A series of modified montmorillonites pillared with ZrO(2) or variously prepared TiO(2) and impregnated with CuO were synthesised, characterized (BET and pore analysis, XRD, TPD, TPR, AAS) and tested in the reaction of catalytic dehydration of glycerol. It was found that catalytic performance was sensitive to the preparation procedure. The acidity resulted in higher initial conversion and higher initial selectivity to acrolein, whereas CuO was found to stabilize higher conversion and to change the product distribution, favouring formation of hydroxyacetone. Titania-pillared, CuO-impregnated montmorillonite showed a long-term selectivity to hydroxyacetone higher than 60% at 74% conversion. (C) 2010 Elsevier B.V. All rights reserved.