Large-scale Screening of Nanoporous Materials 9:00 am Predictive Materials Discovery: Finding Optimal Zeolites for Challenging Separation and Chemical Conversions

s Listed in alphabetical order of first author's name Predictive Materials Discovery: Finding Optimal Zeolites for Challenging Separations and Chemical Conversions Peng Bai, Chris Knight, Michael W. Deem, Michael Tsapatsis, and J. Ilja Siepmann Departments of Chemistry and of Chemical Engineering and Materials Science and Chemical Theory Center, University of Minnesota Leadership Computing Facility, Argonne National Laboratory Departments of Bioengineering and of Physics and Astronomy, Rice University Zeolites play numerous important roles in modern petroleum refineries and have the potential to advance the production of fuels and chemical feedstocks from renewable resources. The performance of a zeolite as separation medium and catalyst depends on its framework structure and the type or location of active sites. To date, 213 framework types have been synthesized and >330000 thermodynamically accessible zeolite structures have been predicted. Hence, identification of optimal zeolites for a given application from the large pool of candidate structures is attractive for accelerating the pace of materials discovery. Here we identify, through a large-scale, multi-step computational screening process, promising zeolite structures for two energy-related applications: (i) with the ability to purify ethanol beyond the ethanol/water azeotropic concentration in a single separation step from fermentation broths and (ii) with up to two orders of magnitude better adsorption capability than current technology for linear and slightly branched alkanes with 18-30 carbon atoms encountered in petroleum refining. These results demonstrate that predictive modeling and data-driven science can now be applied to solve some of the most challenging separation problems involving highly non-ideal mixtures and highly articulated compounds. Snapshots of representative sorbate configurations obtained for adsorption from a liquid phase containing an equimolar hydrocarbon mixture at T = 573 K and p = 3 MPa. Views facing (top row) and along (bottom row) the main channel axis are shown for (a) ATO, (b) MTW, and (c) PCOD 8113534. Zeolite frameworks are depicted as gray lines, and C18, C24, C30, (2C17 and 4C17), and 22C16 molecules as cyan, purple, blue, red, and green spheres, respectively. Prediction of High Deliverable Capacity Metal-Organic Frameworks with an Evolutionary Algorithm Yi Bao, Richard L. Martin, Cory Simon, Maciej Haranczyk, Berend Smit, Michael W. Deem d Department of Physics and Astronomy, Rice University Computational Research Division, Lawrance Berkeley National Laboratory Department of Chemical & Biomolecular Engineering, University of California, Berkeley Department of Bioengineering, Rice University Metal organic frameworks (MOFs) are actively being explored as potential adsorbed natural gas storage materials for small vehicles. We here describe an in silico procedure to identify high methane deliverable capacity MOFs. We efficiently search the composition and conformation space of organic linkers for nine MOF networks, finding a total of 48 predicted materials with higher predicted deliverable capacity (at 65 bar storage, 5.8 bar depletion, and 298 K) than MOF5 in four of the nine networks. Embedding Methodologies for Electrochemistry: Oxidative Decomposition of Lithium-Ion Battery Solvents Taylor Barnes, Jakub Kaminski, Oleg Borodin, Thomas Miller III Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 Department of Mathematics, University of California, Los Angeles, CA 90095 U.S. Army Research Laboratory, Electrochemistry Branch, Sensors & Electron Devices Directorate, 2800 Powder Mill Road, Adelphi, MD 20783 A central challenge in the refinement of lithium-ion batteries is to avoid cathode-induced oxidative decomposition of electrolyte solvents, such as ethylene carbonate (EC) and dimethyl carbonate (DMC). We study the oxidation potentials of neat EC, neat DMC, and 1:1 mixtures of EC and DMC using our newly developed projection-based embedding method, which we demonstrate to be capable of correcting qualitative inaccuracies exhibited by conventional KohnSham density functional theory (DFT) methods. Our wavefunction-in-DFT embedding approach enables accurate calculation of the vertical ionization energy (IE) of individual molecules at the CCSD(T) level of theory, while explicitly accounting for the solvent using a combination of DFT and molecular mechanics interactions. We find that the ensemble-averaged distributions of IEs are consistent with a linear response interpretation of the statistics of the solvent configurations, enabling determination of both the intrinsic adiabatic oxidation potential of the solvents and the corresponding solvent reorganization energies. Interestingly, we demonstrate large contributions