Production of acetic acid

Claim 1

A process for selective conversion of synthesis gas into acetic acid and related oxygenated C 2 -hydrocarbon derivatives which comprises continuously passing a carbon monoxide and hydrogen stream in contact with a rhodium-ruthenium catalyst composition in a reaction zone maintained at a temperature between about 150° C. and 500° C. and a pressure between about 100 and 10,000 psi; wherein said rhodium-ruthenium catalyst is prepared and pretreated by a method which comprises (1) co-impregnating a carrier substrate with an aqueous solution of soluble rhodium and ruthenium compounds, and subjecting the co-impregnated carrier substrate to drying conditions to remove substantially all of the water content, wherein the resultant catalyst composition consists essentially of between about 0.1 and 10 weight percent rhodium metal and between about 0.01 and 2 weight percent ruthenium metal, based on the total catalyst composition weight, (2) calcining and reducing the catalyst composition by contacting said catalyst composition with hydrogen at a temperature between about 200° C. and 500° C., and (3) subsequently heating the catalyst composition in a static atmosphere of carbon monoxide and hydrogen at a temperature between about 150° C. and 350° C. for a time period between about 0.2 and 20 hours.