A method is provided for preparing a mixture of lower aliphatic alcohols characterized by containing a substantial proportion of aliphatic alcohols having from 2 to 6 carbon atoms by reacting a mixture of carbon monoxide and hydrogen under suitable conditions of temperature and pressure in the presence of a catalyst comprising molybdenum, a metal from the group consisting of cobalt, iron and nickel, and silver, said catalyst being modified by the addition of a promoter from the class consisting of potassium, cesium and rubidium, said promoter being employed at a concentration ranging from about 1.8 to 13.0 micromoles of said alkali per square meter of surface area of said catalyst.