Résumé
New nanodispersed Cu-ZrO2 systems (containing 0 and 8.3 mol% Cu) were synthesized by sol-gel method. Homogeneous gels were prepared starting from Zr propoxide and Cu(NO3)(2)center dot 2.5H(2)O. The materials were characterized by XRD, TG/DTA, N-2 adsorption, TPR techniques and N2O surface oxidation. In the Cu-containing material part of Cu2+ ions were incorporated into the zirconia lattice and strongly influenced the crystallisation behaviour of zirconia matrix. After treatment at 450-600 degrees C, the materials contained ZrO2 nanocrystals of the tetragonal polymorph. The samples heat treated up to 450 degrees C showed high surface areas in the range 140-180 m(2)/g. Copper oxide species with different reducibility were detected by TPR measurements. The H-2 reduction treatments gave rise to metallic copper with very high dispersion. The catalysts showed high activity for the oxidative steam reforming of methanol. A noticeable activity was observed also with the not pre-reduced catalyst, although a previous reduction in H-2 led to a higher selectivity and H-2 production. (C) 2009 Elsevier B.V. All rights reserved.