Promotion of Ni/MgAl 2 O 4 Catalysts with Rare Earths for the Ethanol Steam Reforming Reaction Agustı ´n E. Galetti • Mariana N. Barroso • Manuel F. Gomez • Luis A. Arrua • Antonio Monzo ´n • M. Cristina Abello Received: 3 July 2012 / Accepted: 10 October 2012 / Published online: 27 October 2012 Ó Springer Science+Business Media New York 2012 Abstract Hydrogen production by ethanol steam reforming was studied using Ni catalysts supported over MgAl 2 O 4 doped with Ce or Pr. Ni/MgAl 2 O 4 –CeO 2 catalyst obtained from nickel nitrate impregnation was selected as the best one (final steady conversion = 95.8 %, carbon formation = 0.4 wt% and activity decay = 6.6 %) under the experimental condi- tions used in this work. Keywords Hydrogen  Ethanol steam reforming  Ni catalysts  Carbon deposition 1 Introduction In recent years, the scientific community has oriented numerous research works for searching new energy sources as a consequence of the limited fossil resources and envi- ronmental constraints. In this sense, the use of ethanol from biomass to produce hydrogen has a great potential not only due to its renewable origin but also for its rich hydrogen content. Thus, for the ethanol steam reforming (ESR) reaction, C 2 H 5 OH ? 3H 2 O ? 6H 2 ? 2CO 2 , a maximum yield of 6 mol of hydrogen for each mol of ethanol could be obtained. Ni supported catalysts have shown to be active and selective in the ethanol steam reforming for producing hydrogen [1–5]. The high C–C bond breaking activity and the relatively low cost compared to noble metals, makes Ni a suitable active phase for this reaction. The main problem for most of these catalysts is the high deactivation rate related to both the formation of carbonaceous deposits and the sintering of metallic nanoparticles. The deactivation by fouling occurs by the covering of the active Ni nanoparti- cles with graphitic carbon layers formed during the reac- tion. Simultaneously the formation of carbon nanofibers (CNFs) or even nanotubes (CNTs) can be also observed, but these carbonaceous materials do not deactivate the catalyst [6, 7]. Previous works have shown that the addition of Ce [8] or Pr [9] to Ni-based catalysts increases the resistance to the formation of carbonaceous deposits. Several authors [10, 11] have also agreed that the CeO 2 promotes the removal of carbonaceous species due to the high O 2 storage capacity delivering it to the surface by a redox mechanism. A similar effect was found for PrO 2 [12]. The Ni particle size distribution and the metallic dis- persion are also very important factors affecting the carbon deposition mechanism [13, 14] and the rate of carbon formation. It is well known that highly dispersed tiny particles avoid the carbon deposition [15]. The anchorage of Ni particles on the support is affected by the Ni pre- cursor used, the activation pretreatment and the support composition [16, 17]. In addition, suitable supports should be resistant to the high temperatures attained during the ethanol steam reforming, and they also should be able to maintain the metallic dispersion as high as possible during reaction. A. E. Galetti (&)  M. N. Barroso  M. F. Gomez  L. A. Arrua  M. C. Abello Instituto de Investigaciones en Tecnologı ´a Quı ´mica (UNSL-CONICET), Chacabuco y Pedernera, 5700 San Luis, Argentina e-mail: agugaletti@yahoo.com.ar M. C. Abello e-mail: cabello@unsl.edu.ar A. Monzo ´n Department of Chemical and Environmental Engineering, Faculty of Science, University of Zaragoza, 50009 Saragossa, Spain 123 Catal Lett (2012) 142:1461–1469 DOI 10.1007/s10562-012-0927-9