Abstract: A series of Cu-based catalysts were prepared by the co-precipitation method, and their catalytic properties for the dehydration of glycerol to acetol were tested under N₂ atmosphere in a stainless steel autoclave. The results showed that the Cu/SiO₂ catalyst had higher catalytic activity than other catalysts. However, acetol can easily react with hydrogen that originated from the reaction process to 1,2-propanediol, leading to the low selectivity for acetol. Therefore, a fixed-bed reactor was selected to further investigate the effects of reaction atmosphere, reaction temperature, and WHSV on dehydration of glycerol over the Cu/SiO₂ catalyst. In comparison with pure H₂ or pure N₂ atmosphere, the Cu/SiO₂ catalyst exhibited significantly higher activity and selectivity for acetol under the mixed atmosphere of 5% H₂-95% N₂. Under the mixed atmosphere, Cu/SiO₂ showed a slower deactivation rate compared with N₂ atmosphere and a more proper hydrogenation than that under H₂ atmosphere. Under the optimal reaction conditions of 220 ^oC, WHSV of 0.08 h^-1, and ambient 5%H₂/N₂ pressure, glycerol conversion and selectivity for acetol can be as high as 98.8% and 84.6%, respectively.

Key words: glycerol, acetol, dehydration, copper-based catalyst