This SGER award to University of Virginia from the Solid State Materials Chemistry program in the Division of Materials Research is to carry out gravimetric and spectroscopic investigations on new solid state thin films of dihydrogen complexes based on transition metal organometallics. These organometallic complexes will be synthesized by pulsed laser ablation under conditions tailored to appropriately match the vaporized metal with carbon atoms present in the gas plasma. Using both nanogravimetric and in-situ Inelastic Electron Tunneling Spectroscopic measurements, the project will study these dihydrogen complexes for the following: a) the attachment of hydrogen molecules in the organometallic complexes and their binding strength; b) the effect of transition metal atoms clusters on hydrogen uptake; and c) the conditions for optimum rate and degree of hydrogen release from the complexes. Other transition metal complexes synthesized with other carbon sources from alkane and cyclic groups will also be studied to elucidate the mechanism for the dihydrogen complex formation. The outcome from the proposed research is expected to have a direct impact on future hydrogen storage technologies. Results from the studies will be disseminated through publications, talks and presentations with the involvement of graduate students and undergraduate students.
Molecular hydrogen binding mechanism on transition metal organometallic complexes will be studied by this project. This hydrogen binding appear to be neither ?physical? nor ?chemical? but of an intermediate type. The stronger than ?physical? binding means that large numbers of hydrogen molecules can be adsorbed without cooling to cryogenic temperatures and weaker than ?chemical? binding means that the hydrogen can be desorbed at convenient not too high temperatures. The strength of this intermediate type of binding is expected to strongly influence the vibration frequencies of the hydrogen molecule adsorbed on to organometallic complexes. The project will carry out gravimetric and spectroscopic studies using an electronic method that could determine the amount of hydrogen absorbed and its binding affinities. The proposed experimental studies will be correlated with available theoretical predictions based on accurate quantum mechanical calculations. The outcome from the proposed research is expected to have a direct impact on future hydrogen storage technologies. Plans are in place to integrate the proposed research into a chapter on ?Nanomaterials for Energy? that will form part of a new course called ?Introduction to Nanophysics? that was started recently at University of Virginia.
