Vapor-phase catalytic dehydration of 1,5-pentanediol was investigated over rare earth oxides (REOs) at 325-450 degrees C. The conversion of 1,5-pentanediol over REOs calcined at 700 and 800 degrees C was higher than that calcined at 500 degrees C. Sc2O3, Yb2O3, and Lu2O3 with cubic bixbyite structure showed the selectivity to 4-penten-1-ol with higher than 74 mol%, while REOs with hexagonal and monoclinic structures showed the selectivity with less than 50 mol%. Especially. Yb2O3 and Lu2O3 calcined at 1000 degrees C showed high formation rate of 4-penten-1-ol per specific surface area over 1 mmol h(-1) m(-2) at 400 degrees C. In the Yb2O3 catalyst calcined at 800 degrees C, the conversion of 1,5-pentanediol was increased up to 74.4 mol% with increasing contact time, together with stable selectivity to 4-penten-1-ol of 71.8 mol%. In comparing the reactivity of alkanediols to form the corresponding unsaturated alcohols over Yb2O3, we found the reactivity of alkanediols into the corresponding unsaturated alcohols was the following order: 1,4-butanediol >1,3-diols >> 1.5-pentanediol >> 1,6-hexanediol. (C) 2012 Elsevier B.V. All rights reserved.