REFORMING OF ETHANOL - DEHYDROGENATION TO ETHYL-ACETATE AND STEAM REFORMING TO ACETIC-ACID OVER COPPER-BASED CATALYSTS

The title reactions, 2CH3CH2OH --> CH3COOC2H5+2H2 and CH3CH2OH+H2O --> CH3COOH+2H2, were carried out over copper-based catalysts (Cu, Cu/SiO2, Cu/ZrO2, Cu/Al2O3, Cu/MgO, and Cu/ZnO). The selectivities to ethyl acetate and acetic acid markedly depended upon the supports used. Acetaldehyde was formed by the dehydrogenation of ethanol and transformed to either ethyl acetate or acetic acid through steps in which a nucleophilic addition of ethanol (or ethoxide ions) or water (or hydroxide ions) to acetaldehyde occurred. The rats of the transformation steps to ethyl acetate and acetic acid were appreciably affected by the kinds of supports used. The transformation steps proceeded slowly, compared with the dehydrogenation step.