共查询到20条相似文献,搜索用时 31 毫秒
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In this short review, we will briefly discuss the story of hydrogen storage, its impact on clean energy application, especially the challenges of using hydrogen adsorption for onboard application. After a short comparison of the main methods of hydrogen storage (high pressure tank, metal hydride and adsorption), we will focus our discussion on adsorption of hydrogen in graphitic carbon based large surface area adsorbents including carbon nanotubes, graphene and metal organic frameworks. The mechanisms, advantages, disadvantages and recent progresses will be discussed and reviewed for physisorption, metal-assisted storage and chemisorption. In the last section, we will discuss hydrogen spillover chemisorption in detail for the mechanism, status, challenges and perspectives. We hope to present a clear picture of the present technologies, challenges and the perspectives of hydrogen storage for the future studies. 相似文献
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Magnesium hydride remains an attractive hydrogen storage material due to the high hydrogen capacity and low cost of production. A high activation energy and poor kinetics at practical temperatures for the pure material have driven research into different additives to improve the sorption properties. This review details the development of catalytic additives and their effect on the activation energy, kinetics and thermodynamic properties of magnesium hydride. 相似文献
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Salles F Jobic H Maurin G Koza MM Llewellyn PL Devic T Serre C Ferey G 《Physical review letters》2008,100(24):245901
Quasielastic neutron scattering measurements are combined with molecular dynamics simulations to extract the self-diffusion coefficient of hydrogen in the metal organic frameworks MIL-47(V) and MIL-53(Cr). We find that the diffusivity of hydrogen at low loading is about 2 orders of magnitude higher than in zeolites. Such a high mobility has never been experimentally observed before in any nanoporous materials, although it was predicted in carbon nanotubes. Either 1D or 3D diffusion mechanisms are elucidated depending on the chemical features of the MIL framework. 相似文献
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C. Nützenadel A. Züttel D. Chartouni G. Schmid L. Schlapbach 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,8(2):245-250
Metal hydrides are used for electrochemical or gaseous storage of hydrogen because considerable amounts of hydrogen are reversibly
absorbed and desorbed at interstitial sites. Palladium is often used as a model system. Nanophase material is of interest
because properties related to the hydrogen absorption are size dependent. In this study, clusters from the size of 55 to 1415
atoms are investigated and compared with bulk Pd. It turns out that not only the amount of hydrogen per palladium that can
be intercalated changes but also kinetics and chemical potentials are dependent on the cluster size. The clusters used for
this study were chemically synthesised and stabilised by a ligand shell.
Received 9 October 1998 and Received in final form 10 May 1999 相似文献
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The hydrogen adsorption sites in MOF5 were determined using neutron powder diffraction along with first-principles calculations. The metal-oxide cluster is primarily responsible for the adsorption while the organic linker plays only a secondary role. Equally important, at low temperatures and high-concentration, molecules form unique interlinked high-symmetry nanoclusters with intermolecular distances as small as 3.0 Angstrom and H(2) uptake as high as 11 wt %. These results hold the key to optimizing metal-organic framework (MOF) materials for hydrogen storage applications and also suggest that MOFs can be used as templates to create artificial interlinked hydrogen nanocages with novel properties. 相似文献
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R. Checchetto N. Bazzanella P. Mengucci 《Journal of Physics and Chemistry of Solids》2008,69(9):2160-2163
We have prepared two different kinds of composite materials for hydrogen storage and studied their H2 storage capacity and desorption kinetics. The first composite material consists of magnesium-containing transition metal nanoclusters distributed in the Mg matrix (Mg:TM): this composite material shows better H2 desorption performances than pure Mg. This improvement is attributed to the role of the MgH2-TM nanocluster interface as preferential site for hexagonal Mg (h-Mg) nucleation and to the rapid formation of interconnected h-Mg domains where H diffusion during desorption occurs. The second composite material consists of LaNi5 particles (size<30 μm) distributed in a polymeric matrix. The H2 storage capacity is negligible at low metal content (50 wt%) when the metal particles are completely embedded in the polymeric matrix. The H2 storage capacity is comparable to that of the pure LaNi5 powders at high metal content (80 wt%) when a percolative distribution is assumed by the LaNi5 particles: this evidence points out the role of metal-metal interfaces and of interconnected metallic networks for H transport. 相似文献
