Steam reforming of glycerol: The experimental activity of La 1x Ce x NiO 3 catalyst in comparison to the thermodynamic reaction equilibrium Y. Cui, V. Galvita, L. Rihko-Struckmann *, H. Lorenz, K. Sundmacher Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106 Magdeburg, Germany 1. Introduction The interest on the conversion of biomass to hydrogen has increased considerably during the last years. Hydrogen gas has been identified as an ideal energy carrier for sustainable energy supply and it would be an ideal fuel in all fuel cell types to generate electricity with high efficiency [1–4]. In the short term, natural gas is the most viable and inexpensive source for large scale hydrogen production [5], but the reforming of it does not contribute to the reduction of greenhouse gases. Therefore, the production of hydrogen from non-fossil sources (especially from biomass [6]), would have higher environmental impact as it would lower the overall greenhouse gas emissions. Among the various non-fossil feedstock source, glycerol (1,2,3-propantriol) is one alternative because it has a relatively high hydrogen content, it is non-toxic, and its storage and handling is safe. More importantly, glycerol is the main byproduct in the production of the first generation biodiesel made by the transesterification of vegetable oils. The worldwide production of glycerol was more than 0.9 million tons in 2006, and in 2010 its production is estimated to be as high as 1.2 million tons [7]. The recent reviews of Johnson and Taconi [7] and Behr et al. [8] provide excellent overviews of the chemistry of glycerol, and its possible utilisation as renewable resource not only for the production of various chemicals but also for the production of synthesis gas. Aqueous phase reforming of glycerol has been extensively investigated by Dumesic and co-workers [9–11]. Moreover, some experimental studies of photocatalytic [12] and gas phase steam reforming of glycerol [13–20] have been published recently. The aqueous phase reforming of glycerol necessitates the utilisation of high pressure, which decreases the selectivity of hydrogen compared to the gas phase steam reforming of glycerol under atmospheric pressure [9,19]. The formation rate of hydrogen in the photocatalytic conversion of glycerol is considerably lower than that in gas phase steam reforming of glycerol [12,19]. Furthermore, steam reforming is highly energy efficient technology, and it can be carried out at atmospheric pressure. The steam reforming of glycerol has similarities to the reforming of light alcohols: methanol [21–26] and ethanol [2,6,27–37] reforming has inten- sively been investigated experimentally with various catalysts, e.g. with unpromoted and Ce–Zn-promoted Cu, Ni, Rh, Pd, Co, Ir, Ni on carriers such as CeO 2 , CeO 2 /ZrO 2 or alumina. Ni is also the most investigated active metal in the glycerol reforming, due to its well known property to promote the necessary C–C rupture [15–18]. However, in some comparative studies, other metals, e.g. Ru, Ir and Rh have shown even higher activity than Ni [16–17,19–20]. In the primary investigation of Suzuki and co-workers [19], Ru/Y 2 O 3 catalyst was found to have the high activity in the gas phase steam reforming. On the other hand, Ce containing catalysts are known to have high oxygen storage capacity, to disperse the active metal Applied Catalysis B: Environmental 90 (2009) 29–37 ARTICLE INFO Article history: Received 1 September 2008 Received in revised form 11 February 2009 Accepted 13 February 2009 Available online 21 February 2009 Keywords: Glycerol 1,2,3-Propantriol Hydrogen Steam reforming Mixed oxide La 1x Ce x NiO 3 ABSTRACT The steam reforming of glycerol (1,2,3-propantriol) was investigated with non-substituted and partially Ce substituted La 1x Ce x NiO 3 mixed oxides where x = 0, 0.1, 0.3 or 0.7, and the activities were compared with Pt metal catalysts. The catalysts were characterised by temperature-programmed reduction (TPR), X-ray powder diffraction (XRD), BET surface area and carbon content. The Ni was easily reduced in the La 0.3 Ce 0.7 NiO 3 structure. The experimental results were compared with the thermodynamic equilibrium concentrations, which were calculated for the system with non-stochiometric method. The La 0.3 Ce 0.7 NiO 3 catalyst was highly active in the glycerol steam reforming with conversions approaching to the equilibrium at temperatures between 500 and 700 8C. The formation of carbonaceous deposits on the La 0.3 Ce 0.7 NiO 3 was smallest among all the investigated La 1x Ce x NiO 3 catalysts. Unchanged catalyst surface area (BET) during operation and low carbon deposition after reaction confirm the efficient operation and high stability of the non-noble, inexpensive catalyst of La 0.3 Ce 0.7 NiO 3 . ß 2009 Elsevier B.V. All rights reserved. * Corresponding author. Tel.: +49 391 6110318; fax: +49 391 6110566. E-mail address: rihko@mpi-magdeburg.mpg.de (L. Rihko-Struckmann). Contents lists available at ScienceDirect Applied Catalysis B: Environmental journal homepage: www.elsevier.com/locate/apcatb 0926-3373/$ – see front matter ß 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.apcatb.2009.02.006