The present research showed dependence of crystalline phases in titania on the catalytic properties of Co/TiO2 catalysts during CO hydrogenation. A comparative study of anatase TiO2- and rultile-anatase coupled TiO2-supported Co catalysts was conducted. It was found that the presence of rutile phase (19 mol%) in titania resulted in a significant increase in the catalytic activity during CO hydrogenation. It was proposed that the role of rutile phase was to increase the stability of the support. The impact of water vapor produced during reduction on the formation of cobalt species strongly interacted with the support was probably inhibited by the presence of rutile phase in titania leading to a decrease in the reducibility loss during reduction. (C) 2004 Elsevier B.V. All rights reserved.