TY  - JOUR
T1  - A DFT Study of Hydrogen Adsorption Kinetics and Thermodynamics on Mixed
Oxides of Mg<sub>0.5</sub> Ni<sub>0.25</sub> O<sub>1.13</sub>
AU - Sufian, Suriati AU - Salam, M. Abdus 
JO  - Journal of Engineering and Applied Sciences
VL  - 12
IS  - 17
SP  - 4431
EP  - 4436
PY  - 2017
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2017.4431.4436
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2017.4431.4436
KW  - DFT
KW  -kinetic
KW  -thermodynamics
KW  -adsorption
KW  -Hydrogen
KW  -indicating
AB  - Hydrogen sorption mechanism, kinetics and thermodynamics of hydrotalcite derived mixed oxides of Mg<sub>0.5</sub> Ni<sub>0.25</sub> O<sub>1.13</sub> have been studied using the density functional theory. Hydrotalcite based magnesium 0.5 0.25 0.25 1.13
and nickel and aluminum containing mixed oxides showed significant hydrogen sorption kinetics and
thermodynamics. Reduced mixed oxides or active metals of Magnesium (Mg) and Nickel (Ni) converted to
hydrides of MgH<sub>2</sub> and Mg<sub>2</sub> NiH<sub>4</sub>. The study indicated the favorable hydrides formation which is due to the 
electrostatic interaction and strong hydrogen bonding type interaction between them. The materials itself
facilitate to diffuse hydrogen molecules to different layers of the materials and enhances the sorption kinetics.
Hydrogen adsorption and desorption energy of MgH<sub>2</sub> and Mg<sub>2</sub> NiH<sub>4</sub> are 60.13, 64.31, 40.22 and 45.72 kJ/mol, 
respectively. Model predicted values of hydrogen adsorption enthalpy and entropy changes of MgH<sub>2</sub> and Mg<sub>2</sub> NiH<sub>4</sub> are -48.18 Kj/mol, -135j/mol.K, -55.10 Kj/mol and -155 J/mol.K, respectively. The rate constant of adsorption are 6.0&times;10<sup>12</sup> and 1.3&times;10<sup>13</sup> sec<sup>&#150;1</sup> for MgH<sub>2</sub> and Mg<sub>2</sub> NiH<sub>4</sub> hose are indicating physical and chemical adsorption 
of hydrogen.
ER  -