Stability, durability, and reusability studies on transition metal-doped CoeB alloy catalysts for hydrogen production R. Fernandes a, *, N. Patel a , A. Miotello a , R. Jaiswal c , D.C. Kothari b,c a Dipartimento di Fisica, Universita ` degli Studi di Trento, Via Sommarive, 14, I-38123 Povo, Trento, Italy b Department of Physics, University of Mumbai, Vidyanagari, Santacruz, Mumbai 400 098, India c National Centre for Nanomaterials and Nanotechnology, University of Mumbai, Vidyanagari, Santacruz, Mumbai 400 098, India article info Article history: Received 7 June 2011 Received in revised form 28 July 2011 Accepted 8 August 2011 Available online 1 September 2011 Keywords: H 2 generation Sodium borohydride Doped CoeB catalyst Stability Reusability Durability abstract In addition to high catalytic efficiency the catalyst must also comprise important features like high stability in severe conditions, ability to be recycled several times and should have high tolerance against deactivation. This work is oriented specifically to study these properties of already developed efficient transition-metal doped CoeB alloy catalyst. Various transition metals, namely Ni, Fe, Cu, Cr, Mo, and W, were singly added as dopants in CoeB catalyst by chemical reduction of the corresponding metal salts. These alloy catalysts were calcinated, in Ar atmosphere, at 673, 773, and 873 K in order to investigate the stability of the powders at elevated temperatures. The catalytic performances of these treated catalyst powders were tested for H 2 generation by catalytic hydrolysis of sodium borohydride (NaBH 4 ). The alloy powders were exposed to ambient condition for several days to test their tolerance against deactivation and self life. After separation from the reaction course and after rinsing, the catalyst powders were tested for several cycles to evaluate the reusability property. The observed changes in the catalytic activity were discussed on the basis of structural and morphological variations. The CoeB catalyst, when doped with Ni, Mo, and W metals showed high stability and resistance against deteriora- tion, as function of both time and use, as compared to Cr- and Fe-doped alloy powders. A much lower performance with respect to calcination temperature, holding time, and number of cycles was established for Cu doped CoeB catalyst powder. Copyright ª 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 1. Introduction Industrial appliances based on hydrogen powered fuel-cell technology are currently hindered by the requirement of efficient hydrogen storage and production medium with proper safety measures. Due to high hydrogen storage capa- bility of 10.8 wt. %, Sodium Borohydride (NaBH 4 ) appears among the most promising sources to supply pure hydrogen to fuel cell at room temperature [1]. In addition, alkaline solution of NaBH 4 is quite stable, non-flammable and non- toxic in nature and can produce H 2 on demand in presence of appropriate catalyst under ambient condition [2]. For the commercial success of NaBH 4 based hydrogen generation system, the cost of NaBH 4 must be substantially reduced. Recycling of sodium borate reaction product back to NaBH 4 starting material is presently being studied [3]. If this method will be successful, then NaBH 4 solutions could become a cost effective carrier of H 2 gas. * Corresponding author. Tel.: þ39 0461882012; fax: þ39 0461881696. E-mail address: fernandes@science.unitn.it (R. Fernandes). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 36 (2011) 13379 e13391 0360-3199/$ e see front matter Copyright ª 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2011.08.021