title: Adsorption Properties of MFM-400 and MFM-401 with CO2 and Hydrocarbons: Selectivity Derived from Directed Supramolecular Interactions.
abstract: ([Sc2(OH)2(BPTC)]) (H4BPTC = biphenyl-3,3',5,5'-tetracarboxylic acid), MFM-400 (MFM = Manchester Framework Material, previously designated NOTT), and ([Sc(OH)(TDA)]) (H2TDA = thiophene-2,5-dicarboxylic acid), MFM-401, both show selective and reversible capture of CO2. In particular, MFM-400 exhibits a reasonably high CO2 uptake at low pressures and competitive CO2/N2 selectivity coupled to a moderate isosteric heat of adsorption (Qst) for CO2 (29.5 kJ mol(-1)) at zero coverage, thus affording a facile uptake-release process. Grand canonical Monte Carlo (GCMC) and density functional theory (DFT) computational analyses of CO2 uptake in both materials confirmed preferential adsorption sites consistent with the higher CO2 uptake observed experimentally for MFM-400 over MFM-401 at low pressures. For MFM-400, the Sc-OH group participates in moderate interactions with CO2 (Qst = 33.5 kJ mol(-1)), and these are complemented by weak hydrogen-bonding interactions (O···H-C = 3.10-3.22 Å) from four surrounding aromatic -CH groups. In the case of MFM-401, adsorption is provided by cooperative interactions of CO2 with the Sc-OH group and one C-H group. The binding energies obtained by DFT analysis for the adsorption sites for both materials correlate well with the observed moderate isosteric heats of adsorption for CO2. GCMC simulations for both materials confirmed higher uptake of EtOH compared with nonpolar vapors of toluene and cyclohexane. This is in good correlation with the experimental data, and DFT analysis confirmed the formation of a strong hydrogen bond between EtOH and the hydrogen atom of the hydroxyl group of the MFM-400 and MFM-401 framework (FW) with H-OEtOH···H-OFW distances of 1.77 and 1.75 Å, respectively. In addition, the accessible regeneration of MFM-400 and MFM-401 and release of CO2 potentially provide minimal economic and environmental penalties.
authors.affiliation: Berzelii Centre EXSELENT on Porous Materials, and Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden.|Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México , Circuito Exterior s/n, CU, Del. Coyoacán, 04510 Mexico, DF, Mexico.
authors.forename: Ilich A
authors.initials: IA
authors.lastname: Ibarra
authors.affiliation: Berzelii Centre EXSELENT on Porous Materials, and Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden.
authors.forename: Amber
authors.initials: A
authors.lastname: Mace
authors.affiliation: School of Chemistry, University of Nottingham , Nottingham NG7 2RD, U.K.|School of Chemistry, University of Manchester , Manchester M13 9PL, U.K.
authors.forename: Sihai
authors.initials: S
authors.lastname: Yang
authors.affiliation: Berzelii Centre EXSELENT on Porous Materials, and Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden.
authors.forename: Junliang
authors.initials: J
authors.lastname: Sun
authors.affiliation: Catalysis Center for Molecular Engineering, Korea Research Institute of Chemical Technology (KRICT) , P.O. Box 107, Yusung, Daejon 305-600, Korea.
authors.forename: Sukyung
authors.initials: S
authors.lastname: Lee
authors.affiliation: Catalysis Center for Molecular Engineering, Korea Research Institute of Chemical Technology (KRICT) , P.O. Box 107, Yusung, Daejon 305-600, Korea.|Department of Chemistry, Sungkyunkwan University , Suwon 440-476, Korea.
authors.forename: Jong-San
authors.initials: JS
authors.lastname: Chang
authors.affiliation: Berzelii Centre EXSELENT on Porous Materials, and Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden.
authors.forename: Aatto
authors.initials: A
authors.lastname: Laaksonen
authors.affiliation: School of Chemistry, University of Nottingham , Nottingham NG7 2RD, U.K.|School of Chemistry, University of Manchester , Manchester M13 9PL, U.K.
authors.forename: Martin
authors.initials: M
authors.lastname: Schröder
authors.affiliation: Berzelii Centre EXSELENT on Porous Materials, and Department of Materials and Environmental Chemistry, Stockholm University , SE-106 91 Stockholm, Sweden.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zou