The effect of rhodium precursor on ethanol synthesis by catalytic hydrogenation of carbon dioxide over silica supported rhodium catalysts

Ethanol synthesis by CO2 hydrogenation was carried out over Rh/SiO2 catalyst. Several catalysts were prepared using acetate hydrate, nitrate and chloride precursors of rhodium, and the effects of the precursor on reaction behavior were investigated. The remarkable effect of Rh precursor on the ethanol selectivity as well as activity of reaction was observed. The highest ethanol selectivity was obtained over the 5 wt% Rh/SiO2 catalyst prepared from rhodium acetate hydrate precursor. It has been suggested that the difference in Rh precursor changed the mean particle size of Rh/SiO2 catalysts, resulting in the change in the ethanol selectivity.