Structure, Dynamics, and Reactions of Low Dimensional Systems
Abstract
Investigations of fundamental materials physical and chemical processes and of the microscopic origins of materials properties, and explorations aiming at novel materials preparation and design, are major thrusts of modern chemical, physical and materials research. This research program focuses on the development and implementation of computational and simulation methodologies of predictive capabilities, and their use as tools of discovery in a broad range of materials problems of fundamental and technological interest, pertaining to low-dimensional and nanoscale systems. The proposal outlines the development and employment of a versatile arsenal of theoretical methodologies that range from classical molecular dynamics simulations to quantum mechanical first-principles optimization and simulations. Topics of the proposed research program include: (1) Ion-trapped clusters, their methane activation reactions, and water-splitting nano-cluster catalyst. Joint theoretical and ion-trap experimental investigations on: (i) Systematic studies of the size-evolution of geometric and electronic structure of small metal clusters ( e.g. Tan , n=1-10, bare clusters, as well as alloyed, or doped, ones) and their reactions with low hydrocarbons (e.g. C-H activation of methane, CH4), oxidizing agents, as well as non-oxidative coupling of-methane (to circumvent CO2 formation), and H2O, aiming at uncovering size-specific catalysts for the synthesis of higher hydrocarbons and dihydrogen H2, as well as aldehydes, alcohols, and artificial fuels,, with special emphasize on single-atom, or di-atom catalysis (free systems, as well as embedded in matrix environment), bridging the homogeneous and heterogeneous catalysis regimes. (ii) Investigations on size-selected manganese-oxide-based clusters and their interactions with water molecules, aiming at modeling, with increasing hierarchical complexity, artificially built models of the oxygen evolution complex (OEC) of photosystem II, catalyzing the splitting of water. Particular emphasis will be placed on elucidation of the role of calcium doping as a symmetry breaking agent, controlling structural fluctionality and spin states. The theoretical part involves first-principles explorations of the geometrical structure, stability, electronic structure and vibrational spectra, and dynamical pathways of structural transformations and water-splitting reaction channels catalyzed by the synthetically built OEC-analogues. The research targets the formulation of design principles that would aid the design of artificially built water splitting catalytic systems. (2) Ligand protected metal nanoclusters and their two-dimensional assemblies. Explorations of the properties of two-dimensional inorganic-organic hybrid membranes and three-dimensional superlattices made through the self-assembly of nanometer metal cores protected by monolayers of organic ligands. The research program entails the development of molecular dynamics simulations of nanocluster-based materials through the use of first-principles simulations and fitting of interaction potentials. Applications of these methodologies will focus on investigations of mechanical and thermomechanical properties of nanocluster membranes that are grown on fluids, for example water, which could serve as highly efficient high-resolution nanofilters, and on three-dimensional framework solids that could serve as high-impact energy dissipation buffers and pressure sensors.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110198XX0
Entities
People
- Uzi Landman
Organizations
- Air Force Office of Scientific Research
- Georgia Tech Research Corporation
- United States Air Force