Two series of Pt or/and Ni-based gamma-alumina catalysts were prepared using sol-gel and conventional impregnation methods. Their activities were tested in the aqueous phase reforming of glycerol. All catalysts were also characterized by different techniques such as: ICP, BET, TPR-H-2, in situ XPS and XRD to study their textural and physicochemical properties. The effect of preparation method, nature of active phase and possible cooperative effect between Pt and Ni in catalytic performance have been the focus of this investigation. The results obtained showed that sol-gel catalysts present better catalytic properties. TPR-H-2. XPS and XRD showed that sol-gel PtNiAl catalyst contain well dispersed active phases and present high resistance against sintering leading to better and more stable catalytic activities, especially at moderate temperature/pressure conditions. As a result, sol-gel PtNi catalysts allowed higher reforming rates (3-8 times) to gaseous products than PtNi catalysts prepared by incipient wetness impregnation. This better behavior can be explained by the enhancement of textural properties, higher active phases dispersion and cooperative effect between Pt and Ni elements. (C) 2012 Elsevier B.V. All rights reserved.