Vapor-phase reaction of 1,3-butanediol was investigated over rare earth oxide (REO) catalysts. In the reaction of 1,3-butanediol, dehydration and decomposition of 1,3-butanediol occurred simultaneously at 325 degrees C. The formation of unsaturated alcohols such as 3-buten-2-of and trans-2buten-l-ol was predominant over CeO2, Sc2O3, and Tm2O3, while 1,3-butanediol was preferentially decomposed over the other REOs. Especially, light REOs such as La2O3, Pr6O1 >, Nd2O3, and Sm2O3, catalyzed decomposition of 1,3-butanediol into 2-propanol, propanone, methanol, and ethanol. Basic and acidic properties of REOs were measured with temperature-programmed desorption (TPD) of adsorbed CO2 and NH3, respectively. The surface character of REOs was basic but not acidic. Both strength and number of basic sites of REOs increased with increasing ionic radius of rare earth cation in the REO except CeO2: light REOs were more basic. The decomposition of 1,3-butanediol would be attributed to the basicity of catalyst. In the reaction of 1,3-butanediol as well as 1,4-butanediol, the catalytic function of REOs will be discussed in connection with lanthanide contraction. (c) 2007 Elsevier B.V All rights reserved.