Dehydriding and rehydriding processes of well-crystallized Mg(BH4)2 accompanying with formation of intermediate compounds

Li, Haiwen; Kikuchi, Kentaro; Nakamori, Yoshiteru; Ohba, Nobuko; Miwa, Kenji; Towata, Shin‐ichi; Orimo, Shin Ichi

doi:10.1016/j.actamat.2007.11.023

Cited by 209 publications

(156 citation statements)

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“…Mg(BH 4 ) 2 releases approximately 14.9 mass% of hydrogen when heated up to 870 K [56][57][58][59][60][61][62][63][64][65][66]. The dehydrogenation process is found to also proceed through multiple steps together with the formation of intermediate compounds [62,63,65], as summarized in Figure 2.…”

Section: Fundamentals Of Hydrogen Storage Propertiesmentioning

confidence: 89%

“…The dehydrogenation process is found to also proceed through multiple steps together with the formation of intermediate compounds [62,63,65], as summarized in Figure 2. Thus far, one of the intermediate compounds has been theoretically predicted and experimentally confirmed as being MgB 12 H 12 [28,29,62,[65][66][67][68][69][70] [62]. These differences might originate from differences in the measurement conditions.…”

Section: Fundamentals Of Hydrogen Storage Propertiesmentioning

confidence: 98%

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Recent Progress in Metal Borohydrides for Hydrogen Storage

et al. 2011

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Abstract:The prerequisite for widespread use of hydrogen as an energy carrier is the development of new materials that can safely store it at high gravimetric and volumetric densities. Metal borohydrides M(BH 4 ) n (n is the valence of metal M), in particular, have high hydrogen density, and are therefore regarded as one such potential hydrogen storage material. For fuel cell vehicles, the goal for on-board storage systems is to achieve reversible store at high density but moderate temperature and hydrogen pressure. To this end, a large amount of effort has been devoted to improvements in their thermodynamic and kinetic aspects. This review provides an overview of recent research activity on various M(BH 4 ) n , with a focus on the fundamental dehydrogenation and rehydrogenation properties and on providing guidance for material design in terms of tailoring thermodynamics and promoting kinetics for hydrogen storage.

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Section: Fundamentals Of Hydrogen Storage Propertiesmentioning

confidence: 89%

Section: Fundamentals Of Hydrogen Storage Propertiesmentioning

confidence: 98%

Recent Progress in Metal Borohydrides for Hydrogen Storage

et al. 2011

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“…36 Its enthalpy of dehydrogenation is experimentally reported to be between 40-60 kJ mol -1 , 37 an intermediate value that is close to ideal for hydrogen storage at near ambient conditions 38 . Due to its very purpose as a moderate temperature hydrogen storage material, γ-Mg(BH 4 ) 2 cannot be heat-treated and degassed at elevated temperatures in an analogous way to other microporous materials such as activated carbons or aluminosilicates.…”

Section: Representative Resultsmentioning

confidence: 99%

Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials

Stadie

Callini

Mauron

et al. 2015

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Supercritical fluid extraction and drying methods are well established in numerous applications for the synthesis and processing of porous materials. Herein, nitrogen is presented as a novel supercritical drying fluid for specialized applications such as in the processing of reactive porous materials, where carbon dioxide and other fluids are not appropriate due to their higher chemical reactivity. Nitrogen exhibits similar physical properties in the near-critical region of its phase diagram as compared to carbon dioxide: a widely tunable density up to ~1 g ml -1, modest critical pressure (3.4 MPa), and small molecular diameter of ~3.6 Å. The key to achieving a high solvation power of nitrogen is to apply a processing temperature in the range of 80-150 K, where the density of nitrogen is an order of magnitude higher than at similar pressures near ambient temperature. The detailed solvation properties of nitrogen, and especially its selectivity, across a wide range of common target species of extraction still require further investigation. Herein we describe a protocol for the supercritical nitrogen processing of porous magnesium borohydride. Video LinkThe video component of this article can be found at

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“…Mg(BH4)2 is considered as another promising hydrogen storage materials and it releases approximately 14.9 wt% of hydrogen when heated up to 870K [22,23,[85][86][87][88][89][90][91][92][93]. As discussed in Introduction, the dehydrogen process is found to go through multiple steps with formation of some stable intermediates such as MgB12H12 and MgH2 [21].…”

Section: Figure 3 Snapshots From Ab Initio Molecular Dynamics Trajecmentioning

confidence: 99%

“…Two thermodynamically stable intermediates, Mg(B12H12) and MgH2, are formed in the first step (Equation (1)) with enthalpy and entropy of 39 kJ/molH2 [22]. In 2008, a different value of 57 kJ/molH2 was obtained [23]. The hydrogen desorption reactions of equations (2) and (3) have endothermicity of 75 and 87 kJ/molH2.…”

Section: Introductionmentioning

confidence: 99%