Dehydration of diols catalyzed by CeO2

Dehydration of several 1,3-diols into unsaturated alcohols was investigated over pure CeO2 at 325-425 degreesC. 1,3-Diols are more reactive than other diols and monoalcohols over CeO2. In the dehydration of 1,3-propanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 2,4-pentanediol, and 2-methyl-2,4-pentanediol, unsaturated alcohols are selectively produced at 325 degreesC. In the dehydration of 2-methyl-1,3-propanediol, the corresponding unsaturated alcohol is produced with low selectivity: decomposition simultaneously proceeds. TPR experiment reveals that active CeO2 surface is maintained at high valence of Ce4+ in the water-producing reaction. It is speculated that redox nature between Ce4+-Ce3+ affects the dehydration of 1,3-diols. (C) 2004 Elsevier B.V. All rights reserved.