Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636849
Title: Light metal borohydrides and Mg-based hydrides for hydrogen storage
Author: Guo, Sheng
ISNI:       0000 0004 5359 4500
Awarding Body: University of Birmingham
Current Institution: University of Birmingham
Date of Award: 2015
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Abstract:
This work has investigated structural and compositional changes in LiBH\(_4\), Mg(BH\(_4\))\(_2\), Ca(BH\(_4\))\(_2\), LiBH\(_4\)-Ca(BH\(_4\))\(_2\), MgH\(_2\)-B-TiX (TiX = Ti, TiH\(_2\) or TiCl\(_3\)), and hydrided Li-Mg alloy during heating. The crystal and vibrational structures of these borohydrides/composites were characterized using lab-based X-ray diffraction (XRD) and Raman spectroscopy, with particular attention to the frequency/width changes of Raman vibrations of different polymorphs of borohydrides. The thermal stability and decomposition pathway of the borohydrides was studied mainly using differential scanning calorimetry and thermogravimetric analysis, XRD and Raman measurements, whilst the gaseous products during heating were monitored using a mass spectrometry. Hydrogen is the main decomposition gaseous product from all of these compounds, but in some cases a very small amount of diborane release was also detected. These studies suggest that the thermal decomposition of the metal borohydrides occurs via a wide range of reaction pathways, often in several steps, which may involve simultaneous competing reactions. This can include the formation of stable borane intermediates/by-products which largely preclude the possibility of reversibility. Furthermore, the role of diborane in the decomposition and formation of borohydrides, was later studied by heating metal borohydrides (or hydrides) to various temperatures in a gaseous diborane-hydrogen atmosphere; and different types of borane products were observed.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.636849  DOI: Not available
Keywords: TN Mining engineering. Metallurgy
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