uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Hydrogen Storage Materials: Design, Catalysis, Thermodynamics, Structure and Optics
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Physics and Materials Science.
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Hydrogen is abundant, uniformly distributed throughout the Earth's surface and its oxidation product (water) is environmentally benign. Owing to these features, it is considered as an ideal synthetic fuel for a new world energetic matrix (renewable, secure and environmentally friendly) that could allow a sustainable future development. However, for this prospect to become a reality, efficient ways to produce, transport and store hydrogen still need to be developed. In the present thesis, theoretical studies of a number of potential hydrogen storage materials have been performed using density functional theory. In NaAlH4 doped with 3d transition metals (TM), the hypothesis of the formation of Ti-Al intermetallic alloy as the main catalytic mechanism for the hydrogen sorption reaction is supported. The gateway hypothesis for the catalysis mechanism in TM-doped MgH2 is confirmed through the investigation of MgH2 nano-clusters. Thermodynamics of Li-Mg-N-H systems are analyzed with good agreement between theory and experiments. Besides chemical hydrides, the metal-organic frameworks (MOFs) have also been investigated. Li-decorated MOF-5 is demonstrated to possess enhanced hydrogen gas uptake properties with a theoretically predicted storage capacity of 2 wt% at 300 K and low pressure.

The metal-hydrogen systems undergo many structural and electronic phase transitions induced by changes in pressure and/or temperature and/or H-concentration. It is important both from a fundamental and applied viewpoint to understand the underlying physics of these phenomena. Here, the pressure-induced structural phase transformations of NaBH4 and ErH3 were investigated. In the latter, an electronic transition is shown to accompany the structural modification. The electronic and optical properties of the low and high-pressure phases of crystalline MgH2 were calculated. The temperature-induced order-disorder transition in Li2NH is demonstrated to be triggered by Li sub-lattice melting. This result may contribute to a better understanding of the important solid-solid hydrogen storage reactions that involve this compound.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2008. , p. x, 72
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 408
Keywords [en]
Materials science, Hydrogen-storage materials, Density functional theory, Molecular dynamics, Catalysis, Thermodynamics, Optics
Keywords [sv]
Materialvetenskap
Identifiers
URN: urn:nbn:se:uu:diva-8574ISBN: 978-91-554-7129-3 (print)OAI: oai:DiVA.org:uu-8574DiVA, id: diva2:171627
Public defence
2008-04-11, Häggsalen, Ångstromlaboratoriet, SE-75121, Uppsala, 10:15
Opponent
Supervisors
Available from: 2008-03-20 Created: 2008-03-20Bibliographically approved
List of papers
1. Role of Catalyst in Dehydrogenation of MgH2 Nanoclusters
Open this publication in new window or tab >>Role of Catalyst in Dehydrogenation of MgH2 Nanoclusters
Show others...
2008 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 105, no 24, p. 8227-8231Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96881 (URN)10.1073/pnas.0711743105 (DOI)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved
2. Role of titanium in hydrogen desortiption in crystalline sodium Alanate
Open this publication in new window or tab >>Role of titanium in hydrogen desortiption in crystalline sodium Alanate
2005 (English)In: Appl. Phys. Lett., Vol. 86, no 251913, p. 3-Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96882 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
3. Dehydrogenation from 3d-transition-metal-doped NaAlH4: Prediction of catalysts
Open this publication in new window or tab >>Dehydrogenation from 3d-transition-metal-doped NaAlH4: Prediction of catalysts
2007 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 90, no 14, p. 141904-Article in journal (Refereed) Published
Abstract [en]

