A series of titania-supported ruthenium-nickel bimetallic catalysts, with total metal loading of similar to 4.5 wt.% in each, was prepared and characterized for various physico-chemical properties. The hydrogenation of carbon monoxide was studied over these catalysts in the temperature range of 483 493 K, weight hourly space velocity of 1.5 h(-1), H-2/CO mole ratio of 2, and at atmospheric pressure. The effects of ruthenium loading and pretreatment procedures on the hydrogenation activities of these catalysts and product selectivities were studied. The catalyst containing 3.6 wt.% Ni and 0.82 wt.% Ru produced highest proportion of C5+ hydrocarbons (60 wt.%). High olefin selectivities (40 wt.% for C-2(=) and 93 wt.% for C-3(=), respectively) were observed with catalysts containing only ruthenium (5 wt.%). The effect of metal-metal interaction in the bimetallic catalysts on product selectivities was also studied. (C) 2003 Elsevier B.V. All rights reserved.