International Journal of Hydrogen Energy, Vol.39, No.10, 4909-4916, 2014
Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous nickel-phosphorus-alumina aerogel catalyst
A mesoporous nickel phosphorus alumina aerogel catalyst (NPAA) was prepared by a single-step epoxide-driven sal gel method and a subsequent supercritical CO2 drying method for use in the hydrogen production by steam reforming of liquefied natural gas (LNG). In order to investigate the effect of drying method of nickel phosphorus alumina catalysts on their physicochemical properties and catalytic activities, a mesoporous nickel phosphorus alumina xerogel catalyst (NPAX) was also prepared by a single-step epoxide-driven sal gel method and a subsequent evaporative drying method for comparison purpose. It was found that supercritical CO2 drying method was effective for enhancing textural properties of NPAA catalyst. Although both NPAX and NPAA catalysts retained surface nickel aluminate phase, NPAA catalyst showed stronger metal-support interaction than NPAX catalyst. XRD patterns of reduced NPAX and NPAA catalysts revealed that NPAA catalyst retained smaller metallic nickel crystallite than NPAX catalysts. It was also observed that the reduced NPAA catalyst exhibited high nickel dispersion, large amount of strong hydrogen-binding sites, and large amount of methane adsorption compared to the reduced NPAX catalyst. In the steam reforming of LNG, NPAA catalyst with high affinity toward methane showed a better catalytic performance than NPAX catalyst. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Hydrogen production;Steam reforming of LNG;Nickel-phosphorus-alumina catalyst;Epoxide-driven sol-gel method;Supercritical CO2 drying