A fundamental understanding of the role of catalysts in improving the kinetics and thermodynamics of hydrogen sorption in NaAlH4 is the key for using this material in hydrogen storage. The authors present a systematic theoretical study of energies needed to desorb hydrogen in 3d transition metal (Sc-Cu)-doped NaAlH4. They show that Cr and Fe atoms can be far more effective catalysts than Ti in desorbing hydrogen. The role of the 3d metal atoms in improving the thermodynamics of dehydrogenation is attributed to a significant shortening of the bond length with neighboring Al atoms.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96883 (URN)10.1063/1.2719244 (DOI)000245512200023 ()
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved
4. Ti-induced destabilization of NaBH4 from first-principles theory
Open this publication in new window or tab >>Ti-induced destabilization of NaBH4 from first-principles theory
2008 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 20, no 12, p. 122202-Article in journal (Refereed) Published
Abstract [en]

In this work, we have employed first-principles total energy calculations and ab initio molecular dynamics simulations to investigate the Ti doping of NaBH4. We show that Ti destabilizes the BH4 cages, which in turn increases the mobility of hydrogen atoms. Such an effect is shown to be due to the formation of B-Ti bonds, rather than the lowering of the BH4 charge state as expected. These results indicate that Ti may catalyse the dehydrogenation process in NaBH4 as it does for NaAlH4.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96884 (URN)10.1088/0953-8984/20/12/122202 (DOI)000254101300002 ()
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved
5. Vacancy-mediated hydrogen desorption in NaAlH4
Open this publication in new window or tab >>Vacancy-mediated hydrogen desorption in NaAlH4
2005 (English)In: Phys. Rev. B, Vol. 72, no 165101Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96885 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
6. Electronic structure and hydrogen desorption in NaAlH4
Open this publication in new window or tab >>Electronic structure and hydrogen desorption in NaAlH4
2005 (English)In: Mater. Res. Soc. Symp. Proc. (MRS), Vol. 837, no N2.5.1Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96886 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
7. On the structural and energetic properties of the hydrogen absorber Li2Mg(NH)2
Open this publication in new window or tab >>On the structural and energetic properties of the hydrogen absorber Li2Mg(NH)2
2007 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, no 9, p. 091924-Article in journal (Refereed) Published
Abstract [en]

The authors have performed density functional theory based calculations of several possible conformations for the crystal structure of Li2Mg(NH)2 and they confirm the α phase, resolved from both x-ray and neutron diffraction data, as the ground-state configuration. It is also found that although the N-H bond is stronger in Li2Mg(NH)2 than in Li2NH, hydrogen release from Li2Mg(NH)2/LiH mixture displays more favorable thermodynamics than that from the Li2NH/LiH mixture. The insights gained from this seemingly counterintuitive result should prove helpful in the search for promising hydrogen storage materials.

Keywords
Inorganic compounds, Theory of crystal structure, crystal symmetry, calculations and modeling
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96887 (URN)10.1063/1.2775803 (DOI)000249156100047 ()
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved
8. Thermodynamic analysis of hydrogen sorption reactions in Li-Mg-N-H systems
Open this publication in new window or tab >>Thermodynamic analysis of hydrogen sorption reactions in Li-Mg-N-H systems
2008 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 92, no 2, p. 021907-Article in journal (Refereed) Published
Abstract [en]

We report a comprehensive first-principles study of the thermodynamics of the hydrogen release reaction from xLiH-yMg(NH2)(2) mixtures involving the composition ratios (x=2, y=1), (x=8, y=3), and (x=12, y=3), with special emphasis on the effect of the different intermediate steps. For all three mixing ratios of LiH/Mg(NH2)(2) we find that the hydrogen release is initiated by the same reaction with an enthalpy of 46.1 kJ/mol of H-2 in excellent agreement with recent experimental results. Additionally, we also investigated the substitution of LiH by MgH2 as reaction partner of Mg(NH2)(2) in the fully hydrogenated state.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96888 (URN)10.1063/1.2830703 (DOI)000252470900039 ()
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved
9. A comparative investigation of H2 interaction in Cd- and Zn-based Metal Organic Framework-5
Open this publication in new window or tab >>A comparative investigation of H2 interaction in Cd- and Zn-based Metal Organic Framework-5
Show others...
(English)Manuscript (Other academic)
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96889 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-29Bibliographically approved
10. Li-decorated metal-organic framework-5: A route to achieving a suitable hydrogen storage medium
Open this publication in new window or tab >>Li-decorated metal-organic framework-5: A route to achieving a suitable hydrogen storage medium
2007 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 104, no 51, p. 20173-Article in journal (Refereed) Published
Abstract [en]

