Binding of Molecular Hydrogen in Porous Materials Probed by Rotational Tunneling Spectroscopy : Juergen Eckert
Abstract Biography Host: Prof. S. C. Moss 634 S&R 1 - 4PM
Necessary improvements in porous materials for practical use as hydrogen storage media depend critically on a molecular-level understanding of the interactions of hydrogen at the various binding sites encountered in such materials. One of the few molecular level experimental probes available is that of the observation of transitions between the hindered rotor energy levels of the bound H2 by inelastic neutron scattering spectroscopy. The lowest of these transitions may be described as rotational tunneling and it is extraordinarily sensitive to fine details of the interaction of molecular hydrogen with porous host materials. We can thereby readily detail the increase in interaction strength on moving from systems based on simple physisorption to those that employ various chemical modifications and, most importantly, molecular chemisorption of H2 at some metal binding sites. The results of these studies provide clear direction for efforts in the synthesis of new materials with improved hydrogen interactions in porous coordination polymers.
Juergen Eckert received his Ph.D. from Princeton University in 1975 for neutron scattering studies of the lattice dynamics of solid neon at elevated pressures. Following his appointment as Assistant Physicist at BNL, he moved to LANL in 1979 to provide the scientific leadership necessary to help establish a newly constructed, accelerator-based neutron source, now part of the Los Alamos Neutron Science Center (LANSCE). Since 2001 he has also held the position of Research Physicist at the Materials Research Laboratory of the University of California Santa Barbara. His current scientific interests include the molecular level characterization of active sites and guest-host interactions in porous materials, catalysts, geologic and hydrogen storage materials by the combined application of computational, neutron scattering and other experimental methods. as well as the structural, spectroscopic and computational studies of proton dynamics molecular crystals with short, strong hydrogen-bonds.