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           COLLOQUIUM OF THE COMPUTATIONAL MATERIALS SCIENCE CENTER
                              College of Science
                       (CDS Department CSI 898-Sec 001)
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                 Nano Materials for Hydrogen Storage

                             Puru Jena
Department of Physics, Virginia Commonwealth University, Richmond, VA

The limited supply of fossil fuels, its adverse effect on the 
environment, and growing worldwide demand for energy has necessitated 
the search for new and clean sources of energy.  Hydrogen, the third 
most abundant element on Earth, is considered as an alternative to fossil 
fuels.  However, hydrogen, like electricity, is not an energy source but 
an energy carrier.  It needs to be produced.  While considerable challenges 
need to be overcome for its production, distribution, and use in fuel cells, 
it's safe, efficient, and economical storage is considered to be critical for 
a successful hydrogen economy. For the mobile industry which is responsible 
for nearly 80% of our oil needs, hydrogen storage materials need to have high 
gravimetric and volumetric density and operate at ambient thermodynamic 
conditions, as the current methods for storing hydrogen as a compressed gas 
or liquid are not suitable for wide commercial applications. In order for the 
host materials to have gravimetric density of about 10 wt%, they have to 
consist of elements lighter than Aluminum. Unfortunately, the bonding of 
hydrogen in these materials is either too strong or too weak. Ways must, 
therefore, be found to tune the hydrogen bond strength so that host materials 
composed of light elements can be used as effective hydrogen storage materials. 

This talk will discuss how the novel properties of materials at the nanoscale 
can improve the thermodynamics and kinetics of hydrogen.  In particular, I will 
discuss how carbon based nanostructures such as nanotubes and fullerenes can not 
only be used as catalysts to improve hydrogen uptake and release in complex light 
metal hydrides such as sodium alanate, but also how they can be functionalized with 
metal and B atoms to adsorb hydrogen in a novel quasi-molecular form. Such a bonding 
can improve the kinetics and thermodynamics of hydrogen sorption. I will also discuss 
the role of electric fields in hydrogen storage. These results, based upon density 
functional theory and quantum molecular dynamics, provide a fundamental understanding 
of the interaction of molecular hydrogen with hosts consisting of light elements. It 
is hoped that the understanding gained here can be useful in designing better 
materials for hydrogen storage.Results will be compared with available experimental data.

                        Monday, March 30, 2009
                                  4:30 pm
                     Room 301, Research I, Fairfax Campus

Refreshments will be served at 4:15 PM.
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Find the schedule at www.cmasc.gmu.edu/seminar/schedule.html
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