Dynamics of Ammonia Borane Using Neutron Scattering

Journal Article · Wed Nov 15 04:00:00 EST 2006 · Physica B Condensed Matter, 385(Pt.1 ):266-268

DOI:https://doi.org/10.1016/j.physb.2006.05.063· OSTI ID:898624

Brown, Craig; Jacques, Teresa; Hess, Nancy J; Daemen, Luke L; Mamontov, Eugene; Linehan, John C; Stowe, Ashley C; Autrey, Thomas

We have used both the backscattering (HFBS) and time-of-flight (DCS) neutron spectrometers to investigate the proton dynamics in ammonia borane, a compound of intense interest as a model for 'chemical hydrogen storage' materials. Results indicate that the deposition of ammonia borane on a mesoporous silicate results in longer proton residence times and lower energy barriers for proton motion compared to bulk ammonia borane. The reduced activation energy for proton motions may partly explain the improved thermolysis and lowering the activation barrier for the loss of the first equivalent of H2. In addition, the phonon density of states for neat ammonia borane compares well with other spectroscopic results, with the intense peak at 22 meV assigned to the librational NH3 and BH3 modes, whereas ammonia borane on MCM-41 displays a broad, featureless spectrum indicating a poorly crystalline material.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 898624
• Report Number(s): PNNL-SA-49618; KC0302010
• Journal Information: Physica B Condensed Matter, 385(Pt.1 ):266-268, Journal Name: Physica B Condensed Matter, 385(Pt.1 ):266-268
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
ACTIVATION ENERGY
AMMONIA
BACKSCATTERING
BORANES
DEPOSITION
HYDROGEN STORAGE
NEUTRON SPECTROMETERS
NEUTRONS
PHONONS
PROTONS
SCATTERING
SILICATES
ammonia borane
hydrogen storage
neutron scattering
rotational barrier