increased the durability of the WO(3)/Al(2)O(3) catalyst, enabling the sustainable formation of acrolein. In addition, the WO(3)/Al(2)O(3) catalyst with 20 wt% WO(3) loading showed high activity for the dehydration of various polyols to afford the corresponding products in high yield.