Energy, Vol.22, No.2-3, 343-348, 1997
Ethanol synthesis by catalytic hydrogenation of CO2 over Rh-Fe/SiO2 catalysts
Ethanol synthesis by catalytic hydrogenation of CO2 was carried out over Rh-Fe/SiO2 catalysts prepared by coimpregnation. The added amount of Fe influenced ethanol selectivity as well as CO2 conversion in the range Fe/Rh = 0-3. Product selectivity was correlated with %Fe-0 evaluated by XPS. The ethanol selectivity was correlated with the amount of bridged-CO adsorbed species evaluated by in situ FT-IR. It has been suggested that Fe changed the electronic states of Rh and that Fe-0 promoted methanation and prevented ethanol formation, as well as CO and methanol formation. An ethanol selectivity of 16.0% and a CO2 conversion of 26.7% were obtained at 5 MPa and 533 K in a flow of H-2-CO2 premixed gas (H-2/CO2 = 3) with a flow rate of 100 cm(3)/min over 5 wt% Rh-Fe(1:2)/SiO2 catalysts.