scholarly journals Contamination Effects on Improving the Hydrogenation/Dehydrogenation Kinetics of Binary Magnesium Hydride/Titanium Carbide Systems Prepared by Reactive Ball Milling

Materials ◽  
2015 ◽  
Vol 8 (10) ◽  
pp. 6880-6892 ◽  
Author(s):  
M. Sherif El-Eskandarany ◽  
Ehab Shaban
Keyword(s):  
Titanium Carbide ◽  
Ball Milling ◽  
Magnesium Hydride ◽  
Dehydrogenation Kinetics ◽  
Hydride Titanium ◽  
Kinetics Of ◽  
Contamination Effects

scholarly journals Effect of ZrC Nanopowders on Enhancing the Hydro/Dehydrogenation Kinetics of MgH2 Powders

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4962
Author(s):  
Mohamed Sherif El-Eskandarany ◽  
Naser Ali ◽  
Fahad Al-Ajmi ◽  
Mohammad Banyan
Keyword(s):  
Hydrogen Storage ◽  
Ball Milling ◽  
Fine Particles ◽  
High Energy ◽  
Green Energy ◽  
Grain Structure ◽  
Micro Milling ◽  
Dehydrogenation Kinetics ◽  
Energy Ball ◽  
Kinetics Of

Hydrogen has been receiving great attention as an energy carrier for potential green energy applications. Hydrogen storage is one of the most crucial factors controlling the hydrogen economy and its future applications. Amongst the several options of hydrogen storage, light metal hydrides, particularly nanocrystalline magnesium hydride (MgH2), possess attractive properties, making them desired hydrogen storage materials. The present study aimed to improve the hydrogen storage properties of MgH2 upon doping with different concentrations of zirconium carbide (ZrC) nanopowders. Both MgH2 and ZrC were prepared using reactive ball milling and high-energy ball milling techniques, respectively. The as-prepared MgH2 powder was doped with ZrC (2, 5, and 7 wt%) and then high-energy-ball-milled for 25 h. During the ball milling process, ZrC powders acted as micro-milling media to reduce the MgH2 particle size to a minimal value that could not be obtained without ZrC. The as-milled nanocomposite MgH2/ZrC powders consisted of fine particles (~0.25 μm) with a nanosized grain structure of less than 7 nm. Besides, the ZrC agent led to the lowering of the decomposition temperature of MgH2 to 287 °C and the reduction in its apparent activation energy of desorption to 69 kJ/mol. Moreover, the hydrogenation/dehydrogenation kinetics of the nanocomposite MgH2/ZrC system revealed a significant improvement, as indicated by the low temperature and short time required to achieve successful uptake and release processes. This system possessed a high capability to tackle a long continuous cycle lifetime (1400 h) at low temperatures (225 °C) without showing serious degradation in its storage capacity.

Hydriding Properties of MgH2-Mg2Ni0.8Co0.2 Composites Obtained by Ball Milling

2007 ◽  
Vol 62 (7) ◽  
pp. 915-921 ◽  
Author(s):  
Tsveta Mandzhukova ◽  
Jean-Louis Bobet ◽  
Maria Khrussanova ◽  
Pavel Peshev
Keyword(s):  
Mechanical Activation ◽  
Ball Milling ◽  
Hydrogen Absorption ◽  
Catalytic Effect ◽  
Magnesium Hydride ◽  
Absorption Capacity ◽  
Favorable Effect ◽  
Inert Medium ◽  
Kinetics Of ◽  
Hydriding Kinetics

Abstract The hydrogen absorption-desorption characteristics of composites consisting of 90 wt.% MgH2- 10 wt.% Mg2Ni0.8Co0.2 prepared by ball milling for 30 and 180 min under argon have been investigated. The results obtained have been compared with those for the 90 wt.% Mg-10 wt.% Mg2Ni0.8Co0.2 composite synthesized in the same medium after 30 min of milling. The presence of the Mg2Ni0.8Co0.2 phase has been found to improve the hydriding kinetics of magnesium, the absorption capacity remaining high at temperatures below 573 K. The use of magnesium hydride instead of magnesium has proved to have a favorable effect on the properties of the composites after prolonged activation in an inert medium. It has been established that the absorption-desorption characteristics of the composite 90 wt.% MgH2-10 wt.% Mg2Ni0.8Co0.2 activated mechanically for 180 min are comparable with those of the composite 90 wt.% Mg-10 wt.% Mg2Ni0.8Co0.2 after mechanical activation for only 30 min. The favorable absorption-desorption characteristics of the composites have been explained with the catalytic effect of the additive, the presence of magnesium hydride and the duration of ball milling.

Dehydrogenation kinetics of magnesium hydride investigated by DFT and experiment

2010 ◽  
Vol 49 (1) ◽  
pp. S144-S149 ◽  
Author(s):  
Guangxin Wu ◽  
Jieyu Zhang ◽  
Qian Li ◽  
Yongquan Wu ◽  
Kuochih Chou ◽  
...  
Keyword(s):  
Magnesium Hydride ◽  
Dehydrogenation Kinetics ◽  
Kinetics Of

scholarly journals Improvement of Hydrogen Desorption Characteristics of MgH2 With Core-shell Ni@C Composites

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3113 ◽  
Author(s):  
Cuihua An ◽  
Qibo Deng
Keyword(s):  
Low Cost ◽  
Hydrogen Desorption ◽  
Core Shell ◽  
Desorption Kinetics ◽  
Hydrogen Storage Materials ◽  
High Hydrogen ◽  
Dehydrogenation Kinetics ◽  
Materials Research ◽  
High Theoretical Capacity ◽  
Kinetics Of

Magnesium hydride (MgH2) has become popular to study in hydrogen storage materials research due to its high theoretical capacity and low cost. However, the high hydrogen desorption temperature and enthalpy as well as the depressed kinetics, have severely blocked its actual utilizations. Hence, our work introduced Ni@C materials with a core-shell structure to synthesize MgH2-x wt.% Ni@C composites for improving the hydrogen desorption characteristics. The influences of the Ni@C addition on the hydrogen desorption performances and micro-structure of MgH2 have been well investigated. The addition of Ni@C can effectively improve the dehydrogenation kinetics. It is interesting found that: i) the hydrogen desorption kinetics of MgH2 were enhanced with the increased Ni@C additive amount; and ii) the dehydrogenation amount decreased with a rather larger Ni@C additive amount. The additive amount of 4 wt.% Ni@C has been chosen in this study for a balance of kinetics and amount. The MgH2-4 wt.% Ni@C composites release 5.9 wt.% of hydrogen in 5 min and 6.6 wt.% of hydrogen in 20 min. It reflects that the enhanced hydrogen desorption is much faster than the pure MgH2 materials (0.3 wt.% hydrogen in 20 min). More significantly, the activation energy (EA) of the MgH2-4 wt.% Ni@C composites is 112 kJ mol−1, implying excellent dehydrogenation kinetics.

Hydrogen sorption kinetics of magnesium hydride enhanced by the addition of Zr 8 Ni 21 alloy

2012 ◽  
Vol 530 ◽  
pp. 111-115 ◽  
Author(s):  
S.A. Pighin ◽  
G. Capurso ◽  
S. Lo Russo ◽  
H.A. Peretti
Keyword(s):  
Sorption Kinetics ◽  
Magnesium Hydride ◽  
Hydrogen Sorption ◽  
Kinetics Of
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