AbstractBy applying the chemical trapping method to the hydrocondensation reaction of carbon monoxide, we propose a reaction scheme with some novel interesting features. In the chemisorption of CO on Ni/SiO2, Ni/Al2O3, Co, Co/Al2O3we detected species bonded both through the C and O ends of the molecule. This chemisorbed CO can be the intermediate of the dissociation of CO or lead to the formation of a formyl species by reaction with hydrogen. The competition of these two reactions can lead to hydrocarbons or to alcohols.