1 4 CO 2 added to the syngas serves to initiate chain growth to produce both oxygenates and hydrocarbons. This observation prompted a closer examination of the production of alcohols during Fischer-Tropsch synthesis with precipitated iron catalysts containing either silica or alumina and various levels of the potassium promoter. Surprisingly, the catalysts containing alumina produced more alcohols than the silica containing catalysts. The oxygenates fraction increased with increasing potassium content. At high potassium loadings, propanal becomes the dominant C 3 oxygenate, suggesting that aldehyde, and not alcohol, is a primary product.