to the solvation properties of DMC from quadrupolar interactions, resulting in a much larger solvent reorganization energy than that predicted using dielectric continuum models. This insight into the nature of DMC intermolecular interactions supports an improved understanding of the solvation structure of ions in lithium-ion batteries. Figure: Summary of the embedding strategy. First, equilibrium solvent configurations are generated using classical MD simulations. Then, embedding calculations are performed to determine the vertical IE of each configuration. The Projection-Based WFT-in-DFT Embedding Method: Application to Organometallic and Condensed-Phase Systems Taylor Barnes, Pengfei Huo, Jason Goodpaster, Jakub Kaminski, Oleg Borodin, Thomas Miller III Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125 Department of Chemistry, University of California, Berkeley, CA 94720 Department of Mathematics, University of California, Los Angeles, CA 90095 U.S. Army Research Laboratory, Electrochemistry Branch, Sensors & Electron Devices Directorate, 2800 Powder Mill Road, Adelphi, MD 20783 The computational cost of performing accurate ab initio wavefunction theory (WFT) calculations on condensed-phase systems has motivated the development of numerous methods to partition the description of large systems into smaller subsystem calculations. These methods typically describe the interactions between subsystems in an approximate way, often requiring the introduction of fictitious link-atoms between covalently bound subsystems. Our recently developed projection-based WFT-in-DFT embedding method avoids these problems by accounting for interactions between subsystems at the DFT level, without any of the approximations common among other WFT-in-DFT embedding methods. We demonstrate the successful application of this method to challenging problems, including the organometallic catalysis of hydrogen evolution and the condensed-phase oxidation of battery solvents. Our results establish the applicability of the projection-based WFT-in-DFT embedding method to complex, condensed-phase systems, such as metal organic frameworks. Figure: Application of the projection-based WFT-inDFT embedding method to a cobalt-based catalyst for hydrogen evolution. The red region, which includes the cobalt atom, is treated at the CCSD(T) level of theory, while the remainder of the system is treated at the DFT level of theory. Because of the numerically exact DFTlevel treatment of the interactions between subsystems, link-atoms are not necessary for the subsystem calculations. A computational study of water behavior in two Zr6-Based Metal OrganicFrameworks, UiO-66 and NU-1000. Varinia Bernales, David Semrouni, Emmanuel Haldoupis, Joshua Borycz, Joe Hupp Omar Farha, Randy Snurr and Laura Gagliardi a Department of Chemistry, University of Minnesota – Twin Cities b Department of Chemistry, Northwestern University c Department of Chemical and Biological Engineering, Northwestern University Zr6-based Metal Organic-frameworks (MOFs) are considered chemically and thermally stable (up to 500 C) materials. [1] Recently, it was reported that UiO-67 collapses when water vapor is introduced, unlike to its isoreticular analog UiO-66. [2] This shows that the presence of water in the pores of a MOF can lead to instabilities (e.g. hydrolysis and/or capillary force) in the material. These instabilities may lead to a loss of its crystallinity. [3] In this work, we examined the adsorption and diffusion behavior of water in two Zr-based MOFs. We used molecular simulations with available force fields, such as UFF/DREIDING, combined with different set of charges obtained from periodic DFT calculations. As a first step we aim to investigate the reliability of the available force fields and point charge assignment methods for the study of water (solvent) behavior in these systems and subsequently to develop more realistic force fields using quantum chemical calculations. [1] J. Am. Chem. Soc., 2008, 130, 13850-13851. [2] J. Mater. Chem., A, 2013,1, 5642-5650. [3] Chem. Commun., 2014,50, 8944-8946. The Electronic Structure of Nitrosyl Metal Catecholates Gary D. Bondarevsky, Laura Gagliardi, and Randall Snurr a. Department of Chemistry, University of Minnesota b. Department of Chemical and Biological Engineering, Northwestern University Metal organic frameworks (MOFs) are composed of metal centers and organic linker molecules in a crystalline structure. MOFs have a nanoporous structure that is highly tunable in size by adjusting the metal nodes or organic ligands. The metal nodes can be anything from a single metal atom to larger polyoxometalate nodes. The organic linker must be a polydentate linker able to connect multiple nodes. Unlike many materials, MOFs can be used for many different applications by varying the metal centers or the organic linkers. The MOF can be tuned to specific applications such as catalysis or gas