Catalytic evaluation of nickel nanoparticles in methane steam reforming Sardar Ali a,* , Mohammed J. Almarri a , Ahmed G. Abdelmoneim a , Anand Kumar b , Mahmoud M. Khader a a Gas Processing Centre, College of Engineering, Qatar University, 2713 Doha, Qatar b Department of Chemical Engineering, College of Engineering, Qatar University, 2713 Doha, Qatar article info Article history: Received 30 June 2016 Received in revised form 26 August 2016 Accepted 27 August 2016 Available online xxx Keywords: Methane steam reforming Hydrogen production Ni nanoparticles Coke deposition abstract Development of a highly efficient and coke-resistant, nickel nanoparticles (Ni.NPs) based catalyst in the steam reformation reaction of methane is reported. The catalyst was pre- pared by dispersing Ni-nanoparticles over silica functionalized alumina support. The synthesized samples were characterized by a combination of analytical techniques of X- ray diffraction (XRD), nitrogen physisorption (BET surface area), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (H 2 -TPR) and temperature pro- grammed oxidation (TPO). Characterization results revealed that functionalization of alumina resulted in improved physicochemical properties of Ni-nanoparticles catalyst compared to the con- ventional nickel based catalysts. More importantly, a clear improvement on the catalytic hydrogen production and resistance to coke was observed. At all temperature studied Ni.NPs catalyst exhibited high methane conversions which reached to 100% at 750  C. Also, the Ni.NPs catalysts exhibited high H 2 selectivity and excellent thermal stability. The functionalization of alumina with silica improved the dispersion of Ni nano- particles and prevented sintering and aggregation. Ni.NPs catalyst exhibited stable cata- lytic activities for a period of 48 h where no carbon deposition was evidenced neither by TPO nor XPS techniques. Contrary to Ni.NPs the conventional nickel catalyst suffered from severe deactivation due to deposition of filamentous carbon on the surface. © 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Steam reforming of methane is a well-established industrial catalytic process which deals with the conversion of natural gas into synthesis gas (syngas) or hydrogen which are subse- quently transformed into higher value chemicals [1,2]. Methane steam reforming process is a first step in converting natural gas into syngas which can subsequently be converted to various valuable products such as petroleum, diesel, methanol and ammonia [3,4]. Moreover steam reforming processes also are the main source of hydrogen and hence important in emerging hydrogen economy [5e7]. As shown in equations (1)e(3), steam reforming of methane consists of two reversible chemical reactions 1 and 2. Reactions 1 is strongly endothermic reaction whereas 2, the water gas shift reaction (WGS) is moderately exothermic [8e10]. The overall product of the reaction consists of a mixture of carbon monoxide, carbon * Corresponding author. Fax: þ974 4403 4371. E-mail address: ali.sardar@qu.edu.qa (S. Ali). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2016) 1 e10 http://dx.doi.org/10.1016/j.ijhydene.2016.08.200 0360-3199/© 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Ali S, et al., Catalytic evaluation of nickel nanoparticles in methane steam reforming, International Journal of Hydrogen Energy (2016), http://dx.doi.org/10.1016/j.ijhydene.2016.08.200