M. Abdus Salam

Hydrogen Storage of a Fixed Bed of Nanocrystalline Mixed Oxides

Nanocrystalline hydrotalcite derived mixed oxides containing magnesium, cobalt, and aluminum (MCAM) (M(1−x)AlxO(1

Synthesis of Nano-Structured Ni-Co-Al Hydrotalcites and Derived Mixed Oxides

nanostructured hydrotalcite-like compounds that contain nickel, cobalt and aluminum have been synthesized by conventional coprecipitation method without using any surfactants or templating agents. The structure and morphology of the coprecipitated nanohydrotalcites and its derived mixed oxides were characterized by powder X-ray diffraction (XRD), Fourier-transformed Infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption techniques. The results show that the synthesized materials exhibited micro-meso-pore networks. The cobalt-rich calcined hydrotalcites are generally amorphous, having a coral-like morphology whereas nickel-rich hydrotalcites show hexagonal plate-like morphology. The presence of nickel in mixed oxides catalyzed the reduction of Co-Al-O spinels. The Fast Fourier Transform (FFT) analysis of HRTEM revealed the inter planner distances of the crystal of hydrotalcite.

Hydrogen Adsorption Capacity Investigation of Ni-Co-Al Mixed Oxides

Micro-mesoporous mixed oxides containing nickel, cobalt and aluminum have been synthesized using conventional coprecipitation method. FESEM and HRTEM analyses demonstrated the flower and hexagonal plate-like nanostructured of mixed oxides. Different mixed oxide formation, homogenous metal dispersion, textural properties were investigated using XRD, ICP-MS and BET (N2 adsorption-desorption) techniques. nanostructured mixed oxides exhibited 2.6 wt% hydrogen adsorption that were studied using temperature programmed reduction-adsorption-desorption (H2-TPR/TPD) and thermogravimetric and differential thermal analysis (TGA-DTA) techniques. Investigation corresponds that morphologies, textural properties and surface energy of mixed oxides are important in hydrogen adsorption.

Hydrogenated microstructure and its hydrogenation properties: a density functional theory study

The relationship between microstructure and hydrogenation properties of the mixed metals has been investigated via different spectroscopic techniques and the density functional theory (DFT). FESEM and TEM analyses demonstrated the nano-grains of Mg2NiH4 and MgH2 on the hydrogenated microstructure of the adsorbents that were confirmed by using XPS analysis technique. SAED pattern of hydrogenated metals attributed the polycrystalline nature of mixed metals and ensured the hydrogenation to Mg2NiH4 and MgH2 compounds. Flower-like rough surface of mixed metals showed high hydrogenation capacity. The density functional theory (DFT) predicted hydrogenation properties; enthalpy and entropy changes of hydrogenated microstructure of MgH2 and Mg2NiH4 are -62.90 kJ/mol, -158 J/molċK and -52.78 kJ/mol, -166 J/molċK, respectively. The investigation corresponds to the hydrogen adsorption feasibility, reversible range hydrogenation thermodynamics, and hydrogen desorption energy of 54.72 kJ/mol. DFT predicted IR band for MgH2 and Mg2NiH4 attributed hydrogen saturation on metal surfaces.

Synthesis and Characterization of Nano-Structured Mixed Oxides

Nano-structured hydrotalcite based mixed oxides have been synthesized using coprecipitation method under variable pH and low supersaturation condition. XRD technique has been used to confirm the hydrotalcite structure and its derived different phase of mixed oxides. The metal dispersion of mixed oxides was analyzed using ICP-MS. The nanostructures of the mixed oxides have been investigated using FESEM and HRTEM. The textural properties of mixed oxides were analyzed using N2 adsorption-desorption (BET) technique. The Characterizations have revealed that the developed mixed oxides were consisted with hexagonal/rhombohedral well dispersed nano-particles. Polycrystalline mixed oxides formed mesopore surface and narrower pore size distribution.

Stress Analysis of Engineering Products Using the Adventure System – Finite Element Software

Removed at authors request