A significant improvement in molecular hydrogen uptake properties is revealed by our ab initio calculations for Li-decorated metal-organic framework 5. We have found that two Li atoms are strongly adsorbed on the surfaces of the six-carbon rings, one on each side, carrying a charge of +0.9e per Li atom. Each Li can cluster three H-2 molecules around itself with a binding energy of 12 kJ (mol H-2)(-1). Furthermore, we show from ab initio molecular dynamics simulations with a hydrogen loading of 18 H2 per formula unit that a hydrogen uptake of 2.9 wt % at 200 K and 2.0 wt % at 300 K is achievable. To our knowledge, this is the highest hydrogen storage capacity reported for metal-organic framework 5 under such thermodynamic conditions.

Keywords
first-principles calculations, molecular adsorption, molecular dynamics, porous materials
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96890 (URN)10.1073/pnas.0708603104 (DOI)000251885000006 ()
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved
11. Pressure-induced structural phase transition in NaBH4
Open this publication in new window or tab >>Pressure-induced structural phase transition in NaBH4
2005 (English)In: Phys. Rev. B., Vol. 72, no 054125Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96891 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
12. Pressure-induced phase transition in ErH3
Open this publication in new window or tab >>Pressure-induced phase transition in ErH3
2004 (English)In: Phys. Stat. Sol. (c), Vol. 241, no 3219Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96892 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
13. Structural transition in lithium imide triggered by melting of cation sublattice
Open this publication in new window or tab >>Structural transition in lithium imide triggered by melting of cation sublattice
(English)In: Phys. Rev. Lett.Article in journal (Refereed) Submitted
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96893 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-29Bibliographically approved
14. Electronic and optical properties of pressure induced phases of MgH2
Open this publication in new window or tab >>Electronic and optical properties of pressure induced phases of MgH2
2005 (English)In: J. Alloys and Compd., Vol. 404-406, no 220Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96894 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
15. Electronic and optical properties of α, γ and β phases of MgH2: a first-principle GW investigation
Open this publication in new window or tab >>Electronic and optical properties of α, γ and β phases of MgH2: a first-principle GW investigation
Show others...
2005 (English)In: J. Appl. Phys., Vol. 98, no 096106Article in journal (Refereed) Published
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96895 (URN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2012-03-14Bibliographically approved
16. Quasiparticle and optical properties of BeH2
Open this publication in new window or tab >>Quasiparticle and optical properties of BeH2
Show others...
2007 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 19, no 3, p. 036223-Article in journal (Refereed) Published
Abstract [en]

The quasiparticle and optical properties of BeH2 are computed by means of the all-electron GW approximation in conjunction with the projector augmented wave (PAW) method. The GW approximation, through the calculation of the self-energy and the optical dielectric function in the random phase approximation, shows that BeH2 is a large band gap insulator. The results are discussed in view of future experiments.

National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-96896 (URN)10.1088/0953-8984/19/3/036223 (DOI)000243724300030 ()
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-14Bibliographically approved

Open Access in DiVA

fulltext(2796 kB)2317 downloads
File information
File name FULLTEXT01.pdfFile size 2796 kBChecksum SHA-1
e072a79a15e4534a5306f3601cd6dfc6b54c9fd07a3116c105a0a2cc291e3c77dcd24f47
Type fulltextMimetype application/pdf
cover(578 kB)60 downloads
File information
File name COVER01.pdfFile size 578 kBChecksum SHA-1
639d58a9fa9d1a7814b139297e6eb42aa83f41ef2b347023310bf4dfa0e7d7271d9337ce
Type coverMimetype application/pdf
Buy this publication >>

By organisation
Department of Physics and Materials Science

Search outside of DiVA

GoogleGoogle Scholar
Total: 2317 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 2709 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf