Catalytic properties of supported transition metal catalysts for conversion of ethanol in the presence of water vapor

Catalytic properties of supported transition metal catalysts were investigated for conversion of aqueous solution of ethanol in gas phase in order to use effectively ethanol solution from fermentation of biomass. Fourteen supported-metal catalysts (Ti, Zr, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Sb, Ru, Pt and Rh) were prepared by impregnation of aqueous solutions of their salts on alumina. Reactions were carried out at atmospheric pressure and 673 K by use of a conventional flow reactor. When mixture of ethanol and water vapors was fed on the metal catalysts, ethylene, acetaldehyde and acetone mere produced as in the case of the metal oxide catalysts. However, on the metal catalysts of Group 8-10, carbon dioxide, carbon monoxide and methane were produced, suggesting that the steam reforming of ethanol occurred. The selectivity for the reaction was in the order: Co much greater than Ni>Rh>Pt, Ru, Cu. This is practically the reverse order for methanol steam reforming. On Co/Al2O3 the ethanol steam reforming occurred directly without going through methane formation.