Dehydration of butanediols over CeO2 catalysts with different particle sizes

Dehydration of butanediols into unsaturated alcohols was investigated over CeO2 with different particle sizes. The size was controlled by the calcination temperature. Catalytic performance in the dehydration of 1,3-butanediol is greatly affected by the particle size. The selectivity to unsaturated alcohols such as 3-buten-2-ol and trans-2-buten-1-ol increases with increasing the particle size, while decomposition of 1,3-butanediol into methanol and ethanol is catalyzed by CeO2 with small particles. In contrast, in the reaction of 1,4-butanediol, cyclization products such as tetrahydrofuran and γ-butyrolactone increases with decreasing the particle size, instead of the decomposition into methanol and ethanol. CeO2{1 1 1} facets became predominant on the large particles, whereas different surfaces such as {1 0 0} and {1 1 0} facets were exposed on the small CeO2 particles. In the dehydration of butanediols, CeO2 has structure-sensitive catalysis: CeO2{1 1 1} facets have active sites for the formation of unsaturated alcohols, and the other surfaces catalyze the side reactions such as decomposition of 1,3-butanediol and cyclization of 1,4-butanediol.