Hydrogen Desorption Reactions of the Na-Mg-B-H System

2010 ◽  
Vol 72 ◽  
pp. 164-169 ◽  
Author(s):  
Daphiny Pottmaier ◽  
Sebastiano Garroni ◽  
Maria Dolors Barò ◽  
Marcello Baricco
Keyword(s):  
Solid State ◽  
Research And Development ◽  
Ball Milling ◽  
Powder Diffraction ◽  
Hydrogen Desorption ◽  
X Ray ◽  
New Compounds ◽  
Desorption Reaction

Hydrogen storage in the solid state has shown increasing research and development, and recently an approach in mixing two hydride systems together by ball milling (reactive hydride composites) has been investigated in more detail, e.g. NaBH4 plus MgH2. Thermodynamic destabilization may occur by new compounds formation during dehydrogenation, e.g. MgB2. A study of the the role of O2/H2O contamination for the reaction 2NaBH4 + MgH2 ↔ 2NaH + MgB2 + 4H2 was conducted using in-situ X-ray powder diffraction. Desorption reaction is observed to begin by a competition of MgH2 and NaBH4 decomposition due to higher reactivity promoted by ball milling processing summed to O2/H2O contamination. Oxidation of NaBH4 into NaBO2 is observed to happen in higher degree than MgH2/Mg into MgO for the Na-Mg-B-H system.

In situsynchrotron X-ray powder diffraction for studying the role of induced structural defects on the thermoluminescence mechanism of nanocrystalline LiF

2016 ◽  
Vol 23 (2) ◽  
pp. 501-509
Author(s):  
Mostafa El Ashmawy ◽  
Hany Amer ◽  
Mahmoud Abdellatief
Keyword(s):  
Ball Milling ◽  
Powder Diffraction ◽  
Milling Time ◽  
Relative Concentration ◽  
High Energy ◽  
Structural Defects ◽  
X Ray ◽  
Energy Ball

The correlation between the thermoluminescence (TL) response of nanocrystalline LiF and its microstructure was studied. To investigate the detailed TL mechanism, the glow curves of nanocrystalline LiF samples produced by high-energy ball-milling were analyzed. The microstructure of the prepared samples was analyzed by synchrotron X-ray powder diffraction (XRPD) at room temperature. Then, the microstructure of a representative pulverized sample was investigated in detail by performingin situXRPD in both isothermal and non-isothermal modes. In the present study, the dislocations produced by ball-milling alter the microstructure of the lattice where the relative concentration of the vacancies, responsible for the TL response, changes with milling time. An enhancement in the TL response was recorded for nanocrystalline LiF at high-temperature traps (after dislocations recovery starts >425 K). It is also found that vacancies are playing a major role in the dislocations recovery mechanism. Moreover, the interactions among vacancies–dislocations and/or dislocations–dislocations weaken the TL response.

Crystal Structures of New Compounds Na0.5Sm4.5Ti4O15 and Na0.5Eu4.5Ti4O15

2011 ◽  
Vol 415-417 ◽  
pp. 468-471
Author(s):  
Qiao Hong Yu ◽  
Zheng Fa Li ◽  
Yong Xiang Li ◽  
Ping Zhan Si ◽  
Jiang Ying Wang ◽  
...  
Keyword(s):  
Solid State ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordinary Temperature ◽  
Europium Titanate ◽  
New Compounds

New compounds of sodium samarium titanate Na0.5Sm4.5Ti4O15and sodium europium titanate Na0.5Eu4.5Ti4O15were synthesized successfully by solid state reaction at 1300 oC and 1200 oC, respectively. The lattice parameters of Na0.5Sm4.5Ti4O15and Na0.5Eu4.5Ti4O15were determined at ordinary temperature by using X-ray powder diffraction method. Their Lattice types were determined, and their patterns were indexed. Polycrystalline X-ray diffraction data of sodium samarium titanate were listed. Differences of their crystal structures were analyzed and discussed.

scholarly journals Hydrates and polymorphs of lead squarate Pb(C4O4): Structural transformations studied by in situ X-ray powder diffraction and solid state NMR

Polyhedron ◽  
2019 ◽  
Vol 164 ◽  
pp. 123-131 ◽  
Author(s):  
Thierry Bataille ◽  
Amira Bouhali ◽  
Cassandre Kouvatas ◽  
Chahrazed Trifa ◽  
Nathalie Audebrand ◽  
...  
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Structural Transformations ◽  
X Ray

In situ synchrotron X-ray diffraction studies of hydrogen desorption and absorption properties of Mg and Mg–Mm–Ni after reactive ball milling in hydrogen

2009 ◽  
Vol 57 (13) ◽  
pp. 3989-4000 ◽  
Author(s):  
R.V. Denys ◽  
A.B. Riabov ◽  
J.P. Maehlen ◽  
M.V. Lototsky ◽  
J.K. Solberg ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
Absorption Properties ◽  
X Ray ◽  
Milling In Hydrogen

In situsimultaneous Raman/high-resolution X-ray powder diffraction study of transformations occurring in materials at non-ambient conditions

