The catalytic activity of the ruthenium carbonyl polymer [Ru(CO)(4)](n) was studied in the hydroformylation of 1-hexene. Compared to the more commonly used ruthenium carbonyl catalyst, Ru-3(CO)(12), the linear chain polymer showed higher levels of activity. Although [Ru(CO)(4)](n) itself is only sparingly Soluble under catalytic conditions and acts as a heterogeneous catalyst on its own, the effects of supports on catalytic activity were also investigated. A series of potential supports including SiO2 Al2O3 zeolite and multiwalled carbon nanotubes (MWCNT) were explored in order to optimize the catalytic preformance and reusability of the catalyst. The highest activities were obtained with MWCNT supported [Ru(CO)(4)](n). Unlike any of the conventional oxide supports, the MWCNT improved the total catalytic activity in comparison with the unsupported polymer. (C) 2008 Elsevier B.V. All rights reserved.