CATALYTIC CONVERSION OF ETHANOL ON CARBON CATALYSTS

The decomposition of ethanol was studied using carbon catalysts with a different nature of the surface. They were prepared from poly(furfuryl alcohol). The catalytic tests were performed in a flow reactor in the temperature range 323-633 K. Dehydration and dehydrogenation of ethanol, as well as acetal formation, occur under the conditions applied. The products are ethene plus diethyl ether, acetaldehyde and 1,1'-diethoxyethane, respectively. The study supports previous findings that oxidation with nitric acid enhances dehydration activity and selectivity, whereas introduction of Ni2+ ions increases dehydrogenation activity and selectivity. The supported Ni2+ cations, in the hydrated form, act as additional active centers for dehydrogenation. In addition, both these surface modifications also enhance carbon catalytic activity and selectivity for the acetal formation. The acetal results from a secondary reaction between the formed acetaldehyde and ethanol on acidic centers located on the outer surface of the catalyst.