Abstract: Cu/MgO catalysts with different Cu particle sizes were prepared by a precipitation-deposition method and investigated for their activity in the transfer dehydrogenation of alcohols to carbonyl compounds. They were highly active for the conversion of primary aliphatic alcohols, e.g. 1-octanol. With increasing Cu particle size from 4.6 to 7.4 nm, the aldehyde yield decreased from 65% to 55%, which showed a size effect. The copper particle abstracted an -hydrogen from the reactive alkoxide intermediate formed on the surface of MgO and simul-taneously catalyzed the hydrogenation of styrene.

Key words: copper, magnesia, particle size, transfer dehydrogenation, 1-octanol, 1-octanal