Guerbet condensation of methanol with n-propanol to isobutyl alcohol over heterogeneous bifunctional catalysts based on Mg-Al mixed oxides partially substituted by different metal components

The synthesis of isobutyl alcohol ((BuOH)-Bu-i) from methanol (MeOH) and n-propanol (PrOH) through the Guerbet condensation has been studied in batch experiments using bifunctional heterogeneous systems based on a dehydrogenating/hydrogenating metal (Pd, Rh, Ni or Cu) and a basic Mg-Al mixed oxide derived from hydrotalcite-type (HT) precursors. Only copper-based systems showed appreciable performances. In particular, the Cu/Mg/Al mixed oxides catalysts obtained by the co-precipitation method offered the best results in terms of activity and selectivity, thus allowing to reduce pollution problems connected with the up to now adopted copper chromite. These co-precipitated systems were also tested in some preliminary experiments carried out in gas-solid phase in a flow reactor, thus confirming promising application perspectives. (c) 2005 Elsevier B.V. All rights reserved.