Collaborative Research: First-Principles Engineering of Nanoscale Kinetics in Advanced Hydrides

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General adoption of hydrogen as a vehicular fuel depends critically not only on the ability to store hydrogen on-board at high volumetric and gravimetric densities, but also on the ability to extract it at sufficiently rapid rates. Recent experimental and theoretical studies have identified several new complex hydrides with thermodynamic properties and material storage capacities approaching practical levels. However, all these materials suffer from extremely poor kinetics. Intellectual merit: The focus of the proposed work is to develop a systematic, rational approach to designing novel nanostructured materials with fast (de)hydrogenation kinetics and favorable thermodynamics using state-of-the-art scientific computing. The accurate predictive power of first-principles modeling will be used to forecast and understand the microscopic kinetic processes involved in the hydrogen release and uptake and to design new material/catalyst systems with improved properties. An in-depth atomistic picture of the chemical reactions, diffusion pathways, and phase changes controlling the kinetics of hydrogen uptake and release will be developed. Fundamental factors that control hydrogen-metal bond strength, the role of surface structure and finite size on the thermodynamics and kinetics of hydride nanoparticles will also be investigated. The effect of dopants and nanoscale catalysts in achieving fast kinetics and reversibility will be elucidated at the atomic level. Broader impact: The proposed work will aid in the development of computational materials science courses. In addition, there will be student exchange between Northwestern and UCLA, as students from each group will have the opportunity for extensive visits to the other. The results of the research will be disseminated through the education of graduate students, and introduction of undergraduate students to computational methods. It is expected that the skills acquired by the students, for example in the use of computational modeling and simulation, will prepare them for future work in the industrial and educational communities. Finally, successful completion of this research program will greatly assist the development of new hydrogen storage systems for clean, environmentally safe passenger vehicles.