Ziegler-Natta catalysts are commonly employed in alfa-olefin (co)polymerization. Such systems are extremely sensitive to some organic compounds, which may act as poison, reducing polymer productivity. Among them, oxygenated compounds such as acetone can cause catalyst deactivation. In the present study, silica and chrysotile, in their pure form and after chemical modification with Cu and Ag, were characterized by a series of volumetric, spectroscopic and microscopic techniques. The results are discussed in terms of silanol group density, Lewis acid centers introduced by the metal and textural properties of the support. The resulting sorbents were evaluated in the adsorption of acetone from cyclohexane. Solvent containing acetone was percolated through the investigated sorbents and evaluated in the polymerization of ethylene using Ziegler-Natta catalysts. The best results in catalyst activity were observed in the case of silica or chrysotile modified with Cu. (C) 2008 Elsevier B.V. All rights reserved.