Catalytic hydrogenation of carbon dioxide into C2+ alcohols with Ir-Mo/SiO2

Abstract The hydrogenation of CO2 was investigated with SiO2-supported Ir-Mo bimetallic catalysts. The C2+ alcohols (ethanol, 1-propanol and 1-butanol) were found to be formed by the synergistic action of Ir and Mo. The CO2 conversion was dependent upon metal impregnation procedures and Mo/Ir molar ratios, but the selectivity to C2+ alcohols was almost constant regardless of these factors. Iridium-Mo/SiO2 catalysts exhibited the highest CO2 conversion and yield of C2+ alcohols at a Mo/Ir ratio of about 0.3. The results obtained in this work are similar to those in the CO hydrogenation with Ir-Mo/SiO2 catalysts. As a result, it is suggested that the active species of Ir-Mo/SiO2 catalysts might be the same both in the CO2 hydrogenation and in the CO hydrogenation.