PURPOSE: To obtain acetic acid, acetaldehyde and ethanol in high selectivity with suppressed formation of unnecessary compounds, by reacting CO with H2 in the presence of a catalyst, containing a combination of rhodium with silver, as a co- catalyst, and having a high activity.
CONSTITUTION: CO is reacted with H2 in the vapor phase in the presence of a catalyst containing a combination of rhodium with silver as a co-catalyst at 220-350oC and 20-200 atm at an SV of 1,000-50,000 to give a 2 C hydrocarbon compound, e.g. acetic acid, acetaldehyde or ethanol, containing oxygen. The molar ratio between CO and H2 is preferably (3:1)-(1:3). The catalyst is prepared by dissolving a rhodium and a silver compounds in water or an organic solvent, adding a porous inorganic carrier substance to the resultant solution, supporting the compounds on the carrier by the conventional method such as dipping, ion exchange method, and reducing or heat-treating the supported catalyst. The amount of the catalytic component is 0.1-10 wt% expressed in terms of th rhodium content, and 0.2- 15 wt% expressed in terms of the co-catalyst silver.