First-Principles Prediction of Small Molecule Adsorption in MOF-74 Variants

ORAL

Abstract

Using density functional theory (DFT), we predict binding energies of flue gas molecules (CO, CO$_{2}$, H$_{2}$O, H$_{2}$S, N$_{2}$, NH$_{3}$, SO$_{2}$, and H$_{2})$ and small hydrocarbons (CH$_{4}$, C$_{2}$H$_{2}$, C$_{2}$H$_{4}$, C$_{2}$H$_{6}$, C$_{3}$H$_{6}$, and C$_{3}$H$_{8})$ in a variety of ``MOF-74'' variants.~ Using a harmonic approximation to compute quantum zero-point and thermal corrections, we compute binding enthalpies for comparison with experimental heats of adsorption.~ Our study is performed using vdW-DF2, a fully nonlocal dispersion-corrected density functional along with Hubbard U corrections on 3$d$-orbital electrons as appropriate.~ We study MOF-74 variants, ``M-MOF-74'', where ``M'' is chosen to be any divalent third-row metal cation (M$=$ Mg, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn).~ Additionally, we study ``M-MOF-74'' systems with ``meta-dobdc'' as the linker (as compared to the traditional ``para-dobdc'').~ We compare with experiment when available and find reasonable agreement. ~We identify trends, and compare with experiment where available, finding excellent agreement. This work supported by DOE through the EFRC on Gas Separations for Clean Energy Technologies; computational resources provided by NERSC.~

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Authors

  • Joshua Howe

    Dept. of Chemical and Biomolecular Engineering, University of California, Berkeley; The Molecular Foundry, LBNL

  • Kyuho Lee

    Dept. of Chemical and Biomolecular Engineering, University of California, Berkeley; The Molecular Foundry, LBNL, Molecular Foundry, Berkeley Lab

  • Li-Chiang Lin

    Dept. of Chemical and Biomolecular Engineering, University of California, Berkeley

  • Berend Smit

    Dept. of Chemical and Biomolecular Engineering, University of California, Berkeley; Materials Sciences Division, LBNL, University of California, Berkeley

  • Jeffery B. Neaton

    Department of Physics, UC-Berkeley; Molecular Foundry, LBNL, Molecular Foundry, LBNL, Department of Physics, UC Berkeley, Molecular Foundry, LBNL and Dept. Physics, UC Berkeley, Molecular Foundry, Lawrence Berkeley National Laboratory and Department of Physics, University of California, Berkeley, UC Berkeley, Dept of Physics; Materials Science Division, LBNL, Molecular Foundry, Lawrence Berkeley National Laboratory; Department of Physics, UC-Berkeley, The Molecular Foundry, LBNL; Dept. of Physics, University of California, Berkeley, Lawrence Berkeley National Laboratory, UC Berkeley Department of Physics, Lawrence Berkeley Natl Lab and Department of Physics, UC-Berkeley, Physics Department, UC Berkeley; Molecular Foundry, Lawrence Berkeley National Lab