A Relationship between the Production of Oxygenates from Ethanol/Steam Mixtures and the Oxygen Mobility in Transition Metal Oxide Doped CeO2 center dot SiO2 Catalysts

摘要

The catalytic activity of high specific area CeO2 center dot SiO2 was investigated under a flowing ethanol/steam mixture at 773 K. An attempt was made to tune the oxygen mobility of the catalyst further by doping it with small amounts of certain early transition metal oxides (V, Cr, Mn, Nb, Mo, W). Among the dopants studied, Mn, Cr, and, to a lesser extent, W drive the reaction pathway toward acetone synthesis. These dopants likely promote acetone synthesis by (i) enhancing oxygen mobility and thereby accelerating the oxidation of ethanol derived adsorbed species toward acetates, (ii) limiting the buildup of carbonate species, and (iii) suppressing the ethanol dehydration pathway.