A HIGHLY-ACTIVE AND HIGHLY SELECTIVE OXIDE CATALYST FOR THE CONVERSION OF ETHANOL TO ACETONE IN THE PRESENCE OF WATER-VAPOR

In the presence of water vapour and a suitable catalyst, ethanol is co nverted to acetone rather than to ethylene and acetaldehyde. In order to develop an appropriate catalyst for this reaction, steady-state cat alytic activities and selectivities were studied for 24 oxide catalyst s. It was found that the acetone selectivity is high on a catalyst hav ing both surface acidity and basicity, suggesting that the acetone for mation is an acid-base bifunctional catalytic reaction. Iron oxide is superior to the other oxides studied here in both conversion and aceto ne selectivity. The superiority is greatly enhanced by mixing iron oxi de with zinc oxide. The preparation method for the iron-zinc mixed oxi de catalyst was also studied and it was found that the optimal composi tion is Zn/(Fe + Zn) = 0.1-0.4 and that the optimal condition for calc ination is 773 K for 3 h. The catalyst gave 100% ethanol conversion an d 94% acetone selectivity at a reaction temperature of 713 K. It is in itially a mixture of Fe2O3 and ZnO but is converted to a spinel type c ompound, ZnFe2O4, during the reaction. The optimal reaction temperatur e was determined to be 713 K, and at this temperature, the acetone yie ld decreased by 34% after a time of 24 h.