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Nataliya N. Karaush Valentina A. Minaeva Hans Ågren Boris F. Minaev 《Molecular physics》2017,115(17-18):2218-2230
ABSTRACTThis mini-review presents recent advances in theory of electronic and spectral properties of hetero[8]circulenes used as promising fluorescent emitters for organic light-emitting diodes. Special attention is paid to the possibility of their further functionalisation into one-dimensional and two-dimensional (2D) materials. Such materials are predicted to be useful ambipolar organic semiconductors showing high charge carrier mobility. The porous structure of hetero[8]circulene-based nano-arrays can also provide suitable hydrogen storage materials, biomimetic-type nanopores and ionic channels. They serve as a good example of the density functional theory application for design of stable 2D structures, which extends the family of graphene-like materials. 相似文献
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Metal–organic frameworks (MOFs) are a new type of porous materials with numerous current and potential applications in many areas including ion-exchange, catalysis, sensing, separation, molecular recognition, drug delivery and, in particular, gas storage. Solid-state NMR (SSNMR) has played a pivotal role in structural characterization and understanding of host–guest interactions in MOFs. This article provides an overview on application of SSNMR to MOF systems. 相似文献
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Development of metal borohydrides for hydrogen storage 总被引:1,自引:0,他引:1
Y. Nakamori H.-W. Li K. Miwa S. Orimo 《Journal of Physics and Chemistry of Solids》2008,69(9):2292-2296
A metal borohydride M(BH4)n is a potential candidate for hydrogen storage materials because of its high gravimetric hydrogen density. The important research issues for M(BH4)n are to control the thermodynamic stability and to achieve the faster reaction kinetics. To clarify the thermodynamic stability, M(BH4)n (M=Mg, Ca∼Mn, Zn, Al, Y, Zr and Hf; n=2-4) were synthesized by mechanical milling and its thermal desorption properties were investigated. The hydrogen desorption temperature Td of M(BH4)n decreases with increasing Pauling's electronegativities χP of M. Because Mn, Zn, and Al borohydrides (χP?1.5) desorb borane, they are too unstable for hydrogen storage applications. The enthalpy changes of desorption reaction ΔHdes can be estimated by using our predicted heat of formation of M(BH4)n ΔHboro and reported data for decomposed products ΔHprod, which are useful indicators for searching M(BH4)n with appropriate stability for hydrogen storage material. In the latter case, microwave processing was adopted for achieving fast reaction kinetics. Among metal borohydrides, LiBH4 was rapidly heated above 380 K by microwave irradiation, 13.7 mass% of hydrogen was desorbed by microwave irradiation. The composites of LiBH4 with B or C desorbed hydrogen within 3 min. Microwave heating aids in realizing faster kinetics of the hydrogen desorption reaction. 相似文献
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Vanadium alloy has been taken as one of the candidate structural materials for fusion reactors because of its excellent high-temperature mecha nical performances, high thermal stress factor and low radioactivity. It is a kind of potential materials for hydrogen storage as well. Because operated in an environment conta!ning hydrogen and its isotopes or the neutron irradiation resulting transmutation product of H, the problem that H induced degradation of mechanical properties and hydrogen embrittlement has been being one of the key issues for the application for vanadium alloys. 相似文献
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New materials for hydrogen storage of Li-doped fullerene (C20, C28, C36, C50, C60, C70)-intercalated hexagonal boron nitrogen (h-BN) frameworks were designed by using density functional theory (DFT) calculations. First-principles molecular dynamics (MD) simulations showed that the structures of the C n -BN (n = 20, 28, 36, 50, 60, and 70) frameworks were stable at room temperature. The interlayer distance of the h-BN layers was expanded to 9.96–13.59 Å by the intercalated fullerenes. The hydrogen storage capacities of these three-dimensional (3D) frameworks were studied using grand canonical Monte Carlo (GCMC) simulations. The GCMC results revealed that at 77 K and 100 bar (10 MPa), the C50-BN framework exhibited the highest gravimetric hydrogen uptake of 6.86 wt% and volumetric hydrogen uptake of 58.01 g/L. Thus, the hydrogen uptake of the Li-doped C n -intercalated h-BN frameworks was nearly double that of the non-doped framework at room temperature. Furthermore, the isosteric heats of adsorption were in the range of 10–21 kJ/mol, values that are suitable for adsorbing/desorbing the hydrogen molecules at room temperature. At 193 K (–80 °C) and 100 bar for the Li-doped C50-BN framework, the gravimetric and volumetric uptakes of H2 reached 3.72 wt% and 30.08 g/L, respectively. 相似文献
