Catalytic upgrading of ethanol to n-butanol over M-CeO2/AC (M = Cu, Fe, Co, Ni and Pd) catalysts

M-CeO2/AC (M = Cu, Fe, Co, Ni and Pd) catalysts were prepared and evaluated in the continuous catalytic upgrading of ethanol to n-butanol under mild reaction conditions. The highest selectivity to n-butanol (67.6%) was achieved over Pd-CeO2/AC catalyst, while Cu-CeO2/AC catalyst exhibited the highest ethanol conversion (46.2%) with moderate selectivity to n-butanol (41.3%). The catalytic performance of these catalysts was shown for the first time to largely depend on the dehydrogenation, hydrogenation and C-C bond cracking capabilities of each individual supported metal.