Absence of the Structural Phase Transition in Ammonia Borane Dispersed in Mesoporous Silica: Evidence of Novel Thermodynamic Properties

Paolone, A.; Palumbo, O.; Rispoli, Pasquale; Cantelli, R.; Autrey, Tom; Karkamkar, Abhijeet J.

doi:10.1021/jp902341s

Cited by 66 publications

(59 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With both X-ray powder diffraction data, inelastic spectroscopy and differential scanning calorimetry, it was shown that this structural phase transition was suppressed for ammonia borane confined in MCM-41 (ordered mesoporous silica). [61,62] From this first example it became evident that nanoconfinement indeed can significantly alter the properties of hydrogen storage materials. This spurred a range of investigations on the effect of nanosizing and -confinement for most common metal hydride systems that can be used for hydrogen storage.…”

mentioning

confidence: 99%

Nanosizing and Nanoconfinement: New Strategies Towards Meeting Hydrogen Storage Goals

2010

View full text Add to dashboard Cite

Hydrogen is expected to play an important role as an energy carrier in a future, more sustainable society. However, its compact, efficient, and safe storage is an unresolved issue. One of the main options is solid-state storage in hydrides. Unfortunately, no binary metal hydride satisfies all requirements regarding storage density and hydrogen release and uptake. Increasingly complex hydride systems are investigated, but high thermodynamic stabilities as well as slow kinetics and poor reversibility are important barriers for practical application. Nanostructuring by ball-milling is an established method to reduce crystallite sizes and increase reaction rates. Since five years attention has also turned to alternative preparation techniques that enable particle sizes below 10 nanometers and are often used in conjunction with porous supports or scaffolds. In this Review we discuss the large impact of nanosizing and -confinement on the hydrogen sorption properties of metal hydrides. We illustrate possible preparation strategies, provide insight into the reasons for changes in kinetics, reversibility and thermodynamics, and highlight important progress in this field. All in all we provide the reader with a clear view of how nanosizing and -confinement can beneficially affect the hydrogen sorption properties of the most prominent materials that are currently considered for solid-state hydrogen storage.

show abstract

mentioning

confidence: 99%

Nanosizing and Nanoconfinement: New Strategies Towards Meeting Hydrogen Storage Goals

2010

View full text Add to dashboard Cite

show abstract

“…The positive Clapeyron slope indicates that the phase transition from I4mm and Cmc2 1 structure is of exothermic in nature, which is in good agreement with earlier DSC studies [74,75,76]. Recently, it has been reported that ammonia borane embedded in mesoporous silica does not exhibit this low temperature phase transition at 225 K [77,78]. At low temperature and high pressure, the formation of hydrogen clathrate hydrate, H 2 (H 2 O) 2 , which can store 5.3 wt% H 2 and can be preserved to ambient pressure at 77 K was reported [79].…”

Section: High Pressure Studies Of Hydrogen Storage Materialssupporting

confidence: 89%

“…Najiba et al [78] also observed phase B which is evident from the change of Raman modes. This new phase has very narrow temperature and pressure range for stability.…”

Section: High Pressure Studies Of Hydrogen Storage Materialsmentioning

confidence: 88%

High Pressure and Low Temperature Study of Ammonia Borane and Lithium Amidoborane

Najiba¹

View full text Add to dashboard Cite

During this dissertation, Raman spectroscopic study of lithium amidoborane has been carried out at high pressure in a diamond anvil cell. It has been identified that there is no dihydrogen bond in the lithium amidoborane structure, whereas dihydrogen bond is the characteristic bond of the parent compound ammonia borane. At high pressure up to 15 viii GPa, Raman spectroscopic study indicates two phase transformations of lithium amidoborane, whereas synchrotron X-ray diffraction data indicates only one phase transformation.Pressure and temperature has a significant effect on the structural stability of ammonia borane. This dissertation explored the phase transformation behavior of ammonia borane at high pressure and low temperature using in situ Raman spectroscopy.The P-T phase boundary between the tetragonal (I4mm) and orthorhombic (Pmn2 1

show abstract

“…predicted by Equation 3.1, even with prolonged heating at 85 o C. 1,7 As a result, a number of approaches are now being explored to induce efficient AB H 2 -release, including, for example, activation by transition metal catalysts, [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] acid catalysts, 28 base catalysts, 29 and nano and meso-porous scaffolds. [30][31][32] Most of these additives use organic solvents either as the reaction medium or as the AB transport and loading method. The use of organic solvents is not desirable due to their high volatility, which would result in their loss to the environment as well as their contamination of the H 2 -stream.…”

Section: Resultsmentioning

confidence: 99%

Amineborane Based Chemical Hydrogen Storage - Final Report

Sneddon¹

2011

View full text Add to dashboard Cite

Absence of the Structural Phase Transition in Ammonia Borane Dispersed in Mesoporous Silica: Evidence of Novel Thermodynamic Properties

Cited by 66 publications

References 31 publications

Nanosizing and Nanoconfinement: New Strategies Towards Meeting Hydrogen Storage Goals

Nanosizing and Nanoconfinement: New Strategies Towards Meeting Hydrogen Storage Goals

High Pressure and Low Temperature Study of Ammonia Borane and Lithium Amidoborane

Amineborane Based Chemical Hydrogen Storage - Final Report

Contact Info

Product

Resources

About