Measurements of the diffusion of hydrogen atoms in magnesium and Mg2Ni by neutron scattering

Töpler, J.; Büchner, Helmut; Säufferer, H.; Knorr, K.; Prandl, W.

doi:10.1016/0022-5088(82)90248-x

Cited by 100 publications

(44 citation statements)

References 12 publications

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“…MgH 2 is one of the most attractive hydrides for application as a solid state hydrogen storage material. However, its slow kinetics, due to the low hydrogen diffusion rate 3,4 and also due to oxides and hydroxides formed on its surface, may bring difficulties to the hydrogen diffusion and even blocking it 5,6 . Several studies have been conducted to generate alternatives to overcome the limitations mentioned above.…”

Section: Introductionmentioning

confidence: 99%

Severe Plastic Deformation and Additive Distribution in Mg-Fe to Improve Hydrogen Storage Properties

et al. 2017

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Magnesium (Mg) is a light metal with relatively low cost. Its hydride (MgH 2 ) is interesting for the safe hydrogen storage in solid state and has a high gravimetric capacity of 7.6%. Practical application of Mg is still hampered by high reaction temperatures and slow kinetics. In order to improve it and focus on more viable industrial processing conditions, Mg plates, with or without iron (Fe) addition, in the form of wires and powders, were submitted to severe plastic deformation (SPD) in air, starting with extensive cold rolling (ECR), followed by repetitive rolling (ARB). The samples were characterized by X-ray diffraction (XRD), optical microscopy (OM), scanning (SEM) and transmission electron microscopy (TEM). H 2 storage properties were evaluated by differential scanning calorimetry (DSC) and Sievert's volumetric method. Mg processed by ECR+ARB resulted in larger grain refinement and densities of cracks than ECR. In addition, Fe in the form of continuous wires was fragmented and resulted in a better distribution of particles than powders, which agglomerated. Thus, finally, the synergetic effect of microstructural features and Fe as catalyst and its distribution improved activation, kinetics and hydrogen storage capacity.

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Section: Introductionmentioning

confidence: 99%

Severe Plastic Deformation and Additive Distribution in Mg-Fe to Improve Hydrogen Storage Properties

et al. 2017

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“…5 Experimentally, Plummer and Sprunger have used EELS and TDS to study the interaction between both atomic and molecular hydrogen and Mg, finding dissociation and adsorption to be activated; a strongly chemisorbed surface hydride state was also observed. 6,7 The diffusional properties of hydrogen in magnesium have been investigated by Renner and Grabke, who determined a diffusion constant of D = 4.0ϫ 10 −13 m 2 / s at 300 K. 8 Using neutron scattering, Töpler et al found H-diffusion in MgH 2 to be three orders of magnitude lower than in Mg (at 350 K), 9 and Spatz et al have determined the overall hydrogen diffusion coefficient for the Mg-to-MgH 2 -transition (including nucleation and growth) to be as low as DЈ = 1.1 ϫ 10 −20 m 2 / s using XPS. 10 In the present work, a comprehensive investigation of the potential energy surface (PES) of hydrogen on the magnesium(0001) surface is presented.…”

Section: Introductionmentioning

confidence: 99%

Locating the rate-limiting step for the interaction of hydrogen withMg(0001)using density-functional theory calculations and rate theory

2004

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The dissociation of molecular hydrogen on a Mg͑0001͒ surface and the subsequent diffusion of atomic hydrogen into the magnesium substrate is investigated using Density Functional Theory (DFT) calculations and rate theory. The minimum energy path and corresponding transition states are located using the nudged elastic band method, and rates of the activated processes are calculated within the harmonic approximation to transition state rate theory, using both classical and quantum partition functions based atomic vibrational frequencies calculated by DFT. The dissociation/recombination of H 2 is found to be rate-limiting for the ab-and desorption of hydrogen, respectively. Zero-point energy contributions are found to be substantial for the diffusion of atomic hydrogen, but classical rates are still found to be within an order of magnitude at room temperature.

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“…The interval of hydrogen diffusion coefficients reported in Refs. [44,45] for a phase (Mg 2 NiH x ; x ¼ 0e0.3) is slightly higher.…”

Section: Temperature Dependence Of D and Tmentioning

confidence: 94%

Hydrogen diffusion in Mg2NiH4 intermetallic compound

Čermák¹,

Král²,

David³

2008

Intermetallics

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Measurements of the diffusion of hydrogen atoms in magnesium and Mg2Ni by neutron scattering

Cited by 100 publications

References 12 publications

Severe Plastic Deformation and Additive Distribution in Mg-Fe to Improve Hydrogen Storage Properties

Severe Plastic Deformation and Additive Distribution in Mg-Fe to Improve Hydrogen Storage Properties

Locating the rate-limiting step for the interaction of hydrogen withMg(0001)using density-functional theory calculations and rate theory

Hydrogen diffusion in Mg2NiH4 intermetallic compound

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