Journal of Power Sources 196 (2011) 4364–4369 Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour Influence of calcination temperature and atmosphere preparation parameters on CO-PROX activity of catalysts based on CeO 2 /CuO inverse configurations Antonio López Cámara a , Anna Kubacka a , Zoltán Schay b , Zs. Koppány b , Arturo Martínez-Arias a,∗ a Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie 2, Campus de Cantoblanco, 28049 Madrid, Spain b Institute of Isotopes, Hungarian Academy of Sciences, H 1525 Budapest, Hungary article info Article history: Received 30 July 2010 Received in revised form 17 September 2010 Accepted 29 September 2010 Available online 7 October 2010 Keywords: CO-PROX CeO2/CuO TG-DTA XRD TPR DRIFTS abstract Catalysts based on inverse CeO 2 /CuO configurations employed for preferential oxidation of CO in a H 2 - rich stream have been explored with respect to optimization of preparation parameters like calcination temperature and atmosphere. For this purpose, the catalysts precursors prepared by microemulsion have been characterized by TG-DTA, DRIFTS and XRD in order to select most adequate conditions. Selected specimens were further analysed by S BET measurements as well as with respect to catalytic and redox properties by activity measurements and H 2 -TPR tests. Activity differences are explained on the basis of textural, chemical and structural characteristics of the catalysts as a function of variations in the mentioned preparation parameters, with optimum properties being achieved for the specimen calcined under air at 500 ◦ C. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Production of H 2 for polymer fuel cells (PEMFC) is usually accomplished by a multi-step process that includes catalytic reforming of hydrocarbons or oxygenated hydrocarbons followed by water gas-shift (WGS) [1,2]. The gas stream obtained after these processes presents in most cases a relatively high CO concentra- tion that disallows efficient handling of the fuel by the Pt alloy anode usually employed in the PEMFC. Preferential (or selective) oxidation of CO (CO-PROX process) has been recognized as one of the most straightforward and cost-effective methods to achieve acceptable CO concentrations (below ca. 100 ppm) [3–5]. Among different types of catalysts that have shown their ability for this process (based on Pt or Au), a group constituted by catalysts based on closely interacting copper oxide and ceria (or structurally related cerium-containing mixed oxides) has shown promising properties in terms of activity, selectivity and resistance to CO 2 and H 2 O, while their lower cost could make them strongly competitive [3,5–7]. It is generally agreed that optimum catalytic properties for CO oxidation over copper–ceria catalysts are achieved in the presence of well-dispersed copper oxide patches over ceria nanoparticles [6–8]. This has been recently rationalised by spectroscopic anal- ∗ Corresponding author. Tel.: +34 915854940; fax: +34 915854760. E-mail address: amartinez@icp.csic.es (A. Martínez-Arias). ysis under reaction conditions of catalysts of this type showing that active sites for such reaction, under CO-PROX conditions, are related to interfacial copper oxide entities which become partially reduced during the course of interaction with the reactant mixture, for which process ceria apparently plays an important promoter role [9,10]. In turn, such studies have shown that H 2 oxidation, main reaction competing for the available oxygen with the CO oxida- tion one over this type of catalysts (their respective relative activity therefore determining the width of practical conversion window, i.e. temperature range at which values close to 100% CO conversion with the lowest possible H 2 oxidation activity becomes achieved), is apparently promoted when the reduction of the copper oxide par- ticles becomes extended to non-interfacial sites, suggesting that the performance for such reaction can strongly depend on mor- phological characteristics of the copper oxide particles themselves [7,9]. Such results, suggesting a possible separation (at least to a certain extent; it must be noted that both oxidation processes can- not most likely be treated as fully independent [7,11,12]) between most active sites for the two main oxidation reactions (of CO and H 2 , respectively) taking place along the CO-PROX process, obviously provide a key to modulation of the overall CO-PROX behaviour of this kind of systems [9]. On this basis, a recent work shows that enhanced catalytic properties can be achieved by using, instead of traditional direct catalyst configurations, in which copper oxide is dispersed onto ceria, inverse configurations in which large size cop- per oxide particles act as the support for ceria [13]. Such enhanced 0378-7753/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.jpowsour.2010.09.085