Synthesis and hydrogen storage properties of Mg-based alloys

Liang, Guoxian

doi:10.1016/j.jallcom.2003.09.031

Cited by 195 publications

(109 citation statements)

References 41 publications

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“…There are a large number of metals in nature that form hydrides, however, only the lighter ones are thought to be suitable candidates for mobile hydrogen storage purposes (see [2] for an overview). Beside being light weight, a hydride will need to have good cyclability (several hundred times with little loss of performance), fast adsorption/desorption kinetics (the hydride should and theoretical papers in the literature showing that the hydriding properties of MgH 2 are further enhanced by the addition of traces of transition metals which act as a catalyst (see for example [13,14,15,16,17] and references therein). In particular, alloying Mg with Ni can slightly improve the thermodynamic properties of the hydride by favouring H 2 adsorption/dissociation and consequent atomic hydrogen absorption/desorption due to a weakening of the bonding between Mg and H atoms (see for example [11,13,16,17,18] and references therein).…”

Section: Introductionmentioning

confidence: 99%

Hydrogen dissociation and diffusion on Ni- and Ti-doped Mg(0001) surfaces

Pozzo

Alfè

Amieiro

et al. 2008

The Journal of Chemical Physics

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It is well known, both theoretically and experimentally, that alloying MgH2 with transition elements can significantly improve the thermodynamic and kinetic properties for H2 desorption, as well as the H2 intake by Mg bulk. Here we present a density functional theory investigation of hydrogen dissociation and surface diffusion over Ni-doped surface, and compare the findings to previously investigated Ti-doped Mg(0001) and pure Mg(0001) surfaces. Our results show that the energy barrier for hydrogen dissociation on the pure Mg(0001) surface is high, while it is small/null when Ni/Ti are added to the surface as dopants. We find that the binding energy of the two H atoms near the dissociation site is high on Ti, effectively impeding diffusion away from the Ti site. By contrast, we find that on Ni the energy barrier for diffusion is much reduced. Therefore, although both Ti and Ni promote H2 dissociation, only Ni appears to be a good catalyst for Mg hydrogenation, allowing diffusion away from the catalytic sites. Experimental results corroborate these theoretical findings, i.e. faster hydrogenation of the Ni doped Mg sample as opposed to the reference Mg or Ti doped Mg.

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Section: Introductionmentioning

confidence: 99%

Hydrogen dissociation and diffusion on Ni- and Ti-doped Mg(0001) surfaces

Pozzo

Alfè

Amieiro

et al. 2008

The Journal of Chemical Physics

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“…[4][5][6] Experimentally, many studies have been devoted to the catalytic effect on hydrogen adsorption of mixing transition metals or their oxides in small quantities into Mg hydride powder during ball milling. [7][8][9][10] The transition metals, such as Ti, Nb, V, etc. are believed to act as catalysts for enhancing the surface dissociation of molecular hydrogen into adsorbed atoms, [11][12][13][14][15] 17 Clearly, the use of a cheap metal oxide compared to the pure metal for catalytic purposes is an advantage from the cost perspective.…”

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confidence: 99%

The role of V2O5 on the dehydrogenation and hydrogenation in magnesium hydride: An ab initio study

Smith

Yao

et al. 2008

Applied Physics Letters

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“…Particularly, it is suitable to solubilize particular elements into MgH2 or Mg2NiH4 above the thermodynamic equilibrium limit, which is helpful to destabilize MgH2 or Mg2NiH4 [13]. However, the milled Mg and Mg-based alloys exhibit very poor hydrogen absorbing and desorbing stability in the light of the evanishment of the metastable structures formed by ball milling during the multiple hydrogen absorbing and desorbing cycles [14] .…”

Section: Preparation Of Alloysmentioning

confidence: 99%