Dimerisation of ethanol to butanol over solid-base catalysts

Ethanol is converted into 1-butanol over alkali earth metal oxides and modified MgO catalysts (1-20% yield). The MgO catalyst exhibits the highest reaction activity and 1-butanol selectivity amongst the catalysts studied. Reaction of various intermediates (acetaldehde, crotonaldehyde, crotylalcohol, butanal) and butanol over MgO (1bar, 450°C) revealed that the dimerisation reaction does not proceed primarily through the aldol condensation reaction. The reaction is proposed to proceed through a mechanism (Yang and Meng) in which a C-H bond in the β-position in ethanol is activated by the basic metal oxide, and condenses with another molecule of ethanol by dehydration to form 1-butanol. © 2003 Elsevier B.V. All rights reserved.