Synthesis of 3-pentanone from 1-propanol over CeO2-Fe2O3 catalysts

Vapor-phase synthesis of 3-pentanone from 1-propanol over CeO2-Fe2O3 catalysts was investigated, and the reaction pathway was discussed in comparison with the reactions of propanal and n-propyl propionate over the CeO2-Fe2O3. 1-Propanol was preferentially converted into 3-pentanone over the CeO2-Fe2O3 catalysts at 450 degreesC, and propanal, 3-hydroxy-2-methylpentanal, and n-propyl propionate were observed as by-products. The addition of Fe2O3 to CeO2 enhances the ability of CeO2 for the catalytic dehydrogenation of 1-propanol to propanal without losing the ability for the dimerization of propanal. The turnover frequency (TOF) based on a basic site varies with Fe content. Both the selectivity-conversion curves and similarity in the TOF between the reactants of 1-propanol at 450 degreesC and propanal at 400 degreesC suggest that propanal is an initial intermediate converting into the final product, 3-pentanone. The formation of 3-pentanone from 1-propanol over the CeO2-Fe2O3 proceeds via aldol addition of propanal into 3-hydroxy-2-methylpentanal, followed by the decomposition into 3-pentanone, while n-propyl propionate is formed as a mere by-product. (C) 2003 Elsevier B.V. All rights reserved.