Reaction of methanol and n-propanol over hydrotalcite-like catalysts containing vanadium oxide

Vapour phase synthesis of isobutyric aldehyde from methanol and n-propanol (molar ratio 10:1) was carried out in a fixed bed reactor over calcined hydrotalcites and hydrotalcite-like compounds containing various amounts of vanadium oxide. V2O5 was loaded by impregnation or by decomposition of intercalated decavanadate ions. The influence of the Mg/Al ratio, and the V2O5 content as well as effect of some other reaction parameters was studied for both types of catalysts. The mechanism of isobutyric aldehyde formation from n-propyl alcohol and methanol involves formation of metal enolates as intermediates. The catalysts were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), surface area and basicity measurements. (C) 1998 Elsevier Science B.V. All rights reserved.