Research & Publications
Do you like math and applying it to address real-world problems? If your answer is yes then you might want to consider doing research in computational chemistry with me. In my group you will get hands-on experience using the latest approaches in molecular modeling and simulation.
Although my interests span a wide range of topics, e.g., chemical physics (1), quantum dynamics (2), electronic structure theory (3), and just about everything in between, my latest project relates to the search for alternative energy sources. Since a hydrogen-based energy economy has potential to rid the world of many of today's current problems, e.g., air pollution, greenhouse gas production, research into the use of hydrogen as an energy carrier is growing at a rapid pace. A particular challenge that researchers face is the development of materials that are capable storing hydrogen safely.
Figure 1. IRMOF-1, a metal organic framework consisting of Zn, O, C, & H
The particular focus of my research is on the use of modern and novel computational approaches to assist in the design of hydrogen storage materials, materials that require a delicate balance of a variety of properties in order to be practical. For example, to meet the 2015 storage system targets(4) hydrogen storage materials require gravimetric and volumetric densities of at least 7.5 wt % and 70 g/L, respectively, a minimum delivery pressure of 12 bar, and a fueling time of approximately 3 minutes. There are no systems to date that meet these requirements.
My strategy is to use molecular dynamics (MD) calculations to simulate the diffusion of molecular hydrogen within a host lattice, an example of which is shown in Figure 1 to the right. However, in order to obtain accurate diffusion rates it is important that the energetics of the adsorption/desorption reaction profile (see Figure 2) be precise and accurate. To achieve this we often use the results of high-level quantum chemical calculations.3
Figure 2. Schematic of a typical reaction profile.
Other critical pieces of information that will be gleaned from the MD studies are the corresponding thermal properties of the host material, i.e., the heat capacity and thermal conductivity, properties that determine how heat flows throughout the lattice; the buildup of heat within the host material during loading (and cooling during unloading) is a consequence of the fact that the potential energy between the H2 molecules and the host gets converted into kinetic energy, i.e., conservation of energy. The aforementioned thermal properties are necessary to determine whether or not a particular host candidate should be considered for production. With results from the MD calculations as input, the kinetic monte carlo method will be used to simulate the overall loading and unloading process while faithfully capturing temperature fluctuations. The ultimate goal is to give material developers a valuable tool for screening candidates for hydrogen storage.
Clearly there are many facets to the work I described above, and I can use a lot of help. If you would like to have more information and/or discuss the possibility of working in my group please feel free to reach me at: email@example.com
1. T.C. Castonguay, F.Wang, J. Chem. Phys. 128, 124706 (2008)
2. J. Peng, T.C. Castonguay, D.F. Coker, and L.D. Ziegler, J. Chem. Phys. 131, 054501 (2009)
3. B. Temelso, T. E. Morrell, R. M. Shields, M. A. Allodi, E. K. Wood, K. N. Kirschner, T. C. Castonguay, Kaye A. Archer, and George C. Shields, J. Phys. Chem. A 116, 2209-2224 (2012)
4. U.S. Department of Energy's Energy Efficiency and Renewable Energy Website. https://www1.eere.energy.gov/hydrogenandfuelcells/storage/current_technology.html