Hydrogen production by auto-thermal reforming of ethanol over nickel catalyst supported on mesoporous yttria-stabilized zirconia Min Hye Youn, Jeong Gil Seo, Ji Chul Jung, Sunyoung Park, In Kyu Song* School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, Shinlim-dong, Kwanak-ku, Seoul 151-744, South Korea article info Article history: Received 26 April 2009 Accepted 12 May 2009 Available online 6 June 2009 Keywords: Mesoporous yttria-stabilized zirconia Nickel catalyst Ethanol Auto-thermal reforming Hydrogen production abstract Mesoporous yttria-stabilized zirconia (YSZ-X ) supports with different Y/Zr molar ratio (X ) were prepared by a sol–gel method. 20 wt% Ni catalysts supported on YSZ-X (X ¼ 0, 0.1, 0.2, and 0.3) were then prepared by an incipient wetness impregnation method for use in hydrogen production by auto-thermal reforming of ethanol. The effect of Y/Zr molar ratio (X ) on the catalytic performance of Ni/YSZ-X (X ¼ 0, 0.1, 0.2, and 0.3) catalysts was inves- tigated. Hydrogen selectivity and by-product distributions over the catalysts were different depending on the Y/Zr molar ratio (X ). Hydrogen selectivity over Ni/YSZ-X (X ¼ 0, 0.1, 0.2, and 0.3) catalysts showed a volcano-shaped curve with respect to Y/Zr molar ratio (X ). Among the catalysts tested, Ni/YSZ-0.1 showed the best catalytic performance and the lowest carbon deposition in hydrogen production by auto-thermal reforming of ethanol. High reducibility and excellent structural stability of Ni/YSZ-0.1 catalyst were responsible for its superior catalytic performance. ª 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved. 1. Introduction Hydrogen has attracted much attention as a clean and renewable energy source. Many environmental regulations have brought about technological advances in hydrogen utilization such as fuel cell [1]. Steam reforming [2–6], partial oxidation [7–9], auto-thermal reforming [10–12], and CO 2 reforming [13,14] have been widely investigated as primary processes for converting hydrocarbons or alcohols into hydrogen. Among these reforming technologies, auto-thermal reforming, which consists of endothermic steam reforming and exothermic partial oxidation, has been recognized as a feasible process for hydrogen production with regard to both hydrogen yield and heat management. Among various fuel sources for hydrogen production, light alcohols such as methanol and ethanol have attracted much attention, because they can be easily handled and are widely distributed around the world [15,16]. In particular, ethanol has been utilized as a promising hydrogen source because of its low toxicity, high volumetric energy density, and availability [17]. Although noble metals are highly active in the auto- thermal reforming reactions, nickel-based catalysts have also been widely used in the reforming processes due to their high intrinsic activity and low cost [18,19]. However, nickel-based catalysts require a high reaction temperature and an excess amount of steam to prevent the carbon deposition and nickel sintering [20–22]. Such severe reaction conditions are not favorable for on-board hydrogen production. Therefore, * Corresponding author. Tel.: þ82 2 880 9227; fax: þ82 2 889 7415. E-mail address: inksong@snu.ac.kr (I.K. Song). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he 0360-3199/$ – see front matter ª 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2009.05.051 international journal of hydrogen energy 34 (2009) 5390–5397