Apr 28
Chemistry Department Seminar: Mark Allendorf (Sandia National Laboratories)
"Breaking the Rules: Using Nanoscaling to Overcome Unfavorable Thermodynamics and Kinetics of Metal Hydrides for Hydrogen Storage"
Metal hydrides are widely used as reducing reagents in a variety of chemical reactions. They are also useful for hydrogen storage and can be economically attractive alternatives to compressed gas and liquid hydrogen. Their thermodynamic and kinetic limitations remain vexing problems, however. Material-based hydrogen storage is a classic Goldilocks problem: thermodynamic stability is a requirement for long-term storage, but a material cannot be so stable that impractically high temperatures are required for hydrogen release. This presentation will describe how we designed nanoporous hosts to overcome the chemical and thermal limitations of bulk metal hydrides. We discovered that hydrides can be thermodynamically stabilized or destabilized using materials such as Metal-Organic Frameworks (MOFs). Moreover, their slow hydrogen desorption kinetics can be accelerated to achieve rates suitable for practical storage applications. Finally, we obtained the surprising result that a metal hydride within nanoporous carbon can have a higher useable capacity the bulk material. Together, these results demonstrate renewed potential for materials-based hydrogen storage applications.
*This seminar counts towards the chemistry major seminar attendance requirement.