HYDROGEN ADSORPTION OF NANOSTRUCTURED HYDROTALCITE BASED MIXED OXIDES ADSORBENT

• Main Author: MD., ABDUS SALAM
• Format: Thesis
• Language: English
• Published: 2014
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/id/eprint/22466/1/2013%20-CHEMICAL%20-%20HYDROGEN%20ADSORPTION%20OF%20NANOSTRUCTURED%20HYDROTALCITE%20BASED%20MIXED%20OXIDES%20ADSORBENT%20-%20MD.%20ABDUS%20SALAM.pdf; http://utpedia.utp.edu.my/id/eprint/22466/

The research work in this thesis focuses on the reversible hydrogen adsorption using Mg, Ni and Al containing hydrotalcite based adsorbents. Different techniques were applied to form the reversible intermetallic hydride from hydrotalcite based adsorbents for enhancing hydrogen sorption capacity and to get the favorable hydrogen adsorption thermodynamics and kinetics. The nano-structured adsorbents have been synthesized vm the coprecipitation method under variable pH (7-ll) and low supersaturation method. The adsorbents were characterized to find the optimum metal composition and to determine the physical and chemical properties such as crystallinity, surface morphology, surface energy, metals distribution and interactions. The source material and converted mixed oxides adsorbents phases and crystallinity were confirmed by X-ray diffraction (XRD) technique. The specific BET surface area of synthesized adsorbents of Mg(Ni,Al)O are in a range of 110 to 325 m2/g with narrow pore size distribution (PSD) in a range of 5-15 nrn and pore volume of0.86-1.09 cm3/g. Inductive couple plasma mass spectrometry (ICP-MS) analyses ensured the homogenous metals distribution of adsorbents. Hexagonal plate-like and flower-like morphology of the adsorbents were found through field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) analyses and selected area diffraction pattern (SAED) of Mg(Ni,Al)O demonstrated that the adsorbent were poly-crystalline with the crystallite size range of 12-22 nm. Temperature programmed reduction (TPR) analyses revealed the order of interaction between metals and reduction temperature of different oxides phases.