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Grinderslev JB, Häussermann U, Jensen TR, Faraone A, Nagao M, Karlsson M, Udovic TJ, Andersson MS. Reorientational Dynamics in Y(BH 4) 3· xNH 3 ( x = 0, 3, and 7): The Impact of NH 3 on BH 4- Dynamics. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2024; 128:4431-4439. [PMID: 38533240 PMCID: PMC10961835 DOI: 10.1021/acs.jpcc.4c00265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 03/28/2024]
Abstract
The reorientational dynamics of Y(BH4)3·xNH3 (x = 0, 3, and 7) was studied using quasielastic neutron scattering (QENS) and neutron spin echo (NSE). The results showed that changing the number of NH3 ligands drastically alters the reorientational mobility of the BH4- anion. From the QENS experiments, it was determined that the BH4- anion performs 2-fold reorientations around the C2 axis in Y(BH4)3, 3-fold reorientations around the C3 axis in Y(BH4)3·3NH3, and either 2-fold reorientations around the C2 axis or 3-fold reorientations around the C3 axis in Y(BH4)3·7NH3. The relaxation time of the BH4- anion at 300 K decreases from 2 × 10-7 s for x = 0 to 1 × 10-12 s for x = 3 and to 7 × 10-13 s for x = 7. In addition to the reorientational dynamics of the BH4- anion, it was shown that the NH3 ligands exhibit 3-fold reorientations around the C3 axis in Y(BH4)3·3NH3 and Y(BH4)3·7NH3 as well as 3-fold quantum mechanical rotational tunneling around the same axis at 5 K. The new insights constitute a significant step toward understanding the relationship between the addition of ligands and the enhanced ionic conductivity observed in systems such as LiBH4·xNH3 and Mg(BH4)2·xCH3NH2.
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Affiliation(s)
- J. B. Grinderslev
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus DK-8000, Denmark
| | - U. Häussermann
- Department
of Materials and Environmental Chemistry, Stockholm University, SE-10691 Stockholm, Sweden
| | - T. R. Jensen
- Interdisciplinary
Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus DK-8000, Denmark
| | - A. Faraone
- NIST Center
for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United
States
| | - M. Nagao
- NIST Center
for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United
States
- Department
of Materials Science and Engineering, University
of Maryland, College Park, Maryland 20742-2115, United States
- Department
of Physics and Astronomy, University of
Delaware, Newark, Delaware 19716, United States
| | - M. Karlsson
- Department
of Chemistry and Chemical Engineering, Chalmers
University of Technology, Göteborg SE-412 96, Sweden
| | - T. J. Udovic
- NIST Center
for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United
States
- Department
of Materials Science and Engineering, University
of Maryland, College Park, Maryland 20742-2115, United States
| | - M. S. Andersson
- Ångström
Laboratory, Department of Chemistry, Uppsala
University, Box 538, SE-751 21 Uppsala, Sweden
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Synthesis, Structure and Mg2+ Ionic Conductivity of Isopropylamine Magnesium Borohydride. INORGANICS 2022. [DOI: 10.3390/inorganics11010017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The discovery of new inorganic magnesium electrolytes may act as a foundation for the rational design of novel types of solid-state batteries. Here we investigated a new type of organic-inorganic metal hydride, isopropylamine magnesium borohydride, Mg(BH4)2∙(CH3)2CHNH2, with hydrophobic domains in the solid state, which appear to promote fast Mg2+ ionic conductivity. A new synthetic strategy was designed by combination of solvent-based methods and mechanochemistry. The orthorhombic structure of Mg(BH4)2∙(CH3)2CHNH2 was solved ab initio by the Rietveld refinement of synchrotron X-ray powder diffraction data and density functional theory (DFT) structural optimization in space group I212121 (unit cell, a = 9.8019(1) Å, b = 12.1799(2) Å and c = 17.3386(2) Å). The DFT calculations reveal that the three-dimensional structure may be stabilized by weak dispersive interactions between apolar moieties and that these may be disordered. Nanoparticles and heat treatment (at T > 56 °C) produce a highly conductive composite, σ(Mg2+) = 2.86 × 10−7, and 2.85 × 10−5 S cm−1 at −10 and 40 °C, respectively, with a low activation energy, Ea = 0.65 eV. Nanoparticles stabilize the partially eutectic molten state and prevent recrystallization even at low temperatures and provide a high mechanical stability of the composite.
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Abstract
The number of rare earth (RE) starting materials used in synthesis is staggering, ranging from simple binary metal-halide salts to borohydrides and "designer reagents" such as alkyl and organoaluminate complexes. This review collates the most important starting materials used in RE synthetic chemistry, including essential information on their preparations and uses in modern synthetic methodologies. The review is divided by starting material category and supporting ligands (i.e., metals as synthetic precursors, halides, borohydrides, nitrogen donors, oxygen donors, triflates, and organometallic reagents), and in each section relevant synthetic methodologies and applications are discussed.