storage, which are important for energy applications. One such modification has been made to include a catecholate group within the organic linker. The catecholate group can be metallated with various divalent transition metals such as Mn, Fe, Co, Ni, Cu, and Zn. These metal−catecholates can be used to bind NO within the MOF. Nitric oxide (NO) is an environmental contaminant present in flue gas produced from power plants; therefore, it is advantageous to bind NO to reduce the pollution from power plants. The electronic structure and binding of NO to the various metal−catecholate systems have been investigated by density functional theory (DFT), and complete active space self-consistent field (CASSCF) followed by second order perturbation theory (CASPT2) methods. Results will be presented on the Mn and Fe systems. CO2 Adsorption in M-IRMOF10 (M=Mg, Ca, Fe, Cu, Zn, Ge, Sr, Cd, Sn, Ba) Joshua Borycz, Davide Tiana, Emmanuel Haldoupis, Ilja Siepmann, Laura Gagliardi Department of Chemistry, University of Minnesota Department of Chemistry, University of Bath Metal-organic frameworks (MOFs) have been studied extensively for the application of flue gas separation because of their tunability, structural stability, and large surface area. IRMOF10 is one of the most well studied structures, and contains saturated tetrahedral Zn4O nodes and biphenyl dicarboxylate linkers that form a cubic unit cell. The effect of changing the metal within this MOF topology has been studied computationally, but the change in its affinity towards CO2 has never been probed. To study the CO2 interactions within the M-IRMOF10 series, periodic density functional theory (DFT) was used to optimize the structures of each MOF and compute point charges. Clusters centering on the metal node were then designed and used to compute potential energy curves (PECs) that maximize the interaction of CO2 with each metal, with PBE0-D3. These reference curves were then used to fit parameters for each metal. TraPPE parameters were used for all interactions apart from the metals. The results indicate that the 3d metals (Ca, Fe, Cu, Zn) each have very weak interaction with CO2. For heavier ions like Sn and Ba the increase in adsorption of CO2 at low pressure is more noticeable (Figure 1). Both UFF and this newly derived force field can capture this behavior reasonably well. Figure 1: On the left, minimum energy (kJ/mol) versus ionic radius (Å) of the metal center within the IRMOF10 cluster. On the right, low pressure CO2 adsorption isotherms with pure UFF and the TraPPE/parameterized metal force field developed in this work. 1. Yang, Q.; Zhong, C.; Chen, J.-F. Computational Study of CO2 Storage in Metal−Organic Frameworks, J. Phys. Chem. C, 112, 5, 2008, 1562-1569. 2. Hicks, J. M.; Desgranges, C.; Delhommelle, J. Characterization and Comparison of the Performance of IRMOF-1, IRMOF-8, and IRMOF-10 for CO2 Adsorption in the Subcritical and Supercritical Regimes, J. Phys. Chem. C, 116, 43, 2012, 22938-22946. 3. Yang, L.-M.; Ravindran, P.; Vajeeston, P.; Tilset, M. Ab initio invesitgations on the crystal structure, formation enthalpy, electronic, structure, chemical bonding, and optical properties of experimentally synthesized isoreticular metal-organic framework-10 and its analogues: M-IRMOF-10 (M=Zn, Cd, Be, Mg, Ca, Sr, Ba), R. Soc. Chem. Adv., 2, 2012, 1618-1631. The Synergy Between Anion Photoelectron Spectroscopy and Theory Jacob Graham, Allyson Buytendyk, Julian Gould, Kit Bowen Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA Together, anion photoelectron spectroscopy and theory are a synergetic combination. Since negative ion photoelectron spectroscopy provides electronic structure information about the mass-selected anion’s neutral counterpart, as well as the energetic relationship between the anion and its corresponding neutral, it is a powerful tool for benchmarking and validating theoretical calculations. Here, the essential capabilities of anion photoelectron (photodetachment) spectroscopy are summarized, several examples of synergy between anion photoelectron spectroscopy and theory are reviewed, preliminary photoelectron and theoretical work on several porphyrin anions is presented, and plans for future studies are discussed. At this very early stage of our work, porphyrins are seen as primitive models of metal organic frameworks (MOF’s). As next steps, we plan to generate anions of small MOF’s or fragments of MOF’s in the gas phase by bringing together metal atoms and organic linkers in our anion beam source, mass-selecting the species of interest, measuring their photoelectron spectra, and conducting complimentary calculations. Additionally, we will explore bringing anionic MOF’s into the gas phase, where they can be photodetached, by electro-spraying MOF nanocrystals. J. Gould, supported by a JHU Greer Fellowship, thanks M. R. Pederson and Chad Hoyer for help with DFT and CASSCF calculations, respectively.