Superior hydrogen desorption kinetics of Mg(NH2)2 hollow nanospheres mixed with MgH2 nanoparticles

2008 ◽  
Vol 92 (23) ◽  
pp. 231910 ◽  
Author(s):  
Lei Xie ◽  
Yaoqi Li ◽  
Rong Yang ◽  
Yang Liu ◽  
Xingguo Li
Keyword(s):  
Hydrogen Desorption ◽  
Desorption Kinetics ◽  
Hollow Nanospheres ◽  
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.

Investigation of surface and near-surface effects on hydrogen desorption kinetics of MgH2

2014 ◽  
Vol 39 (2) ◽  
pp. 862-867 ◽  
Author(s):  
Sandra Kurko ◽  
Igor Milanović ◽  
Jasmina Grbović Novaković ◽  
Nenad Ivanović ◽  
Nikola Novaković
Keyword(s):  
Surface Effects ◽  
Hydrogen Desorption ◽  
Desorption Kinetics ◽  
Near Surface ◽  
Kinetics Of

scholarly journals Hydrogen desorption kinetics of MgH2 synthesized from modified waste magnesium

2014 ◽  
Vol 32 (3) ◽  
pp. 385-390
Author(s):  
Aysel Kantürk Figen ◽  
Bilge Coşkuner ◽  
Sabriye Pişkin
Keyword(s):  
Hydrogen Desorption ◽  
Nitrogen Atmosphere ◽  
Desorption Kinetics ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrf Scanning ◽  
Isothermal Kinetic ◽  
Kinetics Of

AbstractIn the present study, hydrogen desorption properties of magnesium hydride (MgH2) synthesized from modified waste magnesium chips (WMC) were investigated. MgH2 was synthesized by hydrogenation of modified waste magnesium at 320 °C for 90 min under a pressure of 6 × 106 Pa. The modified waste magnesium was prepared by mixing waste magnesium with tetrahydrofuran (THF) and NaCl additions, applying mechanical milling. Next, it was investigated by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) techniques in order to characterize its structural properties. Hydrogen desorption properties were determined by differential scanning calorimetry (DSC) under nitrogen atmosphere at different heating rates (5, 10, and 15 °C/min). Doyle and Kissenger non-isothermal kinetic models were applied to calculate energy (Ea) values, which were found equal to 254.68 kJ/mol and 255.88 kJ/mol, respectively.

Hydriding and Dehydriding Characteristics of As-Spun Nanocrystalline and Amorphous Mg20Ni10-xMnx (x = 0-4) Alloys

2011 ◽  
Vol 347-353 ◽  
pp. 3420-3424
Author(s):  
Yang Huan Zhang ◽  
Xiao Gang Liu ◽  
Le Le Chen ◽  
Hui Ping Ren ◽  
Guo Fang Zhang ◽  
...  
Keyword(s):  
Amorphous Phase ◽  
Hydrogen Absorption ◽  
Melt Spinning ◽  
Hydrogen Desorption ◽  
Absorption Capacity ◽  
Desorption Kinetics ◽  
Nanocrystalline And Amorphous ◽  
Cast Alloys ◽  
Mn Content ◽  
Kinetics Of

The nanocrystalline and amorphous Mg2Ni-type Mg20Ni10-xMnx (x = 0, 1, 2, 3, 4) alloys were synthesized by melt-spinning technique. The structures of the as-cast and spun alloys were characterized by XRD, SEM and HRTEM. The hydrogen absorption and desorption kinetics of the alloys were measured. The results show that the substitution of Mn for Ni, instead of changing the major phase Mg2Ni, leads to the formation of Mg and MnNi phases. No amorphous phase is detected in the as-spun Mn-free alloy, but the as-spun alloys substituted by Mn display the presence of an amorphous phase, suggesting that the substitution of Mn for Ni enhances the glass forming ability of the Mg2Ni-type alloy. The hydrogen absorption capacity of the as-cast alloys first increases and then decreases with the variation of the amount of Mn substitution. The hydrogen desorption capacity of the alloys markedly increases with growing Mn content.

