Contents lists available at ScienceDirect Catalysis Today journal homepage: www.elsevier.com/locate/cattod Structural and catalytic stability assessment of Ni-La-Sn ternary mixed oxides for hydrogen production by steam reforming of ethanol. J. Bussi a , M. Musso a, ⁎ , A. Quevedo a , R. Faccio b , M. Romero b a Facultad de Química, UdelaR, Laboratorio de Fisicoquímica de Superficies, DETEMA, Gral. Flores 2124, 11800 Montevideo, Uruguay b Facultad de Química, UdelaR, Cryssmat-Lab, DETEMA, Gral. Flores 2124, 11800 Montevideo, Uruguay ABSTRACT NixLaSn trimetallic catalysts (x = 5 and 15% by weight) were prepared by a coprecipitation technique by pH change and then calcined at 700 °C, 850 °C, 900 °C and 950 °C. XRD analysis of the fresh and unreduced catalysts showed the formation of crystalline phases corresponding to the pyrochlore structure La2Sn2O7 and NiO following calcination at 850 °C, 900 °C and 950 °C. Ni3Sn and Ni3Sn2 compounds were formed under a pure hydrogen atmosphere and 650 °C in the well crystallized catalyst containing the pyrochlore. This catalyst was highly active in the ethanol steam reforming reaction at 650 °C, giving yield to gaseous mixtures containing hydrogen, carbon monoxide, carbon dioxide and methane. XRD analysis of the spent catalyst showed the presence of Ni3Sn2, Ni3Sn and the pyrochlore as unique phases after 80 hours of reaction time. After an initial decay, H2 yield kept stable until the end of the test. Carbon formation was observed by TEM, TG and elemental analysis. Lanthanum carbonates were also revealed by Raman spectroscopy. The highly stable biphasic structure containing Ni-Sn intermetallic compounds and the La2Sn2O7 could be the basis of catalysts for the production of H2-rich gaseous mixtures starting from bioethanol. Introduction The expected depletion of fossil fuels along with the long-term rise in prices and the established negative environmental impacts resulting from their combustion has increased the interest in finding new energy sources. Hydrogen is considered as a promising alternative to fossil fuels and its production is a subject of current interest for applications in biorefineries and fuel cells [1–3]. Nowadays, conventional methods for hydrogen production are based on hydrocarbons conversion through several catalytic processes including steam reforming, partial oxidation, autothermal reforming and pyrolysis [4]. Currently, the steam reforming of natural gas is the main and cheapest method for hydrogen production worldwide but however, in this process, carbon is transformed into CO 2 and released to the atmosphere, contributing to the greenhouse effect [4,5]. Alternatively, using renewable sources of hydrocarbons has the significant advantage of being nearly CO 2 neutral, since the carbon dioxide produced is consumed for biomass growth, thus offering a nearly closed carbon loop [4]. In this sense, alcohols have shown good features for hydrogen production because they are easily decomposed in presence of water by steam reforming leading to a H 2 -rich mixture [6–8]. Furthermore, compared to other fuels, they are easier to store, handle and transport due to their lower volatility. In particular, ethanol produced by biomass fermentation, called in this case bio-ethanol, can be used without necessity of water separation [9,10]. Because of that and by its relative low cost, ethanol steam reforming (ESR) represents one of the most promising methods for H 2 production. The main reaction of ESR process can be described with the following equation: C 2 H 5 OH + 3H 2 O → 6H 2 + 2CO 2 (1) ESR process is highly endothermic (ΔH° = 347.4 kJ mol -1 ) and usually needs to be operated at approximately 500–650 °C, atmospheric pressure and water excess [11,12]. Nickel-based catalysts are still the commercially preferred catalysts due to their high activity and lower cost compared with those based on noble metals (Ru, Rh, Pt) [13–15]. Conventional catalysts contain nickel supported on oxides like SiO 2 , Al 2 O 3 , MgO, La 2 O 3 , CeO 2 , ZrO 2 , TiO 2 , MgAl 2 O 4 or their mixtures. However carbon deposition and sintering are always present and may lead to serious catalyst deactivation [16,17]. Removal of the deposited carbon species can occur via gasification with adsorbed water and CO 2 or by the O species supplemented from the lattice oxygen of the catalyst itself [18,19]. The support as well as other catalyst components plays a very important role in preventing these problems. One way to minimize http://dx.doi.org/10.1016/j.cattod.2017.04.024 Received 6 January 2017; Received in revised form 24 March 2017; Accepted 10 April 2017 ⁎ corresponding author. E-mail address: mmusso@fq.edu.uy (M. Musso). Catalysis Today xxx (xxxx) xxx–xxx 0920-5861/ © 2017 Elsevier B.V. All rights reserved. Please cite this article as: Bussi, J., Catalysis Today (2017), http://dx.doi.org/10.1016/j.cattod.2017.04.024