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Sa Li Rajeev Ahuja C. Moysés Araújo Puru Jena 《Journal of Physics and Chemistry of Solids》2010,71(8):1073-16710
Addition of small amount of Ti precursors to sodium alanate has recently been found to substantially improve the kinetics and thermodynamics of hydrogen sorption in sodium alanate. In spite of several attempts, a fundamental understanding of how the catalyst works has remained unattainable. Using first principles methods we have investigated the mechanisms for hydrogen desorption in this material. We conclude that Ti substituted at Al site is energetically most favorable. The small amount of Ti substitution does not introduce large lattice distortion. The Ti atom serves as a magnet that continues to attract nearby H atoms as the nearest ones are successively desorbed. The number of Al atoms near to the Ti site remains at four upon hydrogen desorption when Ti is substituted at the Al site. These results provide important new insight into the design of future catalysts for hydrogen storage materials. 相似文献
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主要关于上海同步辐射装置(SSRF)储存环电子引发产生的韧致辐射和中子辐射的研究. 中子和光子经多种组合材 料(厚度在5cm~115cm之间)屏蔽后的剂量特征由蒙特卡罗代码MCNP和EGSnrc估算得到; 蒙特卡罗计算表明, 单一的材料如铅, 铁和聚乙烯对高能中子是无效的生物屏蔽材料, 而组合材料如铅或者铁加聚乙烯和铅或者铁加混凝土被认为是屏蔽高能中子很好的组合材料. 铅铁等高Z材料加点包含有氢的低Z材料如聚乙烯是同时屏蔽高能中子和韧致辐射的一种比较好的组合材料选择. 相似文献
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A. G. Zaluzhnyi V. P. Kopytin M. A. Kozodaev A. L. Suvorov 《Physics of Atomic Nuclei》2005,68(8):1265-1270
The influence of irradiation conditions on the retention of hydrogen isotopes in structural materials (austenitic steel) under heating is considered. The specimens under study were irradiated either in a reactor or by bombarding them with hydrogen-isotope ions of variable fluence and energy at accelerators. An investigation of irradiated specimens with an EM-300 transition electron microscope was accompanied by studying the kinetics of hydrogen release from samples with a high-vacuum mass spectrometer. Also, the kinetics of hydrogen-isotope release from specimens of structural materials treated with a deuterium plasma was studied. It was found that, under the effect of irradiation, the materials being studied develop radiation defects, which appear to be efficient traps for hydrogen atoms, retaining them up to rather high temperatures (650 K). It is also shown that blisters formed in the materials treated with a hydrogen plasma contain both molecular hydrogen and hydrocarbons—in particular, methane. 相似文献
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氢能是一种理想的能源载体,而经济有效的储氢手段是氢能实现规模应用急需解决的关键问题之一。碳纳米管在存储氢气上表现出来的独特性质,使其最有希望成为一种新的高效的储氢材料。从实验、理论研究两个方面总结了前人在碳纳米管储氢上的研究成果,并对碳纳米管储氢吸附方式,吸附量影响因素等方面做出分析。最后指出为实现碳纳米管储氢大规模应用仍需做的一些基础性研究工作。 相似文献
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Luca Pasquini Elsa Callini Matteo Brighi Federico Boscherini Amelia Montone Torben R. Jensen Chiara Maurizio Marco Vittori Antisari Ennio Bonetti 《Journal of nanoparticle research》2011,13(11):5727-5737
We report on the hydrogen storage behaviour of Mg nanoparticles (NPs) (size range 100 nm–1 μm) with metal-oxide core–shell
morphology synthesized by inert gas condensation and decorated by transition metal (TM) (Pd or Ti) clusters via in situ vacuum
deposition. The structure and morphology of the as-prepared and hydrogenated NPs is studied by electron microscopy, X-ray
diffraction including in situ experiments and X-ray absorption spectroscopy, in order to investigate the relationships with
the hydrogen storage kinetics measured by the volumetric Sieverts method. With both Pd and Ti, the decoration deeply improves
the hydrogen sorption properties: previously inert NPs exhibit complete hydrogenation with fast transformation kinetics, good
stability and reversible gravimetric capacity that can attain 6 wt%. In the case of Pd-decoration, the occurrence of Mg–Pd
alloying is observed at high temperatures and in dependence of the hydrogen pressure conditions. These structural transformations
modify both the kinetics and thermodynamics of hydride formation, while Ti-decoration has an effect only on the kinetics.
The experimental results are discussed in relation with key issues such as the amount of decoration, the heat of mixing between
TM and Mg and the binding energy between TM and hydrogen. 相似文献