2007 ◽  
Vol 40 (4) ◽  
pp. 684-693 ◽  
Author(s):  
Enrico Boccaleri ◽  
Fabio Carniato ◽  
Gianluca Croce ◽  
Davide Viterbo ◽  
Wouter van Beek ◽  
...  
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Powder Diffraction ◽  
Added Value ◽  
Experimental Setup ◽  
Ambient Conditions ◽  
X Ray ◽  
Uv Lamp ◽  
Kinetics Of

Materials containing disordered moieties and/or amorphous or liquid-like phases or showing surface- or defect-related phenomena constitute a problem with respect to their characterization using X-ray powder diffraction (XRPD), and in many cases Raman spectroscopy can provide useful complementary information. A novel experimental setup has been designed and realized for simultaneousin situRaman/high-resolution XRPD experiments, to take full advantage of the complementarities of the two techniques in investigating solid-state transformations under non-ambient conditions. The added value of the proposed experiment is the perfect synchronization of the two probes with the reaction coordinate and the elimination of possible bias caused by different sample holders and conditioning modes used in `in situbut separate' approaches. The setup was tested on three solid-state transformations: (i) the kinetics of the fluorene–TCNQ solid-state synthesis, (ii) the thermal swelling and degradation of stearate–hydrotalcite, and (iii) the photoinduced (2 + 2)-cyclization of (E)-furylidenoxindole. These experiments demonstrated that, even though the simultaneous Raman/XRPD experiment is more challenging than separate procedures, high-resolution XRPD and Raman data can be collected. A gas blower allows studies from room temperature to 700 K, and 100 K can be reached using a nitrogen cryostream. The flexibility of the experimental setup allows the addition of ancillary devices, such as a UV lamp used to study photoreactivity.

scholarly journals Probing the role of ceramide hydroxylation in skin barrier lipid models by 2H solid-state NMR spectroscopy and X-ray powder diffraction

2018 ◽  
Vol 1860 (5) ◽  
pp. 1162-1170 ◽  
Author(s):  
Andrej Kováčik ◽  
Alexander Vogel ◽  
Juliane Adler ◽  
Petra Pullmannová ◽  
Kateřina Vávrová ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Skin Barrier ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Principal component analysis for automatic extraction of solid-state kinetics from combined in situ experiments

2018 ◽  
Vol 20 (29) ◽  
pp. 19560-19571 ◽  
Author(s):  
Pietro Guccione ◽  
Luca Palin ◽  
Benny Danilo Belviso ◽  
Marco Milanesio ◽  
Rocco Caliandro
Keyword(s):  
Principal Component Analysis ◽  
Raman Spectroscopy ◽  
Solid State ◽  
Powder Diffraction ◽  
Principal Component ◽  
Automatic Extraction ◽  
X Ray ◽  
Solid State Kinetics ◽  
In Situ Experiments

A new algorithm to extract in an automatic way kinetic parameters from a set of measurements from in situ experiments is presented and applied to X-ray powder diffraction and Raman spectroscopy.

HREM in solid-state chemistry and crystallography

1992 ◽  
Vol 50 (1) ◽  
pp. 104-105
Author(s):  
Lars Kihlborg ◽  
Margareta Sundberg ◽  
Gunnar Svensson
Keyword(s):  
Solid State ◽  
High Temperature Superconductors ◽  
High Resolution Electron Microscopy ◽  
Atomic Resolution ◽  
Solid State Chemistry ◽  
X Ray ◽  
Solid State Ionics ◽  
Resolution Electron ◽  
New Compounds

High-resolution electron microscopy has had a great impact on solid state chemistry. The possibility it offers of directly imaging the structure of solids has made it an unvaluable complement to conventional diffraction methods. Disorder and extended effects have become accessible to observation, superstructures, structural modulations and microphases can be identified and particles down to nanometer size can be studied. Combined with electron diffraction and x-ray microanalysis it is a powerful tool for phase analysis, giving guidance to synthesis of new compounds. Under certain conditions even chemical reactions can be studied in situ at atomic resolution. Numerous examples in be found in the fields of high-temperature superconductors, zeolites, ferroelectrics and solid state ionics.

scholarly journals Effects of Ball Milling and TiF3 Addition on the Dehydrogenation Temperature of Ca(BH4)2 Polymorphs

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4828
Author(s):  
Isabel Llamas Jansa ◽  
Oliver Friedrichs ◽  
Maximilian Fichtner ◽  
Elisa Gil Bardají ◽  
Andreas Züttel ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Desorption ◽  
Reaction Pathways ◽  
Desorption Peak ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Before And After ◽  
Kinetics Of ◽  
Desorption Reaction

The changes introduced by both ball milling and the addition of small amounts of TiF3 in the kinetics of the hydrogen desorption of three different Ca(BH4)2 polymorphs (α, β and γ) have been systematically investigated. The samples with different polymorphic contents, before and after the addition of TiF3, were characterized by powder X-ray diffraction and vibrational spectroscopy. The hydrogen desorption reaction pathways were monitored by differential scanning calorimetry. The hydrogen desorption of Ca(BH4)2 depends strongly on the amount of coexistent α, β and γ polymorphs as well as additional ball milling and added TiF3 to the sample. The addition of TiF3 increased the hydrogen desorption rate without significant dissociation of the fluoride. The combination of an α-Ca(BH4)2 rich sample with 10 mol% of TiF3 and 8 h of milling led to up to 27 °C decrease of the hydrogen desorption peak temperature.

Sign in / Sign up

Export Citation Format

Share Document