title: Theoretical Investigations of CO2and H2Sorption in Robust Molecular Porous Materials.
abstract: Molecular simulations of CO2and H2sorption were performed in MPM-1-Cl and MPM-1-TIFSIX, two robust molecular porous materials (MPMs) with the empirical formula [Cu2(adenine)4Cl2]Cl2and [Cu2(adenine)4(TiF6)2], respectively. Recent experimental studies have shown that MPM-1-TIFSIX displayed higher CO2uptake and isosteric heat of adsorption (Qst) than MPM-1-Cl [Nugent, P. S.; et al. J. Am. Chem. Soc. 2013, 135, 10950-10953]. This was verified through the simulations executed herein, as the presented simulated CO2sorption isotherms and Qstvalues are in very good agreement with the corresponding experimental data for both MPMs. We also report experimental H2sorption data in both MPMs. Experimental studies revealed that MPM-1-TIFSIX exhibits high H2uptake at low loadings and an initial H2Qstvalue of 9.1 kJ mol-1. This H2Qstvalue is greater than that for a number of existing metal-organic frameworks (MOFs) and represents the highest yet reported for a MPM. The remarkable H2sorption properties for MPM-1-TIFSIX have been confirmed through our simulations. The modeling studies revealed that only one principal sorption site is present for CO2and H2in MPM-1-Cl, which is sorption onto the Cl-counterions within the large channels. In contrast, three different sorption sites were discovered for both CO2and H2in MPM-1-TIFSIX: (1) between two TIFSIX groups within a small passage connecting the large channels, (2) onto the TIFSIX ions lining the large channels, and (3) within the small channels. This study illustrates the detailed insights that molecular simulations can provide on the CO2and H2sorption mechanism in MPMs.
authors.affiliation: Department of Chemistry, University of South Florida , 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Tony
authors.initials: T
authors.lastname: Pham
authors.affiliation: Department of Chemistry, University of South Florida , 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Forrest
authors.affiliation: Department of Chemical and Environmental Sciences, University of Limerick , Limerick, Republic of Ireland.
authors.forename: Kai-Jie
authors.initials: KJ
authors.lastname: Chen
authors.affiliation: Department of Chemical and Environmental Sciences, University of Limerick , Limerick, Republic of Ireland.
authors.forename: Amrit
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Chemical and Environmental Sciences, University of Limerick , Limerick, Republic of Ireland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zaworotko
authors.affiliation: Department of Chemistry, University of South Florida , 4202 East Fowler Avenue, CHE205, Tampa, Florida 33620-5250, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Space