(30a) Effects of Catalytic Supports On the Structure and Dehydrogenation of Ammonia Borane

Hydrogen gas is
encouraged as a fuel as it is more energy efficient and environmental friendly
when compared to other conventional fuels [1]. However, the main concern has
been the storage of hydrogen for its effective usage as a fuel. Recently, hydrogen
storage using metal hydrides and chemical hydrides has been receiving great
attention due to their higher gravimetric storage. Among the chemical hydrides,
B-N compounds are much attractive as both B and N are lighter elements and have
an ability to bear multiple hydrogen atoms [1]. Ammonia Borane (AB), which has
a gravimetric and volumetric hydrogen storage densities up to 19.6 wt. % and
0.16 kg-H₂/L upon complete dissociation of AB [2, 3], is considered
to be one of the best materials for hydrogen storage.

The present work
includes computational studies of the structure and the dehydrogenation of AB. Based
on the experimental studies performed, hydrogen release is observed when the AB
solution came in contact with the Zirconia catalytic support. Computational
studies are performed to interpret the experimental results of the above
mentioned reaction to gain a better understanding of the reaction
thermodynamics and mechanisms, which would help in design of new catalysts. Quantum
Mechanics (QM) and Molecular Dynamics (MD) simulations are performed using
CASTEP programming package to analyze structure, stability and dehydrogenation
of AB.

References:

1.           
C.
W. Hamilton, R. T. Baker, A. Staubitzc, I. Manners, ?B?N compounds for chemical
hydrogen storage,? Chemical Society Reviews, 38, 279-293, 2009.

2.           
C.
R. Miranda and G. Ceder, "Ab initio investigation of ammonia-borane
complexes for hydrogen storage," Journal of Chemical Physics, 126,
1847031-11, 2007.

3.           
M.
E. Bowden, G. J. Gainsford, and W. T. Robinson, "Room temperature
structure of ammonia borane," Australian Journal of Chemistry, 60,
149-153, 2007.