%0 Journal Article
%T Hydrogen Storage of a Fixed Bed of Nanocrystalline Mixed Oxides
%A M. Abdus Salam
%A Suriati Sufian
%A Ye Lwin
%A T. Murugesan
%J ISRN Nanomaterials
%D 2013
%R 10.1155/2013/539534
%X Nanocrystalline hydrotalcite derived mixed oxides containing magnesium, cobalt, and aluminum (MCAM) (M(1£¿x)AlxO(1+x/2); M£¿=£¿Mg or Co/Mg and Co and x£¿=£¿molar ratios) have been synthesized successfully and showed reversible hydrogen storage capacity at near ambient condition using fixed bed. ICP-MS and XRD analysis confirmed the adsorbent phases and their homogeneity. Adsorbent morphology and textural properties have been characterized using FESEM, BET and TEM analysis techniques. Nano-crystalline and porous mixed oxides exhibited 3£¿wt% H2 storage capacity and desorbed 57% of adsorbed H2. Spillover phenomena are observed through FTIR analysis. Adsorption enthalpy ( ) and entropy ( ) change were £¿25.58£¿kJ/mol and £¿59.98£¿J/mol¡¤K, respectively, which implied a prospective feature of reversible hydrogen adsorption on nano-crystalline mixed oxide. 1. Introduction Nanocrystalline particles are believed to enhance hydrogen storage and release kinetics without any catalyst [1, 2]. Nanoparticles often show different behavior compared to bulk particles and are applied, for instance, in catalysis [3, 4]. The structure and properties of hydrogen storage nanomaterials have been studied extensively over the last 10 years that can be summarized from few reviews [5¨C8]. Hydrogen is a potential source to store and transport as energy carrier. The outcome of the process has zero emission except water thus, it is considered environment friendly. Several ways of H2 storage have been investigated such as high pressure gas, liquid hydrogen, and adsorption on porous materials, complex hydrides, and hydrogen intercalation in metals. None of these technologies satisfy all the criteria for effective hydrogen storage. It is believed that adsorption at near-ambient conditions on porous media with weak Van der Waals interaction can fulfill the criteria that have been set by the U.S. Department of Energy (DOE) [9, 10]. Nanocrystalline mixed oxides have gained considerable attention in being designed as adsorbent due to their wide variety of chemical compositions [11, 12] and their textural and surface morphology that can be tuned. A Nanocrystalline sorbent might be a potential hydrogen storage material due to its physisorption capacity of H2 in a molecular form [13]. Mixed oxides with a higher surface area and favorable pore volume can adsorb hydrogen efficiently in different ways [14, 15]. Mixed oxides have been reported as a good adsorbent for carbon dioxide (CO2) [16], nitrogen oxide (NO), and sulfur oxide [17, 18] gas. In the gas phase, hydrogen readily attaches to other molecules
%U http://www.hindawi.com/journals/isrn.nanomaterials/2013/539534/