Applied Catalysis A: General 403 (2011) 128–135 Contents lists available at ScienceDirect Applied Catalysis A: General jo u r n al hom epage: www.elsevier.com/locate/apcata New insight into the preparation of copper/zirconia catalysts by sol–gel method Serena Esposito a,∗ , Maria Turco b , Giovanni Bagnasco b , Claudia Cammarano b , Pasquale Pernice c a Laboratorio Materiali del Dipartimento di Meccanica, Strutture, Ambiente e Territorio, Facoltà di Ingegneria dell’Università di Cassino, Via G. di Biasio, 43, I-03043 Cassino (Fr), Italy b Dipartimento di Ingegneria Chimica, Università di Napoli Federico II, P.le Tecchio, I-80125 Napoli, Italy c Dipartimento di Ingegneria dei Materiali e Produzione, Università di Napoli Federico II, P.le Tecchio, I-80125 Napoli, Italy a r t i c l e i n f o Article history: Received 15 April 2011 Received in revised form 24 June 2011 Accepted 25 June 2011 Available online 2 July 2011 Keywords: Sol–gel synthesis Copper precursors Cu–ZrO2 catalysts Oxidative steam reforming of methanol a b s t r a c t Cu/ZrO 2 catalysts prepared by the sol–gel method were characterized by XRD, N 2 adsorption, DTA/TG, TPR and N 2 O dispersion measurements and tested as catalysts for the oxidative steam reforming of methanol (OSRM). Two synthesis procedures, based on the Cu precursors Cu(CH 3 COO) 2 ·H 2 O (A-ZrCu samples) and Cu(NO 3 ) 2 ·2.5H 2 O (N-ZrCu samples) respectively, were compared to investigate the consequence of synthesis parameters on the physical and chemical properties of the prepared materials. The adopted procedures resulted in remarkable differences in thermal behaviour: the crystallization of tetragonal ZrO 2 was shifted to higher temperature in N-ZrCu samples in comparison with pure ZrO 2 , while this effect was not observed in A-ZrCu. XRD data indicated that Cu 2+ ions were incorporated into the ZrO 2 lattice in N-ZrCu samples. Though both synthesis lead to very high surface areas, the textural properties of the reduced samples suggested the existence of different interactions between Cu ions and the ZrO 2 matrix in A-ZrCu and in N-ZrCu. The Cu/ZrO 2 systems showed noticeable catalytic activity for the oxidative steam reforming of methanol, even without the pre-reduction treatment, but the catalytic response is drastically affected by the preparation procedure and the pre-treatments. N-ZrCu samples gave higher methanol conver- sion and yield to H 2 . Moreover, the distribution of secondary products was completely different: N-ZrCu produced a lot of CO, while A-ZrCu gave large amounts of CH 2 O and (CH 3 ) 2 O. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Recently the methanol oxidative steam reforming, OSRM, has been proposed by several authors as the most performing reaction for the production of hydrogen from methanol [1–5]. The process is based on the combination of the steam reforming (1) and partial oxidation reactions (2). CH 3 OH + H 2 O = 3H 2 + CO 2 H ◦ = +49.4 kJ/mol (1) CH 3 OH + 1/2O 2 = 2H 2 + CO 2 H ◦ = -192.2 kJ/mol (2) The crucial problem of all the researches dealing with hydrogen production from methanol is the formulation of a proper catalyst. Despite the substantial number of papers, literature data strongly indicate that no catalysts with activity and selectivity adequate to a technological development of the OSRM process were yet obtained. It is needed therefore to widen the research by studying systems that were already investigated, with the aim to improve their per- formances, and at the same time by modifying the present systems. ∗ Corresponding author. Tel.: +39 0776 2993697; fax: +39 0776 2993711. E-mail address: s.esposi@unicas.it (S. Esposito). The catalysts proposed in the literature are mainly based on cop- per dispersed in oxide matrix, recognized as the best systems for the production of hydrogen from methanol [6–11]. Recently, Cu/ZrO 2 materials were proposed as catalysts in the process of the oxidative steam reforming of methanol, OSRM. ZrO 2 support is reported to favour the copper dispersion and reducibility and can also play a role in the catalysis, through adsorption and activation of methanol [3,12–14]. The synthesis procedures proposed in the literature for Cu/ZrO 2 systems are mainly focused on coprecipitation and impregnation methods [15–21]. These methods are commonly used, for the preparation of catalyst even if they may cause a phenomenon of agglomeration of the active phase on the support, especially for high copper concentration, not allowing a high and homogeneous dispersion of active phase. It follows that the design of an ade- quate synthesis procedure is the central point in the preparation of a catalyst. Unlike more conventional methods, the sol–gel synthesis allows to obtain nanocomposites characterized by larger surface areas and higher dispersion degree of the metallic phase (up to the molecular scale) [22–26]. Even more, the sol–gel synthesis resulted to possess unique features, namely the possibility of control the physical–chemical properties of the resulting compounds through 0926-860X/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.apcata.2011.06.024