Enhancement of the Hydrogen Uptake and Release Rates of Mg by the Addition of TaF5 and VCl3 with Reactive Mechanical Grinding

2018 ◽  
Vol 10 (5) ◽  
pp. 772-778 ◽  
Author(s):  
Young Jun Kwak ◽  
Myoung Youp Song
Keyword(s):  
Hydrogen Uptake ◽  
Mechanical Grinding ◽  
Release Rates ◽  
Uptake And Release

scholarly journals Effects of Milling in Hydrogen on Magnesium Hydride with a Hydride-Forming Titanium Additive

2021 ◽  
pp. X
Author(s):  
Myoung Youp SONG ◽  
Eunho CHOI
Keyword(s):  
Storage Capacity ◽  
Hydrogen Uptake ◽  
Shear Stresses ◽  
Mechanical Grinding ◽  
Hydrogen Storage Capacity ◽  
Release Rates ◽  
Cycle Number ◽  
Milling In Hydrogen ◽  
Effective Hydrogen ◽  
Uptake And Release

A hydride-forming element titanium (Ti) was selected as an additive to improve the hydrogen uptake and release properties of MgH2. The hydrogen uptake and release properties of three Ti-added MgH2 alloys [named MgH2-xTi (x = 6, 12, and 15)] prepared by milling in hydrogen (reactive mechanical grinding) were investigated and those of MgH2-12Ti were studied in more detail because it had the highest initial hydrogen uptake and release rates and the largest quantities of hydrogen absorbed and released for 60 min. At the cycle number, n, of one (n = 1), MgH2-12Ti absorbed 4.01 wt.% H for 2.5 min and 6.39 wt.% H for 60 min at 573 K in 12 bar H2, having an effective hydrogen storage capacity of 6.39 wt.%. MgH2-12Ti released 0.44 wt.% H for 2.5 min and 1.86 wt.% H for 60 min at 593 K in 1.0 bar H2. γ-MgH2, TiH1.924, and MgO were formed during reactive mechanical grinding. We believe that the brute forces and tensile, compressive, or shear stresses, which are applied to the materials during reactive mechanical grinding, introduce imperfections, fabricate cracks, expose fresh and clean surfaces, decrease the particle size, and disperse the additive among the particles. The γ-MgH2, TiH1.924, and MgO formed during reactive mechanical grinding and their pulverization during reactive mechanical grinding are believed to make these effects stronger.

Study on reversible hydrogen uptake and release of 1,2-dimethylindole as a new liquid organic hydrogen carrier

2019 ◽  
Vol 44 (10) ◽  
pp. 4919-4929 ◽  
Author(s):  
Yuan Dong ◽  
Ming Yang ◽  
Linlin Li ◽  
Ting Zhu ◽  
Xuedi Chen ◽  
...  
Keyword(s):  
Hydrogen Uptake ◽  
Hydrogen Carrier ◽  
Uptake And Release

Amelioration of Hydrogen Uptake and Release Features of Magnesium Adding a Polymer Polyvinylidene Fluoride via Milling in Hydrogen in a Planetary Ball Mill

2020 ◽  
Vol 20 (11) ◽  
pp. 7105-7113
Author(s):  
Young Jun Kwak ◽  
Myoung Youp Song
Keyword(s):  
Ball Milling ◽  
Ball Mill ◽  
Polyvinylidene Fluoride ◽  
Hydrogen Uptake ◽  
Hydrogen Atmosphere ◽  
Hydrogen Release ◽  
Planetary Ball Mill ◽  
Planetary Ball Milling ◽  
Milling In Hydrogen ◽  
Uptake And Release

In the present study, a polymer polyvinylidene fluoride (PVDF) was chosen as an adding material to ameliorate hydrogen uptake and release features of Mg. Samples with a composition of 95 wt.% Mg+5 wt.% PVDF (called 95Mg + 5PVDF) were made via milling in hydrogen atmosphere in a planetary ball mill (reactive planetary ball milling). The hydrogen release reaction of magnesium hydride formed in the as-prepared 95Mg+5PVDF during reactive planetary ball milling started at 681 K. In the third cycle (CN = 3), the amount of hydrogen absorbed for 60 min, A (60 min), was 3.44 wt.% hydrogen at 573 K in 12 bar hydrogen. The PVDF is believed to have melted during reactive planetary ball milling, and the sliding or lubrication between Mg particles and hardened steel balls was avoided, leading to a good contact between them and a highly effective milling. The milling in hydrogen atmosphere in a planetary ball mill of Mg with PVDF is believed to have generated defects and cracks. The Mg2C3 produced from PVDF during hydrogen uptake-release cycling is believed to have been spread among particles and to have kept particles from coalescing. To the best of our knowledge, this is the first study to use a polymer PVDF as an additive material for the amelioration of hydrogen uptake and release features of Mg.

scholarly journals Carbon Nanomaterials as Catalysts for Hydrogen Uptake and Release in NaAlH4

Nano Letters ◽  
2009 ◽  
Vol 9 (4) ◽  
pp. 1501-1505 ◽  
Author(s):  
Polly A. Berseth ◽  
Andrew G. Harter ◽  
Ragaiy Zidan ◽  
Andreas Blomqvist ◽  
C. Moysés Araújo ◽  
...  
Keyword(s):  
Carbon Nanomaterials ◽  
Hydrogen Uptake ◽  
Uptake And Release
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