Direct and selective production of propene from bio-ethanol on Sc-loaded IN2O3 catalysts.

Propene, one of key building blocks for manufacturing plastics and chemicals, could be directly and stably produced from ethanol in good yields. The conversion degree of ethanol to propene reached approximately 60 mol% by using a 3 atom% scandium-loaded indium oxide catalyst at 823 K in the presence of water and hydrogen. The introduction of Sc prevented the reduction of In2O3 to In metal during the reaction, and that of water decreased the coke formation. Both additions resulted in longer lifetimes of the catalysts. The hydrogen addition increased the conversion of acetone to propene. The reaction pathways are also suggested on the basis of the product distributions and the pulse experiments, ethanol→acetaldehyde→acetone→propene, which is quite different from the shape-selective catalysis on zeolites and the dimerization-metathesis of ethene on nickel ion-loaded silica catalysts.