Inelastic neutron scattering of H2 adsorbed on boron substituted single walled carbon nanotubes

Brown, Craig M.; Blackburn, Jeffrey L.; Neumann, D. A.; Gennett, Thomas; Simpson, Lin; Dillon, Anne C.; Heben, Michael J.

doi:10.1016/j.jallcom.2007.01.113

Cited by 16 publications

(6 citation statements)

References 19 publications

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“…Recent research has been focused on lighter storage material with favorable uptake and release kinetics to overcome the issues associated with compression and liquefaction tanks. Hydrogen can be bound to materials, such as fullerenes , and carbon nanotubes, , stored as a solid compound via physisorption. However, materials that utilize physisorption have a low gravimetric uptake compared to that of chemisorption.…”

Section: Introductionmentioning

confidence: 99%

Anharmonicity of Weakly Bound M⁺−H₂ Complexes

2011

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The anharmonicity of weakly bound complexes is studied using the vibrational self-consistent field (VSCF) approach for a series of metal cation dihydrogen (M(+)-H(2)) complexes. The H-H stretching frequency shifts of M(+)-H(2) (M(+) = Li(+), Na(+), B(+), and Al(+)) complexes are calculated with the coupled-cluster method including all single and double excitations with perturbative triples (CCSD(T)) level of theory with the cc-pVTZ basis set. The calculated H-H stretching frequency of Li(+)-H(2), B(+)-H(2), Na(+)-H(2), and Al(+)-H(2) is red-shifted by 121, 202, 74, and 62 cm(-1), respectively, relative to that of unbound H(2). The calculated red shifts and their trends are in good agreement with the available experimental and previously calculated data. Insight into the observed trends is provided by symmetry adapted perturbation theory (SAPT).

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Section: Introductionmentioning

confidence: 99%

Anharmonicity of Weakly Bound M⁺−H₂ Complexes

2011

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“…Additionally, to maximize storage capacity, the material’s microstructure should be optimized for high porosity and surface area. Among a variety of promising materials, which include metal hydrides, complex hydrides, metalorganic frameworks, and zeolites, are several boron-containing substances including boron nitride nanotubes , and boron-doped fullerenes and nanostructures. , Recent density functional and quantum Monte Carlo calculations on boron-doped carbon nanostructures suggest that H 2 attaches nondissociatively at the boron sites, with typical binding energies suitable for reversible hydrogen storage near standard conditions (i.e., 5−15 kcal/mol) and a barrierless hydrogen adsorption process, simplifying the uptake and release kinetics . The existence of an empty, localized boron p z orbital was found to be essential for nondissociative H 2 adsorption.…”

Section: Introductionmentioning

confidence: 99%

Attachment of Molecular Hydrogen to an Isolated Boron Cation: An Infrared and ab initio Study

2008

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Structural properties of the B(+)-H2 electrostatic complex are investigated through its rotationally resolved infrared spectrum in the H-H stretch region (3905-3975 cm(-1)). The spectrum, which was obtained by monitoring B(+) photofragments while the IR wavelength was scanned, is consistent with the complex having a T-shaped structure and a vibrationally averaged intermolecular separation of 2.26 A, which decreases by 0.04 A when the H2 subunit is vibrationally excited. The H-H stretch transition of B(+)-H2 is red-shifted by 220.6 +/- 1.5 cm(-1) from that of the free H2 molecule, much more than for other dihydrogen complexes with comparable binding energies. Properties of B(+)-H2 and the related Li(+)-H2, Na(+)-H2, and Al(+)-H2 complexes are explored through ab initio calculations at the MP2/aug-cc-pVTZ level. The unusually large red-shift for B(+)-H2 is explained as due to electron donation from the H2 sigma(g) bonding orbital to the unoccupied 2p(z) orbital on the B(+) ion.

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“…The B incorporation is limited with a maximum value of 2.35%, and the dispersion of B elements is often inhomogeneous. More recently, BC 3 and B substituted C-nanotubes were also prepared, as well as the theoretical prediction of B effect to the H 2 binding energy . A few years ago, we reported a method to prepare boron-substituted carbon (B/C) materials, containing up to 7 mol% of boron atoms substitutionally incorporated in the C structure, by using boron-containing organic precursors and a pyrolysis process .…”

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Synthesis of Microporous Boron-Substituted Carbon (B/C) Materials Using Polymeric Precursors for Hydrogen Physisorption

et al. 2008

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This paper discusses a new synthesis route to prepare microporous boron substituted carbon (B/C) materials that show a significantly higher hydrogen binding energy and physisorption capacity, compared with the corresponding carbonaceous (C) materials. The chemistry involves a pyrolysis of the designed boron-containing polymeric precursors, which are the polyaddition and polycondensation adducts between BCl3 and phenylene diacetylene and lithiated phenylene diacetylene, respectively. During pyrolysis, most of the boron moieties were transformed into a B-substituted C structure, and the in situ formed LiCl byproduct created a microporous structure. The microporous B/C material with B content > 7% and surface area > 700 m2/g has been prepared, which shows a reversible hydrogen physisorption capacity of 0.6 and 3.2 wt % at 293 and 77 K, respectively, under 40 bar of hydrogen pressure. The physisorption results were further warranted by absorption isotherms indicating a binding energy of hydrogen molecules of approximately 11 kJ/mol, significantly higher than the 4 kJ/mol reported on most graphitic surfaces.

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Inelastic neutron scattering of H2 adsorbed on boron substituted single walled carbon nanotubes

Cited by 16 publications

References 19 publications

Anharmonicity of Weakly Bound M⁺−H₂ Complexes

Anharmonicity of Weakly Bound M⁺−H₂ Complexes

Attachment of Molecular Hydrogen to an Isolated Boron Cation: An Infrared and ab initio Study

Synthesis of Microporous Boron-Substituted Carbon (B/C) Materials Using Polymeric Precursors for Hydrogen Physisorption

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Inelastic neutron scattering of H2 adsorbed on boron substituted single walled carbon nanotubes

Cited by 16 publications

References 19 publications

Anharmonicity of Weakly Bound M+−H2 Complexes

Anharmonicity of Weakly Bound M+−H2 Complexes

Attachment of Molecular Hydrogen to an Isolated Boron Cation: An Infrared and ab initio Study

Synthesis of Microporous Boron-Substituted Carbon (B/C) Materials Using Polymeric Precursors for Hydrogen Physisorption

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Anharmonicity of Weakly Bound M⁺−H₂ Complexes

Anharmonicity of Weakly Bound M⁺−H₂ Complexes