TY - JOUR
T1 - Tuning Binding Tendencies of Small Molecules in Metal-Organic Frameworks with Open Metal Sites by Metal Substitution and Linker Functionalization
AU - You, Wenqin
AU - Liu, Yang
AU - Howe, Joshua D.
AU - Tang, Dai
AU - Sholl, David S.
N1 - Publisher Copyright:
© 2018 American Chemical Society.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2018/12/6
Y1 - 2018/12/6
N2 - Metal-organic frameworks (MOFs) with open metal sites (OMS) are known to be selective for ethylene relative to ethane. In practical applications of this separation, the presence of other small molecules such as H2O, CO, and C2H2 may affect the suitability of sorbents. We used density functional theory (DFT) calculations to compute the binding energies of H2O, CO, C2H2, C2H4, and C2H6 in M-BTC (BTC = 1,3,5-benzenetricarboxylic acid) with 12 different metals forming OMS (M = Mg, Ti, V, Cr, Mo, Mn, Fe, Ru, Co, Ni, Cu, and Zn). To probe the generality of these results for MOFs containing other ligands, we performed similar calculations for metal-substituted MOFs based on four more materials with dimeric Cu sites. Our results provide useful insights into the variations in binding energies that are achievable by metal substitution in this broad class of MOFs, as well as pointing toward feasible adsorption-based separation strategies for complex molecular mixtures. Zn OMS MOFs were predicted to have the highest C2H4/C2H6 selectivity, but the strong binding energy of solvents and other small molecules in these materials may create practical challenges. We used DFT calculations to examine whether functionalizing linkers in these materials with electron withdrawing (-fluorine) and donating (-methyl) groups offer a useful way to tune molecular binding energies on OMS in these materials.
AB - Metal-organic frameworks (MOFs) with open metal sites (OMS) are known to be selective for ethylene relative to ethane. In practical applications of this separation, the presence of other small molecules such as H2O, CO, and C2H2 may affect the suitability of sorbents. We used density functional theory (DFT) calculations to compute the binding energies of H2O, CO, C2H2, C2H4, and C2H6 in M-BTC (BTC = 1,3,5-benzenetricarboxylic acid) with 12 different metals forming OMS (M = Mg, Ti, V, Cr, Mo, Mn, Fe, Ru, Co, Ni, Cu, and Zn). To probe the generality of these results for MOFs containing other ligands, we performed similar calculations for metal-substituted MOFs based on four more materials with dimeric Cu sites. Our results provide useful insights into the variations in binding energies that are achievable by metal substitution in this broad class of MOFs, as well as pointing toward feasible adsorption-based separation strategies for complex molecular mixtures. Zn OMS MOFs were predicted to have the highest C2H4/C2H6 selectivity, but the strong binding energy of solvents and other small molecules in these materials may create practical challenges. We used DFT calculations to examine whether functionalizing linkers in these materials with electron withdrawing (-fluorine) and donating (-methyl) groups offer a useful way to tune molecular binding energies on OMS in these materials.
UR - http://www.scopus.com/inward/record.url?scp=85058193015&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b08855
DO - 10.1021/acs.jpcc.8b08855
M3 - Article
AN - SCOPUS:85058193015
VL - 122
SP - 27486
EP - 27494
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 48
ER -