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Affiliation(s)
- Fabrizio Ortu
- School of Chemistry, University of Leicester, LE1 7RH Leicester, U.K.
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Comanescu C. Complex Metal Borohydrides: From Laboratory Oddities to Prime Candidates in Energy Storage Applications. MATERIALS (BASEL, SWITZERLAND) 2022; 15:2286. [PMID: 35329738 PMCID: PMC8949998 DOI: 10.3390/ma15062286] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/26/2022] [Accepted: 03/11/2022] [Indexed: 01/27/2023]
Abstract
Despite being the lightest element in the periodic table, hydrogen poses many risks regarding its production, storage, and transport, but it is also the one element promising pollution-free energy for the planet, energy reliability, and sustainability. Development of such novel materials conveying a hydrogen source face stringent scrutiny from both a scientific and a safety point of view: they are required to have a high hydrogen wt.% storage capacity, must store hydrogen in a safe manner (i.e., by chemically binding it), and should exhibit controlled, and preferably rapid, absorption-desorption kinetics. Even the most advanced composites today face the difficult task of overcoming the harsh re-hydrogenation conditions (elevated temperature, high hydrogen pressure). Traditionally, the most utilized materials have been RMH (reactive metal hydrides) and complex metal borohydrides M(BH4)x (M: main group or transition metal; x: valence of M), often along with metal amides or various additives serving as catalysts (Pd2+, Ti4+ etc.). Through destabilization (kinetic or thermodynamic), M(BH4)x can effectively lower their dehydrogenation enthalpy, providing for a faster reaction occurring at a lower temperature onset. The present review summarizes the recent scientific results on various metal borohydrides, aiming to present the current state-of-the-art on such hydrogen storage materials, while trying to analyze the pros and cons of each material regarding its thermodynamic and kinetic behavior in hydrogenation studies.
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Affiliation(s)
- Cezar Comanescu
- National Institute of Materials Physics, 405A Atomiștilor St., 077125 Magurele, Romania
- Inorganic Chemistry Department, Politehnica University of Bucharest, 1 Polizu St., 011061 Bucharest, Romania
- Faculty of Physics, University of Bucharest, 405, Atomiștilor St., 077125 Magurele, Romania
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Grinderslev JB, Andersson MS, Trump BA, Zhou W, Udovic TJ, Karlsson M, Jensen TR. Neutron Scattering Investigations of the Global and Local Structures of Ammine Yttrium Borohydrides. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:10.1021/acs.jpcc.1c03629. [PMID: 38487813 PMCID: PMC10938370 DOI: 10.1021/acs.jpcc.1c03629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
Complex metal hydrides are a fascinating and continuously expanding class of materials with many properties relevant for solid-state hydrogen and ammonia storage and solid-state electrolytes. The crystal structures are often investigated using powder X-ray diffraction (PXD), which can be ambiguous. Here, we revisit the crystal structure of Y(11BD4)3·3ND3 with the use of neutron diffraction, which, in comparison to previous PXD studies, provides accurate information about the D positions in the compound. Upon cooling to 10 K, the compound underwent a polymorphic transition, and a new monoclinic low-temperature polymorph denoted as α-Y(11BD4)3·3ND3 was discovered. Furthermore, the series of Y(11BH4)3·xNH3 (x = 0, 3, and 7) were also investigated with inelastic neutron scattering and infrared spectroscopy techniques, which provided information of the local coordination environment of the 11BH4- and NH3 groups and unique insights into the hydrogen dynamics. Partial deuteration using ND3 in Y(11BH4)3·xND3 (x = 3 and 7) allowed for an unambiguous assignment of the vibrational bands corresponding to the NH3 and 11BH4- in Y(11BH4)3·xNH3, due to the much larger neutron scattering cross section of H compared to D. The vibrational spectra of Y(11BH4)3·xNH3 could roughly be divided into three regions: (i) below 55 meV, containing mainly 11BH4- librational motions, (ii) 55-130 meV, containing mainly NH3 librational motions, and (iii) above 130 meV, containing 11B-H and N-H bending and stretching motions.
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Affiliation(s)
- Jakob B Grinderslev
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus 8000, Denmark
| | - Mikael S Andersson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg SE-412 96, Sweden
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
| | - Benjamin A Trump
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
| | - Wei Zhou
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
| | - Terrence J Udovic
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
- Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742-2115, United States
| | - Maths Karlsson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg SE-412 96, Sweden
| | - Torben R Jensen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University, Aarhus 8000, Denmark
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