Hydrogen desorption kinetics of amorphous Mg0.9Ti0.1Ni1−xPdx (x=0, 0.05, 0.1 and 0.15) electrode alloys

2006 ◽  
Vol 16 (4) ◽  
pp. 747-752 ◽  
Author(s):  
Qi-feng TIAN ◽  
Yao ZHANG ◽  
Zhi-cheng TAN ◽  
Fen XU ◽  
Li-xian SUN ◽  
...  
Keyword(s):  
Hydrogen Desorption ◽  
Desorption Kinetics ◽  
Kinetics Of

Effect of hydrogen content on hydrogen desorption kinetics of titanium hydride

2017 ◽  
Vol 709 ◽  
pp. 445-452 ◽  
Author(s):  
Mingwang Ma ◽  
Lei Wang ◽  
Yuan Wang ◽  
Wei Xiang ◽  
Ping Lyu ◽  
...  
Keyword(s):  
Hydrogen Content ◽  
Titanium Hydride ◽  
Hydrogen Desorption ◽  
Desorption Kinetics ◽  
Kinetics Of

Non-isothermal and isothermal hydrogen desorption kinetics of zirconium hydride

2015 ◽  
Vol 467 ◽  
pp. 349-356 ◽  
Author(s):  
Mingwang Ma ◽  
Wei Xiang ◽  
Binghua Tang ◽  
Li Liang ◽  
Lei Wang ◽  
...  
Keyword(s):  
Hydrogen Desorption ◽  
Zirconium Hydride ◽  
Desorption Kinetics ◽  
Kinetics Of

Hydriding and Dehydriding Kinetics of Nanocrystalline and Amorphous Mg20Ni10-xMx (M=Cu, Mn; x = 0-4) Alloys Prepared by Melt Spinning

2012 ◽  
Vol 534 ◽  
pp. 164-168
Author(s):  
Yang Huan Zhang ◽  
Chen Zhao ◽  
Ying Cai ◽  
Hui Ping Ren ◽  
Bao Wei Li ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Nanocrystalline Structure ◽  
Hydrogen Desorption ◽  
Amorphous Structure ◽  
Partial Substitution ◽  
Desorption Kinetics ◽  
Secondary Phases ◽  
Cu Alloy ◽  
Nanocrystalline And Amorphous ◽  
Kinetics Of

The partial substitution of M (M=Cu, Mn) for Ni has been performed in order to ameliorate the hydriding and dehydriding kinetics of Mg2Ni-type hydrogen storage alloys. The melt spinning technology was used to prepare the Mg20Ni10-xMx (M=Cu, Mn; x=0, 1, 2, 3, 4) alloys. The structures of the as-spun alloys were characterized by XRD and TEM. The hydriding and dehydriding kinetics of the alloys were measured by an automatically controlled Sieverts apparatus. The results show that the as-spun (M=Cu) alloys hold a typical nanocrystalline structure, whereas the as-spun (M=Mn) alloys display a nanocrystalline and amorphous structure, confirming that the substitution of Mn for Ni facilitates the glass formation in the Mg2Ni-type alloy. Furthermore, Mn substitution results in the formation of the secondary phases MnNi and Mg instead of changing the major phase of Mg2Ni. The substitution of M (M=Cu, Mn) for Ni exerts an insignificant effect on the hydriding kinetics, but it ameliorates the hydrogen desorption kinetics of the alloys dramatically. The hydrogen desorption ratio ( ) is enhanced form 20.84% to 52.88% for the (M=Cu) alloy spun at 20 m/s, and from 20.84% to 53.87% for the (M=Mn) alloy spun at 20 m/s by increasing the M (M=Cu, Mn) content from 0 to 4.

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